The aim of this study was to investigate the differences in lipid profiles associated with different levels of urothelial cancer cell invasiveness. Comparative lipidomic studies were performed on the RT4 versus T24 urothelial cancer cell lines as models for noninvasive papillary urothelial neoplasm cells and invasive urothelial neoplasm cells. Our results demonstrate that the two types of cells, RT4 and T24 cells, express some significant differences of cellular membranes including changes in lipid composition. The differences between RT4 and T24 cells suggest significantly different organization of the cellular membranes, which can affect the membrane fluidity and membrane-dependent functions, and contribute to the lower stiffness of plasma membrane and reduced cell-cell adhesion required for movement and invasiveness of these T24 urothelial carcinoma cells with a high metastatic potential. We found more tunneling membrane nanotubes between T24 cells. The differences in lipid composition between both cell lines were additionally confirmed using membrane raft-sensing fluorescently-labeled aegerolysin, OlyA-mCherry that was recently developed in our laboratories.
COBISS.SI-ID: 3968591
Vesiculation of cellular membranes is a constitutive process, although it can be induced by external physico-chemical parameters. In this study we explored the blebbing and vesiculation of Madin-Darby canine kidney (MDCK) cells induced by fluorescently-tagged aegerolysin, OlyA-mCherry. The paper shows that vesiculation of MDCK cells induced by OlyA-mCherry is not decreased by low temperatures and does not depend on increased [Ca2+] ions. Our proteomic analysis revealed that these shed extracellular vesicles (EVs) contained 71 proteins. These proteins were mostly of cytosolic and nuclear origin, and only a few were assigned as membrane-associated or typical membrane raft residents. Furthermore, the cellular and EVs lipidome were characterized using liquid chromatography-mass spectrometry and high-resolution nuclear magnetic resonance, which included analysis of the phospholipids and ceramide-based glycosphingolipids. We identified 218 different lipid species in these cells, and 84 different lipid species in EVs. We concluded that shed EVs are potentially interesting model for biophysical research as well as tool for non-invasive sampling of cytosolic proteins from cells and thus metabolic fingerprinting. This knowledge will help us in further investigating the membranes of tunneling membrane nanotubes.
COBISS.SI-ID: 3971151
Aim: We explored the distribution and cellular uptake of intratumorally injected SPIONs-PAA-PEI-pDNA (magnetofection complexes), and antitumor effectiveness of magnetofection with plasmid DNA encoding short hairpin RNA (shRNA) against Mcam (pDNA anti-MCAM ). Materials & methods: Analyses were made based on the histology, ultrastructure and quantitative measurements of magnetofection complexes, and quantification of the antitumor effectiveness in B16F10 melanoma in vivo . Results: Injected magnetofection complexes were distributed around the injection site. Exposure of tumors to external magnetic field contributed to the uptake of magnetofection complexes from extracellular matrix into melanoma cells. Three consecutive magnetofections of tumors with pDNA anti-MCAM resulted in significant reduction of tumor volume. Conclusion: Magnetofection is effective for gene delivery to melanoma tumors, but requires a magnetic field for cellular uptake and antitumor effect.
COBISS.SI-ID: 32548569