Abstract: Objectives To investigate the killing effect and mechanism of histone deacetylase inhibitor, trichostatin A (TSA), on ovarian cancer. Methods The killing effect of TSA on ovarian cancers was detected by using XTT and flow cytometry technique on two of the normal ovarian epithelial cell lines, IOSE-29 and IOSE-329, and three of the ovarian cancer cell lines, ES-2, SKOV-3, and OVCAR-8. The in vivo effect was also observed. Results HDAC6 protein showed higher positivity in ovarian cancer and its cell lines than in normal ovarian epithelia. ES-2, SKOV-3, and OVCAR-8 ovarian cancer cells were more sensitive for HDACs inhibitor, TSA, treatment compared with normal ovarian epithelial cell lines (P<0.05). Also, the ratio of apoptosis and cell death were significantly higher in TSA treated ovarian cancer cells than it in the untreated group. In vivo experiments also showed that ES-2 xenograft treated by TSA was growing much slower compared with untreated ES-2 xenograft. Conclusions TSA could effectively kill the ovarian cancer cells in vivo and in vitro, and the mechanism might be carried out partially by HDAC6 gene inhibition.

Key words: Histone Deacetylase, Ovarian Cancer, Trichostatin A