Knockdown of circRNA circEBF1 inhibits cutaneous squamous cell carcinoma progression by regulating the miR-1247-5p/CSF3 axis

Abstract

Background. Cutaneous squamous cell carcinoma (CSCC) is one of the causes of cancer-related death worldwide. Circular RNAs (circRNAs) play a vital role in the pathological process of many malignant tumors. This study aimed to explore the specific role and potential mechanism of circRNA EBF transcription factor 1 (circEBF1) in CSCC. Methods. The levels of circEBF1, microRNA-1247- 5p (miR-1247-5p) and colony stimulating factor 3 (CSF3) were determined by quantitative real-time PCR and Western blot. Cell proliferation was assessed by colony formation assay. Cell migration, invasion and apoptosis were evaluated by Transwell, wound healing, flow cytometry and Western blot assays. Cellular glycolysis, including glucose consumption, lactate production, and ATP level, was detected by commercial kits. The binding relationship between miR-1247-5p and circEBF1 or CSF3 was verified by dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull-down assay. Xenograft experiment was conducted to analyze tumor growth in vivo. Results. circEBF1 and CSF3 were up-regulated, while miR-1247-5p was down-regulated in CSCC tissues and cells. Interference of circEBF1 hindered the proliferation, migration, invasion, and glycolysis of CSCC cells and promoted apoptosis. In addition, circEBF1 sponged miR-1247-5p to regulate CSCC cell development. Also, miR-1247-5p suppressed CSCC cell progression by inhibiting CSF3. Moreover, depletion of circEBF1 blocked CSCC tumor growth in vivo. Conclusion. Down-regulation of circEBF1 impeded CSCC progression by regulating the miR-1247-5p/CSF3 pathway, suggesting that circEBF1 might be a promising therapeutic target for CSCC