The effect of miRNAs on autophagy in ovarian cancer

Ovarian cancer ranks eighth among the most frequently diagnosed cancer types in women worldwide. Despite the effective application of current treatment methods, about half of ovarian cancer patients survive for an average of five years after diagnosis. Therefore, it is necessary to discover new drugs and new treatment methods to combat this deadly disease and to reveal the mechanism of ovarian cancer in detail. In this context, within the scope of the thesis, it was aimed to investigate autophagy, which is a cell death mechanism, after transfection of ovarian cancer cells (SKOV-3) with miRNA-155. Within the scope of this thesis study, SKOV-3 ovarian cell models with miRNA-155 mimic or miRNA-155 inhibitor transfection were created. In addition, transfected SKOV-3 cell groups incubated under normoxic or hypoxic conditions were treated with different concentra-tions of Chloroquine or Camptothecin. Cell migration rates, cell proliferation, autophagy flux and morphological changes were investigated in these cell groups. Overexpression of miRNA-155 significantly increased proliferation in SKOV-3 cells, whereas suppression of miRNA-155 or administration of Chloroquine or Camptothecin significantly inhibited cell proliferation. Likewise, cell migration rates of SKOV-3 cells were found to increase significantly after miRNA-155 overexpression. Under normoxic and hypoxic conditions, overexpression of miRNA-155 in SKOV-3 cells decreased the rate of autophagy, whereas suppression of miR-NA-155 triggered the autophagic pathway. Therefore, the obtained results show that miRNA-155 has an important anti-cancer role in the proliferation of SKOV-3 cells, the rate of cell migration and triggering the autophagy mecha-nism. In this context, detailed experimental studies are envisaged to examine the autophagy mechanism of SKOV-3 cells triggered by suppression of miRNA-155 at the molecular level.