LncRNA UCA1/miR-124 axis modulates TGF1-induced epithelial-mesenchymal transition and invasion of tongue cancer cells through JAG1/Notch signaling

Tongue cancer remains a massive threat to public health due to the high rate of metastasis. Tumor cell epithelial-mesenchymal transition (EMT), which can be induced by transforming growth factor 1 (TGF1), has been regarded as a significant contributor to cancer invasion and migration. In our previous study, long noncoding RNA (lncRNA) MALAT1/miR-124/JAG1 axis modulates the growth of tongue cancer. In addition to metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), another lncRNA, urothelial cancer associated 1 (UCA1), can promote EMT and cancer metastasis. In the present study, UCA1 was overexpressed in tongue cancer tissues and cell lines. UCA1 overexpression was correlated to the poorer prognosis of patients with tongue cancer. UCA1 knockdown significantly suppressed TGF1-induced tongue cancer cell invasion and EMT by decreasing vimentin and increasing E-cadherin. Regarding the molecular mechanism, UCA1 could directly bind to microRNA-124 (miR-124) and negatively regulate each other. UCA1 knockdown ameliorated, whereas miR-124 inhibition exacerbated TGF1-induced EMT and invasion in tongue cancer cells through miR-124 downstream jagged 1 (JAG1) and Notch signaling. Moreover, miR-124 inhibition partially impaired the effect of UCA1 knockdown. In tongue cancer tissues, miR-124 expression was remarkably decreased, whereas JAG1 mRNA expression was increased. miR-124 was negatively correlated with UCA1 and JAG1. UCA1 and JAG1 were positively correlated. In summary, we provided a novel mechanism by which the EMT process and cancer cell invasion in tongue cancer could be modulated from the perspective of lncRNA-miRNA-mRNA regulation.