Non-Coding RNA in Cholangiocarcinoma: An Update.

Cholangiocarcinoma (CCA) is one of the most common tumors with high malignancy. Its incidence is increasing year by year, and it is insidious and easily metastasized, and most patients are already in advanced stages when they are diagnosed. Surgery is an essential treatment for CCA, but the 5-year survival rate is still unsatisfactory due to the low early diagnosis rate and high malignancy of CCA. Therefore, exploring the molecular mechanisms of CCA to find reliable biomarkers and effective therapeutic targets is essential to improve the early diagnosis and survival rate of CCA. Non-coding RNA (ncRNA) is a class of RNA without protein-coding ability, mainly including microRNA (miRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA). In recent years, numerous pieces of evidence have shown that aberrantly expressed ncRNAs can regulate the occurrence and development of CCA through various mechanisms such as mediating epigenetic, sponge miRNAs regulating the expression of target genes and participating in regulating cancer-related signaling pathways, which provides new approaches and ideas for early diagnosis, prognosis assessment and therapeutic targeting of CCA. In this paper, we review the molecular mechanisms of lncRNAs and circRNAs regulating the progression of CCA in recent years and discuss their potential clinical value in CCA.