miRNA-148a inhibits cell growth of papillary thyroid cancer through STAT3 and PI3K/AKT signaling pathways

The function of miRNA-148a in lymphatic metastases of papillary thyroid cancer and its mechanism were tested. In this investigation, miRNA-148a expression of lymphatic metastases of papillary thyroid cancer patients was inhibited, compared with normal group. We found that miRNA-148a overexpression was effectively reduced cell cell proliferation and metastases, and induced apoptosis of papillary thyroid cancer in vitro. Overexpression of miRNA-148a significantly induced Bax protein expression and caspase-3/9 levels, and suppressed phosphorylation STAT3 (p-STAT3), PI3K and p-Akt protein expression of papillary thyroid cancer in vitro. Next, si-STAT3, could inhibit p-STAT3 protein expression, reducing cell-cell proliferation and metastases, and inducing apoptosis of papillary thyroid cancer following miRNA-148a overexpression. Then, the PI3K inhibitor was able to inhibit PI3K and p-Akt protein expression, reduced cell cell proliferation and metastases, and induced apoptosis of papillary thyroid cancer following miRNA-148a overexpression. Taken together, our results suggest that miRNA-148a inhibits lymphatic metastases of papillary thyroid cancer through STAT3 and PI3K/AKT signaling pathways.