Expression of the cytoskeletal proteins – cytokeratins and beta-III tubulin in human melanoma cell lines from the collection of N. N. Blokhin National Medical Research Center of Oncology

Abstract

Introduction. Despite advances in the treatment of melanoma, the results of therapy cannot be considered satisfactory, and the search for new drugs and effective combinations of medicine continues. The drugs are being developed aimed at reducing the metastatic tumor potential – migrastatics. The targets of the drugs can be cytoskeletal proteins of tumor cells – cytokeratin (CK) intermediate filaments and microtubule protein beta-III tubulin (TUBB3). Aim. To estimate of the CK and TUBB3 expression in melanoma cell lines to form an informative in vitro cell model for screening and studying migrastatics. Materials and methods. The molecular phenotype of 21 human melanoma cell lines from the collection of N. N. Blokhin National Medical Research Center of Oncology, and 18 of which were isolated from tumor metastases in the lymph nodes, soft tissues or subcutaneously. The level of TUBB3 expression and de novo expression of CKs in vimentin-expressing cells (CK + Vim) were assessed by an immunofluorescent method and flow cytometry. Results. Beta-III tubulin expression was detected in all cultures studied, de novo expression of CKs was found in 20 / 21 lines. The exception was primary uveal melanoma 92-1, that did not express CK + Vim. Both parameters significantly differed between the cells of the studied panel: CK + Vim co-expression – from 0 to 91 %, TUBB3 – from 18 to 86 %. No correlation was found between the expression level of TUBB3 and CK + Vim (Pearson’s correlation coefficient r = 0.11; p = 0.65). Three groups of the cell lines with different ratio of TUBB3 expression and CK + Vim co-expression were identified: 1) similar level of expression of both markers; 2) the level of co-expression of CK + Vim more or less high than the index for TUBB3; 3) the level of TUBB3 expression more or less high than the index for CK + Vim co-expression. Conclusion. A panel of 21 human melanoma cell lines was formed with quantitatively estimated expression of cytoske-letal proteins responsible for the migration activity of tumor cells – CKs and TUBB3. Groups of the lines with different expression ratio of the markers can be used for screening and preclinical evaluation potential migrastatics that reduce the metastatic potential of melanoma and may reduce resistance to taxanes.