miR-15b inhibits cancer-initiating cell phenotypes and chemoresistance of cisplatin by targeting TRIM14 in oral tongue squamous cell cancer.

Oral tongue squamous cell carcinoma (TSCC) is one of the most lethal cancers within the oral cavity and its prognosis remains dismal due to the paucity of effective therapeutic targets. The formation of cancer-initiating cells (CICs) and epithelial-mesenchymal transition (EMT) are pivotal events involved in the dismal prognosis. They have been shown to be related to the resistance to cisplatin treatment. In the present study, we showed that TRIM14 induced formation of cancer-initiating cells and EMT in TSCC SCC25 cells. Its overexpression promoted cisplatin resistance in the SCC25 cells. We found that overexpression of miR-15b suppressed TRIM14 and inhibited CIC phenotypes in the SCC25 cells. Moreover, overexpression of miR-15b promoted mesenchymal-epithelial transition (MET) in the SCC25 cells and sensitized cisplatin-resistant SCC25 (SCC25-res) cells to cisplatin. Thus, we conclude that miR-15b inhibited cancer stem cell phenotypes and its restoration reversed the chemoresistance of cisplatin by targeting TRIM14 in TSCC. Elucidating the molecular mechanism of EMT and cancer stem cells in TSCC may further aid in the understanding of the pathogenesis and progression of the disease, and offer novel targets for the discovery of new drugs.