A Review of Recent Research on the Role of MicroRNAs in Renal Cancer

Renal cell carcinoma (RCC) is a most common type of urologic neoplasms; it accounts for 3% of malignant tumors, with high rates of relapse and mortality. The most common types of renal cancer are clear cell carcinoma (ccRCC), papillary renal cell carcinoma (pRCC), and chromophobe renal carcinoma (chRCC), which account for 90%, 6–15%, and 2–5%, respectively, of all renal malignancies. Although surgical resection, chemotherapy, and radiotherapy are the most common treatment method for those diseases, their effects remain dissatisfactory. Furthermore, recent research shows that the treatment efficacy of checkpoint inhibitors in advanced RCC patients is widely variable. Hence, patients urgently need a new molecular biomarker for early diagnosis and evaluating the prognosis of RCC. MicroRNAs (miRNAs) belong to a family of short, non-coding RNAs that are highly conserved, have long half-life evolution, and post-transcriptionally regulate gene expression; they have been predicted to play crucial roles in tumor metastasis, invasion, angiogenesis, proliferation, apoptosis, epithelial-mesenchymal transition, differentiation, metabolism, cancer occurrence, and treatment resistance. Although some previous papers demonstrated that miRNAs play vital roles in renal cancer, such as pathogenesis, diagnosis, and prognosis, the roles of miRNAs in kidney cancer are still unclear. Therefore, we reviewed studies indexed in PubMed from 2017 to 2020, and found several studies suggesting that there are more than 82 miRNAs involved in renal cancers. The present review describes the current status of miRNAs in RCC and their roles in progression, diagnosis, therapy targeting, and prognosis of RCC.