ATP-binding cassette transporter A7 accelerates epithelial-to-mesenchymal transition in ovarian cancer cells by upregulating the transforming growth factor-β signaling pathway.

Ovarian cancer (OC) has the highest fatality rates of all gynecological malignancies worldwide. The epithelial-to-mesenchymal transition (EMT) serves an essential role in the progression of OC. An improved understanding of the molecular mechanism underlying EMT in OC may increase the survival rate. ATP-binding cassette transporter A7 (ABCA7) is a candidate regulator of OC progression. However, the role of ABCA7 in OC is unclear. Using the PROGgeneV2 platform, the present study revealed that increased expression of ABCA7 is associated with poor outcomes in OC. The expression of ABCA7 was higher in OC tissues than in adjacent noncancerous tissues. ABCA7-knockdown decreased the migration of OC cells and the activation of mothers against decapentaplegic homolog 4 (SMAD4). Notably, downregulation of ABCA7 also increased the expression of an epithelial marker (E-cadherin) and decreased that of a mesenchymal marker (N-cadherin). In addition, the decreased expression of SMAD4 and EMT markers induced by ABCA7 depletion could be rescued by transforming growth factor β1 (TGF-β1) stimulation. Overall, these findings suggested that ABCA7 accelerates EMT in OC by upregulating the TGF-β signaling pathway.