EXPRESSION OF OSTEOPONTIN AND OSTEONECTIN IN BREAST AND PROSTATE CANCER CELLS WITH DIFFERENT SENSITIVITY TO DOXORUBICIN.

Abstract

According to modern literature, osteopontin (OPN) and osteonectin (ON) are involved not only in the formation of the aggressive phenotype of malignantly transformed cells, but also in the realization of cytotoxic effects of some antitumor drugs. To study the changes of the expression of OPN and ON and their mRNAs (SPP1and SPARC) upon exposure to doxorubicin (Dox) in breast cancer (BCa) and prostate cancer (PCa) cell lines with different sensitivity to Dox. Cell lines of BCa (MCF-7and MDA-MB-231) and PCa (LNCaP and DU-145) were cultured in the presence of Dox at IC30concentrations for 24h. OPN and ON levels were assessed by immunocytochemical (ICH) and Western blot analysis. SPP1and SPARC mRNA levels were assessed by quantitative PCR. Dox treatment resulted in the significant decrease in the expression of both OPN and ON in MCF-7and LNCaP cells. Similarly, Dox treatment downregulated both SPP1and SPARC in MDA-MB-231and DU-145cells. Dox did not affect ON expression in MDA-MB-231and DU-145cells although the significant decrease in the level of SPARC mRNA has been evident. In contrast, no significant differences in SPP1and SPARC mRNA levels were detected in LNCaP cells. The changes in the expression of OPN and ON proteins and their corresponding genes in BCa and PCa cells may be related to the intrinsic mechanisms of Dox effects in cells differing by malignant phenotype and Dox sensitivity.