Abstract: BACKGROUND ＆ AIM： To determine whether an overexpression of IP-10 by transfection experiments in MA-10 cells has any effect on cell growth and progesterone synthesis. MATERIAL AND METHODS： We cloned the complete IP-10 cDNA in a mammalian expression vector with CMV promoter, pcDNA3.1D/V5-His-TOPO and transfected MA-10 cells. We checked the expression with rat IP-10 antibody and V5 antibody using Western blotting. The effects of overexpression of IP-10 gene on cell growth were checked by [3H]thymidine incorporation experiment. The progesterone synthesis was checked by RIA method. RESULTS: Results showed that IP-10 protein secreted in the medium was 30～40 fold more in the IP-10 transfectants over the basal levels as estimated by Western blotting. Transfection of MA-10 cells with IP-10 decreased 8-bromo-cAMP-induced progesterone synthesis from(38.5±1.7) ng/ml (1.5×105 cells/ml) of control cells to (23.2±1.5) ng/ml in transfected cells (P<0.01).8-bromo-cAMP (0.2 mmol/L) induced StAR D1 mRNA and decreased 30 ％～40 ％ by transfection with IP-10. Transfection of IP-10 gene also significantly decreased insulin-like growth factor (IGF-I, 100 ng/ml) induced [3H]thymidine incorporation into DNA. CONCLUSION: IP-10 inhibits StAR D1 expression, decreases progesterone synthesis and inhibits cell proliferation. IP-10 can be used as gene therapy for prostate cancer due to its antiangiogenic effects and its inhibitory effects on steroidogenesis.

Key words: IFN-γ-introduced protein 10, MA-10 cell, steriodogenesis, cell proliferation