Direct targeting of SUZ12/ROCK2 by miR-200b/c inhibits cholangiocarcinoma tumourigenesis and metastasis

Abstract

Background:The multidrug resistance and distant metastasis of cholangiocarcinoma result in high postoperative recurrence and low long-term survival rates. It has been demonstrated that the ectopic expression of miR-200 suppresses the multidrug resistance and metastasis of cancer. However, the expression and function of miR-200 in cholangiocarcinoma has not yet been described.Methods:In this study, we identified dysregulated microRNAs (miRNAs, miR) in cholangiocarcinoma tissue by microarray analysis, and subsequent real-time PCR and northern blot analyses validated the expression of candidate miR. We performed functional analyses and investigated the relationship between miR-200b/c expression and the properties of cholangiocarcinoma cells. A dual luciferase assay was applied to examine the effect of miRNAs on the 3′-UTR of target genes, and we demonstrated the function of the target gene by siRNA transfection identifying the downstream pathway via western blotting.Results:We found significantly downregulated expression of four miR-200 family members (miR-200a/b/c/429) and then confirmed that ectopic miR-200b/200c inhibits the migration and invasion of cholangiocarcinoma cells both in vitro and in vivo. We found that miR-200b/c influenced the tumourigenesis of cholangiocarcinoma cells including their tumour-initiating capacity, sphere formation, and drug resistance. We further found that miR-200b/c regulated migration and invasion capacities by directly targeting rho-kinase 2 and regulated tumorigenic properties by directly targeting SUZ12 (a subunit of a polycomb repressor complex).Conclusion:Our study shows that miR-200b/c has a critical role in the regulation of the tumorigenic and metastatic capacity of cholangiocarcinoma and reveals the probable underlying mechanisms.

Regulation of Colorectal Carcinoma Stemness, Growth, and Metastasis by an miR-200c-Sox2–Negative Feedback Loop Mechanism

“…These contrary findings may be due, in part, to the different source organization and empirical method models. With regard to the role of miR-200c in tumor growth, several recent studies have reported its conflicting roles (23,(38)(39)(40).…”

Long noncoding RNA GIHCG promotes hepatocellular carcinoma progression through epigenetically regulating miR-200b/a/429

“…The miR-200 family is known for their critical roles in the occurrence and progression of many malignant tumors, including HCC, colorectal cancer, and cholangiocarcinoma [44,45]. So we next evaluated whether the association between GIHCG and EZH2 regulates the binding of EZH2 and DNMT1 to the promoter of miR-200b/a/429, or whether GIHCG is required for the binding of EZH2 to the promoter of miR-200b/a/ 429.…”

MicroRNA-200b Suppresses Arsenic-transformed Cell Migration by Targeting Protein Kinase Cα and Wnt5b-Protein Kinase Cα Positive Feedback Loop and Inhibiting Rac1 Activation

“…The majority of studies showed that miR-200 family inhibits cell migration and cancer metastasis through targeting epithelial to mesenchymal transition (EMT)-inducing transcription factors zinc-finger E-box-binding homeobox factor 1 (ZEB1) and ZEB2 (9 -11). Fewer studies indicated that miR-200 family may also be capable of inhibiting cell migration and cancer metastasis by targeting other genes such as actin cytoskeleton regulator WAVE3 (Wiskott-Aldrich syndrome protein family member 3), moesin and ROCK2 (Rho-kinase2), or extracellular matrix component fibronectin 1 (13,(35)(36)(37). As summarized in Fig.…”