EXPRESSION OF MARKERS OF BONE TISSUE REMODELING IN BREAST CANCER AND PROSTATE CANCER CELLS IN VITRO

The aim of the study was to compare the expression of markers of bone remodeling in vitro in breast cancer (BCa) cells and prostate cancer (PCa) cells varying in their malignancy phenotype. Materials and Methods: The study was performed on human BCa cells (MCF-7 and MDA-MB-231 lines) and PCa cells (LNCaP and DU-145 lines). Expression levels of bone tissue remodeling proteins (osteopontin (OPN), osteonectin (ON) and bone morphogenetic protein 7 (BMP-7) were determined immunocytochemically. The mRNA levels of bone tissue remodeling proteins OPN (SPP1), ON (SPARC), BMP-7 (BMP7)) and miRNA-10b, -27a, -29b, -145, -146a were assessed by quantitative reverse transcription polymerase chain reaction. To search for miRNAs involved in the regulation of target genes, miRNet v. 2.0 resource was used. Results: We have shown that highly malignant MDA-MB-231 cells are characterized by significantly higher expression of OPN and ON on the background of decreased SPARC and BMP7 mRNA expression. In highly malignant DU-145 cells, ON and SPP1, SPARC, and BMP7 mRNA expression was significantly higher compared with low malignant LNCaP cells. MDA-MB-231 line was characterized by significantly higher expression of miRNA-10b, -27a, -29b, -145 and -146a. In DU-145 cells, significantly lower levels of expression of miRNAs-27a and -145 against the background of increasing levels of miRNAs-29b and -146a were recorded. Conclusion: High malignancy phenotype of the BCa and PCa cells is characterized by high levels of expression of bone remodeling proteins, which may be caused by impaired regulation of their expression at the epigenetic level.