HOXC6 gene silencing inhibits epithelial-mesenchymal transition and cell viability through the TGF-β/smad signaling pathway in cervical carcinoma cells

BACKGROUND: Homeobox C6 (HOXC6) plays a part in malignant progression of some tumors. However, the expression of HOXC6 and its clinical significance remains unclear in cervical carcinoma (CC). The purpose of this study is to verify the effects of HOXC6 gene silencing on CC through the TGF-β/smad signaling pathway. METHODS: CC tissues and corresponding paracancerous tissues were collected from CC patients with involvement of a series of HOXC6-siRNA, HA-HOXC6 and the TGF-β/smad pathway antagonist. HOXC6 expression was analyzed in six CC cell lines (C-33A, HeLa, CaSki, SiHa, ME-180, and HCC-94) by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. The mRNA and protein expression of HOXC6, TGF-β1, TGF-β RII, smad4, smad7, E-cadherin, N-cadherin, Vimentin, ki-67, proliferating cell nuclear antigen (PCNA), p27, and Cyclin D1 were determined by RT-qPCR and western blot analysis. Cell proliferation, apoptosis and cell cycle were detected by MTT assay and flow cytometry, respectively. RESULTS: Higher positive expression rate of HOXC6 protein was observed in CC tissues and HOXC6 was related to TNM stage, lymphatic metastasis, cancer types, primary lesion diameter, and histological grade of CC. Silencing HOXC6 inhibited epithelial-mesenchymal transition (EMT) (shown as decreased N-cadherin and Vimentin, and increased E-cadherin) through the inactivation of the TGF-β/smad signaling pathway. HOXC6 gene silencing hindered cell proliferation and accelerated cell apoptosis of CC cells. Furthermore, the effect of HOXC6 silencing was enhanced when the TGF-β/smad signaling pathway was suppressed. CONCLUSION: The results reveal that HOXC6 gene silencing may inhibit EMT event and cell viability in CC through the inhibition of the activation of TGF-β/smad signaling pathway.