MicroRNA-766-3p-mediated downregulation of HNF4G inhibits proliferation in colorectal cancer cells through the PI3K/AKT pathway.

Nuclear receptors (NRs) are a class of transcription factors that play a pivotal role in carcinogenesis, but their function in colorectal cancer (CRC) remains unclear. Here, we investigate the role NRs play in CRC pathogenesis. We found that hepatocyte nuclear factor 4 gamma (HNF4G; NR2A2), hepatocyte nuclear factor 4α (HNF4A; NR2A1), and retinoid-related orphan receptor γ (RORC; NR1F3) were significantly upregulated in CRC tissues analyzed by GEPIA bioinformatics tool. The expression of HNF4G was examined in CRC samples and cell lines by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry. Increased expression of HNF4G was strongly associated with high tumor-node-metastasis stage and poor prognosis. Moreover, overexpression of HNF4G significantly promoted the proliferation of CRC cells in vitro. Next, we found that HNF4G promoted CRC proliferation via the PI3K/AKT pathway through targeting of GNG12 and PTK2. In addition, HNF4G was verified as a direct target of microRNA-766-3p (miR-766-3p). miR-766-3p inhibited the proliferation of CRC cells by targeting HNF4G in vitro and in vivo. Collectively, our study indicates that miR-766-3p reduces the proliferation of CRC cells by targeting HNF4G expression and thus inhibits the PI3K/AKT pathway. Therefore, development of therapies which target the miR-766-3p/HNF4G axis may aid in the treatment of CRC.