No abstract

IntroductionEpithelial-mesenchymal transition (EMT) plays key roles in all stages of cancer progression from primary tumour growth, invasion, and metastasis to resistance to chemotherapy. Earlier we have shown that EMT phenotype in ovarian cancer tumours associated with the increase in the metastatic potential and resistance to anticancer therapy; EMT markers were more often discovered in ascites as compared to solid cancers. The main goal of the present work was the analysis of EMT phenotype during cancer cell adaptation to the growth in vitro. Material and methodsCell lines were purchased from ATCC and were cultured in vitro according to the manufacturer’s recommendations. Level, intensity and integral index (product of level and intensity) of de novo expression vimentin (EMT marker) was estimated in cell cultures originated from solid tumours and extracellular fluids by immunofluorescence assay associated with flow cytometry. Primary anti-vimentin antibodies (CRM312A, Biocare) and secondary DL650 conjugated antibodies (ab98510) were used.Results and discussionsSignificant differences were revealed between BT-474 and HCC1937 cell culture lines originated from solid breast cancer. In BT-474 breast cancer cells expression level of vimentin was more than 2 times lower (29% vs 71%), and well as intensity – 3 times (2.1 vs 6.4), and the index – 6 times (0.7 vs 4.8) lower compared to HCC1937 breast cancer cells. At the same time, vimentin expression was low in MCF-7 and T-47D luminal type breast cancer cells originated from pleural fluid: level – 8% and 20%, intensity – 1.1 and 1.3, and index – 0.2 and 0.4. On the contrary, in ovarian cancer SCOV-3 and breast cancer HBL-100 cells, originated from extracellular tumours (ascites and colostrum), expression level of vimentin was high: level – 51% and 75%, intensity – 3.6 and 6.8, index – 1.9 and 5.1.ConclusionVimentin, one of key EMT markers, in original epithelial tumour does not predict molecular epithelial phenotype of the cells during their adaptation to the growth in vitro. It may be lost, increased or persisted at the same level as in vivo. The results showed the plasticity of epithelial tumour cell phenotype and high level of EMT in some epithelial cell culture what must be taken into account in molecular studies of epithelial tumour cells in vitro. The study was supported by RFBR #18-015-00422, 16-04-00347.