Hepatocyte nuclear factor 6 inhibits the growth and metastasis of cholangiocarcinoma cells by regulating miR-122

Role of ONECUT family transcription factors in cancer and other diseases

Members of ONECUT transcription factor play an essential role in several developmental processes, however, the atypical expression of ONECUT proteins lead to numerous diseases, including cancer. ONECUT family proteins promote cell proliferation, progression, invasion, metastasis, angiogenesis, and stemness. This family of proteins interacts with other proteins such as KLF4, TGF-β, VEGFA, PRC2, SMAD3 and alters their expression involved in the regulation of various signaling pathways including Jak/Stat3, Akt/Erk, TGF-β, Smad2/3, and HIF-1α. Furthermore, ONECUT proteins are proposed as predictive biomarkers for pancreatic and gastric cancers. The present review summarizes the involvement of ONECUT family proteins in the development and progression of various human cancers and other diseases.

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.

Recent Updates on the Therapeutic Prospects of Reversion-Inducing Cysteine-Rich Protein with Kazal Motifs (RECK) in Liver Injuries

The reversion-inducing cysteine-rich protein with Kazal motifs (RECK), a membrane-anchored glycoprotein, negatively regulates various membrane proteins involved in the tissue governing extracellular matrix (ECM) remodeling such as metalloproteases (MMPs) and the sheddases ADAM10 and ADAM17. The significance of the present review is to summarize the current understanding of the pathophysiological role of RECK, a newly discovered signaling pathway associated with different liver injuries. Specifically, this review analyzes published data on the downregulation of RECK expression in hepatic ischemia/reperfusion (I/R) injury, liver-related cancers, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), as well as in the progression of nonalcoholic fatty liver disease (NAFLD) to non-alcoholic steatohepatitis (NASH). In addition, this review discusses the regulation of RECK by inducers, such as FXR agonists. The RECK protein has also been suggested as a potential diagnostic and prognostic marker for liver injury or as a biomarker with predictive value for drug treatment efficacy.

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.

MicroRNA-122 in human cancers: from mechanistic to clinical perspectives

MicroRNAs (miRNAs) are endogenous short non-coding RNAs that can regulate the expression of target genes post-transcriptionally and interact with mRNA-coding genes. MiRNAs play vital roles in many biological functions, and abnormal miRNA expression has been linked to various illnesses, including cancer. Among the miRNAs, miR-122, miR-206, miR-21, miR-210, miR-223, and miR-424 have been extensively studied in various cancers. Although research in miRNAs has grown considerably over the last decade, much is yet to be discovered, especially regarding their role in cancer therapies. Several kinds of cancer have been linked to dysregulation and abnormal expression of miR-122, indicating that miR-122 may serve as a diagnostic and/or prognostic biomarker for human cancer. Consequently, in this review literature, miR-122 has been analyzed in numerous cancer types to sort out the function of cancer cells miR-122 and enhance patient response to standard therapy.

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.

Current challenges to underpinning the genetic basis for cholangiocarcinoma

AREAS COVERED

This review provides an overview regarding the current scenario and knowledge of the CCA genomic landscape and the potentially actionable molecular aberrations in each CCA subtype.

EXPERT OPINION

The establishment and advances of high-throughput methodologies applied to genetic and epigenetic profiling are changing many cancer types' therapeutic landscape , including CCA.The large body of data generated must be interpreted appropriately and eventually implemented in clinical practice. The following advancements toward precision medicine in CCA management will require designing better clinical trials with improved methods to stratify biliary tumor patients.

Pathogenesis of Cholangiocarcinoma

Cholangiocarcinoma (CCA) encompasses a group of malignancies that can arise at any point in the biliary tree. Although considered a rare cancer, the incidence of CCA is increasing globally. The silent and asymptomatic nature of these tumors, particularly in their early stages, in combination with their high aggressiveness, intra- and intertumor heterogeneity, and chemoresistance, significantly compromises the efficacy of current therapeutic options, contributing to a dismal prognosis. During the last few years, increasing efforts have been made to unveil the etiologies and pathogenesis of these tumors and to develop more effective therapies. In this review, we summarize current findings in the field of CCA, mainly focusing on the mechanisms of pathogenesis, cells of origin, genomic and epigenetic abnormalities, molecular alterations, chemoresistance, and therapies.

LncRNA TTN-AS1 promotes the progression of cholangiocarcinoma via the miR-320a/neuropilin-1 axis

Neuropilin-1 regulated by miR-320a participates in the progression of cholangiocarcinoma by serving as a co-receptor that activates multiple signaling pathways. The present study sought to investigate upstream lncRNAs that control the expression of miR-320a/neuropilin-1 axis and dissect some of the underlying mechanisms. Here we report lncRNA TTN-AS1 (titin-antisense RNA1) acts as a sponging ceRNA to downregulate miR-320a and is highly expressed in human cholangiocarcinoma tissues and cells. The expression of the above three molecules is correlated with the clinicopathologic parameters of cholangiocarcinoma patients. In this study, multiple bioinformatics tools and databases were employed to seek potential lncRNAs that have binding sites with miR-320a and TTN-AS1 was identified because it exhibited the largest folds of alteration between cholangiocarcinoma and normal bile duct epithelial cells. The regulatory role of TTN-AS1 on miR-320a was further evaluated by luciferase reporter and RNA pulldown assays, coupled with in situ hybridization and RNA immunoprecipitation analyses, which showed that TTN-AS1 bound to miR-320a through an argonaute2-dependent RNA interference pathway in the cytoplasm of cholangiocarcinoma cells. Knockdown and overexpression assays showed that the regulatory effect between TTN-AS1 and miR-320 was in a one-way manner. TTN-AS1 promoted the proliferation and migration of cholangiocarcinoma cells via the miR-320a/ neuropilin-1 axis. The function of TTN-AS1 on tumor growth and its interaction with miR-320a were confirmed in animal models. Further mechanistic studies revealed that TTA-AS1, through downregulating miR-320a, promoted cell cycle progression, epithelial–mesenchymal transition, and tumor angiogenesis by upregulating neuropilin-1, which co-interacted with the hepatocyte growth factor/c-Met and transforming growth factor (TGF)-β/TGF-β receptor I pathways. In conclusion, the present results demonstrate that lncRNA TTA-AS1 is a sponging ceRNA for miR-320a, which in turn downregulates neuropilin-1 in cholangiocarcinoma cells, indicating these three molecules represent potential biomarkers and therapeutic targets in the management of cholangiocarcinoma.

Variance component analysis of circulating miR-122 in serum from healthy human volunteers

Micro-RNA (miR)-122 is a promising exploratory biomarker for detecting liver injury in preclinical and clinical studies. Elevations in serum or plasma have been associated with viral and autoimmune hepatitis, non-alcoholic steatohepatitis (NASH), hepatocellular carcinoma, and drug-induced liver injury (DILI). However, these associations were primarily based upon population differences between the disease state and the controls. Thus, little is known about the variability and subsequent variance components of circulating miR-122 in healthy humans, which has implications for the practical use of the biomarker clinically. To address this, we set out to perform variance components analysis of miR-122 in a cohort of 40 healthy volunteers. Employing a quantitative real-time polymerase chain reaction (qRT-PCR) assay to detect miR-122 and other circulating miRNAs in human serum, the relative expression of miR-122 was determined using two different normalization approaches: to the mean expression of a panel of several endogenous miRNAs identified using an adaptive algorithm (miRA-Norm) and to the expression of an exogenous miRNA control (Caenorhabditis elegans miR-39). Results from a longitudinal study in healthy volunteers (N = 40) demonstrated high variability with 117- and 111-fold 95% confidence reference interval, respectively. This high variability of miR-122 in serum appeared to be due in part to ethnicity, as 95% confidence reference intervals were approximately three-fold lower in volunteers that identified as Caucasian relative to those that identified as Non-Caucasian. Variance analysis revealed equivalent contributions of intra- and inter-donor variability to miR-122. Surprisingly, miR-122 exhibited the highest variability compared to other 36 abundant miRNAs in circulation; the next variable miRNA, miR-133a, demonstrated a 45- to 62-fold reference interval depending on normalization approaches. In contrast, alanine aminotransferase (ALT) activity levels in this population exhibited a 5-fold total variance, with 80% of this variance due to inter-donor sources. In conclusion, miR-122 demonstrated higher than expected variability in serum from healthy volunteers, which has implications for its potential utility as a prospective biomarker of liver damage or injury.

Neuropilin-1 regulated by miR-320 contributes to the growth and metastasis of cholangiocarcinoma cells

BACKGROUND & AIMS

Neuropilin-1 (NRP-1) activates signalling pathways as multifunctional co-receptors in cancer cells. However, its role and how it is regulated by miRNAs in cholangiocarcinoma (CCA) have not yet been investigated.

METHODS

The expression of NRP-1, miR-320 and key molecules involved in cell proliferation, migration and related signalling pathways were detected by immunohistochemistry, immunoblotting and qRT-PCR. Stable transfectants depleted of NRP-1 were generated. The regulatory effect of miR-320 on NRP-1 was evaluated by luciferase reporter assays. Cell proliferation, cell cycle distribution and migration were examined. Xenograft tumour models were established to assess tumourigenesis, tumour growth and lung metastasis.

RESULTS

Cholangiocarcinoma tissues expressed higher levels of NRP-1 than adjacent normal biliary tissues, and its expression negatively correlated with miR-320. NRP-1 depletion inhibited cell proliferation and induced cell cycle arrest in the G1/S phase by upregulating p27, and downregulating cyclin E and cyclin-dependent kinase 2; and reduced cell migration by inhibiting the phosphorylation of focal adhesion kinase. NRP-1 depletion suppressed tumourigenesis, tumour growth and lung metastasis by inhibiting cell proliferation and tumour angiogenesis in experimental animals. Depletion of NRP-1 inhibited the activation of VEGF/VEGFR2, EGF/EGFR and HGF/c-Met pathways stimulated by respective ligands. MiR-320 negatively regulated the expression of NRP-1 by binding to the 3'-UTR of NRP-1 promoter, and miR-320 mimics inhibited cell proliferation and migration, and the growth of established tumours in animals by downregulating NRP-1.

CONCLUSIONS

The present results indicate that NRP-1 is negatively regulated by miR-320, and both of them may be potentially therapeutic targets for CCA.

Diagnostic and therapeutic potentials of microRNAs in cholangiopathies

Cholangiopathies are a group of rare, devastating diseases that arise from damaged cholangiocytes, the cells that line the intra- and extra-hepatic bile ducts of the biliary epithelium. Cholangiopathies result in significant morbidity and mortality and are a major cause of liver transplantation. A better understanding of the underlying pathogenesis that influences cholangiocyte dysregulation and cholangiopathy progression is necessary, considering the dismal prognosis associated with these diseases. MicroRNAs are a class of small, non-coding RNAs that regulate post-transcriptional mRNA expression of specific genes. The role of microRNAs has expanded to include the initiation and development of many diseases, including cholangiopathies. Understanding microRNA regulation of cholangiopathies may provide diagnostic and therapeutic benefit for these diseases. In this review, the authors primarily focus on studies published within the last five years that help determine the diagnostic and therapeutic potential of microRNAs in cholangiopathies.

Metformin potentiates the anticancer activities of gemcitabine and cisplatin against cholangiocarcinoma cells in vitro and in vivo

Metformin, an oral biguanide drug used to treat type 2 diabetes, has displayed anticancer activities in several types of cancer cells. The combination of gemcitabine and cisplatin is the standard chemotherapy regimen for cholangiocarcinoma, but its benefit is limited. The present study aimed to investigate whether metformin could enhance the activities of gemcitabine and cisplatin against cholangiocarcinoma, and the underlying mechanisms. Metformin inhibited the proliferation of human cholangiocarcinoma RBE and HCCC-9810 cells and induced cell cycle arrest at the G0/G1 phase by increasing the activation of AMP-activated protein kinase (AMPK) pathways. Metformin upregulated the expression of p21Waf1 and p27kip1, and downregulated the expression of cyclin D1, a key protein required for cell cycle progression. The combination of gemcitabine and cisplatin inhibited the proliferation and induced the apoptosis of human cholangiocarcinoma cells by inducing the phosphorylation of AMPK, downregulating cyclin D1, and activating caspase-3. Administration of metformin enhanced the efficacy of gemcitabine and cisplatin to suppress the growth of cholangiocarcinoma tumors established in experimental models by inhibiting cell proliferation and inducing cell apoptosis through their effects on AMPK, cyclin D1 and caspase-3. Given that metformin has been used to treat type 2 diabetes patients for over half a century due to its superior safety profile, the results presented here indicate that metformin may be a potent agent for enhancing the efficacy of gemcitabine and cisplatin in the treatment of cholangiocarcinoma.