Effect of L9Mc lumican-derived peptide on the production and content of exosomes secreted by melanoma cells – Hyaluronan synthases and hyaluronidases in breast cancer

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Γλαρού, Μερόπη
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Skin cancer is one of the most common malignancies in humans. Melanoma is a type of skin cancer, where melanocytes grow out of control. It has been proposed that lumican, which is a member of small leucine rich proteoglycans and components of ECM, is implicated in melanoma. More precisely, Lumican is present in the dermis and in the peritumoral stroma of malignant melanoma and can inhibit melanoma progression in vivo and in vitro. Previous study has revealed an identified short lumican-derived peptide, the L9M (SSLVELDLSYNKLKNIP), a 10 aa peptide from lumcorin central part (underlined) that strongly displays anti-proliferative and anti-migratory effects and it is suggested for perspective therapeutic applications. The next step in that research was the use of the L9M in cyclic form. A scrambled L9M peptide (SCR- SLELDLNKYK), sharing the same residues with L9M but in a different sequence had no effect on the spontaneous migration of both cell types. Extracellular vesicles EVs, though to be waste carriers, now they are considered to act as signaling molecules, exchanging components between cells, in many biological processes and pathologies. More specifically exosomes, a subtype of EVs, promote progression of melanoma by enabling cells to escape immune regulation, by enhancing angiogenesis, extracellular remodeling and supporting pre-metastatic niche formation. Consequently, the aim of this part of the study was to characterize exosomes secreted by B16F1 murine melanoma cell lines and investigate the effects of L9Mc peptide on the production and content of exosomes released by B16F1 melanoma cell lines. A preliminary comparison between two murine melanoma cell lines, less metastatic B16F1 and B16F10, which is a more aggressive variant took place in order to fulfill the last step of this study, to examine the effects of more metastatic B16F10 exosomes on B16F1 proliferation, migration and invasion assays. Breast cancer is a type of cancer with many cases and increased mortality rates. It affects mainly women and it is rare in men. Statins is a family of drugs with main role to lower cholesterol and they are considered to be potential anticancer agents. As statins inhibit cholesterol biosynthesis, it is expected to affect structural organization of the cell membrane and influence all components of the cell membrane. Such components are hyaluronan synthases (HASs), enzymes that synthesize hyaluronan and hyaluronidases (HYALs), hyaluronic acid degradation enzymes. Hyaluronan (HA) is a key component of extracellular matrix (ECM), which contributes to many biological processes and mainly the growth and migration of cancerous tumors. HA synthases HAS1, HAS2, HAS3 are transmembrane enzymes, while hyaluronidases HYAL-2 and PH-20 are GPI-anchored enzymes, located in the plasma membrane, indicating their association with statins. Therefore, it was essential to investigate the effect of statins on the expression of these enzymes on breast cancer cell lines MCF-7 and MDA-MB-231. The effect on statins was also examined on the expression of HYAL-1 and HYAL-3, which are involved in cancer development on the same breast cancer cell lines. Finally, Epithelial to mesenchymal transition (EMT) is a biological event, closely related to increased invasiveness and metastatic potential of cancer cells. EMT markers’ expression, such as E-Cadherin and Vimentin were examined, as changes in the phenotype of breast cancer cells were observed after the simvastatin treatment.
Skin cancer, Melanoma, ECM, Lumican-derived peptide L9Mc, EVs, Exosomes, Breast cancer, Statins, HASs, HYALs, EMT, E-Cadherin, Vimentin