Objective:To explore the expression,biological function and possible mechanism of action of microRNA molecular-196a(miR-196a) in epithelial ovarian cancer.Methods:RT-PCR was used to detect the expression quantities of epithelial ovarian tissue,benign ovarian tissue,normal ovary epithelial tissue,ovarian cancer cell lines and miR-196 a in normal ovarian epithelial cells to analyze the relationship between the expression of miR-196 a and the clinical pathologic parameters of ovarian cancer.Among those cell lines,the cell line of which miR-196 a expressed the most or least was selected and transfected the ovarian cancer cell line by using negative control plasma and miR-196 a inhibitor.After transfection,RT-PCR was used to test the expression quantity of miR-196 a,Transwell chamber method was applied to determine the migration and invasion abilities of ovarian carcinoma cells and Western blot was employed to detect the expression of HOXA10 protein.Results:The relative expression quantities of miR-196 a in ovarian cancer tissue and benign ovarian tissue were significantly higher than that in normal ovarian epithelial tissue,and the expression quantity of miR-196 a in ovarian cancer tissue was distinctively higher than that in benign ovarian tissue(P < 0.05).Among 78 cases of epithelial ovarian cancer,the expression quantities of miR-196 a in patients with low differentiation were all significantly higher than those in patients with high differentiation(P< 0.05).The expression of miR-196 a showed no significant relation with age,clinical stage and whether CA125 was positive or not in patients(P > 0.05).Compared with normal ovarian epithelial cell line IOSE80,the expression quantities of miR-196 a of all ovarian cancer cell lines increased obviously and differences were statistically significant(P < 0.05).Among them,the expression of miR-196 a of ovarian cancer cell line SKOV3 was the highest,while it decreased significantly(4.678 ± 0.785 vs.2.131 ± 0.345,t = 2.938,P < 0.05) after the ovarian cancer cell line SKOV3 was transfected by miR-196 a inhibitor.The results of Transwell chamber method showed that the migration and invasion abilities of ovarian cancer cells SKOV3 were declined significantly after the expression of miR-196 a was down-regulated and the difference showed statistical significance(P < 0.05).The results of Western blot revealed that the relative expression of HOXA10 decreased distinctly after the expression of miR-196 a was down-regulated and also the difference showed statistical significance(P < 0.05).Conclusions:The miR-196 a might serve as a cancer-promoting gene to promote the migration and invasion of epithelial ovarian cancer by downstream target gene HOXA10. Objective: To explore the expression, biological function and possible mechanism of action of microRNA molecular-196a (miR-196a) in epithelial ovarian cancer. Methods: RT-PCR was used to detect the expression quantities of epithelial ovarian tissue, benign ovarian tissue, normal ovary epithelial cells, ovarian cancer cell lines and miR-196 a in normal ovarian epithelial cells to analyze the relationship between the expression of miR-196 a and the clinical pathologic parameters of ovarian cancer. Among those cell lines, the cell line of which miR-196 a expressed the most or least was selected and transfected the ovarian cancer cell line by using negative control plasma and miR-196 a inhibitor. After transfection, RT-PCR was used to test the expression quantity of miR-196 a, Transwell chamber method was applied to determine the migration and invasion abilities of ovarian carcinoma cells and Western blot was employed to detect the expression of HOXA10 protein. Results: The relative expression quantitie s of miR-196 a in ovarian cancer tissue and benign ovarian tissue were significantly higher than that in normal ovarian epithelial tissue, and the expression quantity of miR-196 a in ovarian cancer tissue was distinctively higher than that in benign ovarian tissue (P < 0.05) .Among 78 cases of epithelial ovarian cancer, the expression quantities of miR-196 a in patients with low differentiation were all significantly higher than those in patients with high differentiation (P <0.05). Expression of miR-196 a showed no significant relation with age, clinical stage and whether CA125 was positive or not in patients (P> 0.05). Compared with normal ovarian epithelial cell line IOSE80, the expression quantities of miR-196 a of all ovarian cancer cell lines increased obviously and not were Significant (P <0.05) .Among them, the expression of miR-196 a of ovarian cancer cell line SKOV3 was the highest, while it decreased significantly (4.678 ± 0.785 vs.2.131 ± 0.345, t = 2.938, P < 0.05) after the ovarian cancer cell line SKOV3 was transfected by miR-196 a inhibitor. The results of the Transwell chamber method showed that the migration and invasion abilities of ovarian cancer cells SKOV3 were favored significantly after the expression of miR-196 a was down- regulated and the difference showed statistical significance (P <0.05). The results of Western blot revealed that the relative expression of HOXA10 decreased distinctly after the expression of miR-196 a was down-regulated and also the difference showed statistical significance (P <0.05 ) .Conclusions: The miR-196 a might serve as a cancer-promoting gene to promote the migration and invasion of epithelial ovarian cancer by downstream target gene HOXA10.