MicroRNA-7-5p Inhibits Migration, Invasion and Metastasis of Intrahepatic Cholangiocarcinoma by Inhibiting MyD88

Overexpression of microRNA-205-5p promotes cholangiocarcinoma growth by reducing expression of homeodomain-interacting protein kinase 3

The microRNA miR-205-5p has diverse effects in different malignancies, including cholangiocarcinoma (CCA), but its effects on CCA progression is unclear. Here we investigated the role and function of miR-205-5p in CCA. Three CCA cell lines and human serum samples were found to have much higher expression levels of miR-205-5p than seen in typical cholangiocyte cell lines and healthy controls. Inhibition of miR-205-5p suppressed CCA cell motility, invasion and proliferation of KKU-213B whereby overexpression of miR-205-5p promoted cell proliferation and motility of KKU-100 cells. Bioinformatics tools (miRDB, TargetScan, miRWalk, and GEPIA) all predicted various miR-205-5p targets. Experiments using miR-205-5p inhibitor and mimic indicated that homeodomain-interacting protein kinase 3 (HIPK3) was a potential direct target of miR-205-5p. Overexpression of HIPK3 using HIPK3 plasmid cloning DNA suppressed migration and proliferation of KKU-100 cells. Notably, HIPK3 expression was lower in human CCA tissues than in normal adjacent tissues. High HIPK3 expression was significantly associated with longer survival time of CCA patients. Multivariate regression analysis indicated tissue HIPK3 levels as an independent prognostic factor for CCA patients. These findings indicate that overexpression of miR-205-5p promotes CCA cells proliferation and migration partly via HIPK3-dependent way. Therefore, targeting miR-205-5p may be a potential treatment approach for CCA.

Differentially expressed non-coding RNAs and their regulatory networks in liver cancer

The vast majority of human transcriptome is represented by various types of small RNAs with little or no protein-coding capability referred to as non-coding RNAs (ncRNAs). Functional ncRNAs include microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), which are expressed at very low, but stable and reproducible levels in a variety of cell types. ncRNAs regulate gene expression due to miRNA capability of complementary base pairing with mRNAs, whereas lncRNAs and circRNAs can sponge miRNAs off their target mRNAs to act as competitive endogenous RNAs (ceRNAs). Each miRNA can target multiple mRNAs and a single mRNA can interact with several miRNAs, thereby creating miRNA-mRNA, lncRNA-miRNA-mRNA, and circRNA-miRNA-mRNA regulatory networks. Over the past few years, a variety of differentially expressed miRNAs, lncRNAs, and circRNAs (DEMs, DELs, and DECs, respectively) have been linked to cancer pathogenesis. They can exert both oncogenic and tumor suppressor roles. In this review, we discuss the recent advancements in uncovering the roles of DEMs, DELs, and DECs and their networks in aberrant cell signaling, cell cycle, transcription, angiogenesis, and apoptosis, as well as tumor microenvironment remodeling and metabolic reprogramming during hepatocarcinogenesis. We highlight the potential and challenges in the use of differentially expressed ncRNAs as biomarkers for liver cancer diagnosis and prognosis.