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

BACKGROUND

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.

AIM

To study the changes of the expression of OPN and ON and their mRNAs (SPP1 and SPARC) upon exposure to doxorubicin (Dox) in breast cancer (BCa) and prostate cancer (PCa) cell lines with different sensitivity to Dox.

MATERIALS AND METHODS

Cell lines of BCa (MCF-7 and MDA-MB-231) and PCa (LNCaP and DU-145) were cultured in the presence of Dox at IC30 concentrations for 24 h. OPN and ON levels were assessed by immunocytochemical (ICH) and Western blot analysis. SPP1 and SPARC mRNA levels were assessed by quantitative PCR.

RESULTS

Dox treatment resulted in the significant decrease in the expression of both OPN and ON in MCF-7 and LNCaP cells. Similarly, Dox treatment downregulated both SPP1 and SPARC in MDA-MB-231 and DU-145 cells. Dox did not affect ON expression in MDA-MB-231 and DU-145 cells although the significant decrease in the level of SPARC mRNA has been evident. In contrast, no significant differences in SPP1 and SPARC mRNA levels were detected in LNCaP cells.

CONCLUSION

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.