MicroRNA-135a contributes to the development of portal vein tumor thrombus by promoting metastasis in hepatocellular carcinoma

MicroRNA as Key Players in Hepatocellular Carcinoma: Insights into Their Role in Metastasis

Liver cancer or hepatocellular carcinoma (HCC) remains the most common cancer in global epidemiology. Both the frequency and fatality of this malignancy have shown an upward trend over recent decades. Liver cancer is a significant concern due to its propensity for both intrahepatic and extrahepatic metastasis. Liver cancer metastasis is a multifaceted process characterized by cell detachment from the bulk tumor, modulation of cellular motility and invasiveness, enhanced proliferation, avoidance of the immune system, and spread either via lymphatic or blood vessels. MicroRNAs (miRNAs) are small non-coding ribonucleic acids (RNAs) playing a crucial function in the intricate mechanisms of tumor metastasis. A number of miRNAs can either increase or reduce metastasis via several mechanisms, such as control of motility, proliferation, attack by the immune system, cancer stem cell properties, altering the microenvironment, and the epithelial-mesenchymal transition (EMT). Besides, two other types of non-coding RNAs, such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) can competitively bind to endogenous miRNAs. This competition results in the impaired ability of the miRNAs to inhibit the expression of the specific messenger RNAs (mRNAs) that are targeted. Increasing evidence has shown that the regulatory axis comprising circRNA/lncRNA-miRNA-mRNA is correlated with the regulation of HCC metastasis. This review seeks to present a thorough summary of recent research on miRNAs in HCC, and their roles in the cellular processes of EMT, invasion and migration, as well as the metastasis of malignant cells. Finally, we discuss the function of the lncRNA/circRNA-miRNA-mRNA network as a crucial modulator of carcinogenesis and the regulation of signaling pathways or genes that are relevant to the metastasis of HCC. These findings have the potential to offer valuable insight into the discovery of novel therapeutic approaches for management of liver cancer metastasis.

Research Progress in Predicting Hepatocellular Carcinoma with Portal Vein Tumour Thrombus in the Era of Artificial Intelligence

Hepatocellular Carcinoma (HCC) is a condition associated with significant morbidity and mortality. The presence of Portal Vein Tumour Thrombus (PVTT) typically signifies advanced disease stages and poor prognosis. Artificial intelligence (AI), particularly Machine Learning (ML) and Deep Learning (DL), has emerged as a promising tool for extracting quantitative data from medical images. AI is increasingly integrated into the imaging omics workflow and has become integral to various medical disciplines. This paper provides a comprehensive review of the mechanisms underlying the formation and progression of PVTT, as well as its impact on clinical management and prognosis. Additionally, it outlines the advancements in AI for predicting the diagnosis of HCC and the development of PVTT. The limitations of existing studies are critically evaluated, and potential future research directions in the realm of imaging for the diagnostic prediction of HCC and PVTT are discussed, with the ultimate goal of enhancing survival outcomes for PVTT patients.

Modeling Colorectal Cancer-Induced Liver Portal Vein Microthrombus on a Hepatic Lobule Chip

Colorectal cancer is one of the most common malignant tumors. At the advanced stage of colorectal cancer, cancer cells migrate with the blood to the liver from the hepatic portal vein, eventually resulting in a portal vein tumor thrombus (PVTT). To date, the progression of the early onset of PVTT [portal vein microthrombus (PVmT) induced by tumors] is unclear. Herein, we developed an on-chip PVmT model by loading the spheroid of colorectal cancer cells into the portal vein of a hepatic lobule chip (HLC). On the HLC, the progression of PVmT was presented, and early changes in metabolites of hepatic cells and in structures of hepatic plates and sinusoids induced by PVmT were analyzed. We replicated intrahepatic angiogenesis, thickened blood vessels, an increased number of hepatocytes, disordered hepatic plates, and decreased concentrations of biomarkers of hepatic cell functions in PVmT progression on a microfluidic chip for the first time. In addition, the combined therapy of thermo-ablation and chemo-drug for PVmT was preliminarily demonstrated. This study provides a promising method for understanding PVTT evolution and offers a valuable reference for PVTT therapy.

circPSD3 is a promising inhibitor of uPA system to inhibit vascular invasion and metastasis in hepatocellular carcinoma

BACKGROUND

Vascular invasion is a major route for intrahepatic and distant metastasis in hepatocellular carcinoma (HCC) and is a strong negative prognostic factor. Circular RNAs (circRNAs) play important roles in tumorigenesis and metastasis. However, the regulatory functions and underlying mechanisms of circRNAs in the development of vascular invasion in HCC are largely unknown.

METHODS

High throughput sequencing was used to screen dysregulated circRNAs in portal vein tumor thrombosis (PVTT) tissues. The biological functions of candidate circRNAs in the migration, vascular invasion, and metastasis of HCC cells were examined in vitro and in vivo. To explore the underlying mechanisms, RNA sequencing, MS2-tagged RNA affinity purification, mass spectrometry, and RNA immunoprecipitation assays were performed.

RESULTS

circRNA sequencing followed by quantitative real-time PCR (qRT-PCR) revealed that circRNA pleckstrin and Sect. 7 domain containing 3 (circPSD3) was significantly downregulated in PVTT tissues. Decreased circPSD3 expression in HCC tissues was associated with unfavourable characteristics and predicted poor prognosis in HCC. TAR DNA-binding protein 43 (TDP43) inhibited the biogenesis of circPSD3 by interacting with the downstream intron of pre-PSD3. circPSD3 inhibited the intrahepatic vascular invasion and metastasis of HCC cells in vitro and in vivo. Serpin family B member 2 (SERPINB2), an endogenous bona fide inhibitor of the urokinase-type plasminogen activator (uPA) system, is the downstream target of circPSD3. Mechanistically, circPSD3 interacts with histone deacetylase 1 (HDAC1) to sequester it in the cytoplasm, attenuating the inhibitory effect of HDAC1 on the transcription of SERPINB2. In vitro and in vivo studies demonstrated that circPSD3 is a promising inhibitor of the uPA system.

CONCLUSIONS

circPSD3 is an essential regulator of vascular invasion and metastasis in HCC and may serve as a prognostic biomarker and therapeutic target.

Emerging role of MicroRNA-Based theranostics in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC), with its high mortality and short survival rate, continues to be one of the deadliest malignancies despite relentless efforts and several technological advances. The poor prognosis of HCC and the few available treatments are to blame for the low survival rate, which emphasizes the importance of creating new, effective diagnostic markers and innovative therapy strategies. In-depth research is being done on the potent biomarker miRNAs, a special class of non-coding RNA and has shown encouraging results in the early identification and treatment of HCC in order to find more viable and successful therapeutics for the disease. It is beyond dispute that miRNAs control cell differentiation, proliferation, and survival and, depending on the genes they target, can either promote tumorigenesis or suppress it. Given the vital role miRNAs play in the biological system and their potential to serve as ground-breaking treatments for HCC, more study is required to fully examine their theranostic potential.

Progress on the molecular mechanism of portal vein tumor thrombosis formation in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors, with poor prognosis and high mortality. Early-stage HCC has no obvious clinical symptoms, and most patients are already at an advanced stage when they are diagnosed. Portal vein tumor thrombus (PVTT) is the most common complication and a poor prognostic factor for HCC, which frequently leads to portal vein hypertension, ascites, gastrointestinal bleeding, and tumor metastasis. The formation of PVTT is related to the complex structure and hemodynamic changes of the portal vein and is closely related to changes at the cellular and molecular levels. The differentially-expressed genes (DEGs) between PVTT and primary tumor (PT) suggest that the two tissues may have different clonal origins. Epigenetic and proteomic analyses also suggest complex and diverse mechanisms for the formation of PVTT. In addition, the tumor microenvironment and energy metabolism pathways are interrelated in regulating the invasion and progression of PVTT. Aerobic glycolysis and the tumor immune microenvironment have been the focus of recent studies on PVTT. In this review, we summarize the mechanism of PVTT formation at the cellular and molecular levels to provide information to guide better prevention and treatment of PVTT in the clinic.

The role of miRNAs in liver diseases: Potential therapeutic and clinical applications

MicroRNAs (miRNAs) are a class of short, non-coding RNAs that function post-transcriptionally to regulate gene expression by binding to particular mRNA targets and causing destruction of the mRNA or translational inhibition of the mRNA. The miRNAs control the range of liver activities, from the healthy to the unhealthy. Considering that miRNA dysregulation is linked to liver damage, fibrosis, and tumorigenesis, miRNAs are a promising therapeutic strategy for the evaluation and treatment of liver illnesses. Recent findings on the regulation and function of miRNAs in liver diseases are discussed, with an emphasis on miRNAs that are highly expressed or enriched in hepatocytes. Alcohol-related liver illness, acute liver toxicity, viral hepatitis, hepatocellular carcinoma, liver fibrosis, liver cirrhosis, and exosomes in chronic liver disease all emphasize the roles and target genes of these miRNAs. We briefly discuss the function of miRNAs in the etiology of liver diseases, namely in the transfer of information between hepatocytes and other cell types via extracellular vesicles. Here we offer some background on the use of miRNAs as biomarkers for the early prognosis, diagnosis, and assessment of liver diseases. The identification of biomarkers and therapeutic targets for liver disorders will be made possible by future research into miRNAs in the liver, which will also help us better understand the pathogeneses of liver diseases.

Portal vein tumor thrombosis in hepatocellular carcinoma: molecular mechanism and therapy

Portal vein tumor thrombosis (PVTT), a common complication of advanced hepatocellular carcinoma (HCC), remains the bottleneck of the treatments. Liver cancer cells potentially experienced multi-steps during PVTT process, including cancer cells leave from cancer nest, migrate in extracellular matrix, invade the vascular barrier, and colonize in the portal vein. Accumulated evidences have revealed numerous of molecular mechanisms including genetic and epigenetic regulation, cancer stem cells, immunosuppressive microenvironment, hypoxia, et al. contributed to the PVTT formation. In this review, we discuss state-of-the-art PVTT research on the potential molecular mechanisms and experimental models. In addition, we summarize PVTT-associated clinical trials and current treatments for PVTT and suppose perspectives exploring the molecular mechanisms and improving PVTT-related treatment for the future.

The role of microRNAs on the pathogenesis, diagnosis and management of portal hypertension in patients with chronic liver disease

INTRODUCTION

Portal hypertension (PH) is the elevated pressure in the portal vein, which results in poor functioning of the liver and is influenced by various factors like liver cirrhosis, nonalcoholic fatty liver disease, schistosomiasis, thrombosis, and angiogenesis. Though the diagnosis and treatment have been advanced, early diagnosis of the disease remains a challenge, and the diagnosis methods are often invasive. Hence, the clear understanding of the molecular mechanisms of PH can give rise to the development of novel biomarkers which can pave way for early diagnosis in noninvasive methods, and also the identification of target genes can elucidate an efficient therapeutic target.

AREAS COVERED

PubMed and Embase database was used to search articles with search terms 'Portal Hypertension' or 'pathophysiology' and 'diagnosis' and 'treatment' or "role of miRNAs in portal hypertension.

EXPERT OPINION

Interestingly, biomarkers like microRNAs (miRNAs) have been studied for their potential role in various diseases including hypertension. In recent years, miRNAs have been proved to be an efficient biomarker and therapeutic target and few studies have assessed the roles of miRNAs in PH. The present paper highlights the potential roles of miRNAs in PH.

The Key Role of microRNAs in Initiation and Progression of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the main type of primary liver malignancy and the fourth leading cause of cancer-related death worldwide. MicroRNAs (miRNAs), a type of non-coding RNA that regulates gene expression mainly on post-transcriptional level has a confirmed and important role in numerous biological process. By regulating specific target genes, miRNA can act as oncogene or tumor suppressor. Recent evidence has indicated that the deregulation of miR-NAs is closely associated with the clinical pathological features of HCC. However, the precise regulatory mechanism of each miRNA and its targets in HCC has yet to be illuminated. This study demonstrates that both oncogenic and tumor suppressive miRNAs are crucial in the formation and development of HCC. miRNAs influence biological behavior including proliferation, invasion, metastasis and apoptosis by targeting critical genes. Here, we summarize current knowledge about the expression profile and function of miRNAs in HCC and discuss the potential for miRNA-based therapy for HCC.

miR-517b-3p promotes the progression of portal vein tumor thrombus via activating Wnt/β-catenin signaling pathway in hepatocellular carcinoma

AIMS

This study was aimed to investigate the expression patterns and prognostic value of microRNA-517b-3p (miR-517b-3p) in hepatocellular carcinoma (HCC) patients with portal vein tumor thrombus (PVTT).

METHODS

The expression of miR-517b-3p in PVTT tissues and cells was estimated using qRT-PCR. Through Kaplan-Meier survival analysis, Cox regression assay and ROC analysis, the significance of miR-517b-3p was explored. In addition, cell experiments were performed to examine the functional role of miR-517b-3p during progression of PVTT. Moreover, the biological process and biological pathway analysis analyses were conducted through GSEA and FunRich. Besides, the protein-protein interaction (PPI) network of the DEGs was established through cBioPortal website.

RESULTS

Compared with the controls, the miR-517b-3p was upregulated in both PVTT tissues and cells. The upregulated miR-517b-3p, which served as a potential diagnostic biomarker to distinguish PVTT from PT and controls, was associated with poor overall survival and acted as an independent prognostic factor. The cell proliferation, migration and invasion were proved to be enhanced by overexpression of miR-517b-3p. Furthermore, Wnt/β-catenin signaling was suppressed by miR-517b-3p knockdown and might be involved in the progression of PVTT.

CONCLUSION

miR-517b-3p may promote PVTT cell proliferation, migration and invasion via activation of Wnt/β-catenin signaling pathway. Meanwhile, miR-517b-3p has overexpression in PVTT samples, and serves as a candidate diagnostic and prognostic biomarker in HCC patients with PVTT.

MicroRNA-135a expression is upregulated in hepatocellular carcinoma and targets long non-coding RNA TONSL-AS1 to suppress cell proliferation

Dysregulation of long non-coding RNAs (lncRNAs) results in development of human diseases, including hepatocellular carcinoma (HCC). lncRNA TONSL-AS1 has been reported to act as a tumor suppressor in gastric cancer. The present study aimed to investigate the role of TONSL-AS1 in hepatocellular carcinoma (HCC). Reverse transcription-quantitative PCR analysis was performed to detect the expression levels of TONSL-AS1 and microRNA (miRNA/miR)-135a in HCC tissues and paired adjacent normal tissues. A 5-year follow-up study was performed to determine the prognostic value of TONSL-AS1 in HCC. The association between miR-135a and TONSL-AS1 was assessed via overexpression experiments. The Cell Counting Kit-8 assay was performed to assess cell proliferation. The results demonstrated that TONSL-AS1 expression was downregulated in HCC tissues, which was associated with a lower survival rate in patients with HCC. TONSL-AS1 and miR-135a were predicted to interact with each other, whereby overexpression of miR-135a downregulated TONSL-AS1 expression. The results demonstrated that TONSL-AS1 and miR-135a were inversely correlated with each other. Notably, overexpression of TONSL-AS1 inhibited HCC cell proliferation, while overexpression of miR-135a promoted HCC cell proliferation and decreased the effect of overexpression of TONSL-AS1 on cell proliferation. Taken together, the results of the present study suggest that miR-135a expression is upregulated in HCC and targets lncRNA TONSL-AS1 to suppress cell proliferation.

Role of Serum Vitamin D, Interleukin 13, and microRNA-135a in Hepatocellular Carcinoma and Treatment Failure in Egyptian HCV-Infected Patients Receiving Direct Antiviral Agents

Direct-acting antivirals (DAAs) are used for hepatitis C virus (HCV) treatment. However, treatment failure and hepatocellular carcinoma (HCC) development following treatment was reported. In this study, we assessed the role of serum vitamin D, interleukin 13 (IL-13), and microRNA-135a in the prediction of treatment failure with DAA and HCC development among Egyptian HCV-infected patients. A total of 950 patients with HCV-related chronic liver disease underwent DAA treatment. Before DAAs, serum vitamin D and IL-13 were determined by ELISA, and gene expression of miRNA-135a was assessed in serum by real-time PCR. The predictive abilities of these markers were determined using the receiver operating characteristic (ROC) curve. Sustained virological response (SVR) was achieved in 92.6% of HCV-infected patients (responders). High viral load, IL-13, miRNA-135a, and low vitamin D levels were associated with treatment failure and HCC development. HCC development was recorded in non-responders, but not in the responders (35.7% vs. 0% p < 0.001). In conclusion: serum IL-13, Vitamin D, and miRNA-135a could be potential biomarkers in monitoring DAA treatment and HCC prediction. DAAs-induced SVR may decrease the incidence of HCC.

Screening potential prognostic biomarkers for portal vein emboli in patients with hepatocellular carcinoma

Background

The formation of portal vein tumor thrombus (PVTT) is closely related to the prognosis of patients with hepatocellular carcinoma (HCC). However, the mechanisms by which PVTTs form and the biomarkers involved are still little understood.

Methods

The Genome Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases were used to obtain transcriptome data from normal tissue, HCC tissue, primary tumors (PTs) of HCC, and paired PVTT tissue. Differentially expressed genes (DEGs) in PTs and PVTTs were analyzed. The differentially expressed immune genes were further investigated in terms of their prognostic significance, immune infiltration, function. Finally, we explored the relationship between risk scores and drug sensitivity based on the R package.

Results

In the two datasets, there were 458 DEGs identified in the PT and PVTT tissues, of which, 58 were immune-related genes. The differentially expressed immune genes may promote the progression of PVTT by participating in the regulation of non-cellular components such as the extracellular matrix, inflammatory factors, and chemokines. Furthermore, the immune genes KDR, AKT3, FCGR2B, KIAA1429, and TPT1 were correlated with the prognosis of HCC in patients with PVTT. Using this data, a model was constructed to predict the prognosis of patients, thus allowing for the identification of high- and low-risk patients.

Conclusions

This study demonstrated that immune-related genes may be involved in the regulation of the extracellular matrix and acellular components, and subsequently, in the formation of PVTT. These five genes KDR, AKT3, FCGR2B, KIAA1429, and TPT1 may be potential prognostic biomarkers and treatment targets for HCC patients with PVTT.

Portal Vein Tumor Thrombosis and Hepatocellular Carcinoma - The Changing Tides

Portal vein involvement is considered one of the most fearful complications of hepatocellular carcinoma (HCC). Portal vein tumor thrombosis (PVTT) is associated with aggressive tumor biology (high grade), high tumor burden (number and size of lesions), high levels of serum markers (AFP), poor liver function (deranged LFT), and poor performance status of patients. The Barcelona Clinic Liver Cancer staging system places HCC patients with PVTT in advanced stage (BCLC Stage-C). This group contains a fairly heterogeneous patient population, previously considered candidates for palliative systemic therapy with sorafenib. However, this provided modest overall survival (OS) benefit. The results of a recent Phase III (IMbrave150) trial favor the combination of atezolizumab and bevacizumab over sorafenib as a standard of care in advanced unresectable HCC. While only lenvatinib proved to be non-inferior against sorafenib in a phase III (REFLECT trial), regorafenib (RESORCE trial), ramucirumab (REACH-2), and cabozantinib (CELESTIAL) have been approved second-line therapy in phase III clinical trials. Recently, the data on the prospect of other modalities in the management of HCC with PVTT is mounting with favorable results. Targeting multiple pathways in the HCC cascade using a combination of drugs and other modalities such as RT, TACE, TARE, and HAIC appear effective for systemic and loco-regional control. The quest for the ideal combination therapy and the sequence set is still widely unanswered and prospective trials are lacking. With the armament of available therapeutic options and the advances and refinements in the delivery system, down-staging patients to make them eligible for curative resection has been reported. In a rapidly evolving treatment landscape, performing surgery when appropriate, in the form of LR and even LT to achieve cure does not seem farfetched. Likewise, adjuvant therapy and prompt management of the recurrences holds the key to prolong OS and DFS. This review discusses the management options of HCC patients with PVTT.

MicroRNAs: Regulators of immunological reactions in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third prominent cause of cancer mortality, with increasing prevalence and poor survival worldwide. Being diagnosed at an advanced stage, HCC frequently results in poor prognosis, treatment failure, and recurrence. Post-treatment reactivation and recurrence often amplify the immunosuppressed state induced by HCC pathogenesis. Therefore, stimulating the immune system may be a potential therapy measure for the treatment of HCC. Immune responses of the body may be potentiated by modulation of various effector cells such as B-cells, T-cells, Treg cells, natural killer cells, dendritic cells, cytotoxic T-lymphocytes, and other antigen-presenting cells. microRNAs (small non-coding RNAs) are the regulators of gene expression via translational inhibition or mRNA degradation. Various activities and developmental stages of the immune system are governed by miRNAs and they have a regulative impact on innate and adaptive immune cells in both, healthy and diseased conditions. Their misexpression has been associated with the initiation, development, and metastasis of various cancer types, including HCC. This review summarizes the functional impact of these immuno-miRNAs in the improvement of tumor conditions.

NET1 promotes HCC growth and metastasis in vitro and in vivo via activating the Akt signaling pathway

Neuroepithelial cell transforming gene 1 (NET1), a member of the guanine nucleotide exchange factor family, is involved in various cancers, including gastric cancer, breast cancer and glioma. However, the role of NET1 in hepatocellular carcinoma (HCC) remains largely uncovered. In this study, we found that NET1 expression was upregulated in HCC, and that upregulated NET1 expression was closely associated with poor prognosis and some clinical characteristics in HCC patients. Whilst forced expression of NET1 in HCC cells was observed to significantly promote cell growth and metastasis in vitro and in vivo; downregulation of NET1 was shown to exhibit an opposite inhibitory effect. RNA-seq analysis and gene set enrichment analysis demonstrated that knockdown of NET1 significantly suppressed the level of Akt phosphorylation level and the expression of Akt downstream genes in HCC cells. Moreover, MK2206, a potent Akt inhibitor was shown to block the NET1-induced effects in HCC. Taken together, this study demonstrated that, through the Akt signaling pathway, NET1 plays an oncogenic role in HCC progression and metastasis. Hence, NET1 may potentially be used as a potential therapeutic target and prognostic marker of HCC.

FOXM1 and Cancer: Faulty Cellular Signaling Derails Homeostasis

Forkhead box transcription factor, FOXM1 is implicated in several cellular processes such as proliferation, cell cycle progression, cell differentiation, DNA damage repair, tissue homeostasis, angiogenesis, apoptosis, and redox signaling. In addition to being a boon for the normal functioning of a cell, FOXM1 turns out to be a bane by manifesting in several disease scenarios including cancer. It has been given an oncogenic status based on several evidences indicating its role in tumor development and progression. FOXM1 is highly expressed in several cancers and has also been implicated in poor prognosis. A comprehensive understanding of various aspects of this molecule has revealed its role in angiogenesis, invasion, migration, self- renewal and drug resistance. In this review, we attempt to understand various mechanisms underlying FOXM1 gene and protein regulation in cancer including the different signaling pathways, post-transcriptional and post-translational modifications. Identifying crucial molecules associated with these processes can aid in the development of potential pharmacological approaches to curb FOXM1 mediated tumorigenesis.

MicroRNAs in the Pathogenesis of Hepatocellular Carcinoma: A Review

Simple Summary

Hepatocellular carcinoma (HCC) is one of the most frequently occurring cancers, and the prognosis for late-stage HCC remains poor. A better understanding of the pathogenesis of HCC is expected to improve outcomes. MicroRNAs (miRNAs) are small, noncoding, single-stranded RNAs that regulate the expression of various target genes, including those in cancer-associated genomic regions or fragile sites in various human cancers. We summarize the central roles of miRNAs in the pathogenesis of HCC and discuss their potential utility as valuable biomarkers and new therapeutic agents for HCC.

Abstract

Hepatocellular carcinoma (HCC) is the seventh most frequent cancer and the fourth leading cause of cancer mortality worldwide. Despite substantial advances in therapeutic strategies, the prognosis of late-stage HCC remains dismal because of the high recurrence rate. A better understanding of the etiology of HCC is therefore necessary to improve outcomes. MicroRNAs (miRNAs) are small, endogenous, noncoding, single-stranded RNAs that modulate the expression of their target genes at the posttranscriptional and translational levels. Aberrant expression of miRNAs has frequently been detected in cancer-associated genomic regions or fragile sites in various human cancers and has been observed in both HCC cells and tissues. The precise patterns of aberrant miRNA expression differ depending on disease etiology, including various causes of hepatocarcinogenesis, such as viral hepatitis, alcoholic liver disease, or nonalcoholic steatohepatitis. However, little is known about the underlying mechanisms and the association of miRNAs with the pathogenesis of HCC of various etiologies. In the present review, we summarize the key mechanisms of miRNAs in the pathogenesis of HCC and emphasize their potential utility as valuable diagnostic and prognostic biomarkers, as well as innovative therapeutic targets, in HCC diagnosis and treatment.

Loss of STAT5A promotes glucose metabolism and tumor growth through miRNA-23a-AKT signaling in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Here, we identified that increased miR‐23a expression in HCC tissues was associated with worse survival. More importantly, we found that STAT5A was a target of miR‐23a, whose levels significantly decreased in tumor tissues. Stable expression of STAT5A in Huh7 cells suppressed glucose metabolism and tumor growth. Finally, this study showed that increased miR‐23a negatively regulated STAT5A, which further activated AKT signaling to enable rapid metabolism for accelerated tumor growth in HCC. Taken together, our results demonstrated that the miR‐23a‐STAT5A‐AKT signaling pathway is critical to alter glucose metabolism in HCC and may offer new opportunities for effective therapy.

MicroRNA-135a Protects Against Ethanol-Induced Apoptosis in Neural Crest Cells and Craniofacial Defects in Zebrafish by Modulating the Siah1/p38/p53 Pathway

MicroRNAs (miRNAs) are small non-coding RNAs that are involved in various biological processes, including apoptosis, by regulating gene expression. This study was designed to test the hypothesis that ethanol-induced downregulation of miR-135a contributes to ethanol-induced apoptosis in neural crest cells (NCCs) by upregulating Siah1 and activating the p38 mitogen-activated protein kinase (MAPK)/p53 pathway. We found that treatment with ethanol resulted in a significant decrease in miR-135a expression in both NCCs and zebrafish embryos. Ethanol-induced downregulation of miR-135a resulted in the upregulation of Siah1 and the activation of the p38 MAPK/p53 pathway and increased apoptosis in NCCs and zebrafish embryos. Ethanol exposure also resulted in growth retardation and developmental defects that are characteristic of fetal alcohol spectrum disorders (FASD) in zebrafish. Overexpression of miRNA-135a significantly reduced ethanol-induced upregulation of Siah1 and the activation of the p38 MAPK/p53 pathway and decreased ethanol-induced apoptosis in NCCs and zebrafish embryos. In addition, ethanol-induced growth retardation and craniofacial defects in zebrafish larvae were dramatically diminished by the microinjection of miRNA-135a mimics. These results demonstrated that ethanol-induced downregulation of miR-135a contributes to ethanol-induced apoptosis in NCCs by upregulating Siah1 and activating the p38 MAPK/p53 pathway and that the overexpression of miRNA-135a can protect against ethanol-induced apoptosis in NCCs and craniofacial defects in a zebrafish model of FASD.

Next-generation des-r-carboxy prothrombin for immunohistochemical assessment of vascular invasion by hepatocellular carcinoma

Background

We have previously shown the value of next-generation des-r-carboxy prothrombin (NX-DCP) for predicting vascular invasion in hepatocellular carcinoma (HCC). Since conventional DCP is inaccurate under some conditions, this study aimed to assess whether NX-DCP immunohistochemical staining was related to vascular invasion in HCC.

Methods

Fifty-six patients scheduled to undergo resection for single HCC were divided into two groups, with and without pathological portal vein invasion. Immunohistochemical features of HCC and sites of vascular invasion were assessed using alpha-fetoprotein (AFP), conventional DCP, and NX-DCP.

Results

Pathological portal vein invasion was absent in 43 patients and present in 13 patients. Patient characteristics, pathological background of the liver parenchyma, and tumor-related factors did not differ significantly between the groups. There was no significant difference in the serum AFP level between the groups, whereas levels of conventional DCP (p < 0.0001) and NX-DCP (p < 0.0001) were significantly higher in the vascular invasion group. Immunohistochemical staining showed no significant difference in the staining rate of tumor (67.9% vs. 80.7%, p = 0.08), but NX-DCP stained significantly more at the sites of vascular invasion (15.4% vs. 46.2%, p = 0.01) than conventional DCP. No vascular invasion was stained by AFP.

Conclusions

NX-DCP offers better sensitivity for detecting sites of vascular invasion than AFP and conventional DCP.

Epigenetic Associations between lncRNA/circRNA and miRNA in Hepatocellular Carcinoma

Simple Summary

Non-coding RNAs such as microRNAs, long non-coding RNAs, and circular RNAs contribute to the development and progression of hepatocellular carcinoma through epigenetic association. Long non-coding RNAs and circular RNAs act as competing endogenous RNAs that contain binding sites for miRNAs and thus compete with the miRNAs, which results in promotion of miRNA target gene expression, thereby leading to proliferation and metastasis of hepatocellular carcinoma. Competing endogenous RNAs have the potential to become diagnostic biomarkers and therapeutic targets for treatment of hepatocellular carcinoma.

Abstract

The three major members of non-coding RNAs (ncRNAs), named microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), play an important role in hepatocellular carcinoma (HCC) development. Recently, the competing endogenous RNA (ceRNA) regulation model described lncRNA/circRNA as a sponge for miRNAs to indirectly regulate miRNA downstream target genes. Accumulating evidence has indicated that ceRNA regulatory networks are associated with biological processes in HCC, including cancer cell growth, epithelial to mesenchymal transition (EMT), metastasis, and chemoresistance. In this review, we summarize recent discoveries, which are specific ceRNA regulatory networks (lncRNA/circRNA-miRNA-mRNA) in HCC and discuss their clinical significance.

Methylation Status of the Nanog Promoter Determines the Switch between Cancer Cells and Cancer Stem Cells

Cancer stem cells (CSCs) are the main cause of tumor development, metastasis, and relapse. CSCs are thus considered promising targets for cancer therapy. However, it is hard to eradicate CSCs due to their inherent plasticity and heterogeneity, and the underlying mechanism of the switch between non-CSCs and CSCs remains unclear. Here, it is shown that miR-135a combined with SMYD4 activates Nanog expression and induces the switch of non-CSCs into CSCs. The miR-135a level, once elevated, lowers the methylation level of the CG5 site in the Nanog promoter by directly targeting DNMT1. SMYD4 binds to the unmethylated Nanog promoter to activate Nanog expression in Nanog-negative tumor cells. The in vivo regulation of miR-135a levels could significantly affect both the CSCs proportion and tumor progression. These findings indicate that DNA methylation of the Nanog promoter modulates the switch of non-CSCs into CSCs under the control of the miRNA-135 level. In addition, the related pathways, miR-135a/DNMT1 and SMYD4, involved in these processes are potential targets for CSC-targeted therapy.

HIPK2 suppresses tumor growth and progression of hepatocellular carcinoma through promoting the degradation of HIF-1α

Aberrant angiogenesis of hepatocellular carcinoma (HCC) leads to tumor growth and local or distant metastasis. Uncovering the underlying mechanisms for the neoangiogenesis of HCC can provide novel potential therapeutic targets in the clinic. Here, we reported that serine/threonine homeodomain-interacting protein kinase 2 (HIPK2) was frequently downregulated in HCC tissues compared with the adjacent normal tissues, and patients with lower HIPK2 protein expression were associated with worse overall survival. Both in vitro and in vivo, HIPK2 inhibited the migration of HCC cells, as well as tumor growth and metastasis in xenograft and orthotopic syngeneic HCC mouse models. Furthermore, HIPK2 inhibited the angiogenesis in HCC tumors. Under the hypoxic condition, HIPK2 knockdown enhanced the angiogenesis and the key regulator, HIF-1α signaling pathway; however, HIPK2 overexpression downregulated the tumoral angiogenesis and HIF-1α signaling. In HCC cells, HIPK2 could directly bind to HIF-1α and stimulate the ubiquitination of HIF-1α for proteasomal degradation. HIF-1α knockout partially rescued the promoting effect of HIPK2 depletion on angiogenesis and tumor growth. In conclusion, the downregulation of HIPK2 could enhance the angiogenesis in HCC through inducing the HIF-1α pathway, and further contribute to tumor growth and metastasis, which may provide a novel therapeutic strategy for HCC.

MiR-135a biogenesis and regulation in malignancy: a new hope for cancer research and therapy

MicroRNAs (miRNAs) are evolutionarily conserved small non-coding RNAs that affect posttranscriptional regulation by binding to the 3′-untranslated region of target messenger RNAs. MiR-135a is a critical miRNA that regulates gene expression, and many studies have focused on its function in cancer research. MiR-135a is dysregulated in various cancers and regulates cancer cell proliferation and invasion via several signaling pathways, such as the MAPK and JAK2/STAT3 pathways. MiR-135a has also been found to promote or inhibit the epithelial-mesenchymal transition and chemoresistance in different cancers. Several studies have discovered the value of miR-135a as a novel biomarker for cancer diagnosis and prognosis. These studies have suggested the potential of therapeutically manipulating miR-135a to improve the outcome of cancer patients. Although these findings have demonstrated the role of miR-135a in cancer progression and clinical applications, a number of questions remain to be answered, such as the dual functional roles of miR-135a in cancer. In this review, we summarize the available studies regarding miR-135a and cancer, including background on the biogenesis and expression of miR-135a in cancer and relevant signaling pathways involved in miR-135a-mediated tumor progression. We also focus on the clinical application of miR-135a as a biomarker in diagnosis and as a therapeutic agent or target in cancer treatment, which will provide a greater level of insight into the translational value of miR-135a.

Role of MicroRNA in the Diagnosis and Management of Hepatocellular Carcinoma

INTRODUCTION

Hepatocellular Carcinoma (HCC) is one of the most common malignant tumors in the world and comes third in cancer-induced mortality. The need for improved and more specific diagnostic methods that can detect early-stage disease is immense, as it is amenable to curative modalities, while advanced HCC is associated with low survival rates. microRNA (miRNA) expression is deregulated in HCC and this can be implemented both diagnostically and therapeutically.

OBJECTIVE

To provide a concise review on the role of miRNA in diagnosis, prognosis, and treatment of HCC.

METHODS

We conducted a comprehensive review of the PubMed bibliographic database.

RESULTS

Multiple miRNAs are involved in the pathogenesis of HCC. Measurement of the levels of these miRNAs either in tumor tissue or in the blood constitutes a promising diagnostic, as well as prognostic tool. OncomiRs are miRNAs that promote tumorigenesis, thus inhibiting them by administering antagomiRs is a promising treatment option. Moreover, replacement of the depleted miRNAs is another potential therapeutic approach for HCC. Modification of miRNA levels may also regulate sensitivity to chemotherapeutic agents.

CONCLUSION

miRNA play a pivotal role in HCC pathogenesis and once the underlying mechanisms are elucidated, they will become part of everyday clinical practice against HCC.

MicroRNAs Involved in Metastasis of Hepatocellular Carcinoma: Target Candidates, Functionality and Efficacy in Animal Models and Prognostic Relevance

Hepatocellular carcinoma (HCC) is responsible for the second-leading cancer-related death toll worldwide. Although sorafenib and levantinib as frontline therapy and regorafenib, cabazantinib and ramicurimab have now been approved for second-line therapy, the therapeutic benefit is in the range of only a few months with respect to prolongation of survival. Aggressiveness of HCC is mediated by metastasis. Intrahepatic metastases and distant metastasis to the lungs, lymph nodes, bones, omentum, adrenal gland and brain have been observed. Therefore, the identification of metastasis-related new targets and treatment modalities is of paramount importance. In this review, we focus on metastasis-related microRNAs (miRs) as therapeutic targets for HCC. We describe miRs which mediate or repress HCC metastasis in mouse xenograft models. We discuss 18 metastasis-promoting miRs and 35 metastasis-inhibiting miRs according to the criteria as outlined. Six of the metastasis-promoting miRs (miR-29a, -219-5p, -331-3p, 425-5p, -487a and -1247-3p) are associated with unfavourable clinical prognosis. Another set of six down-regulated miRs (miR-101, -129-3p, -137, -149, -503, and -630) correlate with a worse clinical prognosis. We discuss the corresponding metastasis-related targets as well as their potential as therapeutic modalities for treatment of HCC-related metastasis. A subset of up-regulated miRs -29a, -219-5p and -425-5p and down-regulated miRs -129-3p and -630 were evaluated in orthotopic metastasis-related models which are suitable to mimic HCC-related metastasis. Those miRNAs may represent prioritized targets emerging from our survey.

Prognostic significance of microRNA-135 in patients with digestive system cancers: a systematic review and meta-analysis

Background: MicroRNA-135 (miR-135) is a well-known non-coding RNA that has been demonstrated to participate in tumorigenesis and cancer development; however, the clinical prognostic value of miR-135 in digestive system cancers remains controversial. This meta-analysis aims to explore the potential value of miR-135 as a prognostic marker for digestive system cancers.

Methods: The PubMed, Embase, Cochrane Library, and Web of Science databases were searched for eligible articles published before 31 August 2019. Stata 12.0 software was used to analyze the overall survival (OS), disease-free survival (DFS), and recurrence-free survival (RFS) rates to access the prognostic value of miR-135 in digestive system cancers. We then used The Cancer Genome Atlas (TCGA) datasets to validate the meta-analysis results.

Results A total of 1470 patients from 17 studies were included in this meta-analysis. The pooled results showed that enhanced miR-135 expression was significantly associated with poor OR (hazard ratio (HR): 1.790; 95% confidence interval (95% CI): 1.577–2.031; P=0.000), DFS (HR: 1.482; 95% CI: 0.914–2.403; P=0.110), and RFS (HR: 3.994; 95% CI: 1.363–11.697; P=0.012) in digestive system cancers. A sensitivity analysis confirmed the reliability of our findings, and no significant publication bias was observed.

Conclusion: MiR-135 can be used as a novel biomarker for patients with digestive system cancers. We look forward to future large-scale clinical studies that will investigate the prognostic value of miR-135.

Progress in research of hepatocellular carcinoma with tumor thrombus

Hepatocellular carcinoma (HCC) with tumor thrombus is a hot and difficult issue in the study of HCC, and many key issues concerning this condition are still controversial. Clinical guidelines and treatment recommendations vary widely between the East and the West, and efficacy remains unsatisfactory. In recent years, with the progress of comprehensive tumor treatment concept and the rapid development of surgical techniques, perioperative management, interventional therapy, radiotherapy, targeted therapy, and other treatment methods, the overall survival rate of HCC with tumor thrombus has been significantly extended and encouraging efficacy has been achieved. However, the core issues on how to select individualized treatment to achieve optimal treatment and how to prevent postoperative recurrence still need to be studied and discussed. This article reviews the progress in the research of hepatic carcinoma with portal vein thrombus, inferior vena cava thrombus, or bile duct thrombus.

Based on Integrated Bioinformatics Analysis Identification of Biomarkers in Hepatocellular Carcinoma Patients from Different Regions

Accumulating statistics have shown that liver cancer causes the second highest mortality rate of cancer-related deaths worldwide, of which 80% is hepatocellular carcinoma (HCC). Given the underlying molecular mechanism of HCC pathology is not fully understood yet, identification of reliable predictive biomarkers is more applicable to improve patients' outcomes. The results of principal component analysis (PCA) showed that the grouped data from 1557 samples in Gene Expression Omnibus (GEO) came from different populations, and the mean tumor purity of tumor tissues was 0.765 through the estimate package in R software. After integrating the differentially expressed genes (DEGs), we finally got 266 genes. Then, the protein-protein interaction (PPI) network was established based on these DEGs, which contained 240 nodes and 1747 edges. FOXM1 was the core gene in module 1 and highly associated with FOXM1 transcription factor network pathway, while FTCD was the core gene in module 2 and was enriched in the metabolism of amino acids and derivatives. The expression levels of hub genes were in line with The Cancer Genome Atlas (TCGA) database. Meanwhile, there were certain correlations among the top ten genes in the up- and downregulated DEGs. Finally, Kaplan–Meier curves and receiver operating characteristic (ROC) curves were plotted for the top five genes in PPI. Apart from CDKN3, the others were closely concerned with overall survival. In this study, we detected the potential biomarkers and their involved biological processes, which would provide a new train of thought for clinical diagnosis and treatment.

Abnormal regulation of non-coding RNAs plays a role in development and progression of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an aggressive tumor with a poor prognosis. Non-coding RNAs (ncRNAs) are RNAs transcribed from the genome but not translated into protein. In recent years, ncRNAs have been recognized to be key factors in tumorigenesis because of their ability to regulate multiple targets, cell proliferation, differentiation, apoptosis, and development. In this review, we discuss the pathological significance of ncRNAs (microRNAs, long-chain non-coding RNAs, and cyclic RNAs) in the development and progression of HCC. We also discuss the potential role of ncRNAs in the diagnosis and treatment of HCC.

Significantly different expression levels of microRNAs associated with vascular invasion in hepatocellular carcinoma and their prognostic significance after surgical resection

BACKGROUND

Although gross vascular invasion (VI) has prognostic significance in patients with hepatocellular carcinoma (HCC) who have undergone hepatic resection, few studies have investigated the relationship between gross VI and aberrant expression of microribonucleic acids (miRNAs and miRs). Thus, the objective of this study was to identify miRNAs selectively expressed in HCC with gross VI and investigate their prognostic significance.

MATERIALS AND METHODS

Eligible two datasets (accession number: GSE20594 and GSE67140) were collected from the National Center for Biotechnology Information's (NCBI) Gene Expression Omnibus (GEO) database to compare miRNAs expression between HCC with and without gross VI. Differentially expressed miRNAs were externally validated using expression data from The Cancer Genome Atlas (TCGA) database. Prognostic significance and predicted functions of selected miRNAs for HCC were also investigated.

RESULTS

Thirty-five miRNAs were differentially expressed between HCC with and without gross VI in both datasets. Among them, three miRNAs were validated using TCGA database. miR-99a, miR-100, and miR-148a were downregulated to a greater extent in patients with HCC and gross VI than in those with HCC but no gross VI. Receiver operating characteristic (ROC) curve analysis showed discriminatory power of these miRNAs in predicting gross VI. Multivariate survival analysis revealed that types of surgery, advanced tumor node metastasis (TNM) stage, and low expression of miR-100-5p were independently associated with tumor recurrence. It also revealed that types of surgery, advanced TNM stage, low expression of miR-100-5p and miR-148a-3p were independent risk factors for overall survival (OS) after hepatic resection for HCC. A text mining analysis revealed that these miRNAs were linked to multifaceted hallmarks of cancer, including "invasion and metastasis."

CONCLUSIONS

Low expressions of miR-100-5p and miR-148a-3p were associated with gross VI and poor survival of patients after hepatic resection for HCC.

Thrombocytopenia: A prognostic factor for hepatocellular carcinoma patients with portal vein tumor thrombus after hepatectomy

BACKGROUND AND AIM

Portal vein tumor thrombus (PVTT) predicts a poor prognosis in hepatocellular carcinoma (HCC) patients. Platelets (PLTs) play an important role in HCC progression and metastasis. However, the relationship between PLTs and PVTT remains unclear. This study aimed to evaluate the value of PLT counts in the prognosis of HCC patients with PVTT after hepatectomy.

METHODS

From January 2002 to December 2012, 694 HCC patients with PVTT after hepatectomy were evaluated. The patients were divided into the thrombocytopenia group (PLT < 100 × 10⁹ /L), the normal group, and the thrombocytosis group (PLT > 300 × 10⁹ /L) based on the preoperative PLT level. A propensity score matching (PSM) analysis was used.

RESULTS

Before the PSM, PVTT patients with thrombocytopenia exhibited longer recurrence-free survival (RFS) and overall survival (OS) compared with those with normal PLT counts (both P < 0.001) or thrombocytosis (P = 0.008 and P = 0.046). For the thrombocytopenia group and the normal group, the 1-, 2-, and 3-year RFS values were 30.0%, 17.6%, and 15.7% and were 10.8%, 6.6%, and 5.8% (P < 0.001), respectively; the 1-, 2-, and 3-year OS values were 61.9%, 37.9%, and 31.2% and were 38.3%, 23.3%, and 16.0% (P < 0.001), respectively. After the PSM, the median survival time was 16.6 versus 8.6 months (P < 0.002) in the two groups. A subgroup analysis revealed that thrombocytopenia is associated with improved OS in those with type I PVTT (P = 0.021) or type II PVTT (P = 0.029).

CONCLUSION

According to the PSM, preoperative thrombocytopenia predicts an increased RFS and OS in HCC patients with PVTT after hepatectomy.

Therapeutics for advanced hepatocellular carcinoma: Recent advances, current dilemma, and future directions

Hepatocellular carcinoma (HCC) is one of the most common malignancies and is a serious threat to people's health worldwide. The prognosis of advanced HCC is dim if left untreated. In the clinic, the treatment options for advanced HCC include surgery, radiotherapy, transcatheter arterial chemoembolization, and so forth. In recent years, molecular targeted therapy and immunotherapy have also made great progress, bringing new hope to patients with advanced HCC. In this study, therapeutic advances, current dilemma, and future directions of advanced HCC are reviewed, which might serve as a summary for clinicians and may stimulate future research.

Role of non-coding RNAs in liver disease progression to hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a tumor with poor prognosis and frequently aggressive. The development of HCC is associated with fibrosis and cirrhosis, which mainly results from nonalcoholic fatty liver disease, excessive alcohol consumption, and viral infections. Non-coding RNAs (ncRNAs) are RNAs transcribed from the genome, but are not translated into proteins. Recently, ncRNAs emerged as key contributors to tumor development and progression because of their abilities to regulate various targets and modulate cell proliferation, differentiation, apoptosis, and development. In this review, we summarize the frequently activated pathways in HCC and discuss the pathological implications of ncRNAs in the context of human liver disease progression, in particular HCC development and progression. This review aims to summarize the role of ncRNA dysregulation in the diseases and discuss the diagnostic and therapeutic potentials of ncRNAs.

MicroRNA-135a Modulates Hepatitis C Virus Genome Replication through Downregulation of Host Antiviral Factors

Cellular microRNAs (miRNAs) have been shown to modulate HCV infection via directly acting on the viral genome or indirectly through targeting the virus-associated host factors. Recently we generated a comprehensive map of HCV–miRNA interactions through genome-wide miRNA functional screens and transcriptomics analyses. Many previously unappreciated cellular miRNAs were identified to be involved in HCV infection, including miR-135a, a human cancer-related miRNA. In the present study, we investigated the role of miR-135a in regulating HCV life cycle and showed that it preferentially enhances viral genome replication. Bioinformatics-based integrative analyses and subsequent functional assays revealed three antiviral host factors, including receptor interacting serine/threonine kinase 2 (RIPK2), myeloid differentiation primary response 88 (MYD88), and C-X-C motif chemokine ligand 12 (CXCL12), as bona fide targets of miR-135a. These genes have been shown to inhibit HCV infection at the RNA replication stage. Our data demonstrated that repression of key host restriction factors mediated the proviral effect of miR-135a on HCV propagation. In addition, miR-135a hepatic abundance is upregulated by HCV infection in both cultured hepatocytes and human liver, likely mediating a more favorable environment for viral replication and possibly contributing to HCV-induced liver malignancy. These results provide novel insights into HCV–host interactions and unveil molecular pathways linking miRNA biology to HCV pathogenesis.

Comprehensive treatments for hepatocellular carcinoma with portal vein tumor thrombosis

Portal vein tumor thrombosis (PVTT) is one of the most common complications in hepatocellular carcinoma (HCC). HCC with PVTT usually indicates poor prognosis, which has a number of characteristics including a rapidly progressive disease course, worse liver function, complications connected with portal hypertension, and poorer tolerance to treatment. The exact mechanisms of PVTT remain unknown, even though some concerned signal transduction or molecular pathways have been identified. In western countries, sorafenib is the only recommended therapeutic strategy regardless of PVTT types. However, multiple treatment options including transhepatic arterial chemoembolization, hepatectomy, radiotherapy, and sorafenib available in the clinic. In this review, we enumerate and discuss therapeutics against patients with HCC having PVTT available in the clinic and put forward directions for future research.

Loss of Estrogen-Regulated MIR135A1 at 3p21.1 Promotes Tamoxifen Resistance in Breast Cancer

The dysregulation of miRNAs has been increasingly recognized as a critical mediator of cancer development and progression. Here, we show that frequent deletion of the MIR135A1 locus is associated with poor prognosis in primary breast cancer. Forced expression of miR-135a decreased breast cancer progression, while inhibition of miR-135a with a specific miRNA sponge elicited opposing effects, suggestive of a tumor suppressive role of miR-135a in breast cancer. Estrogen receptor alpha (ERα) bound the promoter of MIR135A1 for its transcriptional activation, whereas tamoxifen treatment inhibited expression of miR-135a in ERα+ breast cancer cells. miR-135a directly targeted ESR1, ESRRA, and NCOA1, forming a negative feedback loop to inhibit ERα signaling. This regulatory feedback between miR-135a and ERα demonstrated that miR-135a regulated the response to tamoxifen. The tamoxifen-mediated decrease in miR-135a expression increased the expression of miR-135a targets to reduce tamoxifen sensitivity. Consistently, miR-135a expression was downregulated in ERα+ breast cancer cells with acquired tamoxifen resistance, while forced expression of miR-135a partially resensitized these cells to tamoxifen. Tamoxifen resistance mediated by the loss of miR-135a was shown to be partially dependent on the activation of the ERK1/2 and AKT pathways by miR-135a-targeted genes. Taken together, these results indicate that deletion of the MIR135A1 locus and decreased miR-135a expression promote ERα+ breast cancer progression and tamoxifen resistance.Significance: Loss of miR-135a in breast cancer disrupts an estrogen receptor-induced negative feedback loop, perpetuating disease progression and resistance to therapy.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/17/4915/F1.large.jpg Cancer Res; 78(17); 4915-28. ©2018 AACR.

Ultrasound-mediated nanobubble destruction (UMND) facilitates the delivery of A10-3.2 aptamer targeted and siRNA-loaded cationic nanobubbles for therapy of prostate cancer

The Forkhead box M1 (FoxM1) transcription factor is an important anti-tumor target. A novel targeted ultrasound (US)-sensitive nanobubble that is likely to make use of the physical energy of US exposure for the improvement of delivery efficacy to target tumors and specifically silence FoxM1 expression appears as among the most potential nanocarriers in respect of drug delivery. In this study, we synthesized a promising anti-tumor targeted FoxM1 siRNA-loaded cationic nanobubbles (CNBs) conjugated with an A10-3.2 aptamer (siFoxM1-Apt-CNBs), which demonstrate high specificity when binding to prostate-specific membrane antigen (PSMA) positive LNCaP cells. Uniform nanoscaled siFoxM1-Apt-CNBs were developed using a thin-film hydration sonication, carbodiimide chemistry approaches, and electrostatic adsorption methods. Fluorescence imaging as well as flow cytometry evidenced the fact that the siFoxM1-Apt-CNBs were productively developed and that they specifically bound to PSMA-positive LNCaP cells. siFoxM1-Apt-CNBs combined with ultrasound-mediated nanobubble destruction (UMND) significantly improved transfection efficiency, cell apoptosis, and cell cycle arrest in vitro while reducing FoxM1 expression. In vivo xenografts tumors in nude-mouse model results showed that siFoxM1-Apt-CNBs combined with UMND led to significant inhibition of tumor growth and prolonged the survival of the mice, with low toxicity, an obvious reduction in FoxM1 expression, and a higher apoptosis index. Our study suggests that siFoxM1-Apt-CNBs combined with UMND might be a promising targeted gene delivery strategy for therapy of prostate cancer.

MiR-200a negatively regulates TGF-β1-induced epithelial-mesenchymal transition of peritoneal mesothelial cells by targeting ZEB1/2 expression

Although epithelial-mesenchymal transition (EMT) of peritoneal mesothelial cells was recognized as the key process of peritoneal fibrosis, which is a major cause of peritoneal failure related to peritoneal dialysis (PD), mechanisms underlying these processes remain largely unknown. In this study, we found that miR-200a was significantly downregulated in peritoneal tissues with fibrosis in a rat model of PD. In vitro, transforming growth factor (TGF)-β1-induced EMT, identified by de novo expression of α-smooth muscle actin and a loss of E-cadherin in human peritoneal mesothelial cells (HPMCs), was associated with downregulation of miR-200a but upregulation of zinc finger E-box-binding homeobox 1/2 (ZEB1/2), suggesting a close link between miR-200a and ZEB1/2 in TGF-β1-induced EMT. It was further demonstrated that miR-200a was able to bind to the 3′UTR of ZEB1/2, and overexpression of miR-200a blocked TGF-β1-induced upregulation of ZEB1/2 and, therefore, inhibited EMT and collagen expression. In contrast, overexpression ZEB1/2 blocked miR-200a inhibition of EMT and collagen expression in HMPCs. In conclusion, miR-200a could negatively regulate TGF-β1-induced EMT by targeting ZEB1/2 in peritoneal mesothelial cells. Blockade of EMT in HPMCS indicates the therapeutic potential of miR-200a as a treatment for peritoneal fibrosis associated with PD.

MicroRNA-135a alleviates oxygen-glucose deprivation and reoxygenation-induced injury in neurons through regulation of GSK-3β/Nrf2 signaling

MicroRNAs (miRNAs) have been suggested as pivotal regulators in the pathological process of cerebral ischemia and reperfusion injury. In this study, we aimed to investigate the role of miR-135a in regulating neuronal survival in cerebral ischemia and reperfusion injury using an in vitro cellular model induced by oxygen-glucose deprivation and reoxygenation (OGD/R). Our results showed that miR-135a expression was significantly decreased in neurons with OGD/R treatment. Overexpression of miR-135a significantly alleviated OGD/R-induced cell injury and oxidative stress, whereas inhibition of miR-135a showed the opposite effects. Glycogen synthase kinase-3β (GSK-3β) was identified as a potential target gene of miR-135a. miR-135a was found to inhibit GSK-3β expression, but promote the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and downstream signaling. However, overexpression of GSK-3β significantly reversed miR-135a-induced neuroprotective effect. Overall, our results suggest that miR-135a protects neurons against OGD/R-induced injury through downregulation of GSK-3β and upregulation of Nrf2 signaling.

miR-135a-5p-mediated downregulation of protein tyrosine phosphatase receptor delta is a candidate driver of HCV-associated hepatocarcinogenesis

BACKGROUND AND AIMS

HCV infection is a leading risk factor of hepatocellular carcinoma (HCC). However, even after viral clearance, HCC risk remains elevated. HCV perturbs host cell signalling to maintain infection, and derailed signalling circuitry is a key driver of carcinogenesis. Since protein phosphatases are regulators of signalling events, we aimed to identify phosphatases that respond to HCV infection with relevance for hepatocarcinogenesis.

METHODS

We assessed mRNA and microRNA (miRNA) expression profiles in primary human hepatocytes, liver biopsies and resections of patients with HCC, and analysed microarray and RNA-seq data from paired liver biopsies of patients with HCC. We revealed changes in transcriptional networks through gene set enrichment analysis and correlated phosphatase expression levels to patient survival and tumour recurrence.

RESULTS

We demonstrate that tumour suppressor protein tyrosine phosphatase receptor delta (PTPRD) is impaired by HCV infection in vivo and in HCC lesions of paired liver biopsies independent from tissue inflammation or fibrosis. In liver tissue adjacent to tumour, high PTPRD levels are associated with a dampened transcriptional activity of STAT3, an increase of patient survival from HCC and reduced tumour recurrence after surgical resection. We identified miR-135a-5p as a mechanistic regulator of hepatic PTPRD expression in patients with HCV.

CONCLUSIONS

We previously demonstrated that STAT3 is required for HCV infection. We conclude that HCV promotes a STAT3 transcriptional programme in the liver of patients by suppressing its regulator PTPRD via upregulation of miR-135a-5p. Our results show the existence of a perturbed PTPRD-STAT3 axis potentially driving malignant progression of HCV-associated liver disease.

Encoding activities of non-coding RNAs

The universal expression of various non-coding RNAs (ncRNAs) is now considered the main feature of organisms' genomes. Many regions in the genome are transcribed but not annotated to encode proteins, yet contain small open reading frames (smORFs). A widely accepted opinion is that a vast majority of ncRNAs are not further translated. However, increasing evidence underlines a series of intriguing translational events from the ncRNAs, which were previously considered to lack coding potential. Recent studies also suggest that products derived from such novel translational events display important regulatory functions in many fundamental biological and pathological processes. Here we give a critical review on the potential coding capacity of ncRNAs, in particular, about what is known and unknown in this emerging area. We also discuss the possible underlying coding mechanisms of these extraordinary ncRNAs and possible roles of peptides or proteins derived from the ncRNAs in disease development and theranostics. Our review offers an extensive resource for studying the biology of ncRNAs and sheds light into the use of ncRNAs and their corresponding peptides or proteins for disease diagnosis and therapy.

miR-135a inhibits tumor metastasis and angiogenesis by targeting FAK pathway

Tumor metastasis has been the major cause of recurrence and death in patients with gastric cancer. Here, we find miR-135a has a decreased expression in the metastatic cell lines compared with its parental cell lines by analyzing microRNA array. Further results show that miR-135a is downregulated in the majority of human gastric cancer tissues and cell lines. Decreased expression of miR-135a is associated with TNM stage and poor survival. Besides, regaining miR-135a in gastric cancer cells obviously inhibits tumor growth, migration, invasion and angiogenesis by targeting focal adhesion kinase (FAK) pathway. Bioinformatics analysis and molecular experiments further prove that miR-135a is a novel downstream gene of tumor suppressor p53. Blocking FAK with its inhibitor can also enhance miR-135a expression through inducing p53. In summary, this study reveals the expression and function of miR-135a in gastric cancer and uncovers a novel regulatory mechanism of miR-135a.

Effects of microRNA-135a on the epithelial-mesenchymal transition, migration and invasion of bladder cancer cells by targeting GSK3β through the Wnt/β-catenin signaling pathway

This study investigated the effects of microRNA-135a (miR-135a) targeting of glycogen synthase kinase 3β (GSK3β) on the epithelial–mesenchymal transition (EMT), migration and invasion of bladder cancer (BC) cells by mediating the Wnt/β-catenin signaling pathway. BC and adjacent normal tissues were collected from 165 BC patients. Western blotting and quantitative real-time PCR were used to detect the expression of GSK3β, β-catenin, cyclinD1, E-cadherin, vimentin and miR-135a in BC tissues and cells. Cells were assigned to blank, negative control (NC), miR-135a mimics, miR-135a inhibitors, small interfering RNA (siRNA)-GSK3β or miR-135a inhibitors+siRNA-GSK3β groups. miR-135a, β-catenin, cyclinD1 and vimentin expression increased, while GSK3β and E-cadherin expression decreased in BC tissues compared with adjacent normal tissues. Compared with the blank and NC groups, the expression of miR-135a, β-catenin, cyclinD1 and vimentin was higher, and cell proliferation, migration, invasion and tumor growth were increased in the miR-135a mimics and siRNA-GSK3β groups. These groups showed an opposite trend in GSK3β and E-cadherin expression and cell apoptosis. The miR-135a inhibitors group was inversely correlated with the blank and NC groups. It was concluded that miR-135a accelerates the EMT, invasion and migration of BC cells by activating the Wnt/β-catenin signaling pathway through the downregulation of GSK3β expression.

MiRSEA: Discovering the pathways regulated by dysfunctional MicroRNAs

Recent studies have shown that dysfunctional microRNAs (miRNAs) are involved in the progression of various cancers. Dysfunctional miRNAs may jointly regulate their target genes and further alter the activities of canonical biological pathways. Identification of the pathways regulated by a group of dysfunctional miRNAs could help uncover the pathogenic mechanisms of cancer and facilitate development of new drug targets. Current miRNA-pathway analyses mainly use differentially-expressed miRNAs to predict the shared pathways on which they act. However, these methods fail to consider the level of differential expression level, which could improve our understanding of miRNA function. We propose a novel computational method, MicroRNA Set Enrichment Analysis (MiRSEA), to identify the pathways regulated by dysfunctional miRNAs. MiRSEA integrates the differential expression levels of miRNAs with the strength of miRNA pathway associations to perform direct enrichment analysis using miRNA expression data. We describe the MiRSEA methodology and illustrate its effectiveness through analysis of data from hepatocellular cancer, gastric cancer and lung cancer. With these analyses, we show that MiRSEA can successfully detect latent biological pathways regulated by dysfunctional miRNAs. We have implemented MiRSEA as a freely available R-based package on CRAN (https://cran.r-project.org/web/packages/MiRSEA/).

14-3-3ζ promotes hepatocellular carcinoma venous metastasis by modulating hypoxia-inducible factor-1α

Portal vein tumor thrombus (PVTT) is a type of intrahepatic metastasis arising from hepatocellular carcinoma (HCC) and is highly correlated with a poor prognosis. Hypoxia is common in solider tumors, including HCC, where it alters the behavior of HCC cells. We asked whether and how hypoxia contributes to PVTT formation. We demonstrated that increased intratumoral hypoxia is strongly associated with PVTT formation in HCC. We also showed that 14-3-3ζ is induced by hypoxia in HCC cells and correlates with PVTT formation in clinical HCC samples. In addition, 14-3-3ζ up-regulates HIF-1α expression by recruiting HDAC4, which prevents HIF-1α acetylation, thereby stabilizing the protein. Under hypoxic conditions in vitro, 14-3-3ζ knockdown inhibits hypoxia-induced HCC invasion by the HIF-1α/EMT pathway. Blockade of 14-3-3ζ in HCC cells reduces PVTT formation and distant lung metastasis in vivo. Moreover, a combination of 14-3-3ζ and HIF-1α expression is more prognostic for HCC patients than either protein alone. These results suggest that the hypoxia/14-3-3ζ/HIF-1α pathway plays an important role in PVTT formation and HCC metastasis.