Kirsten Sandvig

• Skotland, Tore & Sandvig, Kirsten (2026). Plasma membranes: does one model fit all? Trends in Cell Biology. ISSN 0962-8924. 36(7), s. 537–544. doi: 10.1016/j.tcb.2026.03.001. Fulltekst i vitenarkiv Vis sammendrag

  Biological membranes consist of a lipid bilayer with a highly asymmetric distribution of lipids in the two leaflets. This asymmetry is maintained by enzymes whose activities depend on cytosolic ATP and Ca2+ concentrations. Recently, a new model for plasma membranes (PMs) was introduced. It is based on studies with human erythrocytes and suggests that there is a 50% overabundance of lipids with two hydrophobic chains in the cytosolic leaflet, compensated by the presence of three times more cholesterol in the outer leaflet. In this opinion article, we discuss the large differences in lipid composition between erythrocytes and other cell types, the assumptions used to reach the new membrane model, and whether this model would fit PMs of other cell types.

• Tiron, Crina Elena; Luta, Gabriel; Ghiarasim, Razvan; Tiron, Adrian; Nastasa, Valentin & Anita, Dragos Constantin [Vis alle 11 forfattere av denne artikkelen] (2025). Trastuzumab-Conjugated pH-Sensitive Micelles Exhibit Antitumor Activity and Induce Mesenchymal-to-Epithelial Transition in Triple-Negative Breast Cancer Cell Lines. Pharmaceutics. 17(12). doi: 10.3390/pharmaceutics17121554. Fulltekst i vitenarkiv Vis sammendrag

  Background: Despite improved knowledge on cancer prevention, progression, and treatment, the incidence of cancer is still increasing. Patients with highly aggressive triple-negative breast cancer benefit from chemotherapy as the only systemic therapeutic alternative. Here, we performed studies that demonstrate the effects of trastuzumab linked to nanostructures with pH-dependent release on triple-negative models. Methods: We assessed in vitro cell proliferation, migration, invasion, mammospheres, spheroids, and organoid formation of human and murine cell lines. Balb/c mice were used to investigate the in vivo anti-tumoral effects of functionalized nanostructures. Ex vivo samples and cell lines were used to investigate, using immunohistochemistry and Western blot, the modulation of key molecular pathways. Results: Using a human normal cell line and human and murine triple-negative breast cancer cell lines, we found that trastuzumab exhibits anti-tumoral properties on triple-negative breast cancer cell lines only when linked to pH-sensitive micelles. In addition, the data demonstrates that functionalized micelles induce mesenchymal-to-epithelial transitions, impairing the metastasis. Conclusions: Taken together, these results indicate that functionalization of micelles by linking trastuzumab may open the way of treating triple-negative patients with trastuzumab, a treatment which is currently in use for patients with Her2 overexpression. The functionalized micelles may be loaded with various molecules to further improve the anti-tumoral effects.

• Kumari, Remya Valsala; Pandya, Abhilash D.; Pettersen, Solveig; Kvalvaag, Audun Sverre Myrset; Myrann, Anne-Grethe & Ghiarasim, Razvan [Vis alle 12 forfattere av denne artikkelen] (2025). Evaluation of HER2 Targeted Poly(Ethylene Glycol)-Poly(L-histidine) Copolymer Micelles in Breast Cancer Models. Macromolecular Bioscience. ISSN 1616-5187. s. 1–15. doi: 10.1002/mabi.202500047. Fulltekst i vitenarkiv Vis sammendrag

  Breast cancer positive for human epidermal growth factor receptor-2 (HER2) is challenging to treat due to the development of drug resistance, even with recently developed antibody-mediated therapeutics. However, nanotechnology provides new innovative therapeutic strategies. This study evaluates the efficacy of new HER2-targeted, pH-sensitive poly(ethylene glycol)-poly(L-histidine) copolymer micelles (PEG-PHis micelles), either empty, loaded with the drug doxorubicin (DOX), or the fluorophore Rhodamine-B (RB) for imaging purposes. Cellular association of the micelles, in vitro effects on proliferation and cytotoxicity, as well as ex vivo and in vivo responses on tumor growth are assessed. The results indicate that trastuzumab (TZM) conjugation enhances the specific cellular association of PEG-PHis micelles in HER2 overexpressing cells and improves the cytotoxic effects of the micelles themselves. Although the TZM conjugation of DOX-loaded micelles did not contribute to an enhancement in overall efficacy in cell lines and tumor explant cultures, the findings highlight the potential of TZM conjugation on these micelles in targeting HER2-positive tumors.

• Skotland, Tore; Ekroos, Kim; Llorente, Alicia & Sandvig, Kirsten (2025). Quantitative Lipid Analysis of Extracellular Vesicle Preparations: A Perspective. Journal of Extracellular Vesicles. 14(3). doi: 10.1002/jev2.70049. Fulltekst i vitenarkiv Vis sammendrag

  Quantitative lipidomic analysis performed by mass spectrometry is required for determination of the lipid content of extracellular vesicles (EVs). Such methods can provide information about the total amount of lipids, the lipid species composition, the purity of EV samples as well as the cellular origin of the EVs. There are, however, many pitfalls when performing lipid analyses. Thus, any non-specialist should collaborate with experts in lipidomics. In addition to many good review articles giving advice about lipid analyses, we recommend the information and guidelines published by the Lipidomic Standard Initiative, an interest group affiliated with the International Lipidomics Society.

• Feith, Marek; Sajib, Saikat Das; Myrann, Anne-Grethe; Høgset, Anders; Garrido, Pablo & Martinez, Alfredo [Vis alle 11 forfattere av denne artikkelen] (2025). Induction of Cell Death by Combined Treatment with Photosensitizer-Chitosan Nanoparticles and the Ferroptosis Inducer RSL3 in Breast Cancer Cell Lines. Advanced NanoBiomed Research. 5(5). doi: 10.1002/anbr.202400208. Fulltekst i vitenarkiv Vis sammendrag

  Breast cancer, a prevalent malignancy worldwide, includes the triple-negative subtype (TNBC) characterized by poor treatment outcomes. TNBC has been shown to be sensitive to ferroptotic cell death, an iron-dependent cell death mechanism involving reactive oxygen species (ROS) and lipid peroxidation. Herein, biodegradable tetraphenylchlorin-conjugated chitosan nanoparticles (TPC-CS NPs) in combination with the free ferroptosis inducer RSL3 is used in MCF7 (hormone receptor-positive, epithelial) and MDA-MB-231 (hormone receptor-negative, mesenchymal-like) breast cancer cell lines. The results show that RSL3 treatment has no cytotoxic effect in MCF7 and there is no enhanced sensitivity when combined with TPC-CS NPs, while the combination sensitizes MDA-MB-231 cells. Western blot analysis reveals that the combined treatment decreases and differently affects GPX4 levels and the ratio between the two GPX isoforms in the two cell lines. In MDA-MB-231 cells, the combined treatment shows enhanced effects on lipid peroxidation, mitochondrial potential, and basal and maximal respiration, as compared to single treatments. Finally, ferroptosis expression signatures distinguish breast cancer cell lines with an increasing score in mesenchymal-like cells. Moreover, the signatures correlate with breast cancer subtypes, exhibiting the highest scores in subtypes rich in mesenchymal-like cells, particularly basal-like and claudin-low tumors, suggesting their susceptibility to ferroptosis induction.

• Kumari, Remya Valsala; Feith, Marek; Pettersen, Solveig; Åslund, Karl Olof Andreas; Mørch, Yrr Asbjörg & Skotland, Tore [Vis alle 9 forfattere av denne artikkelen] (2025). Combinatorial Effects of Free and Nanoencapsulated Forms of Cabazitaxel and RAS-Selective Lethal 3 in Breast Cancer Cells. Pharmaceutics. 17(5), s. 1–20. doi: 10.3390/pharmaceutics17050657. Fulltekst i vitenarkiv Vis sammendrag

  Background: Combination therapies for cancer have gained considerable attention due to their potential for enhancing therapeutic efficacy and decreasing drug resistance. Introducing nanodrug delivery systems in this context may further improve the therapy due to targeted delivery, improved drug stability, sustained drug release, and prevention of rapid clearance from circulation. This study evaluates the combinatorial effects of two cytotoxic drugs, cabazitaxel (CBZ) and RSL3 (RAS-selective lethal 3), in free form as well as encapsulated within poly(2-ethyl butyl cyanoacrylate) (PEBCA) nanoparticles (NPs) in breast cancer cell lines. Methods: Cell proliferation was assessed using IncuCyte technology, and synergistic drug effects were determined with SynergyFinder Plus. Cell viability was measured with the MTT assay. Additionally, we investigated whether the combinatorial effects were reflected in alterations of metabolic activity or reactive oxygen species (ROS) production using Seahorse technology and the CM-H₂DCFDA assay, respectively. Results: The data presented reveal, for the first time, that CBZ and RSL3 exhibit synergistically or additively combinatorial effects on various breast cancer cell lines. The pattern of cytotoxic effects was consistent, whether the drugs were in free form or encapsulated in NPs. Moreover, the combinatorial effects were not observed to be associated with early changes in metabolic activity or ROS production. Conclusion: This study highlights the potential of CBZ and RSL3 in combinatorial nanomedicine as they may act synergistically. Further studies are warranted to better understand the mechanisms behind these combinatorial effects.

• Sandvig, Kirsten; Iversen, Tore Geir & Skotland, Tore (2024). Entry of nanoparticles into cells and tissues: status and challenges. Beilstein Journal of Nanotechnology. ISSN 2190-4286. 15, s. 1017–1029. doi: 10.3762/bjnano.15.83. Fulltekst i vitenarkiv Vis sammendrag

  In this article we discuss how nanoparticles (NPs) of different compositions may interact with and be internalized by cells, and the consequences of that for cellular functions. A large number of NPs are made with the intention to improve cancer treatment, the goal being to increase the fraction of injected drug delivered to the tumor and thereby improve the therapeutic effect and decrease side effects. Thus, we discuss how NPs are delivered to tumors and some challenges related to investigations of biodistribution, pharmacokinetics, and excretion. Finally, we discuss requirements for bringing NPs into clinical use and aspects when it comes to usage of complex and slowly degraded or nondegradable NPs.

• Kumari, Remya Valsala; Pandya, Abhilash D.; Prasmickaite, Lina; Kvalvaag, Audun Sverre Myrset; Åslund, Karl Olof Andreas & Myrann, Anne-Grethe [Vis alle 17 forfattere av denne artikkelen] (2024). Preclinical Efficacy of Cabazitaxel Loaded Poly(2-alkyl cyanoacrylate) Nanoparticle Variants. International Journal of Nanomedicine. ISSN 1176-9114. 19, s. 3009–3029. doi: 10.2147/IJN.S450283. Fulltekst i vitenarkiv Vis sammendrag

  Background: Biodegradable poly(alkyl cyanoacrylate) (PACA) nanoparticles (NPs) are receiving increasing attention in anti-cancer nanomedicine development not only for targeted cancer chemotherapy, but also for modulation of the tumor microenvironment. We previously reported promising results with cabazitaxel (CBZ) loaded poly(2-ethylbutyl cyanoacrylate) NPs (PEBCA-CBZ NPs) in a patient derived xenograft (PDX) model of triple-negative breast cancer, and this was associated with a decrease in M2 macrophages. The present study aims at comparing two endotoxin-free PACA NP variants (PEBCA and poly(2-ethylhexyl cyanoacrylate); PEHCA), loaded with CBZ and test whether conjugation with folate would improve their effect. Methods: Cytotoxicity assays and cellular uptake of NPs by flow cytometry were performed in different breast cancer cells. Biodistribution and efficacy studies were performed in PDX models of breast cancer. Tumor associated immune cells were analyzed by multiparametric flow cytometry. Results: In vitro studies showed similar NP-induced cytotoxicity patterns despite difference in early NP internalization. On intravenous injection, the liver cleared the majority of NPs. Efficacy studies in the HBCx39 PDX model demonstrated an enhanced effect of drug-loaded PEBCA variants compared with free drug and PEHCA NPs. Furthermore, the folate conjugated PEBCA variant did not show any enhanced effects compared with the unconjugated counterpart which might be due to unfavorable orientation of folate on the NPs. Finally, analyses of the immune cell populations in tumors revealed that treatment with drug loaded PEBCA variants affected the myeloid cells, especially macrophages, contributing to an inflammatory, immune activated tumor microenvironment. Conclusion: We report for the first time, comparative efficacy of PEBCA and PEHCA NP variants in triple negative breast cancer models and show that CBZ-loaded PEBCA NPs exhibit a combined effect on tumor cells and on the tumor associated myeloid compartment, which may boost the anti-tumor response.

• Skotland, Tore; Ekroos, Kim; McDonald, Jeffrey; Ahrends, Robert; Liebisch, Gerhard & Sandvig, Kirsten (2024). Pitfalls in lipid mass spectrometry of mammalian samples — a brief guide for biologists. Nature reviews. Molecular cell biology. ISSN 1471-0072. 25, s. 759–760. doi: 10.1038/s41580-024-00758-4. Fulltekst i vitenarkiv
• Hessvik, Nina Pettersen; Sagini, Krizia; Romero, Silvana Angelica Troncoso; Ramirez, Manuel; Rodriguez, Marta & Tutturen, Astrid Elisabeth Voorham [Vis alle 11 forfattere av denne artikkelen] (2023). siRNA screening reveals that SNAP29 contributes to exosome release. Cellular and Molecular Life Sciences (CMLS). ISSN 1420-682X. 80. doi: 10.1007/s00018-023-04822-8. Fulltekst i vitenarkiv Vis sammendrag

  Cells release extracellular vesicles (EVs) of different sizes. Small EVs (< 200 nm) can originate from the fusion of multive- sicular bodies with the plasma membrane, i.e. exosomes, and from budding of the plasma membrane, i.e. small ectosomes. To investigate the molecular machinery required for the release of small EVs, we developed a sensitive assay based on incor- poration of radioactive cholesterol in EV membranes and used it in a siRNA screening. The screening showed that depletion of several SNARE proteins affected the release of small EVs. We focused on SNAP29, VAMP8, syntaxin 2, syntaxin 3 and syntaxin 18, the depletion of which reduced the release of small EVs. Importantly, this result was verified using gold standard techniques. SNAP29 depletion resulted in the largest effect and was further investigated. Immunoblotting analysis of small EVs showed that the release of several proteins considered to be associated with exosomes like syntenin, CD63 and Tsg101 was reduced, while the level of several proteins that have been shown to be released in ectosomes (annexins) or by secretory autophagy (LC3B and p62) was not affected by SNAP29 depletion. Moreover, these proteins appeared in different fractions when the EV samples were further separated by a density gradient. These results suggest that SNAP29 depletion mainly affects the secretion of exosomes. To investigate how SNAP29 affects exosome release, we used microscopy to study the distribution of MBVs using CD63 labelling and CD63-pHluorin to detect fusion events of MVBs with the plasma membrane. SNAP29 depletion caused a redistribution of CD63-labelled compartments but did not change the number of fusion events. Further experiments are therefore needed to fully understand the function of SNAP29. To conclude, we have developed a novel screening assay that has allowed us to identify several SNAREs involved in the release of small EVs.

• Skotland, Tore; Llorente, Alicia & Sandvig, Kirsten (2023). Lipids in Extracellular Vesicles: What Can Be Learned about Membrane Structure and Function? Cold Spring Harbor Perspectives in Biology. 15(8), s. 1–18. doi: 10.1101/cshperspect.a041415. Fulltekst i vitenarkiv
• Sandvig, Kirsten; Kavaliauskiene, Simona; Myrann, Anne-Grethe; Iversen, Tore Geir & Skotland, Tore (2022). Modulation of Ricin Intoxication by the Autophagy Inhibitor EACC. Toxins. 14(5), s. 1–13. doi: 10.3390/toxins14050360. Fulltekst i vitenarkiv Vis sammendrag

  The compound EACC (ethyl (2-(5-nitrothiophene-2-carboxamido) thiophene-3-carbonyl) carbamate) was recently reported to inhibit fusion of autophagosomes with lysosomes in a reversible manner by inhibiting recruitment of syntaxin 17 to autophagosomes. We report here that this compound also provides a strong protection against the protein toxin ricin as well as against other plant toxins such as abrin and modeccin. The protection did not seem to be caused by inhibition of endocytosis and retrograde transport, but rather by inhibited release of the enzymatically active A-moiety to the cytosol. The TANK-binding kinase 1 (TBK1) has been reported to phosphorylate syntaxin 17 and be required for initiation of autophagy. The inhibitor of TBK1, MRT68601, induced in itself a strong sensitization to ricin, apparently by increasing transport to the Golgi apparatus. Importantly, MRT68601 increased Golgi transport of ricin even in the presence of EACC, but EACC was still able to inhibit intoxication, supporting the idea that EACC protects at a late step along the retrograde pathway. These results also indicate that phosphorylation of syntaxin 17 is not required for the protection observed.

• Skotland, Tore; Iversen, Tore Geir; Llorente, Alicia & Sandvig, Kirsten (2022). Biodistribution, pharmacokinetics and excretion studies of intravenously injected nanoparticles and extracellular vesicles: Possibilities and challenges. Advanced Drug Delivery Reviews. ISSN 0169-409X. 186(186), s. 1–17. doi: 10.1016/j.addr.2022.114326. Fulltekst i vitenarkiv Vis sammendrag

  There is a large interest in developing nanoparticles and extracellular vesicles for delivery of therapeutics or imaging agents. Regulatory approval of such products requires knowledge about their biodistribution, metabolism and excretion. We here discuss possibilities and challenges of methods used for such studies, which most often are performed after labelling with radioactive isotopes or fluorescent molecules. It is important to evaluate if the labelled and unlabeled products can be expected to behave similarly in the body. Furthermore, one needs to critically consider whether the labels are still associated with the product at the time of analyses. We discuss advantages and disadvantages of different imaging modalities such as PET, SPECT, MRI, CT, ultrasound and optical imaging for whole-body biodistribution, and describe how to estimate the amount of labelled product in harvested organs and tissue. Microscopy of cells and tissues and various mass spectrometry methods are also discussed in this review.

• Bousquet, Paula; Manna, Dipankar; Sandvik, Joe Alexander; Arntzen, Magnus Øverlie; Moreno, Ernesto & Sandvig, Kirsten [Vis alle 7 forfattere av denne artikkelen] (2022). SILAC-based quantitative proteomics and microscopy analysis of cancer cells treated with the N-glycolyl GM3-specific anti-tumor antibody 14F7. Frontiers in Immunology. 13. doi: 10.3389/fimmu.2022.994790. Fulltekst i vitenarkiv Vis sammendrag

  Cancer immunotherapy represents a promising approach to specifically target and treat cancer. The most common mechanisms by which monoclonal antibodies kill cells include antibody-dependent cell-mediated cytotoxicity, complement-dependent cytotoxicity and apoptosis, but also other mechanisms have been described. 14F7 is an antibody raised against the tumor-associated antigen NeuGc GM3, which was previously reported to kill cancer cells without inducing apoptotic pathways. The antibody was reported to induce giant membrane lesions in tumor cells, with apparent changes in the cytoskeleton. Here, we investigated the effect of humanized 14F7 on HeLa cells using stable isotope labeling with amino acids in cell culture (SILAC) in combination with LC-MS and live cell imaging. 14F7 did not kill the HeLa cells, however, it caused altered protein expression (MS data are available via ProteomeXchange with identifier PXD024320). Several cytoskeletal and nucleic-acid binding proteins were found to be strongly down-regulated in response to antibody treatment, suggesting how 14F7 may induce membrane lesions in cells that contain higher amounts of NeuGc GM3. The altered expression profile identified in this study thus contributes to an improved understanding of the unusual killing mechanism of 14F7.

• Skotland, Tore & Sandvig, Kirsten (2022). Need for more focus on lipid species in studies of biological and model membranes. Progress in lipid research. ISSN 0163-7827. 86, s. 1–12. doi: 10.1016/j.plipres.2022.101160. Fulltekst i vitenarkiv Vis sammendrag

  The lipid composition of cellular membranes can impact a number of physiological processes such as signaling, cell migration, endocytosis and intracellular transport. In this article we focus on some aspects concerning analysis of lipids and research on lipid structure and function in mammalian cells that in our opinion have not obtained sufficient attention. This includes interleaflet coupling between the two layers of the membrane, and the role of lipid species, i.e. the role of the complete structure of the lipids, including lipid chain length and the position of double bonds. We highlight the role of PS species for membrane function. We also discuss the large diversity of PS species in different biological samples and the possible functional consequences, and we provide an overview of PS species from 40 different samples. Furthermore, recent studies show that there seems to be a coregulation concerning the levels of sphingolipids and ether lipids. We review and discuss the published data indicating such a coregulation. Moreover, we point to some of the pitfalls in the field of lipidomics and present suggestions for improvement. Finally, we discuss the importance of using asymmetric membrane models with a composition of lipid species that are common in biological membranes.

• Skotland, Tore & Sandvig, Kirsten (2021). Transport of nanoparticles across the endothelial cell layer. Nano Today. ISSN 1748-0132. 36. doi: 10.1016/j.nantod.2020.101029. Fulltekst i vitenarkiv Vis sammendrag

  Studies of how intravenously injected nanoparticles (NPs) enter tumours and are taken up by tumour cells have been discussed for more than three decades. Despite this, we still have much to learn about interactions between NPs and how they can be transported across the endothelial cell layer. More studies are required before firm conclusions can be drawn regarding the contribution of passive or energy dependent mechanisms for transport of NPs over the endothelial cells allowing the NPs to reach solid tumours.

• Skotland, Tore; Iversen, Tore Geir & Sandvig, Kirsten (2021). Cellular uptake of nanoparticles: Involvement of caveolae? Precision Nanomedicine (PRNANO). 4(2), s. 782–786. doi: 10.33218/001c.22201. Fulltekst i vitenarkiv Vis sammendrag

  Here we discuss some pitfalls and challenges briefly when investigating which endocytic mechanisms are involved in the cellular uptake of nanoparticles. We specifically discuss some common misunderstandings regarding studies claimed to demonstrate uptake via caveolae. Scientists in the nanomedicine field should be aware that reducing the membrane content of cholesterol by adding methyl-β-cyclodextrin removes caveolae and inhibits other uptake mechanisms, such as macropinocytosis as well. Furthermore, the general tyrosine kinase inhibitor genistein is not a specific inhibitor of uptake from caveolae. Moreover, one can still see that scientists in the field write that they want to direct transport of their particles to caveolae and caveosomes to avoid lysosomal degradation. However, caveosomes are artifacts caused by overexpression of caveolin-1 constructs, and ligands or particles taken up by caveolae are transported to endosomes and lysosomes as reported for other types of endocytosis.

• Øverbye, Anders; Torgersen, Maria Lyngaas; Sønstevold, Tonje; Iversen, Tore Geir; Mørch, Ýrr Asbjørg & Skotland, Tore [Vis alle 7 forfattere av denne artikkelen] (2021). Cabazitaxel-loaded poly(alkyl cyanoacrylate) nanoparticles: Toxicity and changes in the proteome of breast, colon and prostate cancer cells. Nanotoxicology. ISSN 1743-5390. 15(7), s. 865–884. doi: 10.1080/17435390.2021.1924888. Fulltekst i vitenarkiv Vis sammendrag

  Nanoparticles composed of poly(alkyl cyanoacrylate) (PACA) have shown great promise due to their biodegradability and high drug loading capacity. Development of optimal PACA nanocarriers requires detailed analysis of the overall cellular impact exerted by PACA variants. We here perform a comprehensive comparison of cabazitaxel (CBZ)-loaded nanocarriers composed of three different PACA monomers, i.e. poly(n-butyl cyanoacrylate) (PBCA), poly(2-ethylbutyl cyanoacrylate) (PEBCA) and poly(octyl cyanoacrylate) (POCA). The cytotoxicity of drug-loaded and empty PACA nanoparticles were compared to that of free CBZ across a panel of nine cancer cell lines by assessing cellular metabolism, proliferation and protein synthesis. The analyses revealed that the cytotoxicity of all CBZ-loaded PACAs was similar to that of free CBZ for all cell lines tested, whereas the empty PACAs exerted much lower toxicity. To increase our understanding of the toxic effects of these treatments comprehensive MS-based proteomics were performed with HCT116, MDA-MB-231 and PC3 cells incubated with PACA-CBZ variants or free CBZ. Interestingly, PACA-CBZ specifically led to decreased levels of proteins involved in focal adhesion and stress fibers in all cell lines. Since we recently demonstrated that encapsulation of CBZ within PEBCA nanoparticles significantly improved the therapeutic effect of CBZ on a patient derived xenograft model in mice, we investigated the effects of this PACA variant more closely by immunoblotting. Interestingly, we detected several changes in the protein expression and degree of phosphorylation of SRC-pathway proteins that can be relevant for the therapeutic effects of these substances.

• Pandya, Abhilash D.; Iversen, Tore Geir; Moestue, Siver Andreas; Grinde, Maria Tunset; Mørch, Ýrr Asbjørg & Snipstad, Sofie [Vis alle 13 forfattere av denne artikkelen] (2021). Biodistribution of Poly(alkyl cyanoacrylate) Nanoparticles in Mice and Effect on Tumor Infiltration of Macrophages into a Patient-Derived Breast Cancer Xenograft. Nanomaterials. 11(5). doi: 10.3390/nano11051140. Fulltekst i vitenarkiv Vis sammendrag

  We have investigated the biodistribution and tumor macrophage infiltration after intravenous injection of the poly(alkyl cyanoacrylate) nanoparticles (NPs): PEBCA (poly(2-ethyl-butyl cyanoacrylate), PBCA (poly(n-butyl cyanoacrylate), and POCA (poly(octyl cyanoacrylate), in mice. These NPs are structurally similar, have similar PEGylation, and have previously been shown to give large variations in cellular responses in vitro. The PEBCA NPs had the highest uptake both in the patient-derived breast cancer xenograft MAS98.12 and in lymph nodes, and therefore, they are the most promising of these NPs for delivery of cancer drugs. High-resolution magic angle spinning magnetic resonance (HR MAS MR) spectroscopy did not reveal any differences in the metabolic profiles of tumors following injection of the NPs, but the PEBCA NPs resulted in higher tumor infiltration of the anti-tumorigenic M1 macrophages than obtained with the two other NPs. The PEBCA NPs also increased the ratio of M1/M2 (anti-tumorigenic/pro-tumorigenic) macrophages in the tumors, suggesting that these NPs might be used both as a vehicle for drug delivery and to modulate the immune response in favor of enhanced therapeutic effects.

• Rudolph, Michael J.; Poon, Amanda Y.; Kavaliauskiene, Simona; Myrann, Anne-Grethe; Reynolds-Peterson, Claire & Davis, Simon A. [Vis alle 9 forfattere av denne artikkelen] (2021). Structural Analysis of Toxin-Neutralizing, Single-Domain Antibodies that Bridge Ricin's A-B Subunit Interface. Journal of Molecular Biology (JMB). ISSN 0022-2836. 433(15), s. 1–20. doi: 10.1016/j.jmb.2021.167086. Fulltekst i vitenarkiv
• Sandvig, Kirsten; Kavaliauskiene, Simona & Skotland, Tore (2021). The Protein Toxins Ricin and Shiga Toxin as Tools to Explore Cellular Mechanisms of Internalization and Intracellular Transport. Toxins. 13(6). doi: 10.3390/toxins13060377. Fulltekst i vitenarkiv Vis sammendrag

  Protein toxins secreted by bacteria and found in plants can be threats to human health. However, their extreme toxicity can also be exploited in different ways, e.g., to produce hybrid toxins directed against cancer cells and to study transport mechanisms in cells. Investigations during the last decades have shown how powerful these molecules are as tools in cell biological research. Here, we first present a partly historical overview, with emphasis on Shiga toxin and ricin, of how such toxins have been used to characterize processes and proteins of importance for their trafficking. In the second half of the article, we describe how one can now use toxins to investigate the role of lipid classes for intracellular transport. In recent years, it has become possible to quantify hundreds of lipid species using mass spectrometry analysis. Thus, it is also now possible to explore the importance of lipid species in intracellular transport. The detailed analyses of changes in lipids seen under conditions of inhibited toxin transport reveal previously unknown connections between syntheses of lipid classes and demonstrate the ability of cells to compensate under given conditions.

• Valsalakumari, Remya; Yadava, Sunil Kumar; Szwed, Marzena; Pandya, Abhilash D.; Mælandsmo, Gunhild Mari & Torgersen, Maria Lyngaas [Vis alle 10 forfattere av denne artikkelen] (2021). Mechanism of cellular uptake and cytotoxicity of paclitaxel loaded lipid nanocapsules in breast cancer cells. International Journal of Pharmaceutics. ISSN 0378-5173. 597(120217). doi: 10.1016/j.ijpharm.2021.120217. Fulltekst i vitenarkiv Vis sammendrag

  Lipid nanocapsules (LNCs) have proven their efficacy in delivering different drugs to various cancers, but no studies have yet described their uptake mechanisms, paclitaxel (PTX) delivery or resulting cytotoxicity towards breast cancer cells. Herein, we report results concerning cellular uptake of LNCs and cytotoxicity studies of PTX-loaded LNCs (LNCs-PTX) on the three breast cancer cell lines MCF-7, MDA-MB-231 and MDA-MB-468. LNCs-PTX of sizes 50 ± 2 nm, 90 ± 3 nm and 120 ± 4 nm were developed by the phase inversion method. Fluorescence microscopy and flow cytometry were used to observe the uptake of fluorescently labeled LNCs and cellular uptake of LNCs-PTX was measured using HPLC analyses of cell samples. These studies revealed a higher uptake of LNCs-PTX in MDA-MB-468 cells than in the other two cell lines. Moreover, free PTX and LNCs-PTX exhibited a similar pattern of toxicity towards each cell line, but MDA-MB-468 cells appeared to be more sensitive than the other two cell lines, as evaluated by the MTT cytotoxicity assay and a cell proliferation assay based upon [3H]thymidine incorporation. Studies with inhibitors of endocytosis indicate that the cellular uptake is mainly via the Cdc42/GRAF-dependent endocytosis as well as by macropinocytosis, whereas dynamin-dependent processes are not required. Furthermore, our results indicate that endocytosis of LNCs-PTX is important for the toxic effect on cells. Western blot analysis revealed that LNCs-PTX induce cytotoxicity by means of apoptosis in all the three cell lines. Altogether, the results demonstrate that LNCs-PTX exploit different mechanisms of endocytosis in a cell-type dependent manner, and subsequently induce apoptotic cell death in the breast cancer cells here studied. The article also describes biodistribution studies following intravenous injection of fluorescently labeled LNCs in mice.

• Szwed, Marzena; Torgersen, Maria Lyngaas; Kumari, Remya Valsala; Yadava, Sunil Kumar; Pust, Sascha & Iversen, Tore Geir [Vis alle 9 forfattere av denne artikkelen] (2020). Biological response and cytotoxicity induced by lipid nanocapsules. Journal of Nanobiotechnology. 18(5). doi: 10.1186/s12951-019-0567-y. Fulltekst i vitenarkiv Vis sammendrag

  Background Lipid nanocapsules (LNCs) are promising vehicles for drug delivery. However, since not much was known about cellular toxicity of these nanoparticles in themselves, we have here investigated the mechanisms involved in LNC-induced intoxication of the three breast cancer cell lines MCF-7, MDA-MD-231 and MDA-MB-468. The LNCs used were made of Labrafac™ Lipophile WL1349, Lipoid® S75 and Solutol® HS15. Results High resolution SIM microscopy showed that the DiD-labeled LNCs ended up in lysosomes close to the membrane. Empty LNCs, i.e. without encapsulated drug, induced not only increased lysosomal pH, but also acidification of the cytosol and a rapid inhibition of protein synthesis. The cytotoxicity of the LNCs were measured for up to 72 h of incubation using the MTT assay and ATP measurements in all three cell lines, and revealed that MDA-MB-468 was the most sensitive cell line and MCF-7 the least sensitive cell line to these LNCs. The LNCs induced generation of reactive free oxygen species and lipid peroxidation. Experiments with knock-down of kinases in the near-haploid cell line HAP1 indicated that the kinase HRI is essential for the observed phosphorylation of eIF2α. Nrf2 and ATF4 seem to play a protective role against the LNCs in MDA-MB-231 cells, as knock-down of these factors sensitizes the cells to the LNCs. This is in contrast to MCF-7 cells where the knock-down of these factors had a minor effect on the toxicity of the LNCs. Inhibitors of ferroptosis provided a large protection against LNC toxicity in MDA-MB-231 cells, but not in MCF-7 cells. Conclusions High doses of LNCs showed a different degree of toxicity on the three cell lines studied, i.e. MCF-7, MDA-MD-231 and MDA-MB-468 and affected signaling factors and the cell fate differently in these cell lines.

• Torgersen, Maria Lyngaas; Judge, Peter J.; Juarez, Juan F. Bada; Pandya, Abhilash D.; Fusser, Markus & Davies, Charlie W. [Vis alle 12 forfattere av denne artikkelen] (2020). Physicochemical characterization, toxicity and in vivo biodistribution studies of a discoidal, lipid-based drug delivery vehicle: Lipodisq nanoparticles containing doxorubicin. Journal of Biomedical Nanotechnology. ISSN 1550-7033. 16(4), s. 419–431. doi: 10.1166/jbn.2020.2911. Fulltekst i vitenarkiv Vis sammendrag

  Many promising pharmaceutically active compounds have low solubility in aqueous environments and their encapsulation into efficient drug delivery vehicles is crucial to increase their bioavailability. Lipodisq nanoparticles are approximately 10 nm in diameter and consist of a circular phospholipid bilayer, stabilized by an annulus of SMA (a hydrolysed copolymer of styrene and maleic anhydride). SMA is used extensively in structural biology to extract and stabilize integral membrane proteins for biophysical studies. Here, we assess the potential of these nanoparticles as drug delivery vehicles, determining their cytotoxicity and the in vivo excretion pathways of their polymer and lipid components. Doxorubicin-loaded Lipodisqs were cytotoxic across a panel of cancer cell lines, whereas nanoparticles without the drug had no effect on cell proliferation. Intracellular doxorubicin release from Lipodisqs in HeLa cells occurred in the low-pH environment of the endolysosomal system, consistent with the breakdown of the discoidal structure as the carboxylate groups of the SMA polymer become protonated. Biodistribution studies in mice showed that, unlike other nanoparticles injected intravenously, most of the Lipodisq components were recovered in the colon, consistent with rapid uptake by hepatocytes and excretion into bile. These data suggest that Lipodisqs have the potential to act as delivery vehicles for drugs and contrast agents.

• Sønstevold, Tonje; Engedal, Nikolai; Mørch, Ýrr Asbjørg; Iversen, Tore Geir; Skotland, Tore & Sandvig, Kirsten [Vis alle 7 forfattere av denne artikkelen] (2020). Structural Variants of poly(alkylcyanoacrylate) Nanoparticles Differentially Affect LC3 and Autophagic Cargo Degradation. Journal of Biomedical Nanotechnology. ISSN 1550-7033. 16(4), s. 432–445. doi: 10.1166/jbn.2020.2906. Fulltekst i vitenarkiv Vis sammendrag

  Nanoparticle drug carriers trigger a variety of cellular stress responses, including ER stress and antioxidant responses, but may also affect the intracellular degradative pathway autophagy. This can impose profound effects on drug delivery, cellular treatment responses, and nanoparticle cytotoxicity. We recently demonstrated that even small variations in the alkyl side chains of poly(alkylcyanoacrylate) (PACA) drug carrier nanoparticles, namely butyl (PBCA), ethylbutyl (PEBCA), or octyl (POCA), differentially induce ER stress and redox imbalance in human cell lines. Here, we systematically investigate how these PACA variants affect autophagy. Interestingly, treatment with PEBCA or POCA particles led to intracellular accumulation of the autophagosome marker LC3-II, but via different mechanisms. PEBCA induced an integrated stress response-and ATF4-mediated increase in LC3B mRNA, whereas POCA blocked autophagic degradation of LC3-II and long-lived proteins in bulk. PBCA also increased LC3B mRNA via the integrated stress response and ATF4, but unlike PEBCA, it inhibited LC3 lipidation and autophagic cargo degradation. Our data demonstrate that even subtle variations in NP structure can have profoundly different impacts on autophagy, and that careful monitoring of autophagic flux and cargo degradation is critical for drawing accurate conclusions. Our findings have important implications for the choice of PACA monomer in different therapeutic settings.

• Skotland, Tore; Sagini, Krizia; Sandvig, Kirsten & Llorente, Alicia (2020). An emerging focus on lipids in extracellular vesicles. Advanced Drug Delivery Reviews. ISSN 0169-409X. 159, s. 308–321. doi: 10.1016/j.addr.2020.03.002. Fulltekst i vitenarkiv Vis sammendrag

  Extracellular vesicles contain a lipid bilayer membrane that protects the encapsulated material, such as proteins, nucleic acids, lipids and metabolites, from the extracellular environment. These vesicles are released from cells via different mechanisms. During recent years extracellular vesicles have been studied as possible biomarkers for different diseases, as biological nanoparticles for drug delivery, and in basic studies as a tool to understand the structure of biological membranes and the mechanisms involved in vesicular trafficking. Lipids are essential molecular components of extracellular vesicles, but at the moment our knowledge about the lipid composition and the function of lipids in these vesicles is limited. However, the interest of the research community in these molecules is increasing as their role in extracellular vesicles is starting to be acknowledged. In this review, we will present the status of the field and describe what is needed to bring it forward.

• Lingelem, Anne Berit Dyve; Kavaliauskiene, Simona; Halsne, Ruth; Klokk, Tove Irene; Surma, Michal A. & Klose, Christian [Vis alle 8 forfattere av denne artikkelen] (2020). Diacylglycerol Kinase and Phospholipase D Inhibitors Alter the Cellular Lipidome and Endosomal Sorting Towards the Golgi Apparatus. Cellular and Molecular Life Sciences (CMLS). ISSN 1420-682X. doi: 10.1007/s00018-020-03551-6. Fulltekst i vitenarkiv Vis sammendrag

  Abstract The membrane lipids diacylglycerol (DAG) and phosphatidic acid (PA) are important second messengers that can regulate membrane transport by recruiting proteins to the membrane and by altering biophysical membrane properties. DAG and PA are involved in the transport from the Golgi apparatus to endosomes, and we have here investigated whether changes in these lipids might be important for regulation of transport to the Golgi using the protein toxin ricin. Modulation of DAG and PA levels using DAG kinase (DGK) and phospholipase D (PLD) inhibitors gave a strong increase in retrograde ricin transport, but had little impact on ricin recycling or degradation. Inhibitor treatment strongly affected the endosome morphology, increasing endosomal tubulation and size. Furthermore, ricin was present in these tubular structures together with proteins known to regulate retrograde transport. Using siRNA to knock down different isoforms of PLD and DGK, we found that several isoforms of PLD and DGK are involved in regulating ricin transport to the Golgi. Finally, by performing lipidomic analysis we found that the DGK inhibitor gave a weak, but expected, increase in DAG levels, while the PLD inhibitor gave a strong and unexpected increase in DAG levels, showing that it is important to perform lipidomic analysis when using inhibitors of lipid metabolism.

• Tsjokajev, Ahmad; Røberg-Larsen, Hanne; Wilson, Steven Ray Haakon; Dyve, Lingelem Anne Berit; Skotland, Tore & Sandvig, Kirsten [Vis alle 7 forfattere av denne artikkelen] (2020). Mass spectrometry-based measurements of cyclic adenosine monophosphate in cells, simplified using reversed phase liquid chromatography with a polar characterized stationary phase. Journal of chromatography. B. ISSN 1570-0232. 1160, s. 1–6. doi: 10.1016/j.jchromb.2020.122384. Fulltekst i vitenarkiv Vis sammendrag

  3′, 5′ – Cyclic adenosine monophosphate (cAMP) is a ubiquitous second messenger that is involved in many cellular functions and biological processes. In several cell types, cholera toxin will increase the level of cAMP, which mediates toxic effects on cells. In this context, we have developed a fast and simple method based on extraction with 5% trichloroacetic acid (TCA) and quantitation with liquid chromatography-mass tandem spectrometry (LC-MS/MS) for measuring cAMP in cells. A main feature of the LC-MS method was employing a reversed phase C18 column (2.1 mm × 50 mm, 1.6 µm particles) compatible with a 100% aqueous mobile phase, providing retention of the highly polar analyte. Isocratic separations allowed for fast subsequent injections. Negative mode electrospray ionization detection was performed with a triple quadrupole (QqQ)MS. cAMP was extracted from cell samples (~106 cells per well) and spiked with a labelled internal standard, using 200 µL of 5% TCA. The extraction solvent was fully compatible for direct injection onto the reversed phase column. After 10 min incubation, the supernatant was removed, and 10 µL of the supernatant was directly analysed by LC-MS. The method was characterized by the simplicity of the extraction, and the speed (3 min retention time of cAMP), sensitivity (250 pg/mL detection limit), and selectivity (separation from interferences e.g. isomeric compounds) of the LC-MS method, and could be used for quantitation of cAMP in the range 1–500 ng/mL cell extract.

• Pandya, Abhilash D.; Øverbye, Anders; Saharia, Priyanka; Gaware, Vivek S.; Høgset, Håkon & Masson, Már [Vis alle 11 forfattere av denne artikkelen] (2020). Drug-Loaded Photosensitizer-Chitosan Nanoparticles for Combinatorial Chemo- and Photodynamic-Therapy of Cancer. Biomacromolecules. ISSN 1525-7797. 21, s. 1489–1498. doi: 10.1021/acs.biomac.0c00061. Fulltekst i vitenarkiv Vis sammendrag

  In this study we have developed biodegradable polymeric nanoparticles (NPs) containing the cytostatic drugs mertansine (MRT) or cabazitaxel (CBZ). The NPs are based on chitosan (CS) conjugate polymers synthesized with different amounts of the photosensitizer tetraphenylchlorin (TPC). These TPC–CS NPs have high loading capacity and strong drug retention due to π–π stacking interactions between the drugs and the aromatic photosensitizer groups of the polymers. CS polymers with 10% of the side chains containing TPC were found to be optimal in terms of drug loading capacity and NP stability. The TPC–CS NPs loaded with MRT or CBZ displayed higher cytotoxicity than the free form of these drugs in the breast cancer cell lines MDA-MB-231 and MDA-MB-468. Furthermore, light-induced photochemical activation of the NPs elicited a strong photodynamic therapy effect on these breast cancer cells. Biodistribution studies in mice showed that most of the TPC–CS NPs accumulated in liver and lungs, but they were also found to be localized in tumors derived from HCT-116 cells. These data suggest that the drug-loaded TPC–CS NPs have a potential in combinatory anticancer therapy and as contrast agents.

• Skotland, Tore; Kavaliauskiene, Simona & Sandvig, Kirsten (2020). The role of lipid species in membranes and cancer-related changes. Cancer Metastasis Review. ISSN 0167-7659. 39, s. 343–360. doi: 10.1007/s10555-020-09872-z. Fulltekst i vitenarkiv Vis sammendrag

  Several studies have demonstrated interactions between the two leaflets in membrane bilayers and the importance of specific lipid species for such interaction and membrane function. We here discuss these investigations with a focus on the sphingolipid and cholesterol-rich lipid membrane domains called lipid rafts, including the small flask-shaped invaginations called caveolae, and the importance of such membrane structures in cell biology and cancer. We discuss the possible interactions between the very long-chain sphingolipids in the outer leaflet of the plasma membrane and the phosphatidylserine species PS 18:0/18:1 in the inner leaflet and the importance of cholesterol for such interactions. We challenge the view that lipid rafts contain a large fraction of lipids with two saturated fatty acyl groups and argue that it is important in future studies of membrane models to use asymmetric membrane bilayers with lipid species commonly found in cellular membranes. We also discuss the need for more quantitative lipidomic studies in order to understand membrane function and structure in general, and the importance of lipid rafts in biological systems. Finally, we discuss cancer-related changes in lipid rafts and lipid composition, with a special focus on changes in glycosphingolipids and the possibility of using lipid therapy for cancer treatment.

• Sowa-Rogozińska, Natalia; Sominska, Hanna; Nowakowska-Gołacka, Jowita; Sandvig, Kirsten & Słomińska-Wojewódzka, Monika (2019). Intracellular transport and cytotoxicity of the protein toxin ricin. Toxins. 11:350(6), s. 1–37. doi: 10.3390/toxins11060350. Fulltekst i vitenarkiv Vis sammendrag

  Ricin can be isolated from the seeds of the castor bean plant (Ricinus communis). It belongs to the ribosome-inactivating protein (RIP) family of toxins classified as a bio-threat agent due to its high toxicity, stability and availability. Ricin is a typical A-B toxin consisting of a single enzymatic A subunit (RTA) and a binding B subunit (RTB) joined by a single disulfide bond. RTA possesses an RNA N-glycosidase activity; it cleaves ribosomal RNA leading to the inhibition of protein synthesis. However, the mechanism of ricin-mediated cell death is quite complex, as a growing number of studies demonstrate that the inhibition of protein synthesis is not always correlated with long term ricin toxicity. To exert its cytotoxic effect, ricin A-chain has to be transported to the cytosol of the host cell. This translocation is preceded by endocytic uptake of the toxin and retrograde traffic through the trans-Golgi network (TGN) and the endoplasmic reticulum (ER). In this article, we describe intracellular trafficking of ricin with particular emphasis on host cell factors that facilitate this transport and contribute to ricin cytotoxicity in mammalian and yeast cells. The current understanding of the mechanisms of ricin-mediated cell death is discussed as well. We also comment on recent reports presenting medical applications for ricin and progress associated with the development of vaccines against this toxin.

• Pandya, Abhilash D.; Jäger, Eliézer; Fam, Shahla Bagheri; Höcherl, Anita; Jäger, Alessandro & Sincari, Vladimir [Vis alle 12 forfattere av denne artikkelen] (2019). Paclitaxel-loaded biodegradable ROS-sensitive nanoparticles for cancer therapy. International Journal of Nanomedicine. ISSN 1176-9114. 14, s. 6269–6285. doi: 10.2147/IJN.S208938. Fulltekst i vitenarkiv Vis sammendrag

  <i>Background</i>: Reactive oxygen species (ROS), such as hydrogen peroxide and superoxide, trigger biodegradation of polymer-based nanoparticles (NPs) bearing pinacol-type boronic ester groups. These NPs may selectively release their cargo, in this case paclitaxel (PTX), at the high levels of ROS present in the intracellular environment of inflamed tissues and most tumors.<p> <p><i>Purpose</i>: The main objective was to determine anti-tumor efficacy of PTX-loaded ROS-sensitive NPs and to examine whether macrophage infiltration had any impact on treatment efficacy.<p> <p><i>Methods</i>: NPs were synthesized and their characteristics in the presence of H₂O₂ were demonstrated. Both confocal microscopy as well as flow cytometry approaches were used to determine degradation of ROS-sensitive NPs. HeLa cells were cultured in vitro and used to establish tumor xenografts in nude mice. In vivo experiments were performed to understand toxicity, biodistribution and anti-tumor efficacy of the NPs. Moreover, we performed immunohistochemistry on tumor sections to study infiltration of M1 and M2 subsets of macrophages.<p> <p><i>Results</i>: We demonstrated that PTX delivered in NPs containing a ROS-sensitive polymer exhibits a better anti-tumor efficacy than PTX in NPs containing ROS-non-sensitive polymer, free PTX or Abraxane® (nab-PTX). The biodistribution revealed that ROS-sensitive NPs exhibit retention in liver, spleen and lungs, suggesting a potential to target cancer metastasizing to these organs. Finally, we demonstrated a correlation between infiltrated macrophage subsets and treatment efficacy, possibly contributing to the efficient anti-tumor effects.<p> <p><i>Conclusion</i>: Treatment with ROS-sensitive NPs containing PTX gave an improved therapeutic effect in HeLa xenografts than their counterpart, free PTX or nab-PTX. Our data revealed a correlation between macrophage infiltration and efficiency of the different antitumor treatments, as the most effective NPs resulted in the highest infiltration of the anti-tumorigenic M1 macrophages.

• Szwed, Marzena; Sønstevold, Tonje; Øverbye, Anders; Engedal, Nikolai; Grallert, Beata & Mørch, Ýrr Asbjørg [Vis alle 11 forfattere av denne artikkelen] (2019). Small variations in nanoparticle structure dictate differential cellular stress responses and mode of cell death. Nanotoxicology. ISSN 1743-5390. 13(6), s. 761–782. doi: 10.1080/17435390.2019.1576238. Fulltekst i vitenarkiv Vis sammendrag

  For optimal exploitation of nanoparticles (NPs) in biomedicine, and to predict nanotoxicity, detailed knowledge of the cellular responses to cell-bound or internalized NPs is imperative. The final outcome of NP-cell interaction is dictated by the type and magnitude of the NP insult and the cellular response. Here, this has been systematically studied by using poly(alkylcyanoacrylate) (PACA) particles differing only in their alkyl side chains; butyl (PBCA), ethylbutyl (PEBCA), or octyl (POCA), respectively. Surprisingly, these highly similar NPs induced different stress responses and modes of cell death in human cell lines. The POCA particles generally induced endoplasmic reticulum stress and apoptosis. In contrast, PBCA and PEBCA particles induced oxidative stress and lipid peroxidation depending on the level of the glutathione precursor cystine and transcription of the cystine transporter SLC7A11. The latter was induced as a protective response by the transcription factors ATF4 and Nrf2. PBCA particles strongly activated ATF4 downstream of the eIF2α kinase HRI, whereas PEBCA particles more potently induced Nrf2 antioxidant responses. Intriguingly, PBCA particles activated the cell death mechanism ferroptosis; a promising option for targeting multidrug-resistant cancers. Our findings highlight that even minor differences in NP composition can severely impact the cellular response to NPs. This may have important implications in therapeutic settings.

• Skotland, Tore; Hessvik, Nina Pettersen; Sandvig, Kirsten & Martinez, Alicia Llorente (2019). Exosomal lipid composition and the role of ether lipids and phosphoinositides in exosome biology. Journal of Lipid Research. ISSN 0022-2275. 60, s. 9–18. doi: 10.1194/jlr.R084343. Fulltekst i vitenarkiv Vis sammendrag

  Exosomes are a type of extracellular vesicle released from cells after fusion of multivesicular bodies with the plasma membrane. These vesicles are often enriched in cholesterol, SM, glycosphingolipids, and phosphatidylserine. Lipids not only have a structural role in exosomal membranes but also are essential players in exosome formation and release to the extracellular environment. Our knowledge about the importance of lipids in exosome biology is increasing due to recent technological developments in lipidomics and a stronger focus on the biological functions of these molecules. Here, we review the available information about the lipid composition of exosomes. Special attention is given to ether lipids, a relatively unexplored type of lipids involved in membrane trafficking and abundant in some exosomes. Moreover, we discuss how the lipid composition of exosome preparations may provide useful information about their purity. Finally, we discuss the role of phosphoinositides, membrane phospholipids that help to regulate membrane dynamics, in exosome release and how this process may be linked to secretory autophagy. Knowledge about exosome lipid composition is important to understand the biology of these vesicles and to investigate possible medical applications.

• Skotland, Tore & Sandvig, Kirsten (2019). The role of PS 18:0/18:1 in membrane function. Nature Communications. 10(1), s. 1–10. doi: 10.1038/s41467-019-10711-1. Fulltekst i vitenarkiv Vis sammendrag

  Various studies have demonstrated that the two leaflets of cellular membranes interact, potentially through so-called interdigitation between the fatty acyl groups. While the molecular mechanism underlying interleaflet coupling remains to be fully understood, recent results suggest interactions between the very-long-chain sphingolipids in the outer leaflet, and phosphatidylserine PS18:0/18:1 in the inner leaflet, and an important role for cholesterol for these interactions. Here we review the evidence that cross-linking of sphingolipids may result in clustering of phosphatidylserine and transfer of signals to the cytosol. Although much remains to be uncovered, the molecular properties and abundance of PS 18:0/18:1 suggest a unique role for this lipid.

• Fusser, Markus; Øverbye, Anders; Pandya, Abhilash D.; Mørch, Ýrr Asbjørg; Borgos, Sven Even F. & Kildal, Wanja [Vis alle 16 forfattere av denne artikkelen] (2018). Cabazitaxel-loaded Poly(2-ethylbutyl cyanoacrylate) nanoparticles improve treatment efficacy in a patient derived breast cancer xenograft. Journal of Controlled Release. ISSN 0168-3659. 293, s. 183–192. doi: 10.1016/j.jconrel.2018.11.029. Fulltekst i vitenarkiv Vis sammendrag

  The effect of poly(2-ethyl-butyl cyanoacrylate) nanoparticles containing the cytotoxic drug cabazitaxel was studied in three breast cancer cell lines and one basal-like patient-derived xenograft model grown in the mammary fat pad of immunodeficient mice. Nanoparticle-encapsulated cabazitaxel had a much better efficacy than similar concentrations of free drug in the basal-like patient-derived xenograft and resulted in complete remission of 6 out of 8 tumors, whereas free drug gave complete remission only with 2 out of 9 tumors. To investigate the different efficacies obtained with nanoparticle-encapsulated versus free cabazitaxel, mass spectrometry quantification of cabazitaxel was performed in mice plasma and selected tissue samples. Nanoparticle-encapsulated drug had a longer circulation time in blood. There was approximately a three times higher drug concentration in tumor tissue 24 h after injection, and two times higher 96 h after injection of nanoparticles with drug compared to the free drug. The tissue biodistribution obtained after 24 h using mass spectrometry analyses correlates well with biodistribution data obtained using IVIS® Spectrum in vivo imaging of nanoparticles labeled with the fluorescent substance NR668, indicating that these data also are representative for the nanoparticle distribution. Furthermore, immunohistochemistry was used to estimate infiltration of macrophages into the tumor tissue following injection of nanoparticle-encapsulated and free cabazitaxel. The higher infiltration of anti-tumorigenic versus pro-tumorigenic macrophages in tumors treated with the nanoparticles might also contribute to the improved effect obtained with the nanoparticle-encapsulated drug. Tumor infiltration of pro-tumorigenic macrophages was four times lower when using nanoparticles containing cabazitaxel than when using particles without drug, and we speculate that the very good therapeutic efficacy obtained with our cabazitaxel-containing particles may be due to their ability to reduce the level of pro-tumorigenic macrophages in the tumor. In summary, encapsulation of cabazitaxel in poly(2-ethyl-butyl cyanoacrylate) nanoparticles seems promising for treatment of breast cancer.

• Sandvig, Kirsten; Kavaliauskiene, Simona & Skotland, Tore (2018). Clathrin-independent endocytosis: an increasing degree of complexity. Histochemistry and Cell Biology. ISSN 0948-6143. 150, s. 107–118. doi: 10.1007/s00418-018-1678-5. Fulltekst i vitenarkiv Vis sammendrag

  This article aims at providing an update on the complexity of clathrin-independent endocytosis. It is now almost 30 years since we first wrote a review about its existence; at that time many people believed that with the exception of macropinocytosis, which will only be briefly mentioned in this review, all uptake could be accounted for by clathrin-dependent endocytosis. Now it is generally accepted that there are different clathrin-independent mechanisms, some of them regulated by ligands and membrane lipid composition. They can be both dynamin-dependent and -independent, meaning that the uptake cannot be accounted for by caveolae and other dynamin-dependent processes such as tubular structures that can be induced by toxins, e.g. Shiga toxin, or the fast endophilin mediated endocytosis recently described. Caveolae seem to be mostly quite stable structures with other functions than endocytosis, but evidence suggests that they may have cell-type dependent functions. Although several groups have been working on endocytic mechanisms for years, and new advanced methods have improved our ability to study mechanistic details, there are still a number of important questions we need to address, such as: How many endocytic mechanisms does a cell have? How quantitatively important are they? What about the complexity in polarized cells where clathrin-independent endocytosis is differentially regulated on the apical and basolateral poles? These questions are not easy to answer since one and the same molecule may contribute to more than one process, and manipulating one mechanism can affect another. Also, several inhibitors of endocytic processes commonly used turn out to be less specific than originally thought. We will here describe the current view of clathrin-independent endocytic processes and the challenges in studying them.

• Ailte, Ieva; Dyve, Lingelem Anne Berit; Kvalvaag, Audun Sverre Myrset; Kavaliauskiene, Simona; Brech, Andreas & Koster, Gerbrand [Vis alle 10 forfattere av denne artikkelen] (2017). Exogenous lysophospholipids with large head groups perturb clathrin-mediated endocytosis. Traffic: The moving front of cell biology. ISSN 1398-9219. 18(3), s. 176–191. doi: 10.1111/tra.12468. Fulltekst i vitenarkiv Vis sammendrag

  In this study, we have investigated how clathrin-dependent endocytosis is affected by exogenously added lysophospholipids (LPLs). Addition of LPLs with large head groups strongly inhibits transferrin (Tf ) endocytosis in various cell lines, while LPLs with small head groups do not. Electron and total internal reflection fluorescence microscopy (EM and TIRF) reveal that treatment with lysophosphatidylinositol (LPI) with the fatty acyl group C18:0 leads to reduced numbers of invaginated clathrin-coated pits (CCPs) at the plasma membrane, fewer endocytic events per membrane area and increased lifetime of CCPs. Also, endocytosis of Tf becomes dependent on actin upon LPI treatment. Thus, our results demonstrate that one can regulate the kinetics and properties of clathrin-dependent endocytosis by addition of LPLs in a head group size- and fatty acyl-dependent manner. Furthermore, studies performed with optical tweezers show that less force is required to pull membrane tubules outwards from the plasma membrane when LPI is added to the cells. The results are in agreement with the notion that insertion of LPLs with large head groups creates a positive membrane curvature which might have a negative impact on events that require plasma membrane invagination, while it may facilitate membrane bending toward the cell exterior.

• Skotland, Tore; Ekroos, Kim; Kauhanen, Dimple; Simolin, Helena; Seierstad, Therese & Berge, Viktor [Vis alle 8 forfattere av denne artikkelen] (2017). Molecular lipid species in urinary exosomes as potential prostate cancer biomarkers. European Journal of Cancer. ISSN 0959-8049. 70, s. 122–132. doi: 10.1016/j.ejca.2016.10.011. Fulltekst i vitenarkiv
• Kavaliauskiene, Simona; Dyve, Lingelem Anne Berit; Skotland, Tore & Sandvig, Kirsten (2017). Protection against Shiga Toxins. Toxins. 9(2). doi: 10.3390/toxins9020044. Fulltekst i vitenarkiv Vis sammendrag

  Shiga toxins consist of an A-moiety and five B-moieties able to bind the neutral glycosphingolipid globotriaosylceramide (Gb3) on the cell surface. To intoxicate cells efficiently, the toxin A-moiety has to be cleaved by furin and transported retrogradely to the Golgi apparatus and to the endoplasmic reticulum. The enzymatically active part of the A-moiety is then translocated to the cytosol, where it inhibits protein synthesis and in some cell types induces apoptosis. Protection of cells can be provided either by inhibiting binding of the toxin to cells or by interfering with any of the subsequent steps required for its toxic effect. In this article we provide a brief overview of the interaction of Shiga toxins with cells, describe some compounds and conditions found to protect cells against Shiga toxins, and discuss whether they might also provide protection in animals and humans.

• Taubenschmid, Jasmin; Stadlmann, Johannes; Jost, Markus; Klokk, Tove Irene; Rillahan, Cory D. & Leibbrandt, Andreas [Vis alle 16 forfattere av denne artikkelen] (2017). A vital sugar code for ricin toxicity. Cell Research. ISSN 1001-0602. 27(11), s. 1351–1364. doi: 10.1038/cr.2017.116. Fulltekst i vitenarkiv
• Simm, Roger; Kvalvaag, Audun Sverre Myrset; Deurs, Bo van; Lindback, Toril & Sandvig, Kirsten (2017). Benzyl alcohol induces a reversible fragmentation of the Golgi apparatus and inhibits membrane trafficking between endosomes and the trans-Golgi network. Experimental Cell Research. ISSN 0014-4827. 357(1), s. 67–78. doi: 10.1016/j.yexcr.2017.04.025. Fulltekst i vitenarkiv
• Skotland, Tore; Sandvig, Kirsten & Llorente, Alicia (2017). Lipids in exosomes: Current knowledge and the way forward. Progress in lipid research. ISSN 0163-7827. 66, s. 30–41. doi: 10.1016/j.plipres.2017.03.001. Fulltekst i vitenarkiv Vis sammendrag

  Lipids are essential components of exosomal membranes, and it is well-known that specific lipids are enriched in exosomes compared to their parent cells. In this review we discuss current knowledge about the lipid composition of exosomes. We compare published data for different lipid classes in exosomes, and what is known about their lipid species, i.e. lipid molecules with different fatty acyl groups. Moreover, we elaborate on the hypothesis about hand-shaking between the very-long-chain sphingolipids in the outer leaflet and PS 18:0/18:1 in the inner leaflet, and we propose this to be an important mechanism in membrane biology, not only for exosomes. The similarity between the lipid composition of exosomes, HIV particles, and detergent resistant membranes, used as lipid rafts models, is also discussed. Furthermore, we summarize knowledge about the role of specific lipids and lipid metabolizing enzymes on the formation and release of exosomes. Finally, the use of exosomal lipids as biomarkers and how the lipid composition of exosomes may be of importance for researchers aiming to use exosomes as drug delivery vehicles is discussed. In conclusion, we have summarized what is presently known about lipids in exosomes and identified issues that should be taken into consideration in future studies.

• Øverbye, Anders; Holsæter, Ann Mari; Fusser, Markus; Skalko-Basnet, Natasa; Iversen, Tore Geir & Torgersen, Maria Lyngaas [Vis alle 12 forfattere av denne artikkelen] (2017). Ceramide-containing liposomes with doxorubicin: time and cell-dependent effect of C6 and C12 ceramide. OncoTarget. 8(44), s. 76921–76934. doi: 10.18632/oncotarget.20217. Fulltekst i vitenarkiv Vis sammendrag

  Doxorubicin, a widely used chemotherapeutic drug, has several potential high- risk side effects including cardiomyopathy. Furthermore, cellular resistance to this drug develops with time. By using liposomes as carrier vesicles both the side effects and drug resistance might be avoided. In this study we have investigated the cytotoxic effect of doxorubicin encapsulated in liposomes with and without ceramides containing 6 or 12 carbon atoms in the N-amidated fatty acyl chains. The short-chain ceramide species were included in the liposomal compositions due to their pro-apoptotic properties, which might cause a synergistic anticancer effect. We demonstrate that the ceramide species enhance the liposomal doxorubicin toxicity in a cell-specific manner. The C6-ceramide effect is most pronounced in cervical cancer cells (HeLa) and colon cancer cells (HCT116), whereas the C12-ceramide effect is strongest in breast cancer cells (MDA-MB-231). Moreover, the study reveals the importance of investigating cell toxicity at several time points and in different cell-lines, to assess drug-and formulation-induced cytotoxic effects in vitro . Furthermore, our data show that the cytotoxicity obtained with the nanocarriers in vitro , does not necessarily reflect their ability to inhibit tumor growth in vivo . We speculate that the larger effect of Caelyx® than our liposomes in vivo is due to a greater in vivo stability of Caelyx®.

• Manna, Dipankar; Pust, Sascha; Torgersen, Maria Lyngaas; Cordara, Gabriele; Kunzler, Markus & Krengel, Ute [Vis alle 7 forfattere av denne artikkelen] (2017). Polyporus squamosus lectin 1a (PSL1a) exhibits cytotoxicity in mammalian cells by disruption of focal adhesions, inhibition of protein synthesis and induction of apoptosis. PLOS ONE. 12(1). doi: 10.1371/journal.pone.0170716. Fulltekst i vitenarkiv Vis sammendrag

  PSL1a is a lectin from the mushroom Polyporus squamosus that binds to sialylated glycans and glycoconjugates with high specificity and selectivity. In addition to its N-terminal carbohydrate-binding domain, PSL1a possesses a Ca2+-dependent proteolytic activity in the C-terminal domain. In the present study, we demonstrate that PSL1a has cytotoxic effects on mammalian cancer cells, and we show that the cytotoxicity is dependent on the cysteine protease activity. PSL1a treatment leads to cell rounding and detachment from the substratum, concomitant with disruption of vinculin complexes in focal adhesions. We also demonstrate that PSL1a inhibits protein synthesis and induces apoptosis in HeLa cells, in a time- and concentration-dependent manner.

• Ling, Wang; Skotland, Tore; Berge, Viktor; Sandvig, Kirsten & Llorente, Alicia (2017). Exosomal proteins as prostate cancer biomarkers in urine: From mass spectrometry discovery to immunoassay-based validation. European Journal of Pharmaceutical Sciences. ISSN 0928-0987. 98, s. 80–85. doi: 10.1016/j.ejps.2016.09.023. Fulltekst i vitenarkiv
• Vestad, Beate; Llorente, Alicia; Neurauter, Axl; Phuyal, Santosh; Kierulf, Bente & Kierulf, Peter [Vis alle 10 forfattere av denne artikkelen] (2017). Size and concentration analyses of extracellular vesicles by nanoparticle tracking analysis: a variation study. Journal of Extracellular Vesicles. 6(1), s. 1–11. doi: 10.1080/20013078.2017.1344087. Fulltekst i vitenarkiv Vis sammendrag

  Current methods for characterisation of extracellular vesicles (EVs) need further standardisation in order to obtain an acceptable level of data comparability. Size and concentration of EVs can be determined by nanoparticle tracking analysis (NTA). However, both the heterogeneity of EVs and the choice of instrument settings may cause an appreciable analytical variation. Intra-assay (within-day, n = 6) and inter-assay (day-to-day, n = 6) variations (coefficient of variation, % CV) of different preparations of EVs and artificial vesicles or beads were determined using two NanoSight NS500 instruments, located at different laboratories. All analyses were performed by the same operator. The effect of applying identical software settings or instrument-optimised settings for each sample type and instrument was also evaluated. Finally, the impact of different operators and the use of two different software versions were investigated. The intra-assay CVs were 1–12% for both EVs and artificial samples, measured on the same instrument. The overall day-to-day variation was similar for both instruments, ranging from 2% to 25%. However, significantly different results were observed between the two instruments using identical software settings. The effect of applying instrument-optimised settings reduced the mismatch between the instruments, resulting in little to no significant divergences. The impact of using different operators and software versions when analysing silica microspheres and microvesicles from monocytes using instrument-optimised settings on the same instrument did not contribute to significant variation compared to the overall day-to-day variation of one operator. Performance differences between two similar NTA instruments may display significant divergences in size and concentration measurements when analysing EVs, depending on applied instrument settings and technical conditions. The importance of developing a streamlined and standardised execution of analysis, as well as monitoring longitudinal variation parameters on both biological and synthetic samples, should be highlighted.

• Sulheim, Einar; Iversen, Tore Geir; To, Vu; Klinkenberg, Geir; Sletta, Håvard & Schmid, Ruth [Vis alle 12 forfattere av denne artikkelen] (2017). Cytotoxicity of poly(Alkyl cyanoacrylate) nanoparticles. International Journal of Molecular Sciences. ISSN 1661-6596. 18(11). doi: 10.3390/ijms18112454. Fulltekst i vitenarkiv Vis sammendrag

  Although nanotoxicology has become a large research field, assessment of cytotoxicity is often reduced to analysis of one cell line only. Cytotoxicity of nanoparticles is complex and should, preferentially, be evaluated in several cell lines with different methods and on multiple nanoparticle batches. Here we report the toxicity of poly(alkyl cyanoacrylate) nanoparticles in 12 different cell lines after synthesizing and analyzing 19 different nanoparticle batches and report that large variations were obtained when using different cell lines or various toxicity assays. Surprisingly, we found that nanoparticles with intermediate degradation rates were less toxic than particles that were degraded faster or more slowly in a cell-free system. The toxicity did not vary significantly with either the three different combinations of polyethylene glycol surfactants or with particle size (range 100–200 nm). No acute pro- or anti-inflammatory activity on cells in whole blood was observed.

• Hardes, Kornelia; Ivanova, Teodora; Thaa, Bastian; McInerney, Gerald M; Klokk, Tove Irene & Sandvig, Kirsten [Vis alle 9 forfattere av denne artikkelen] (2017). Elongated and shortened peptidomimetic inhibitors of the proprotein furin. ChemMedChem. ISSN 1860-7179. 12(8), s. 613–620. doi: 10.1002/cmdc.201700108. Fulltekst i vitenarkiv
• Yermakova, Anastasiya; Klokk, Tove Irene; O'Hara, Joanne M.; Cole, Richard; Sandvig, Kirsten & Mantis, Nicholas J. (2016). Neutralizing Monoclonal Antibodies against Disparate Epitopes on Ricin Toxin's Enzymatic Subunit Interfere with Intracellular Toxin Transport. Scientific Reports. 6. doi: 10.1038/srep22721. Fulltekst i vitenarkiv
• Asp, Nagham Theres; Kvalvaag, Audun Sverre Myrset; Sandvig, Kirsten & Pust, Sascha (2016). Regulation of ErbB2 localization and function in breast cancer cells by ERM proteins. OncoTarget. 7(18), s. 25443–25460. doi: 10.18632/oncotarget.8327. Fulltekst i vitenarkiv
• Klokk, Tove Irene; Kavaliauskiene, Simona & Sandvig, Kirsten (2016). Cross-linking of glycosphingolipids at the plasma membrane: Consequences for intracellular signaling and traffic. Cellular and Molecular Life Sciences (CMLS). ISSN 1420-682X. 73(6), s. 1301–1316. doi: 10.1007/s00018-015-2049-1. Fulltekst i vitenarkiv
• Herrera, Cristina; Klokk, Tove Irene; Cole, Richard; Sandvig, Kirsten & Mantis, Nicholas J (2016). A bispecific antibody promotes aggregation of ricin toxin on cell surfaces and alters dynamics of toxin internalization and trafficking. PLOS ONE. 11:0156893(6). doi: 10.1371/journal.pone.0156893. Fulltekst i vitenarkiv
• Hjelseth, Ieva Ailte; Lingelem, Anne Berit Dyve; Kavaliauskiene, Simona; Bergan, Jonas; Kvalvaag, Audun Sverre Myrset & Myrann, Anne-Grethe [Vis alle 8 forfattere av denne artikkelen] (2016). Addition of lysophospholipids with large head groups to cells inhibits Shiga toxin binding. Scientific Reports. 6. doi: 10.1038/srep30336. Fulltekst i vitenarkiv
• Torgersen, Maria Lyngaas; Klokk, Tove Irene; Kavaliauskiene, Simona; Klose, Christian; Simons, Kai & Skotland, Tore [Vis alle 7 forfattere av denne artikkelen] (2016). The anti-tumor drug 2-hydroxyoleic acid (Minerval) stimulates signaling and retrograde transport. OncoTarget. 7(52), s. 86871–86888. doi: 10.18632/oncotarget.13508. Fulltekst i vitenarkiv
• Skotland, Tore; Ekroos, Kim; Kavaliauskiene, Simona; Bergan, Jonas; Kauhanen, Dimple & Lintonen, Tuulia [Vis alle 7 forfattere av denne artikkelen] (2016). Determining the turnover of glycosphingolipid species by stable-isotope tracer lipidomics. Journal of Molecular Biology (JMB). ISSN 0022-2836. 428(24), s. 4856–4866. doi: 10.1016/j.jmb.2016.06.013. Fulltekst i vitenarkiv
• Hessvik, Nina Pettersen; Øverbye, Anders; Brech, Andreas; Torgersen, Maria Lyngaas; Jakobsen, Ida Seim & Sandvig, Kirsten [Vis alle 7 forfattere av denne artikkelen] (2016). PIKfyve inhibition increases exosome release and induces secretory autophagy. Cellular and Molecular Life Sciences (CMLS). ISSN 1420-682X. 73(24), s. 4717–4737. doi: 10.1007/s00018-016-2309-8. Fulltekst i vitenarkiv
• Kavaliauskiene, Simona; Torgersen, Maria Lyngaas; Lingelem, Anne Berit Dyve; Klokk, Tove Irene; Lintonen, Tuulia & Simolin, Helena [Vis alle 9 forfattere av denne artikkelen] (2016). Cellular effects of fluorodeoxyglucose: Global changes in the lipidome and alteration in intracellular transport. OncoTarget. 7(48), s. 79885–79900. doi: 10.18632/oncotarget.13089. Fulltekst i vitenarkiv
• Rog, Tomasz; Orlowski, Adam; Llorente, Alicia; Skotland, Tore; Sylvänne, Tuulia & Kauhanen, Dimple [Vis alle 9 forfattere av denne artikkelen] (2016). Interdigitation of long-chain sphingomyelin induces coupling of membrane leaflets in a cholesterol dependent manner. Biochimica et Biophysica Acta - Biomembranes. ISSN 0005-2736. 1858(2), s. 281–288. doi: 10.1016/j.bbamem.2015.12.003. Fulltekst i vitenarkiv
• Róg, Tomasz; Orłowski, Adam; Llorente, Alicia; Skotland, Tore; Sylvänne, Tuulia & Kauhanen, Dimple [Vis alle 9 forfattere av denne artikkelen] (2016). Data including GROMACS input files for atomistic molecular dynamics simulations of mixed, asymmetric bilayers including molecular topologies, equilibrated structures, and force field for lipids compatible with OPLS-AA parameters. Data in Brief. 7, s. 1171–1174. doi: 10.1016/j.dib.2016.03.067. Fulltekst i vitenarkiv
• Skotland, Tore; Iversen, Tore Geir; Torgersen, Maria Lyngaas & Sandvig, Kirsten (2015). Cell-penetrating peptides: Possibilities and challenges for drug delivery in vitro and in vivo. Molecules. ISSN 1431-5157. 20(7), s. 13313–13323. doi: 10.3390/molecules200713313. Fulltekst i vitenarkiv
• Sandvig, Kirsten; Lingelem, Anne Berit Dyve; Skotland, Tore & Bergan, Jonas (2015). Shiga toxins: Properties and action on cells. I Alouf, Joseph E; Ladant, Daniel & Popoff, Michel R (Red.), The Comprehensive Sourcebook of Bacterial Protein Toxins, Fourth Edition. Elsevier. ISSN 9780128001882. s. 267–286. Fulltekst i vitenarkiv
• Hardes, Kornelia; Becker, Gero L.; Lu, Yinghui; Dahms, Sven O.; Köhler, Susanne & Beyer, Wolfgang [Vis alle 14 forfattere av denne artikkelen] (2015). Novel furin inhibitors with potent anti-infectious activity. ChemMedChem. ISSN 1860-7179. 10(7), s. 1218–1231. doi: 10.1002/cmdc.201500103. Fulltekst i vitenarkiv
• Øverbye, Anders; Skotland, Tore; Koehler, Christian; Thiede, Bernd; Seierstad, Therese & Berge, Viktor [Vis alle 8 forfattere av denne artikkelen] (2015). Identification of prostate cancer biomarkers in urinary exosomes. OncoTarget. 6(30), s. 30357–30376. doi: 10.18632/oncotarget.4851. Fulltekst i vitenarkiv
• Kymre, Linn Furebotten; Simm, Roger; Skotland, Tore & Sandvig, Kirsten (2015). Different roles of the C-terminal end of Stx1A and Stx2A for AB5 complex integrity and retrograde transport of Stx in HeLa cells. Pathogens and Disease. 73(9), s. 1–9. doi: 10.1093/femspd/ftv083. Fulltekst i vitenarkiv
• Sokołowska, Iwona; Piłka, Ewa S.; Sandvig, Kirsten; Węgrzyn, Grzegorz & Słomińska-Wojewódzka, Monika (2015). Hydrophobicity of protein determinants influences the recognition of substrates by EDEM1 and EDEM2 in human cells. BMC Cell Biology. 16(1). doi: 10.1186/s12860-015-0047-7. Fulltekst i vitenarkiv Vis sammendrag

  Background EDEM1 and EDEM2 are crucial regulators of the endoplasmic reticulum (ER)-associated degradation (ERAD) that extracts misfolded glycoproteins from the calnexin chaperone system. The degradation of ERAD substrates involves mannose trimming of N-linked glycans; however the precise mechanism of substrate recognition and sorting to the ERAD pathway is still poorly understood. It has previously been demonstrated that EDEM1 and EDEM2 binding does not require the trimming of substrate glycans or even ERAD substrate glycosylation, thus suggesting that both chaperones probably recognize misfolded regions of aberrant proteins. Results In this work, we focused on the substrate recognition by EDEM1 and EDEM2, asking whether hydrophobicity of protein determinants might be important for these interactions in human cells. In the study we used ricin, a protein toxin that utilizes the ERAD pathway in its retrotranslocation from the ER to the cytosol, and a model misfolded protein, the pancreatic isoform of human β-secretase, BACE457. Mutations in the hydrophobic regions of these proteins allowed us to obtain mutated forms with increased and decreased hydrophobicity. Conclusions Our data provide the first evidence that recognition of ERAD substrates by EDEM1 and EDEM2 might be determined by a sufficiently high hydrophobicity of protein determinants. Moreover, EDEM proteins can bind hydrophobic transmembrane regions of misfolded ERAD substrates. These data contribute to the general understanding of the regulation of ERAD in mammalian cells.

• Kavaliauskiene, Simona; Skotland, Tore; Sylvänne, Tuulia; Simolin, Helena; Klokk, Tove Irene & Torgersen, Maria Lyngaas [Vis alle 10 forfattere av denne artikkelen] (2015). Novel actions of 2-deoxy-D-glucose: Protection against Shiga toxins and changes in cellular lipids. Biochemical Journal. ISSN 0264-6021. 470, s. 23–37. doi: 10.1042/BJ20141562. Fulltekst i vitenarkiv
• Slominska-Wojewodzka, Monika & Sandvig, Kirsten (2015). The role of lectin-carbohydrate interactions in the regulation of ER-associated protein degradation. Molecules. ISSN 1431-5157. 20(6), s. 9816–9846. doi: 10.3390/molecules20069816. Fulltekst i vitenarkiv
• Lingelem, Anne Berit Dyve; Hjelseth, Ieva Ailte; Simm, Roger; Torgersen, Maria Lyngaas & Sandvig, Kirsten (2015). Geldanamycin enhances retrograde transport of Shiga toxin in HEp-2 cells. PLOS ONE. 10:e0129214(5). doi: 10.1371/journal.pone.0129214. Fulltekst i vitenarkiv
• Phuyal, Santosh; Skotland, Tore; Hessvik, Nina Pettersen; Simolin, Helena; Øverbye, Anders & Brech, Andreas [Vis alle 10 forfattere av denne artikkelen] (2015). The ether lipid precursor hexadecylglycerol stimulates the release and changes the composition of exosomes derived from PC-3 cells. Journal of Biological Chemistry. ISSN 0021-9258. 290, s. 4225–4237. doi: 10.1074/jbc.M114.593962. Fulltekst i vitenarkiv
• Sandvig, Kirsten; Bergan, Jonas; Kavaliauskiene, Simona & Skotland, Tore (2014). Lipid requirements for entry of protein toxins into cells. Progress in lipid research. ISSN 0163-7827. 54(1), s. 1–13. doi: 10.1016/j.plipres.2014.01.001. Fulltekst i vitenarkiv
• Holland, Petter; Torgersen, Maria Lyngaas; Sandvig, Kirsten & Simonsen, Anne (2014). LYST affects lysosome size and quantity, but not trafficking or degradation through autophagy or endocytosis. Traffic: The moving front of cell biology. ISSN 1398-9219. 15(12), s. 1390–1405. doi: 10.1111/tra.12227. Fulltekst i vitenarkiv
• Asp, Nagham; Pust, Sascha & Sandvig, Kirsten (2014). Flotillin depletion affects ErbB protein levels in different human breast cancer cells. BBA - Molecular Cell Research. ISSN 0167-4889. 1843(9), s. 1987–1996. doi: 10.1016/j.bbamcr.2014.04.013. Fulltekst i vitenarkiv
• Bergan, Jonas; Skotland, Tore; Dyve, Lingelem Anne Berit; Simm, Roger; Spilsberg, Bjørn & Lindback, Toril [Vis alle 10 forfattere av denne artikkelen] (2014). The ether lipid precursor hexadecylglycerol protects against Shiga toxins. Cellular and Molecular Life Sciences (CMLS). ISSN 1420-682X. 71, s. 4285–4300. doi: 10.1007/s00018-014-1624-1. Fulltekst i vitenarkiv
• Cordara, Gabriele; Winter, Harry C.; Goldstein, Irwin J.; Krengel, Ute & Sandvig, Kirsten (2014). The fungal chimerolectin MOA inhibits protein and DNA synthesis in NIH/3T3 cells and may induce BAX-mediated apoptosis. Biochemical and Biophysical Research Communications - BBRC. ISSN 0006-291X. 447(4), s. 586–589. doi: 10.1016/j.bbrc.2014.04.043. Fulltekst i vitenarkiv
• Yermakova, Anastasiya; Klokk, Tove Irene; Cole, Richard; Sandvig, Kirsten & Mantis, Nicholas J (2014). Antibody-mediated inhibition of ricin toxin retrograde transport. mBio. ISSN 2161-2129. 5(2). doi: 10.1128/mBio.00995-13. Fulltekst i vitenarkiv
• Phuyal, Santosh; Hessvik, Nina Pettersen; Skotland, Tore; Sandvig, Kirsten & Llorente, Alicia (2014). Regulation of exosome release by glycosphingolipids and flotillins. The FEBS Journal. ISSN 1742-464X. 281(9), s. 2214–2227. doi: 10.1111/febs.12775. Fulltekst i vitenarkiv
• Kvalvaag, Audun Sverre Myrset; Pust, Sascha & Sandvig, Kirsten (2014). Vps11, a subunit of the tethering complexes HOPS and CORVET, is involved in regulation of glycolipid degradation and retrograde toxin transport. Communicative & Integrative Biology. 7. doi: 10.4161/cib.28129. Fulltekst i vitenarkiv
• Kavaliauskiene, Simona; Nymark, Carl-Martin; Bergan, Jonas; Simm, Roger; Sylvänne, Tuulia & Simolin, Helena [Vis alle 9 forfattere av denne artikkelen] (2014). Cell density-induced changes in lipid composition and intracellular trafficking. Cellular and Molecular Life Sciences (CMLS). ISSN 1420-682X. 71(6), s. 1097–1116. doi: 10.1007/s00018-013-1441-y. Fulltekst i vitenarkiv
• Slominska-Wojewodska, Monika; Pawlik, A; Sokolowska, Iwona; Antoniewicz, J; Wegrzyn, Grzegorz & Sandvig, Kirsten (2014). The role of EDEM2 versus EDEM1 in ricin transport fro the endoplasmic reticulum to the cytosol. Biochemical Journal. ISSN 0264-6021. 457(3), s. 485–496. doi: 10.1042/BJ20130155. Fulltekst i vitenarkiv
• Pust, Sascha; Klokk, Tove Irene; Musa, Nagham; Jenstad, Monica; Risberg, Bjørn Åke & Erikstein, Bjørn K [Vis alle 11 forfattere av denne artikkelen] (2013). Flotillins as regulators of ErbB2 levels in breast cancer. Oncogene. ISSN 0950-9232. 32(29), s. 3443–3451. doi: 10.1038/onc.2012.357. Fulltekst i vitenarkiv
• Sandvig, Kirsten; Skotland, Tore; Deurs, Bo Van & Klokk, Tove Irene (2013). Retrograde transport of protein toxins through the Golgi apparatus. Histochemistry and Cell Biology. ISSN 0948-6143. 140(3), s. 317–326. doi: 10.1007/s00418-013-1111-z. Fulltekst i vitenarkiv

Se alle arbeider i NVA

• Feith, Marek; Pandya, Abhilash D.; Hyldbakk, Astrid; Høgset, Anders; Sandvig, Kirsten & Skotland, Tore [Vis alle 8 forfattere av denne artikkelen] (2025). Photodynamic therapy in breast cancer by photosensitizer-chitosan particles inducing ferroptosis. Cancer Research. ISSN 0008-5472. 85(8_Supplement_1), s. 4483–4483. doi: 10.1158/1538-7445.am2025-4483. Fulltekst i vitenarkiv Vis sammendrag

  Triple-negative breast cancer (TNBC) is a subtype of breast cancer associated with poor prognosis and limited treatment options. While chemotherapy has traditionally been the main treatment, resistance frequently emerges, reducing its effectiveness. Recently, a range of immunotherapy strategies, including combinations of chemotherapy and immunotherapy, have expanded treatment possibilities. To further enhance the therapeutic efficacy, there is a desire to combine chemotherapy with other currently used modalities such as photodynamic therapy (PDT) or to encapsulate drugs into nanoparticles (NPs). Ferroptosis has been described as a highly immunogenic type of cell death, characterized by increased ROS and lipid peroxidation. Mesenchymal cancer cells have been reported to be more sensitive to ferroptosis than epithelial cells. We have previously shown that tetraphenylchlorin-conjugated chitosan nanoparticles (TPC-CS NPs) loaded with mertansine and cabazitaxel induce ferroptosis in TNBC.1 In this project, we investigated the effect of TPC-CS NPs together with free RSL3, a ferroptosis inducer. We show that such treatment induces cell death in a mesenchymal breast cancer cell line but not in an epithelial one. The combined treatment also significantly affects lipid peroxidation and mitochondrial function. Based on these results, we encapsulated RSL3 into TPC-CS NPs and used them in two different breast cancer cell lines. We explored the photodynamic effect of empty and RSL3 loaded TPC-CS NPs upon illumination on cell viability by using an MTS assay. Since we have not observed any beneficial effect of TPC-CS NPs-RSL3, we explored the uptake of only empty TPC-CS NPs by using fluorescence microscopy and flow cytometry in these two cell lines. Currently, a biodistribution study in immunocompetent animals bearing 4T1 tumors is being performed. We will perform the maximum tolerable dose experiments for illumination to determine the light dose for further experiments. Moreover, we will perform efficacy studies of TPC-CS NPs and investigate the immune cell composition of tumors and tumor microenvironment using a flow cytometry panel of 25 markers. 1.Pandya AD, Øverbye A, Sahariah P, et al. Drug-Loaded Photosensitizer-Chitosan Nanoparticles for Combinatorial Chemo- and Photodynamic-Therapy of Cancer. Biomacromolecules. 2020/04/13 2020;21(4):1489-1498. This project has received funding from the Europe Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement 956544. Citation Format: Marek Feith, Abhilash D. Pandya, Astrid Hyldbakk, Anders Høgset, Kirsten Sandvig, Tore Skotland, Tore-Geir Iversen, Gunhild Mari Mælandsmo. Photodynamic therapy in breast cancer by photosensitizer-chitosan particles inducing ferroptosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4483.

• Fusser, Markus; Øverbye, Anders; Pandya, Abhilash D.; Mørch, Ýrr Asbjørg; Borgos, Sven Even F. & Kildal, Wanja [Vis alle 16 forfattere av denne artikkelen] (2022). Corrigendum to “Cabazitaxel-loaded Poly(2-ethylbutyl cyanoacrylate) nanoparticles improve treatment efficacy in a patient derived breast cancer xenograft”, [Journal of Control Release, 293 (2019) 183–192, (Journal of Control Release, (2019) 293(183-192) (S0168365918306928), (10.1016/j.jconrel.2018.11.029)). Journal of Controlled Release. ISSN 0168-3659. 349, s. 1–1. doi: 10.1016/j.jconrel.2022.06.040. Fulltekst i vitenarkiv
• Torgersen, Maria Lyngaas; Szwed, Marzena; Sønstevold, Tonje; Øverbye, Anders; Engedal, Nikolai & Grallert, Beata [Vis alle 11 forfattere av denne artikkelen] (2018). Small variations in nanoparticle structure dictate differential cellular stress responses and mode of cell death. Fulltekst i vitenarkiv
• Rodriguez, Marta; Bajo-Santos, Cristina; Hessvik, Nina Pettersen; Lorenz, Susanne; Fromm, Bastian & Berge, Viktor [Vis alle 9 forfattere av denne artikkelen] (2017). Identification of non-invasive miRNAs biomarkers for prostate cancer by deep sequencing analysis of urinary exosomes. Molecular Cancer. 16:156, s. 1–6. doi: 10.1186/s12943-017-0726-4. Fulltekst i vitenarkiv Vis sammendrag

  The aim of this study was to identify microRNAs in urinary exosomes that are differently expressed in prostate cancer patients and healthy donors. For this purpose, RNA was extracted from urinary exosomes from 20 prostate cancer patients and 9 healthy males and the microRNAs were analyzed by next generation sequencing. Interestingly, 5 microRNAs - miR-196a-5p, miR-34a-5p, miR-143-3p, miR-501-3p and miR-92a-1-5p - were significantly downregulated in exosomes from prostate cancer patients. Furthermore, RT-qPCR analysis of an independent cohort of 28 prostate cancer patients and 19 healthy males confirmed that miR-196a-5p and miR-501-3p were downregulated in prostate cancer samples. These results suggest that specific microRNAs in urinary exosomes might serve as non-invasive biomarkers for prostate cancer. In particular, miR-196a-5p and miR-501-3p are promising biomarkers that need to be further studied in large patient cohorts.

• Sulheim, Einar; Iversen, Tore Geir; To, Vu; Klinkenberg, Geir; Sletta, Håvard & Schmid, Ruth [Vis alle 12 forfattere av denne artikkelen] (2017). Cytotoxicity of Poly (alkyl cyanoacrylate) Nanoparticles. Fulltekst i vitenarkiv
• Manna, Dipankar; Krengel, Ute & Sandvig, Kirsten (2016). Structure-function characterization and cytotoxicity studies of fungal chimerolections. NBS-nytt. ISSN 0801-3535. Fulltekst i vitenarkiv
• Manna, Dipankar; Cordara, Gabriele; Sandvig, Kirsten & Krengel, Ute (2016). I Robot- Biological nanomachines for fungal defense. Fulltekst i vitenarkiv
• Øverbye, Anders; Holsæter, Ann Mari; Skalko-Basnet, Natasa; Tore-Geir, Iversen; Torgersen, Maria Lyngaas & Sønstevold, Tonje [Vis alle 8 forfattere av denne artikkelen] (2016). Biodegradable nanoparticles in cancer diagnosis and therapy (NANOCAN):Ceramide modulation of liposomal doxorubicin. Fulltekst i vitenarkiv
• Manna, Dipankar; Cordara, Gabriele; Pust, Sascha; Goldstein, Irwin J; Winter, Harry C. & Krengel, Ute [Vis alle 7 forfattere av denne artikkelen] (2015). PSL1a: a new member in the growing family of fungal chimerolectin. Fulltekst i vitenarkiv
• Skotland, Tore; Iversen, Tore Geir & Sandvig, Kirsten (2014). Development of nanoparticles for clinical use. Nanomedicine. ISSN 1743-5889. 9(9), s. 1295–1299. doi: 10.2217/NNM.14.81. Fulltekst i vitenarkiv
• Kvalvaag, Audun Sverre Myrset & Sandvig, Kirsten (2015). Shiga toxin: Uptake and transport in cancer cells. Akademika Publishing. Fulltekst i vitenarkiv
• Phuyal, Santosh; Llorente, Alicia & Sandvig, Kirsten (2014). Composition and cellular release of exosomes from cancer cells. Akademika publishing. Fulltekst i vitenarkiv
• Asp, Nagham; Sandvig, Kirsten; Pust, Sascha & Klokk, Tove Irene (2014). Regulation of ErbB2 and ErbB3 Growth factor receptors in human breast cancer. Akademika Publishing. Fulltekst i vitenarkiv
• Sandvig, Kirsten; Simm, Roger & Kymre, LInn (2014). Structure-function relationship of Shiga toxins; Role of the A-subunit in complex stability and endocytosis. Universitetet i Oslo. Fulltekst i vitenarkiv
• Svensson, Karin; Klokk, Tove Irene & Sandvig, Kirsten (2014). The role of evectin-2 and its binding partner PS in toxin transport. Universitetet i Oslo. Fulltekst i vitenarkiv
• Sandvig, Kirsten & Bergan, Jonas (2013). Investigation of membrane dynamics in cancer cells by following Shiga toxin. Universitetet i Oslo. Fulltekst i vitenarkiv
• Cordara, Gabriele; Krengel, Ute & Sandvig, Kirsten (2013). Structure-function studies on the Marasmius oreades agglutinin (MOA), a cytotoxic protease. Akademika Publishing. Fulltekst i vitenarkiv
• Jakobsen, Ida Seim; Llorente, Alicia & Sandvig, Kirsten (2013). Exosome release: Role of PIKfyve and ERM proteins. Universitetet i Oslo. Fulltekst i vitenarkiv

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