Chemotherapy-Induced Long Non-coding RNA 1 Promotes Metastasis and Chemo-Resistance of TSCC via the Wnt/β-Catenin Signaling Pathway

Increasing evidence has shown that chemo-resistance is related to the process of epithelial-mesenchymal transition (EMT) and increased invasiveness by tongue squamous cell carcinoma (TSCC) cells. Long non-coding RNAs (lncRNAs) play pivotal roles in tumor metastasis and progression. However, the roles and mechanisms of lncRNAs in cisplatin-resistance-induced EMT and metastasis are not well understood. In this study, a chemotherapy-induced lncRNA 1 (CILA1) was discovered by using microarrays and was functionally identified as a regulator of chemo-sensitivity in TSCC cells. Upregulation of CILA1 promotes EMT, invasiveness, and chemo-resistance in TSCC cells, whereas the inhibition of CILA1 expression induces mesenchymal-epithelial transition (MET) and chemosensitivity, and inhibits the invasiveness of cisplatin-resistant cells both in vitro and in vivo. We also found that CILA1 exerts its functions via the activation of the Wnt/beta-catenin signaling pathway. High CILA1 expression levels and low levels of phosphorylated beta-catenin were closely associated with cisplatin resistance and advanced disease stage, and were predictors of poor prognosis in TSCC patients. These findings provided a new biomarker for the chemo-sensitivity of TSCC tumors and a therapeutic target for TSCC treatment.