MiR­381 regulates cell motility, growth and colony formation through PIK3CA in endometriosis­associated clear cell and endometrioid ovarian cancer.

ABSTRACT

Ovarian cancer is the one of the most lethal gynecological cancer types. MicroRNAs (miRs) are noncoding RNAs that modulate the translation of their target mRNAs via binding to a complementary sequence in the target 3' untranslated region, and the dysregulation of certain miRs has been demonstrated to contribute to cancer progression. In this regard, the current study extended our previous work and used next­generation sequencing data to search for upstream regulators of genetic alterations that are common in ovarian cancer, as well as the miRs that are involved in controlling the expression of these regulators. An miR prediction program was used to identify miR­381 as an upstream regulator of phosphatidylinositol 3­kinase catalytic subunit α (PIK3CA) in the context of ovarian cancer. Levels of miR­381 were decreased in clear cell and endometrioid carcinoma ovarian cancer. Experimentally induced upregulation of miR­381 led to a decrease in the level of PIK3CA in ovarian cancer cells. Furthermore, experimentally induced upregulation of miR­381 inhibited the proliferation of ovarian cancer cells in vitro and their ability to form colonies and migrate. The observed decrease in miR­381 in ovarian cancer could be reversed upon overexpression of the gene encoding the tumor suppressor homeobox D10. The current results highlight the role of miR­381­mediated regulation of PIK3CA in the development and progression of ovarian cancer and suggest that restoration of miR­381 to normal levels in ovarian cancer cells may constitute a therapeutic strategy for patients.