miR-1246 Targets CCNG2 to Enhance Cancer Stemness and Chemoresistance in Oral Carcinomas

MiRNAs have been recognized as crucial components in carcinogenesis, but whether miR-1246 affects the cancer stemness and drug resistance in oral squamous cell carcinoma (OSCC) has not been fully understood and its downstream targets still need to be unraveled. In the present work, we employed miRNAs RT-PCR analysis to evaluate the expression of miR-1246 in tumor tissues and oral cancer stem cells (OCSC). Stemness phenotypes, including self-renewal, migration, invasion, colony formation capacities, and in vivo oncogenicity of oral cancer cells following transfected with miR-1246 inhibitors or mimics were examined. Our results suggested that the expression level of miR-1246 was significantly upregulated in the tumor tissues and OCSC. Kaplan-Meier survival analysis of OSCC patients with high levels of miR-1246 had the worst survival rate compared to their low-expression counterparts. Inhibition of miR-1246 in OCSC significantly reduced the stemness hallmarks, while overexpression of miR-1246 enhanced these characteristics. Moreover, we showed that downregulation of miR-1246 decreased chemoresistance. In addition, we verified that miR-1246-inhibited CCNG2 contributed to the cancer stemness of OSCC. These results demonstrated the significance of miR-1246 in the regulation of OSCC stemness. Targeting miR-1246-CCNG2 axis may be beneficial to suppress cancer relapse and metastasis in OSCC patients.