Abstract: Objective To investigate the expression of X-ray-repaired cross complementary protein 6 (Ku70/XRCC6) in epithelial ovarian cancer(EOC) and its effects on the proliferation, apoptosis and migration of ovarian cancer cells. Methods Western blot was used to detect the expression of Ku70 in 9 ovarian cancer tissues of different grades and 3 normal ovarian tissues. Immunohistochemistry was used to detect the expression of Ku70 in 119 ovarian cancer tissues, and the relationship between Ku70 expression and clinicopathological parameters was analyzed. Kaplan-meier survival curve was used to analyze the relationship between Ku70 expression and 5-year survival. Colony formation and CCK-8 assay were used to analyze the effect of Ku70 expression on proliferation of ovarian cancer cells, and flow cytometry was used to detect the effect of Ku70 expression on apoptosis of ovarian cancer cells. The effect of Ku70 expression on ovarian cancer cell migration was analyzed by scratch test and Transwell chamber method. Results The expression of Ku70 in ovarian cancer tissues was higher than that in normal ovarian tissues. The expression of Ku70 was closely correlated with pathological features (P＜0.05). The survival rate of ovarian cancer patients with high Ku70 expression was lower than that of patients with low Ku70 expression(P＜0.05). Inhibiting the expression of Ku70 decreased poliferation and migration, and increased apoptosis of ovarian cancer cells (P＜0.05). Conclusions The abnormal expression of Ku70 is closely related to the occurrence of ovarian cancer and so Ku70 is a potential therapeutic target for ovarian cancer treatment.

Key words: Ku70/XRCC6, epithelial ovarian cancer, proliferation, apoptosis, migration