Abstract: BACKGROUND AND AIM: To study the alteration of CYP1B1 gene expression in ovarian cancer cell HO-8910 after PTX chemotherapy in vitro, which can help us study the relationship between CYP1B1 gene expression and drug-resistance of cancer cells. MATERIALS AND METHODS:Ovarian cancer cells HO-8910 were cultured by tumor cell culture technique, inhibition of ovarian cancer cell growth induced by different concentration of PTX was assessed by methyl thiazolyl tetrazolium(MTT). Alterations of CYP1B1 mRNA and protein expression were evaluated by reverse transcription polymerase (RT-PCR) and Western blot in ovarian cancer cells cultured with PTX of 5 μg/ml for 24 h,48 h and 72 h or 50 μg/ml for 24 h. RESULTS: PTX inhibited the growth of ovarian cancer cell HO-8910, the inhibition rates by different concentrations of PTX after 72 h were 89.10％,76.82％,67.39％,57.27％,46.21％,37.02％,17.56％. The rate of cell inhibition decreased accordingly with the PTX concentration. In the surviving cells that had been cultured in PTX ,the expression of CYP1B1 mRNA and protein increased compared with control group. The CYP1B1 expression increased more in groups that had been treated with 5 μg/ml PTX for 48 h,72 h and 50 μg/ml compared to 5 μg/ml for 24 h group. CONCLUSION: CYP1B1 gene was highly expressed in ovarian cancer cell line, CYP1B1 gene may play an inhibitory role in PIX treatment of ovarian cancer cells HO-8910 in vitro.

Key words: CYP1B1, ovarian cancer, paclitaxel, tumor cell