Ovarian cancer is one of the leading causes of death among gynecological malignancies. Increasing evidence indicate that dysregulation of microRNAs (miRNAs) plays an important role in tumor radioresistance. The aim of the present study is to investigate whether microRNA-214 (miR-214) was involved in radioresistance of human ovarian cancer. Here, we showed that miR-214 was significantly up-regulated in ovarian cancer tissues and radioresistance ovarian cancer cell lines. Transfection of miR-214 agomir in radiosensitive ovarian cancer cell lines promoted them for resistance to ionizing radiation, whereas transfection of miR-214 antagomir in radioresistance ovarian cancer cell lines sensitized them to ionizing radiation again. Furthermore, we found miR-214 effectively promoted tumor radioresistance in xenograft animal experiment. Western blotting and quantitative real-time PCR demonstrated that miR-214 negatively regulated PTEN in radioresistance ovarian cancer cell lines and ovarian cancer tissues. Taken together, our data conclude that miR-214 contributes to radioresistance of ovarian cancer by directly targeting PTEN.
Difference between genomic actions of estrogen versus raloxifene in human ovarian cancer cell lines
