Objective To investigate the effects of human endostatin(hES)on ovarian cancer cells A2780 growth in vitro and in vivo and the possible mechanism.Methods The coding region for hES was amplified by PCR from human liver tissue and then subcloned into pcDNA3.1 vector.The growth rate of A2780 cells transfected with hES was observed.A2780 cells(1× 10~7/ml)were inoculated subcutaneously into 20 nude mice,and the mice were randomly divided into two groups:the hES-trans-fected group(group A,n=10)and the control group(group B,n=10).One month later,the size of subcutaneous tumor was measured,and the tumor inhibition rate was calculated.The specimens were stained with HE for the histological analysis.Cell apoptosis in ovarian neoplasm transplantation tissues was determined by flow cytometry.The expression of hES and Bcl-2 was detected by Western blot.Results The growth rate of the hES-transfected ovarian cancer cells A2780 was significantly decreased.In group A,growth of tumor in nude mice was significantly slowed as compared with group B(P<0.01),with the tumor inhibition rate being 74% in group A.The tumor necrosis was increased and the basophilia stain of nucleus decreased significantly in group A as compared with group B.The expression of hES was increased significantly,but that of Bcl-2 was decreased significantly in group A.Flow cytometry revealed that hES transfection could significantly incyease the apoptosis rate of tumor cells(P<0.05).Conclusion Transfection of hES could suppress the growth of ovarian cancer cells A2780 in vitro and in vivo,which may be related tO the promotion of apoptosis.