Long noncoding RNA UCA1 regulates CCR7 expression to promote tongue squamous cell carcinoma progression by sponging miR-138-5p.

Tongue squamous cell carcinoma (TSCC) is a malignant tumor. Long noncoding RNAs (lncRNAs) have been proved to be involved in the regulation of the progression of various cancers. However, the mechanism of lncRNA urothelial cancer-associated 1 (UCA1) in the progression of TSCC remains unclear. The expression levels of UCA1, microRNA-138-5p (miR-138-5p), and CC chemokine receptor 7 (CCR7) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation, migration, and invasion were detected using colony formation assay and transwell assay, respectively. Western blot (WB) analysis was used to test the levels of proliferation and metastasis-related proteins and CCR7 protein. Moreover, the extracellular acidification rate (ECAR) of cells was measured by the Seahorse XF Extracellular Flux Analyzer, and the adenosine triphosphate (ATP) level, glucose uptake, and lactate produce of cells were tested by their corresponding assay kits. Further, the dual-luciferase reporter assay was used to confirm the interaction between miR-138-5p and UCA1 or CCR7. In addition, the effect of UCA1 on TSCC tumor growth in vivo was evaluated by animal experiments. We found that UCA1 and CCR7 were upregulated, while miR-138-5p was downregulated in TSCC tissues. Silenced UCA1 restrained the proliferation, migration, invasion, and glycolysis metabolism of TSCC cells. Similarly, knockdown of CCR7 also could suppress the progression of TSCC. Besides, UCA1 overexpression promoted TSCC progression, while this promotion effect could be reversed by CCR7 silencing. miR-138-5p could be sponged by UCA1 and could target CCR7. Additionally, miR-138-5p overexpression could reverse the promotion effect of overexpressed UCA1 on TSCC progression. Furthermore, the UCA1 knockdown reduced TSCC tumor growth in vivo. In conclusion, lncRNA UCA1 might function as an oncogene in TSCC through regulating the miR-138-5p/CCR7 axis, providing a new biomarker for TSCC treatment.