miR-124 regulates STAT3-mediated cell proliferation, migration and apoptosis in bladder cancer

The etiology and pathogenesis of bladder cancer (BCa) is complex. MicroRNA (miRNA) has been implicated in BCa. Targeting of signal transducer and activator of transcription 3 (STAT3) by miR-124 to regulate tumorigenesis has been demonstrated in other types of cancer. In the present study, miR-124 levels were downregulated in the BCa T24 cell line and STAT3 was increased in BCa cell lines. Transfection of miR-124 mimics into T24 cells significantly inhibited STAT3 expression. A luciferase assay confirmed that miR-124 directly targeted the STAT3 3′untranslated region to inhibit STAT expression. Knockdown of STAT3 expression led to increased apoptosis of T24 cells and reduced tumor growth in vitro. The results demonstrated the molecular mechanisms and biological functions of the miR-124/STAT3 signal pathway at the cellular level and indicate the potential of miR-124 as a therapeutic target for BCa.