Unscheduled expression of cyclins by anti-cancer drug exposure.

The scheduled expressions of cyclins are observed in the normal cells or the tumor cells whose phenotype is characterized by scheduled expression of cyclins, while unscheduled expression of cyclins were reported in several leukemic and solid tumor cell lines by anti-cancer drugs. We studied the effects of cytotoxic concentrations of Taxol (TXL) on cyclin D1 and B1 expression on human ovarian cancer cell lines. In KFr13 cells, the control group showed low degree of cyclin D1 and moderate degree of cyclin B1 expression in all cell cycles, while 1 microM TXL exposure resulted remarkable cyclin D1 and B1 expression in G2+M phase cells. OVCAR-3 cells showed relatively high degree of cyclin D1 expression and mild to moderate degrees of cyclin B1 expression in control group. 1 microM TXL showed no significant changes in cyclin D1 expression, while decreased expression cyclin B1 in G0+1 and S and moderate degree of expression in G2+M.