miR-132 targets FOXA1 and exerts tumor-suppressing functions in thyroid cancer.

MicroRNA-132 (miR-132) has been proven to be a tumor suppressor in several types of tumors. However, the expression andthe role of miR-132 in human thyroid cancer are still poorly understood. The aim of the present study was to examine the potential roles and molecular mechanism of miR-132 in thyroid cancer. We found that miR-132 expression levels were significantly downregulated in thyroid cancer tissues and cell lines. Function assays showed that overexpression of miR-132 in TPC1 inhibited cell proliferation, migration and invasion. Forkhead box protein A1 (FOXA1) was identified as a direct target of miR-132 in thyroid cancer cells. Knockdown of FOXA1 in TPC1 cells significantly inhibited cell proliferation, migration, invasion, which mimicked the suppression effect induced by miR-132 overexpression. Restoration of FOXA1 expression partially reversed the suppression effect induced by miR-132 overexpression. Taken together, these results suggested that miR-132 acts as a tumor suppressor in thyroid cancer through targeting FOXA1.