The Roles of MicroRNA-122 Overexpression in Inhibiting Proliferation and Invasion and Stimulating Apoptosis of Human Cholangiocarcinoma Cells

Role of miRNA‑122 in cancer (Review)

MicroRNAs (miRNAs) are small non‑coding RNAs that serve key roles in cell proliferation, migration, invasion and apoptosis by regulating gene expression. In malignant tumors, miRNA‑122 serves either as a tumor suppressor or oncogene, influencing tumor progression via downstream gene targeting. However, the precise role of miRNA‑122 in cancer remains unclear. miRNA‑122 is a potential biomarker and modulator of radiotherapy and chemotherapy. The present review aimed to summarize the roles of miRNA‑122 in cancer, its potential as a biomarker for diagnosis and prognosis and its implications in cancer therapy, including radiotherapy and chemotherapy, alongside strategies for systemic delivery.

Activation of IGFBP4 via unconventional mechanism of miRNA attenuates metastasis of intrahepatic cholangiocarcinoma

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver malignancy. Although its incidence is lower than that of hepatocellular carcinoma (HCC), ICC has a worse prognosis, and it is more prone to recur and metastasize, resulting in a far greater level of malignancy.

METHODS

Bioinformatics analysis and qRT-PCR were applied to assess the level of miR-122-5p and IGFBP4. Western blot, transwell assays, wound-healing assays, real-time cellular invasion monitoring, in vivo study were applied to explore the function of miR-122-5p and IGFBP4. Dual luciferase reporter assays and chromatin isolation by RNA purification (ChiRP) were applied to explore the regulation of IGFBP4 by miR-122-5p.

RESULTS

Using The Cancer Genome Atlas (TCGA) data set, Sir Run Run Shaw hospital data set and bioinformatics analyses, we identified miR-122-5p as a potential tumor suppressor in ICC and validated its suppressive effect in metastasis and invasion of ICC. Transcriptome sequencing, rescue and complement experiments were used to identify insulin-like growth factor binding protein 4 (IGFBP4) as a target of miR-122-5p. The mechanism by which miR-122-5p regulates IGFBP4 was clarified by chromatin separation RNA purification technology, and dual-luciferase reporter assays. We discovered a rare novel mechanism by which miR-122-5p promotes IGFBP4 mRNA transcription by binding to its promoter region. Furthermore, in mouse orthotopic metastasis model, miR-122-5p inhibited the invasion of ICC.

CONCLUSION

In summary, our study revealed a novel mechanism of miR-122-5p and function of the miR-122-5p/IGFBP4 axis in the metastasis of ICC. We also highlighted the clinical value of miR-122-5p and IGFBP4 in inhibiting ICC invasion and metastasis.

The role and mechanism of action of microRNA-122 in cancer: Focusing on the liver

microRNA-122 (miR-122) is a highly conserved microRNA that is predominantly expressed in the liver and plays a critical role in the regulation of liver metabolism. Recent studies have shown that miR-122 is involved in the pathogenesis of various types of cancer, particularly liver cancer. In this sense, The current findings highlighted the potential role of miR-122 in regulating many vital processes in cancer pathophysiology, including apoptosis, signaling pathway, cell metabolism, immune system response, migration, and invasion. These results imply that miR-122, which has been extensively studied for its biological functions and potential therapeutic applications, acts as a tumor suppressor or oncogene in cancer development. We first provide an overview and summary of the physiological function and mode of action of miR-122 in liver cancer. We will examine the various signaling pathways and molecular mechanisms through which miR-122 exerts its effects on cancer cells, including the regulation of oncogenic and tumor suppressor genes, the modulation of cell proliferation and apoptosis, and the regulation of metastasis. Most importantly, we will also discuss the potential diagnostic and therapeutic applications of miR-122 in cancer, including the development of miRNA-based biomarkers for cancer diagnosis and prognosis, and the potential use of miR-122 as a therapeutic target for cancer treatment.

Prediction of tissue-of-origin of early stage cancers using serum miRNomes

BACKGROUND

Noninvasive detection of early stage cancers with accurate prediction of tumor tissue-of-origin could improve patient prognosis. Because miRNA profiles differ between organs, circulating miRNomics represent a promising method for early detection of cancers, but this has not been shown conclusively.

METHODS

A serum miRNA profile (miRNomes)-based classifier was evaluated for its ability to discriminate cancer types using advanced machine learning. The training set comprised 7931 serum samples from patients with 13 types of solid cancers and 5013 noncancer samples. The validation set consisted of 1990 cancer and 1256 noncancer samples. The contribution of each miRNA to the cancer-type classification was evaluated, and those with a high contribution were identified.

RESULTS

Cancer type was predicted with an accuracy of 0.88 (95% confidence interval [CI] = 0.87 to 0.90) in all stages and an accuracy of 0.90 (95% CI = 0.88 to 0.91) in resectable stages (stages 0-II). The F1 score for the discrimination of the 13 cancer types was 0.93. Optimal classification performance was achieved with at least 100 miRNAs that contributed the strongest to accurate prediction of cancer type. Assessment of tissue expression patterns of these miRNAs suggested that miRNAs secreted from the tumor environment could be used to establish cancer type-specific serum miRNomes.

CONCLUSIONS

This study demonstrates that large-scale serum miRNomics in combination with machine learning could lead to the development of a blood-based cancer classification system. Further investigations of the regulating mechanisms of the miRNAs that contributed strongly to accurate prediction of cancer type could pave the way for the clinical use of circulating miRNA diagnostics.

Pan-cancer analysis of mRNA stability for decoding tumour post-transcriptional programs

Measuring mRNA decay in tumours is a prohibitive challenge, limiting our ability to map the post-transcriptional programs of cancer. Here, using a statistical framework to decouple transcriptional and post-transcriptional effects in RNA-seq data, we uncover the mRNA stability changes that accompany tumour development and progression. Analysis of 7760 samples across 18 cancer types suggests that mRNA stability changes are ~30% as frequent as transcriptional events, highlighting their widespread role in shaping the tumour transcriptome. Dysregulation of programs associated with >80 RNA-binding proteins (RBPs) and microRNAs (miRNAs) drive these changes, including multi-cancer inactivation of RBFOX and miR-29 families. Phenotypic activation or inhibition of RBFOX1 highlights its role in calcium signaling dysregulation, while modulation of miR-29 shows its impact on extracellular matrix organization and stemness genes. Overall, our study underlines the integral role of mRNA stability in shaping the cancer transcriptome, and provides a resource for systematic interrogation of cancer-associated stability pathways.

The role of mRNA stability in shaping the cancer transcriptome is revealed using a statistical analysis of transcriptomic data.

Analysis of MicroRNA in Bile Cytologic Samples Is Useful for Detection and Diagnosis of Extrahepatic Cholangiocarcinoma

OBJECTIVES

This study aimed to develop reliable biomarkers that improve the ability of bile cytology to diagnose cholangiocarcinoma vs benign biliary lesions.

METHODS

Many studies indicate that microRNAs (miRNAs) are potential candidates for the early diagnosis of cancer. We analyzed the expression of five tumor-associated miRNAs (miR-31-5p, miR-122-5p, miR-378d, miR-182-5p, and miR-92a-3p) in cytology samples using quantitative reverse transcription polymerase chain reaction. We collected 52 surgically resected tissue samples, 84 cytologic specimens from smears (53 cases of cancer and 31 cases of noncancer), and 40 residual sediments after smearing for routine cytology at Hiroshima University Hospital.

RESULTS

The expression of miR-31-5p, miR-378d, and miR-122-5p was significantly higher in cancer tissues than those in normal tissues, while miR-182-5p expression was lower. The expression of miR-31-5p, miR-378d, miR-182-5p, and miR-92a-3p was significantly higher in detached cell samples from smears of cholangiocarcinoma cases than in those from noncancer cases.

CONCLUSIONS

These results suggest that the analysis of miRNAs in bile cytologic specimens is a promising auxiliary tool for distinguishing cholangiocarcinoma from benign biliary lesions.

A High-Accuracy Model Based on Plasma miRNAs Diagnoses Intrahepatic Cholangiocarcinoma: A Single Center with 1001 Samples

Objectives: Intrahepatic cholangiocarcinoma (iCCA) is a highly malignant cancer. More than 70% of patients are diagnosed at an advanced stage. The aim of this study was to evaluate the diagnostic value of plasma miR-21, miR-122, and CA19-9, hoping to establish a novel model to improve the accuracy for diagnosing iCCA. Materials and methods: Plasma miR-21 and miR-122 were detected in 359 iCCA patients and 642 controls (healthy, benign liver lesions, other malignant liver tumors). All 1001 samples were allocated to training cohort (n = 668) and validation cohort (n = 333) in a chronological order. A logistic regression model was applied to combine these markers. Area under the receiver operating characteristic curve (AUC) was used as an accuracy index to evaluate the diagnostic performance. Results: Plasma miR-21 and miR-122 were significantly higher in iCCA patients than those in controls. Higher plasma miR-21 level was significantly correlated with larger tumor size (p = 0.030). A three-marker model was constructed by using miR-21, miR-122 and CA19-9, which showed an AUC of 0.853 (95% CI: 0.824–0.879; sensitivity: 73.0%, specificity: 87.4%) to differentiate iCCA from controls. These results were subsequently confirmed in the validation cohort with an AUC of 0.866 (0.825–0.901). The results were similar for diagnosing early (stages 0–I) iCCA patients (AUC: 0.848) and CA19-9^negative iCCA patients (AUC: 0.795). Conclusions: We established a novel three-marker model with a high accuracy based on a large number of participants to differentiate iCCA from controls. This model showed a great clinical value especially for the diagnosis of early iCCA and CA19-9^negative iCCA.

Aspirin inhibits cholangiocarcinoma cell proliferation via cell cycle arrest in vitro and in vivo

Cholangiocarcinoma is the most common biliary duct malignancy and the second most common primary liver cancer, accounting for 10-20% of hepatic malignancies. With high mortality and poor prognosis, the 5-year survival rate of cholangiocarcinoma is only 10%. A previous study demonstrated a significant association between aspirin use and a decreased risk of cholangiocarcinoma. However, the effect of aspirin on cholangiocarcinoma remains unknown. Therefore, the aim of the present study was to investigate the effects of aspirin on cholangiocarcinoma in vitro and in vivo. Three cholangiocarcinoma cell lines were used to analyze the effect of aspirin on cell proliferation, cell cycle progression, apoptosis, and the regulation of microRNAs. MicroRNAs are known to regulate the development and progression of various types of cancer. An HuCCT-1 xenograft model was used for the in vivo study. It was determined that aspirin inhibited the proliferation of human cholangiocarcinoma cells (except TKKK cells). Aspirin induced cell cycle arrest in the G₀/G₁ phase and regulated cell-cycle related proteins in cholangiocarcinoma cells (HuCCT-1 cells) but did not induce apoptosis. The expression of miR-340-5p was significantly upregulated after treatment, and overexpression of miR-340-5p inhibited the proliferation of HuCCT-1 cells and decreased the levels of cyclin D1. TKKK cells had low miR-340-5p expression, which may explain why aspirin had no effect on their proliferation. In vivo, aspirin reduced the growth of xenografted tumors. In conclusion, the present study indicated that aspirin partially inhibited cholangiocarcinoma cell proliferation and tumor growth by inducing G₀/G₁ phase cell cycle arrest, potentially through the miR-340-5p/cyclin D1 axis.

A Modified Magnified Analysis of Proteome (MAP) Method for Super-Resolution Cell Imaging that Retains Fluorescence

Biological systems consist of a variety of distinct cell types that form functional networks. Super-resolution imaging of individual cells is required for better understanding of these complex systems. Direct visualization of 3D subcellular and nano-scale structures in cells is helpful for the interpretation of biological interactions and system-level responses. Here we introduce a modified magnified analysis of proteome (MAP) method for cell super-resolution imaging (Cell-MAP) which preserves cell fluorescence. Cell-MAP expands cells more than four-fold while preserving their overall architecture and three-dimensional proteome organization after hydrogel embedding. In addition, Optimized-Cell-MAP completely preserves fluorescence and successfully allows for the observation of tagged small molecular probes containing peptides and microRNAs. Optimized-Cell-MAP further successfully applies to the study of structural characteristics and the identification of small molecules and organelles in mammalian cells. These results may give rise to many other applications related to the structural and molecular analysis of smaller assembled biological systems.

MiRNA-134 suppresses esophageal squamous cell carcinoma progression by targeting FOXM1

Previous studies showed that the dysregulation of miRNAs was closely associated with cancer progression. The aim of this study was to verify whether miR-134, miR-10a, miR-29c, miR-942, miR-93, and miR-218 could inhibit esophageal squamous cell carcinoma (ESCC) cell invasion and migration. ESCC tissue and normal esophageal tissue adjacent to carcinoma from patients (54 cases) undergoing surgery were collected. RT-PCR was used to test the expression of miR-134, miR-10a, miR-29c, miR-942, miR-93, and miR-218 in these tissues. In addition, western blot was applied to test the expression of MMP-2, MMP-9, COL1A1, COL1A5 and FOXM1. In the vitro experiment, EC9706 cells were transfected with miR-134 mimics, then wound healing was employed to test the migratory ability of EC9706 cells. Transwell chambers was used to test the invasion ability of cells. The expression of MMP-2, MMP-9, COL1A1, COL1A5, and FOXM1 waas detected by western blot. In order to confirm whether FOXM1-3'-UTR was the target gene of miR-134, we performed a luciferase assay. FOXM1 over-expression plasmid was transfected to further confirm miR-134 played its role by targeting FOXM1. Our results showed that the expression of miR-134 was decreased in the ESCC tissue compared with normal esophageal tissue, (P<0.01), but the expression of MMP-2, MMP-9, COL1A1, COL1A5 and FOXM1 were significantly increased (P<0.01). In an in vitro experiment, compared with the mimic control, the expression of MMP-2, MMP-9, COL1A1, COL1A5 and FOXM1 were decreased in the miR-134 mimic-transfected EC9706 cells (P<0.01). The migration and invasion activity of EC9706 cells was also decreased after transfection with miR-134 mimics (P<0.01). The luciferase activity of the FOXM1-3'-UTR plasmid was significantly suppressed by miR-134 (P<0.01). Overexpression of FOXM1 abrogated miR-134-mediated inhibition of EC9706 cell migration and invasion. In conclusion, miR-134 inhibited EC9706 cell migration and invasion by targeting FOXM1. miR-134 may be a novel treatment target for ESCC.

Comprehensive analysis of aberrantly expressed profiles of lncRNAs, miRNAs and mRNAs with associated ceRNA network in cholangiocarcinoma

Cholangiocarcinoma (CCA) is a highly malignant and poorly differentiated bile duct cancer with an extremely poor prognosis, but the pathogenesis of CCA remains not well-known. Attention has been increasingly focused on long noncoding RNAs, which plays an important role in tumorigenesis. However, the roles of cancer specific lncRNA and its related competitive endogenous RNAs (ceRNA) network in CCA remain elusive. In this study, we comprehensively integrated expression profiles, including data on mRNAs, lncRNAs and miRNAs obtained from 36 CCA tissues and 9 normal tissues in The Cancer Genome Atlas. 1434 cancer specific lncRNAs, 68 miRNAs and 3538 mRNAs (|logFC|> 1, p< 0.05) were identified. Based on bioinformatics generated from miRcode, starBase, miRTarBase, TargetScan and miRDB, we constructed an lncRNA-miRNA-mRNA network (ceRNA network) in CCA. We constructed the lncRNA-miRNA-mRNA ceRNA network consisting of 206 molecules and 454 interactions. In addition, we used Cytoscape software to visualize the ceRNA network in WGCNA, 22 mRNA network modules were identified, five of which were significantly related to tumor grade and survival time. Moreover, three lncRNAs COL18A1-AS1, SLC6A1-AS1 and HULC were found to be significantly associated with overall survival. The present study provides novel insight for better understanding of lncRNA-related ceRNA network in CCA and useful resource for identifcation of novel biomarkers of CCA.

MicroRNA-494-dependent WDHDI inhibition suppresses epithelial-mesenchymal transition, tumor growth and metastasis in cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) represents a devastating malignancy characterized by high mortality, and notoriously problematic to diagnose. Recently, microRNAs (miRs) have been intensively investigated due to their potential usefulness from a tumor treatment perspective.

AIMS

The current study was aimed to investigate whether miR-494 influences epithelial-mesenchymal transition (EMT), tumor growth and metastasis of CCA.

METHODS

The regulatory miRNAs of WDHD1 in CCA expression chip were predicted, followed by determination of the miR-494 and WDHD1 expression in normal cholangiocyte tissues and CCA tissues. The related protein levels were determined. CCA cell migration, invasion, viability, and cell cycle distribution and the dosage-dependent effect of miR-494 on CCA cell growth were subsequently detected. Finally, tumorigenicity and lymph node metastasis (LNM) were measured.

RESULTS

Initially, miR-194 affected the CCA development via negatively regulating WDHD1 and miR-494 which were downregulated while WDHD1 was upregulated in CCA. In addition, miR-494 overexpression elevated E-cadherin expression while decreased expressions of WDHD1, N-cadherin, Vimentin, Snail, Twist and MMP-9. Finally, overexpressed miR-494 was observed to suppress EMT, cell viability, migration, invasion, arrest cell cycle progression, tumor formation, and LNM while accelerating cell apoptosis in vivo.

CONCLUSION

This study indicated that miR-494 overexpression suppresses EMT, tumor formation and LNM while promoting CCA cell apoptosis through inhibiting WDHD1 in CCA.

Clinical value of miRNA-122 in the diagnosis and prognosis of various types of cancer

The present study aimed to systematically analyze the value of microRNA-122 (miRNA-122) in the diagnosis and prognosis of hepatocellular carcinoma (HCC) and other types of cancer. First, the reverse transcription-quantitative polymerase chain reaction method was used to detect the expression levels of miRNA-122 in the serum samples of patients with HCC, benign lesions and healthy volunteers. Next, miRNA-seq data of miRNA-122 from The Cancer Genome Atlas database were used to analyze the differential expression and overall survival rate associated with a variety of types of cancer. Meanwhile, the target gene prediction of miRNA-122 was performed using four different software programs. Finally, 353 significant target genes were identified for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis. Finally, it was demonstrated that the expression levels of miRNA-122 in the HCC group were increased compared with the healthy group (P<0.001), but decreased with respect to the benign group (P<0.001). In addition, the combination of the miRNA-122 and a fetoprotein may further improve the diagnostic accuracy between the HCC and healthy groups (area under the curve, 0.980; 95% confidence interval, 0.958–1.000). It was also demonstrated that miRNA-122 exhibited significantly differential expression and the overall survival rate was predicted for various other types of cancer, including colorectal cancer, renal carcinoma, cholangiocarcinoma, prostate cancer and thyroid carcinoma. Functional enrichment analysis demonstrated that the target genes of miRNA-122 may contribute to the composition of the nucleus and cytoplasm, and regulate a variety of biological processes, including cardiac muscle cell differentiation and glucose metabolic processes via protein biosynthesis, estrogen and glucagon associated signaling pathways. These results revealed that miRNA-122 may be an indispensable biomarker for the diagnosis, prognostic evaluation and targeted therapy in pan-cancer.

Molecular Mechanisms Driving Cholangiocarcinoma Invasiveness: An Overview

The acquisition of invasive functions by tumor cells is a first and crucial step toward the development of metastasis, which nowadays represents the main cause of cancer-related death. Cholangiocarcinoma (CCA), a primary liver cancer originating from the biliary epithelium, typically develops intrahepatic or lymph node metastases at early stages, thus preventing the majority of patients from undergoing curative treatments, consistent with their very poor prognosis. As in most carcinomas, CCA cells gradually adopt a motile, mesenchymal-like phenotype, enabling them to cross the basement membrane, detach from the primary tumor, and invade the surrounding stroma. Unfortunately, little is known about the molecular mechanisms that synergistically orchestrate this proinvasive phenotypic switch. Autocrine and paracrine signals (cyto/chemokines, growth factors, and morphogens) permeating the tumor microenvironment undoubtedly play a prominent role in this context. Moreover, a number of recently identified signaling systems are currently drawing attention as putative mechanistic determinants of CCA cell invasion. They encompass transcription factors, protein kinases and phosphatases, ubiquitin ligases, adaptor proteins, and miRNAs, whose aberrant expression may result from either stochastic mutations or the abnormal activation of upstream pro-oncogenic pathways. Herein we sought to summarize the most relevant molecules in this field and to discuss their mechanism of action and potential prognostic relevance in CCA. Hopefully, a deeper knowledge of the molecular determinants of CCA invasiveness will help to identify clinically useful biomarkers and novel druggable targets, with the ultimate goal to develop innovative approaches to the management of this devastating malignancy.

miR-26a induced the suppression of tumor growth of cholangiocarcinoma via KRT19 approach

Background and Aims

KRT19 was identified as one of the key biomarkers for distinguishing cholangiocarcinoma (CCA) and hepatocellular carcinoma. The detailed role of miRNAs involved in the oncogenic incident of KRT19 was poor investigated.

Results

Based on prediction and validation, miR-26a was inversely correlated with KRT19 in patients’ tissues samples and biopsies. Ectopic expression of miR-26a dramatically suppressed cell proliferation and tumor growth in vitro and in vivo. Knock-down miR-26a could induce an increasing population of SP cells by promoting KRT19 expression. The KRT19 was also suppressed via directly binding at 3′UTR region by miR-26a.

Materials and Methods

Bioinformatics prediction was first applied to screening the potential miRNA involved. RT-PCR, Immunohistochemistry and Western blot were used to examine the expression of miRNAs and candidate genes in 65 pairs of cholangiocarcinoma. The loss-and gain-function assay was employed to detect the role of certain miRNA in vitro and vivo. Side-population (SP) cells were detected and sorted by flow cytometry.

Conclusions

Aberrant decreased miR-26a could promote cell proliferation by regulating KRT19 which play important roles in the pathogenesis of CCA.

miR-365 Suppresses Cholangiocarcinoma Cell Proliferation and Induces Apoptosis by Targeting E2F2

Cholangiocarcinoma (CCA) is one of the most malignant adenocarcinomas arising from bile duct epithelial cells. However, the molecular mechanism regulating CCA development and progression still needs to be investigated. Here we found that miR-365 was downregulated in CCA tissues compared with adjacent normal tissues. By functional experiments, we found that overexpression of miR-365 significantly inhibited CCA cell proliferation and promoted cellular apoptosis in vitro. Furthermore, administration with miR-365 markedly suppressed the growth of tumor tissues in vivo. Mechanistically, we identified E2F2 as the target gene of miR-365 in CCA cells. We found that overexpression significantly inhibited the expression of E2F2 in CCA cells, and there was an inverse correlation between the expression levels of E2F2 and miR-365 in CCA tissues. We also found that E2F2 was highly expressed in CCA tissues and cell lines. Restoration of E2F2 in miR-365-overexpressing CCA cells promoted cell viability and reduced cellular apoptosis in CCA. Collectively, our study demonstrated the essential role of miR-365 and its functional mechanism in CCA cells, which provided a new insight on the design of therapeutic targets for CCA treatment.

MiR-525-3p mediates antiviral defense to rotavirus infection by targeting nonstructural protein 1

MicroRNAs (miRNAs) are short RNAs of approximately 22 nucleotides that post-transcriptionally regulate gene expression by controlling mRNA stability or translation. They play critical roles in intricate networks of host-pathogen interactions and innate immunity. Rotaviruses (RVs) are the leading cause of severe diarrhea among infants and young children worldwide. This study was undertaken to demonstrate the importance of cellular miRNAs during RV (human Wa RV or Rhesus RV) strains infection. Twenty-nine differentially regulated miRNAs were identified during RV infection, and miR-525-3p was downregulated and validated by quantitative real-time polymerase chain reaction (qRT-PCR). MiR-525-3p mimic inhibited RV replication in dose-dependent manner. Correspondingly, the miR-525-3p inhibitors enhanced RV replication. We confirmed that miR-525-3p was complementary to the 3' untranslated region (UTR) of nonstructural protein 1(NSP1) of RV (Wa or Rhesus) strains. Interestingly, miR-525-3p induced type I interferon (IFN) expression and proinflammatory cytokines during RV infection through IFN regulatory factor (IRF) 3/IRF7 and NF-κB activation, which can induce an antiviral state to further suppress RV infection. In addition, RV suppressed miR-525-3p expression to evade host innate immunity through the action of the RV protein NSP1. These results suggest that miR-525-3p has the potential to be used as an antiviral therapeutic against RV infection.

CG200745, an HDAC inhibitor, induces anti-tumour effects in cholangiocarcinoma cell lines via miRNAs targeting the Hippo pathway

Cholangiocarcinoma is a devastating malignancy with fatal complications that exhibits low response and resistance to chemotherapy. Here, we evaluated the anticancer effects of CG200745, a novel histone deacetylase inhibitor, either alone or in combination with standard chemotherapy drugs in cholangiocarcinoma cells. CG200745 dose-dependently reduced the viability of cholangiocarcinoma cells in vitro and decreased tumour volume and weight in a xenograft model. Administering CG200745 along with other chemotherapeutic agents including gemcitabine, 5-fluorouracil (5-FU), cisplatin, oxaliplatin, or gemcitabine plus cisplatin further decreased cholangiocarcinoma cell viability, with a combination index < 1 that indicated synergistic action. CG200745 also enhanced the sensitivity of gemcitabine-resistant cells to gemcitabine and 5-FU, thereby decreasing cell viability and inducing apoptosis. This was accompanied by downregulation of YAP, TEAD4, TGF-β2, SMAD3, NOTCH3, HES5, Axl, and Gas6 and upregulation of the miRNAs miR-22-3p, miR-22-5p, miR-194-5p, miR-194-3p, miR-194-5p, miR-210-3p, and miR-509-3p. The Ingenuity Pathway Analysis revealed that CG200745 mainly targets the Hippo signalling pathway by inducing miR-509-3p expression. Thus, CG200745 inhibits cholangiocarcinoma growth in vitro and in vivo, and acts synergistically when administered in combination with standard chemotherapeutic agents, enabling dose reduction. CG200745 is therefore expected to improve the outcome of cholangiocarcinoma patients who exhibit resistance to conventional therapies.

miRNA profiling for diagnosis, prognosis and stratification of cancer treatment in cholangiocarcinoma

Cholangiocarcinoma (CCA) is a lethal malignancy originating from the biliary tract epithelium. Most patients are diagnosed at an advanced stage. Even after resection with curative intent, prognosis remains poor. Previous studies have reported the evolving role of miRNAs as novel biomarkers in cancer diagnosis, prognostication and chemotherapy response. Various miRNAs, such as miR-21, miR-26, miR-122 and miR-150, have been identified as possible blood-based biomarkers for noninvasive diagnosis of CCA. Moreover, epithelial-mesenchymal transition (EMT)- and angiogenesis-associated miRNAs have been implicated in tumor cell dissemination and are able to determine clinical outcome. In fact, miRNAs involved in cell survival might even determine chemotherapy response. This review provides an overview of known miRNAs as CCA-specific biomarkers.

miRNA and lncRNA as biomarkers in cholangiocarcinoma(CCA)

The microRNAs are a group of 20 nucleotides-long non-coding RNAs. By binding to the 3'UTR region of target mRNA, microRNAs can perform extensive actions mediating gene expression at post-trancriptional stages. It makes microRNAs serve as very crucial regulators in various biological progress including carcinogenesis. Long non-coding RNAs, however, are a subgroup of RNA with the length of 200 nucleotides. Unlike microRNAs, long non-coding RNAs can form secondary of tertiary domain based on their length. With the ability of directly interacting with DNA, RNA, protein, long non-coding RNAs have promoting or inhibitive functions in gene expression regulation. Furthermore, the abnormal expression of certain long non-coding RNAs has roused people's interest in the role of long non-coding RNAs in tumorigenesis. Although the connection between microRNA/long non-coding RNA and CCA has been a hot field to researchers, the link between molecular mechanism and clinical outcome has been barely built. This review takes a retrospect at the latest researches on the link between microRNA/long non-coding RNA and cholangiocarcinoma and the potential of microRNA/long non-coding RNA serving as distinctive biomarkers for CCA in clinical practice.

MicroRNA-224 regulates self-renewal of mouse spermatogonial stem cells via targeting DMRT1

MicroRNAs (miRs) play a key role in the control of gene expression in a wide array of tissue systems, where their functions include the regulation of self-renewal, cellular differentiation, proliferation and apoptosis. However, the function and mechanisms of individual miRs in regulating spermatogonial stem cell (SSC) homeostasis remain unclear. In the present study, we report for the first time that miR-224 is highly expressed in mouse SSCs. Functional assays using miRNA mimics and inhibitors reveal that miR-224 is essential for differentiation of SSCs. Mechanistically, miR-224 promotes differentiation of SSCs via targeting doublesex and Mab-3-related transcription factor 1 (DMRT1). Moreover, WNT/β-catenin signalling pathway is involved in miR-224-mediated regulation of SSCs self-renewal. We further demonstrate that miR-224 overexpression increases the expression of GFRα1 and PLZF, accompanied by the down-regulation of DMRT1 in mouse testes. Our findings provide novel insights into molecular mechanisms regulating differentiation of SSCs and may have important implications for regulating male reproduction.