miRNA in hepatocellular carcinoma

Exploring non-coding RNA mechanisms in hepatocellular carcinoma: implications for therapy and prognosis

Hepatocellular carcinoma (HCC) is a significant contributor to cancer-related deaths in the world. The development and progression of HCC are closely correlated with the abnormal regulation of non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). Important biological pathways in cancer biology, such as cell proliferation, death, and metastasis, are impacted by these ncRNAs, which modulate gene expression. The abnormal expression of non-coding RNAs in HCC raises the possibility that they could be applied as new biomarkers for diagnosis, prognosis, and treatment targets. Furthermore, by controlling the expression of cancer-related genes, miRNAs can function as either tumor suppressors or oncogenes. On the other hand, lncRNAs play a role in the advancement of cancer by interacting with other molecules within the cell, which, in turn, affects processes such as chromatin remodeling, transcription, and post-transcriptional processes. The importance of ncRNA-driven regulatory systems in HCC is being highlighted by current research, which sheds light on tumor behavior and therapy response. This research highlights the great potential of ncRNAs to improve patient outcomes in this difficult disease landscape by augmenting the present methods of HCC care through the use of precision medicine approaches.

Clinical Significance of Apurinic/Apyrimidinic Endodeoxyribonuclease 1 and MicroRNA Axis in Hepatocellular Carcinoma

Background and Aims

Identification of prognostic factors for hepatocellular carcinoma (HCC) opens new perspectives for therapy. Circulating and cellular onco-miRNAs are noncoding RNAs which can control the expression of genes involved in oncogenesis through post-transcriptional mechanisms. These microRNAs (miRNAs) are considered novel prognostic and predictive factors in HCC. The apurinic/apyrimidinic endodeoxyribonuclease 1 (APE1) contributes to the quality control and processing of specific onco-miRNAs and is a negative prognostic factor in several tumors. The present work aims to: a) define APE1 prognostic value in HCC; b) identify miRNAs regulated by APE1 and their relative target genes and c) study their prognostic value.

Methods

We used The Cancer Genome Atlas (commonly known as TCGA) data analysis to evaluate the expression of APE1 in HCC. To identify differentially-expressed miRNAs (DEmiRNAs) upon APE1 depletion through specific small interfering RNA, we used NGS and nanostring approaches in the JHH-6 HCC tumor cell line. Bioinformatics analyses were performed to identify signaling pathways involving APE1-regulated miRNAs. Microarray analysis was performed to identify miRNAs correlating with serum APE1 expression.

Results

APE1 is considerably overexpressed in HCC tissues compared to normal liver, according to the TCGA-liver HCC (known as LIHC) dataset. Enrichment analyses showed that APE1-regulated miRNAs are implicated in signaling and metabolic pathways linked to cell proliferation, transformation, and angiogenesis, identifying Cyclin Dependent Kinase 6 and Lysosomal Associated Membrane Protein 2 as targets. miR-33a-5p, miR-769, and miR-877 are related to lower overall survival in HCC patients. Through array profiling, we identified eight circulating DE-miRNAs associated with APE1 overexpression. A training phase identified positive association between sAPE1 and miR-3180-3p and miR-769.

Conclusions

APE1 regulates specific miRNAs having prognostic value in HCC.

Nonalcoholic fatty liver disease and hepatocellular carcinoma:Insights in epidemiology, pathogenesis, imaging, prevention and therapy

Hepatocellular carcinoma (HCC) is estimated to be the third leading cause of cancer-related mortality and is characterized by low survival rates. Nonalcoholic fatty liver disease (NAFLD) is emerging as a leading cause of HCC, whose rates are increasing, owing to the increasing prevalence of NAFLD. The pathogenesis of NAFLD-associated HCC is multifactorial: insulin resistance, obesity, diabetes and the low-grade hepatic inflammation, which characterizes NAFLD, seem to play key roles in the development and progression of HCC. The diagnosis of NAFLD-associated HCC is based on imaging in the presence of liver cirrhosis, preferably computerized tomography or magnetic resonance imaging, but liver biopsy for histological confirmation is usually required in the absence of liver cirrhosis. Some preventive measures have been recommended for NAFLD-associated HCC, including weight loss, cessation of even moderate alcohol drinking and smoking, as well as the use of metformin, statins and aspirin. However, these preventive measures are mainly based on observational studies, thus they need validation in trials of different design before introducing in clinical practice. The treatment of NAFLD should be tailored on an individual basis and should be ideally determined by a multidisciplinary team. In the last two decades, new medications, including tyrosine kinase inhibitors and immune checkpoints inhibitors, have improved the survival of patients with advanced HCC, but trials specifically designed for patients with NAFLD-associated HCC are scarce. The aim of this review was to overview evidence on the epidemiology and pathophysiology of NAFLD-associated HCC, then to comment on imaging tools for its appropriate screening and diagnosis, and finally to critically summarize the currently available options for its prevention and treatment.

Primary and Secondary micro-RNA Modulation the Extrinsic Pathway of Apoptosis in Hepatocellular Carcinoma

Abstract-One of the most common malignant liver diseases is hepatocellular carcinoma, which has a high recurrence rate and a low five-year survival rate. It is very heterogeneous both in structure and between patients, which complicates the diagnosis, prognosis and response to treatment. In this regard, an individualized, patient-centered approach becomes important, in which the use of mimetics and hsa-miRNA inhibitors involved in the pathogenesis of the disease may be determinative. From this point of view hsa-miRNAs are of interest, their aberrant expression is associated with poor prognosis for patients and is associated with tumor progression due to dysregulation of programmed cell death (apoptosis). However, the effect of hsa-miRNA on tumor development depends not only on its direct effect on expression of genes, the primary targets, but also on secondary targets mediated by regulatory pathways. While the former are actively studied, the role of secondary targets of these hsa-miRNAs in modulating apoptosis is still unclear. The present work summarizes data on hsa-miRNAs whose primary targets are key genes of the extrinsic pathway of apoptosis. Their aberrant expression is associated with early disease relapse and poor patient outcome. For these hsa-miRNAs, using the software package ANDSystem, we reconstructed the regulation of the expression of secondary targets and analyzed their impact on the activity of the extrinsic pathway of apoptosis. The potential effect of hsa-miRNAs mediated by action on secondary targets is shown to negatively correlate with the number of primary targets. It is also shown that hsa-miR-373, hsa-miR-106b and hsa-miR-96 have the highest priority as markers of hepatocellular carcinoma, whose action on secondary targets enhances their anti-apoptotic effect.

Antitumor and off-target effects of cholesterol-conjugated let-7a mimics in an orthotopic hepatocellular carcinoma xenograft nude mouse model

To explore the antitumor and potential off-target effects of systemically delivered cholesterol-conjugated let-7a mimics (Chol-let-7a) and control mimics (Chol-miRCtrl) on hepatocellular carcinoma in vivo.

Methods

The antitumor effects of two intravenous dosing regimens of Chol-let-7a on heptocellular carcinoma growth were compared using an orthotopic xenograft mouse model. Off-targets were analyzed with histopathological and ultrapathological features of heparenal tissue and cells in the Chol-let-7a-, Chol-miRCtrl-, and saline-treated (blank) xenograft mice and normal control mice. Then, let-7a abundance in orthotopic tumors, corresponding paracancerous hepatic tissue, and normal liver tissue from healthy nude mice was examined by reverse transcription-polymerase chain reaction. The distribution of Chol-let-7a and Chol-miRCtrl in vivo was examined by whole-animal imaging and frozen-sections observation. The experiments were approved by the Institutional Research Board of Peking Union Medical College Hospital.

Results

Continuous treatment with Chol-let-7a resulted in tumors that were 35.86% and 40.02% the size of those in the Chol-miRCtrl and blank xenograft group (P < 0.01 and P < 0.01, respectively), while intermittent dosing with Chol-let-7a resulted in tumors that were 65.42% and 56.66% the size of those in the Chol-miRCtrl and the blank control group, respectively (P < 0.05 and P < 0.05). In addition, some histopathological and ultrapathological features were only observed after treatment with the two cholesterol-conjugated molecules, however mild with intermittent dosing Chol-let-7a treatment, such as diffuse sinusoidal dilation and edema, primarily around the centrolobular vein in heptic tissues; mild hypercellularity with dilated capillary lumens in the renal tissue; and some organelle abnormalities found in heptic and renal cells. Furthermore, whole-animal imaging showed that Chol-let-7a and Chol-miRCtrl were predominantly distributed in the liver, kidney, and bladder regions after injection, and that the concentration of Chol-let-7a and Chol-miRCtrl in the kidney and the bladder decreased much slowly in the xenograft animals, especially in the Chol-miRCtrl group. Finally, RT-PCR analysis showed that let-7a levels were significantly increased in Chol-let-7a-treated xenografts compared with Chol-miRCtrl group (P=0.003) and blank xenograft group (P=0.001); however, the level was only equivalent to 50.6% and 40.7% of that in paracancerous hepatic tissue and hepatic tissue in normal mice, respectively.

Conclusions

Chol-let-7a, administered either continuously or intermittently, showed effective antitumor efficacy. Chol-let-7a had some off-target effects, such as mild acute hepatitis-like inflammation and non-specific drug-induced kidney injury. The intermittent dosing regimen resulted in less damage than the continuous regimen, while maintaining relatively satisfactory antitumor efficacy, which could be useful for the investigation and possible clinical use of miRNA treatment regimens in the future.

Antitumor Effect of Regorafenib on MicroRNA Expression in Hepatocellular Carcinoma Cell Lines

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and is one of the leading causes of cancer-related deaths worldwide. Regorafenib, a multi-kinase inhibitor, is used as a second-line treatment for advanced HCC. Here, we aimed to investigate the mechanism of the antitumor effect of regorafenib on HCC and evaluate altered microRNA (miRNA) expression. Cell proliferation was examined in six HCC cell lines (HuH-7, HepG2, HLF, PLC/PRF/5, Hep3B, and Li-7) using the Cell Counting Kit-8 assay. Xenografted mouse models were used to assess the effects of regorafenib in vivo. Cell cycle analysis, western blotting analysis, and miRNA expression analysis were performed to identify the antitumor inhibitory potential of regorafenib on HCC cells. Regorafenib suppressed proliferation in HuH-7 cell and induced G0/G1 cell cycle arrest and cyclin D1 downregulation in regorafenib-sensitive cells. During miRNA analysis, miRNA molecules associated with the antitumor effect of regorafenib were found. Regorafenib suppresses cell proliferation and tumor growth in HCC by decreasing cyclin D1 via alterations in intracellular and exosomal miRNAs in HCC.

Long non-coding RNA (lncRNA) CYTOR promotes hepatocellular carcinoma proliferation by targeting the microRNA-125a-5p/LASP1 axis

This study investigated the function of long non-coding RNA (lncRNA) cytoskeleton regulator RNA (CYTOR) in hepatocellular carcinoma (HCC). In HCC, the expression of CYTOR and microRNA (miR)-125a-5p were measured by quantitative real-time PCR (qRT-PCR). The expression of actin skeletal protein 1 (LASP1) was evaluated by Western blot analysis. Flow cytometry assays, transwell assays, colony formation assay, and cell counting kit-8 (CCK-8) assay were used to evaluate the roles of miR-125a-5p and CYTOR in HCC cells. The target genes of CYTOR and miR-125a-5p were identified by bioinformatics analysis and Luciferase assay. CYTOR was upregulated in HCC cell lines, and knockdown of CYTOR inhibited HCC cell growth. MiR-125a-5p was downregulated in HCC cells and a target of CYTOR in regulating HCC progression. Furthermore, LASP1 was a downstream target of miR-125a-5p. Finally, CYTOR was found to be involved in HCC progression in vivo. CYTOR promotes HCC development by regulating the miR-125a-5p/LASP1 axis.

Galectin‑9 suppresses the tumor growth of colon cancer in vitro and in vivo

Colon cancer is the second leading cause of cancer-related mortality worldwide, and the prognosis of advanced colon cancer has remained poor in recent years. Galectin-9 (Gal-9) is a tandem-repeat type galectin that has recently been shown to exert antiproliferative effects on various types of cancer cells. The present study aimed to assess the effects of Gal-9 on human colon and colorectal cancer cells in vitro and in vivo, as well as to evaluate the microRNAs (miRNAs/miRs) associated with the antitumor effects of Gal-9. We examined the ability of Gal-9 to inhibit cell proliferation via apoptosis, and the effects of Gal-9 on cell cycle-related molecules in various human colon and colorectal cancer cell lines. In addition, Gal-9-mediated changes in activated tyrosine kinase receptors and angiogenic molecules were assessed using protein array chips in colon and colorectal cancer cells. Moreover, miRNA array analysis was performed to examine Gal-9-induced miRNA expression profiles. We also elucidated if Gal-9 inhibited tumor growth in a murine in vivo model. We found that Gal-9 suppressed the cell proliferation of colon cancer cell lines in vitro and in vivo. Our data further revealed that Gal-9 increased caspase-cleaved keratin 18 levels in Gal-9-treated colon cancer cells. In addition, Gal-9 enhanced the phosphorylation of ALK, DDR1, and EphA10 proteins. Furthermore, the miRNA expression levels, such as miR-1246, miR-15b-5p, and miR-1237, were markedly altered by Gal-9 treatment in vitro and in vivo. In conclusion, Gal-9 suppresses the cell proliferation of human colon cancer by inducing apoptosis, and these findings suggest that Gal-9 can be a potential therapeutic target in the treatment of colon cancer.

MicroRNA-4325 Suppresses Cell Progression in Hepatocellular Carcinoma via GATA-Binding Protein 6

MicroRNAs (miRs) are regulators of the formation and development of hepatocellular carcinoma (HCC). The biological role of miR-4325 in HCC has yet to be determined. This study is aimed at dissecting the role of miR-4325 in HCC and the underlying mechanism. Reverse transcription-quantitative PCR (RT-qPCR) was used to detect miR-4325 expression in HCC tissue specimens and cells. Cell proliferation, migration, and invasion were assessed by using the MTT assay and Transwell assay, respectively. The miR-4325 target was predicted based on bioinformatics analysis and validated using the dual-luciferase reporter assay. Rescue experiments in the cells were utilized to functionally characterize the downstream molecular targets of miR-4325. We observed that miR-4325 expression levels were significantly reduced in both HCC tissue specimens and cell lines. Meanwhile, a lower miR-4325 level was associated with a poorer prognosis. Gain and loss of function assays revealed that miR-4325 markedly downregulated HCC cell growth, migration, and invasion. Moreover, we identified GATA-binding protein 6 (GATA6) as a miR-4325 target and found that GATA6 was abnormally expressed in HCC. Rescue assays demonstrated that the regulatory function of miR-4325 in HCC was mediated by GATA6. Taken together, miR-4325 suppresses HCC cell growth, migration, and invasion by targeting GATA6, suggesting that miR-4325 may potentially serve as a novel therapeutic target for HCC.

Role of exopolysaccharides (EPSs) as anti-Mir-155 in cancer cells

Micro-RNAs (MiRNAs) are a class of small non-coding RNAs that regulate cellular gene expression. MiR-155 overexpression has been implicated in many types of cancer. Besides, miR-155 appears to help tumor invasion and migration and works as a moderator of epithelial-to-mesenchymal transition (EMT). Exopolysaccharides (EPSs) are a large group of natural heterogeneous polymers of sugars with a biologically antitumor effect. Herein, we test a hypothesis that EPS might promote its anti-tumorigenic effect via regulating miR-155 expression and its target pathways. Expression of miR-155 and a panel of targeted genes were investigated by real-time PCR. In our study, we have succeeded in the extraction, purification of exopolysaccharide with great cytotoxicity to different cancer cell lines, HepG II, Caco-2, and MCF-7. We reported that EPSs have a suppression effect on the oncogenic miR-155. In conclusion, this work clarifies a new possible mechanism for the anti-tumorigenic effect of EPSs in cancer cells and provides insights into the biological pathways through which EPSs act. Moreover, it paves the way for new prospective cancer therapeutics as anti-miRNA.

Identification of microRNA associated with the elimination of hepatitis C virus genotype 1b by direct-acting antiviral therapies

BACKGROUND AND AIM

Direct-acting antiviral (DAA) therapies have been proven to be highly effective for the eradication of hepatitis C virus (HCV) without resistance-associated substitutions (RASs). However, even in cases with no detected RASs, treatment sometimes fails, suggestive of the existence of some host-related factors involved in HCV eradication by DAAs. To explore such factors, we analyzed the serum microRNAs (miRNAs) of patients who received DAA treatment.

METHODS

The serum miRNA expression levels of 39 patients with chronic HCV infection without any detectable RASs, who achieved sustained virological response with asunaprevir/daclatasvir or grazoprevir/elbasvir therapy, were investigated cyclopedically, using oligonucleotide microarrays. The effects of specific miRNAs on the replication of HCV were measured in the HCV genomic replicon containing Huh-7 hepatoma cells.

RESULTS

Along with the disappearance of HCV, the expression quantiles of 16 miRNAs in the asunaprevir/daclatasvir group and 18 miRNAs in the grazoprevir/elbasvir group showed a tendency to increase or decrease. Among these molecules, adjustments for multiple testing yielded a significant differential expression at a false discovery rate of less than 5% for only one molecule, hsa-miR-762. Its expression quantile increased after HCV exclusion in all patients who had achieved sustained virological response. Quantitative polymerase chain reaction analysis validated a significant increase in the serum hsa-miR-762 after disappearance of HCV. On the contrary, hsa-miR-762 was decreased in the relapse and breakthrough of HCV in DAA failures. Transfection of hsa-miR-762 into cultured HCV-infected hepatocytes significantly decreased HCV-RNA replication.

CONCLUSION

These data suggest that hsa-miR-762 is one of the host factors participating in HCV exclusion by DAA therapy.

XIAP, commonly targeted by tumor suppressive miR-3607-5p and miR-3607-3p, promotes proliferation and inhibits apoptosis in hepatocellular carcinoma

MicroRNAs (miRNAs) are frequently aberrantly expressed in hepatocellular carcinoma (HCC) and are involved in its development. However, their role and mechanism in HCC are still not fully elucidated. Differential expression analysis and survival analysis were performed to identify potential miRNAs in HCC and miR-3607 was identified as a candidate therapeutic target and prognostic biomarker. RT-qPCR confirmed the low expression of mature miR-3607-3p and miR-3607-5p in HCC. Functional experiments suggested that both miR-3607-3p and miR-3607-5p significantly inhibited HCC proliferation and induced apoptosis. Next, the detailed mechanism of miR-3607-3p and miR-3607-5p in HCC was explored by combination of bioinformatic analysis and experimental validation, and uncovered that XIAP, a common target gene of miR-3607-3p and miR-3607-5p, was involoved in their tumor suppressive effects. Finally, a XIAP-associated protein-protein interaction network, consisting of 10 positively correlated genes, was established. Collectively, we for the first time suggest that miR-3607-3p and miR-3607-5p inhibit HCC by acting one common target XIAP.

miR-26b enhances the sensitivity of hepatocellular carcinoma to Doxorubicin via USP9X-dependent degradation of p53 and regulation of autophagy

Multi-drug resistance is a major challenge to hepatocellular carcinoma (HCC) treatment, and the over-expression or deletion of microRNA (miRNA) expression is closely related to the drug-resistant properties of various cell lines. However, the underlying molecular mechanisms remain unclear. CCK-8, EdU, flow cytometry, and transmission electron microscopy were performed to determine cell viability, proliferation, apoptosis, autophagic flow, and nanoparticle characterization, respectively. In this study, the results showed that the expression of miR-26b was downregulated following doxorubicin treatment in human HCC tissues. An miR-26b mimic enhanced HCC cell doxorubicin sensitivity, except in the absence of p53 in Hep3B cells. Delivery of the proteasome inhibitor, MG132, reversed the inhibitory effect of miR-26b on the level of p53 following doxorubicin treatment. Tenovin-1 (an MDM2 inhibitor) protected p53 from ubiquitination-mediated degradation only in HepG2 cells with wild type p53. Tenovin-1 pretreatment enhanced HCC cell resistance to doxorubicin when transfected with an miR-26b mimic. Moreover, the miR-26b mimic inhibited doxorubicin-induced autophagy and the autophagy inducer, rapamycin, eliminated the differences in the drug sensitivity effect of miR-26b. In vivo, treatment with sp94dr/miR-26b mimic nanoparticles plus doxorubicin inhibited tumor growth. Our current data indicate that miR-26b enhances HCC cell sensitivity to doxorubicin through diminishing USP9X-mediated p53 de-ubiquitination caused by DNA damaging drugs and autophagy regulation. This miRNA-mediated pathway that modulates HCC will help develop novel therapeutic strategies.

Association between microRNA-527 and glypican-3 in hepatocellular carcinoma

The present study aimed to identify the specific microRNAs (miRNAs/miRs) and their corresponding target genes involved in hepatocellular carcinomas (HCCs). Microarray analysis was performed to examine the miRNA expression profiles of four paired HCC and corresponding non-cancerous (N) liver tissues using 985 miRNA probes. The Human miRNA Target database was used to identify the target genes of differentially expressed miRNAs between the HCC and N tissues. The protein expression levels of target genes in the HCC tissues and cell lines were evaluated using western blotting. miRNA-mediated suppression of target gene expression was evaluated by transiently transfecting the miRNA into the HCC cell lines. Of the 985 miRNAs evaluated, four miRNAs were differentially expressed (three upregulated and one downregulated miRNAs). Of these four miRNAs, miRNA-527 was highly downregulated in the HCC tissues. Glypican-3 (GPC-3) was predicted as a target gene of miRNA-527. Western blotting revealed that GPC-3 protein is highly expressed in the HCC tissues and HCC cell lines compared with N and normal cell lines. Transfection with miR-527 resulted in suppression of GPC-3 protein expression in the Cos7 cells. Furthermore, transfection with miR-527 also inhibited the intrinsic expression of GPC-3 in the Huh-7 cell line. This indicated that miR-527 in the HCC tissues may be an important novel miRNA that targets the GPC-3 gene expression. GPC-3, whose expression is regulated by miR-527, may be involved in the development and progression of HCC.

MiRNA Polymorphisms and Hepatocellular Carcinoma Susceptibility: A Systematic Review and Network Meta-Analysis

Background

Hepatocellular carcinoma (HCC) is an intractable public health threat worldwide, representing the second leading cause of cancer-related mortality, with limited early detection and therapeutic options. Recent findings have revealed that the susceptibility of HCC is closely related to microRNA (miRNA). We performed this systematic review with a network meta-analysis to investigated four single nucleotide polymorphisms (SNPs) that most regularly reported in miRNAs, exploring their involvement in HCC susceptibility and interaction with hepatitis B virus (HBV).

Methods

Databases were reviewed for related studies published up to May 2019 to identify all studies that compared genotypes of miR-146a rs2910164, miR-149 rs2292832, miR-196a2 rs11614913, and miR-499 rs3746444 with no language and date restrictions. A pairwise meta-analysis was performed to estimate pooled odds ratios and 95% confidence intervals incorporating heterogeneity to assess the relationship between four miRNA polymorphisms and HCC. To further clarify the effect of polymorphisms on HCC, a Bayesian network meta-analysis was conducted to combine the effective sizes of direct and indirect comparisons. Calculations were performed by R version 3.6.1 and STATA 14.0. All steps were performed according to PRISMA guidelines.

Results

A total of 20 studies were enrolled in this network meta-analysis, providing 5,337 hepatocellular carcinoma cases and 6,585 controls. All included studies had an acceptable quality. Pairwise meta-analysis demonstrated that miR-196a2 rs11614913 was significantly associated with the susceptibility of HCC, while the other three SNPs were not found to have a significant association. In the analysis of HCC patients under different HBV infection status, only miR-196a2 revealed correlation of threefold risk. The network results showed no significant difference in the distribution of genotype frequencies except for miR-196a2, which appeared to have the highest superiority index when comparing and ranking four SNPs.

Conclusion

MiR-196a2 rs11614913 was significantly associated with the susceptibility of HCC, especially for HBV- related HCC, and that individuals with TC/CC were more susceptible. No significant association was found in the other three miRNA genes. MiR-196a2 could serve as the best predictor of susceptibility in HCC.

Anti-diabetic drug metformin inhibits cell proliferation and tumor growth in gallbladder cancer via G0/G1 cell cycle arrest

Gallbladder cancer is the most common biliary tract cancer with poor prognosis and wide variation in incidence rates worldwide, being very high in some countries in Latin America and Asia. Treatment of type 2 diabetes with metformin causes a reduction in the incidence of cancer. Till date, there are no reports on the anti-tumor effects of metformin in gall bladder cancer. Therefore, this study evaluated the effects of metformin on the proliferation of human gallbladder adenocarcinoma cells in vitro and in vivo, as well as explored the microRNAs associated with the anti-tumor effects of metformin. Metformin inhibited the proliferation in gallbladder adenocarcinoma cell lines NOZ, TGBC14TKB, and TGBC24TKB, and blocked the G0 to G1 transition in the cell cycle. This was accompanied by strong reduction in the expression of G1 cyclins, especially cyclin D1 and its catalytic subunits including cyclin-dependent kinase 4, and in retinoblastoma protein phosphorylation. In addition, metformin reduced the phosphorylation of receptor tyrosine kinases, especially Tie-2, ALK, PYK, EphA4, and EphA10, as well as angiogenesis-related proteins, including RANTES, TGF-β, and TIMP-1. Moreover, metformin also markedly altered microRNA expression profile leading to an anti-tumor effect. Treatment of athymic nude mice bearing xenograft tumors with metformin inhibited tumor growth. These results suggest that metformin may be used clinically for the treatment of gallbladder adenocarcinoma.

mirPLS: a partial linear structure identifier method for cancer subtyping using microRNAs

MOTIVATION

MicroRNAs (miRNAs) are small non-coding RNAs that have been successfully identified to be differentially expressed in various cancers. However, some miRNAs were reported to be up-regulated in one subtype of a cancer but down-regulated in another, making overall associations between these miRNAs and the heterogeneous cancer non-linear. These non-linearly associated miRNAs, if identified, are thus informative for cancer subtyping.

RESULTS

Here, we propose mirPLS, a Partial Linear Structure identifier for miRNA data that simultaneously identifies miRNAs of linear or non-linear associations with cancer status when non-linearly associated miRNAs can then be used for subsequent cancer subtyping. Simulation studies showed that mirPLS can identify both non-linearly and linearly outcome-associated miRNAs more accurately than the comparison methods. Using the identified non-linearly associated miRNAs much improves the cancer subtyping accuracy. Applications to miRNA data of three different cancer types suggest that the cancer subtypes defined by the non-linearly associated miRNAs identified by mirPLS are consistently more predictive of patient survival and more biological meaningful.

AVAILABILITY AND IMPLEMENTATION

The R package mirPLS is available for downloading from https://github.com/pfruan/mirPLS.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

The Effect of Gemcitabine on Cell Cycle Arrest and microRNA Signatures in Pancreatic Cancer Cells

BACKGROUND/AIM

Gemcitabine, an inhibitor of DNA synthesis, is the gold standard chemotherapeutic agent for pancreatic ductal adenocarcinoma (PDAC). MicroRNAs (miRNAs) play critical roles in cancers, including PDAC. However, less is known about the effect of gemcitabine on PDAC cells and miRNA expression in PDAC. We evaluated the effect of gemcitabine on the cell cycle of PDAC cells in vitro and in vivo and on the miRNA expression profile.

MATERIALS AND METHODS

Effects of gemcitabine on PK-1 and PK-9 cell growth were evaluated using a cell counting kit-8 assay. Xenografted mouse models were used to assess gemcitabine effects in vivo.

RESULTS

Gemcitabine inhibited the proliferation and tumour growth of PK-1 cells, and induced S phase cell cycle arrest. Numerous miRNAs were altered upon gemcitabine treatment of PK-1 cells and xenograft models.

CONCLUSION

Altered miRNAs may serve as potential therapeutic targets for improving the efficacy of gemcitabine in PDAC.

Construction of a potential microRNA, transcription factor and mRNA regulatory network in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and the third leading cause of cancer-related death. MicroRNAs and transcription factors (TFs) cooperate to regulate the same target gene, thus affecting the progression of HCC.

Methods

Differentially expressed miRNAs and mRNAs were screened. Functional enrichment analysis of these HCC-related mRNAs was performed, and a protein-protein interaction network was constructed. TFs that regulate these miRNAs and hub genes were also screened.

Results

Ten differentially upregulated miRNAs and 5 differentially downregulated miRNAs were screened. Additionally, 183 downregulated mRNAs and 303 upregulated mRNAs that are potentially bound to these differentially expressed miRNAs were identified. The Kyoto Encyclopedia of Genes and Genomes (KEGG) results showed that the differentially expressed mRNAs were significantly enriched in pathways in cancer, the Wnt signaling pathway, and the Rap1 signaling pathway. Then, 220 TFs were identified for 5 candidate genes of the downregulated mRNAs, and 258 TFs were identified for 9 candidate genes of the upregulated mRNAs. Finally, the 9 upregulated hub genes were related to higher overall survival (OS) in the low-expression group, and 4/5 downregulated hub genes were related to higher OS in the high-expression group.

Conclusions

This study constructed a potential regulatory network between candidate molecules and that need to be further verified. These regulatory relationships are expected to clarify the new molecular mechanisms of the occurrence and development of HCC.

Comprehensive analysis of circulating microRNAs as predictive biomarkers for sorafenib therapy outcome in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Clinical management has improved the prognosis of early HCC, but that of advanced HCC remains poor. Sorafenib, an oral multikinase inhibitor, provided a treatment option for advanced-stage HCC, and prolonged the survival and inhibited tumor progression as first-line therapy in patients with advanced HCC. In this study, we investigated if specific microRNAs could act as predictive biomarkers of sorafenib effectiveness and indicate the best time to switch to second-line therapies. Sorafenib inhibited the proliferation of the Li-7, Hep3B, HepG2 and Huh7 liver cancer cell lines (effective group), but not that of the HLE, HLF and ALEX cancer cell lines (non-effective group). A microRNA (miRNA/miR) analysis was performed comparing sorafenib-effective and non-effective cells lines as well as serum samples from patients with HCC from sorafenib-effective (complete response/partial response) and -non-effective (progressive disease) groups before sorafenib administration and detected three differentially-expressed miRNAs that were common among the in vivo and in vitro samples. The increase rate (effective/non-effective) of hsa-miR-30d in the medium was higher than that in the cancer cells. hsa-miR-30d was highly expressed in the serum and exosomes of patients with HCC in the effective group when compared to those of the non-effective group. Additionally, the hsa-miR-30d expression in the medium of cancer cell lines was highly upregulated in the effective group compared with the non-effective group. These results suggested that hsa-miR-30d might be secreted by the cancer cells to the serum through the exosomes. We identified a specific circulating miRNA that is related to refractory HCC under sorafenib therapy. Therefore, hsa-miR-30d might serve as a predictive biomarker for the efficacy of sorafenib therapy in HCC.

Propofol suppresses hypoxia-induced esophageal cancer cell migration, invasion, and EMT through regulating lncRNA TMPO-AS1/miR-498 axis

Background

Propofol has been reported to be related to the migration, invasion, and epithelial‐mesenchymal transition (EMT) of esophageal cancer (EC) cells. However, the detailed mechanism has not yet been fully reported. The purpose of this research was to elucidate the function of long non‐coding RNA TMPO antisense RNA 1 (lncRNA TMPO‐AS1) and microRNA‐498 (miR‐498) in propofol‐regulated EC.

Methods

Transwell assay was performed to assess cell migratory and invasive abilities. Western blot assay was employed to determine the levels of EMT markers and hypoxia inducible factor‐1 (HIF‐1α). Quantitative real‐time polymerase chain reaction (qRT‐PCR) was carried out to detect the levels of TMPO‐AS1 and miR‐498. Moreover, the interaction between TMPO‐AS1 and miR‐498 was predicted by starBase, and then confirmed by the dual‐luciferase reporter assay and RNA immunoprecipitation (RIP) assay.

Results

Propofol suppressed hypoxia‐induced EC cell migration, invasion, and EMT. Both TMPO‐AS1 overexpression and miR‐498 knockdown weakened the effect of propofol on hypoxia‐induced EC cell progression. Interestingly, TMPO‐AS1 targeted miR‐498 and suppressed miR‐498 expression. TMPO‐AS1 regulated EC cell progression via downregulating miR‐498 expression.

Conclusions

Collectively, our findings demonstrated that propofol inhibited hypoxia‐induced EC cell mobility through modulation of the TMPO‐AS1/miR‐498 axis, providing a theoretical basis for the treatment of EC.

Aspirin inhibits hepatocellular carcinoma cell proliferation in vitro and in vivo via inducing cell cycle arrest and apoptosis

Aspirin, a nonsteroidal anti‑inflammatory drug (NSAID), is known to inhibit cell proliferation in a variety of cancers. However, the underlying mechanism of this inhibition remains unknown. We investigated the effects of aspirin on hepatocellular carcinoma (HCC) cells using in vitro and in vivo models. Six HCC cell lines and a liver cancer cell line including Huh‑7 were used in assays that evaluated cell proliferation, cell cycle, and apoptosis. Flow cytometry, enzyme‑linked immunosorbent assay (ELISA), western blot analysis, and phosphorylated receptor tyrosine kinase array were used to evaluate the effects of aspirin on the cells, and microRNAs (miRNAs) were analyzed by a miRNA array chip. The results were validated in vivo using a nude mouse model of Huh‑7‑xenografted tumors. Our results showed that aspirin exhibited an antiproliferative effect on all cell lines. Moreover, aspirin induced G0/G1 cell cycle arrest and modulated the levels of cell cycle‑related molecules such as cyclin E, cyclin D1, and cyclin‑dependent kinase 2 (Cdk2). In addition, aspirin upregulated the levels of caspase‑cleaved cytokeratin 18, increased the proportion of early apoptotic cells, decreased the levels of clusterin and heat shock protein 70 (HSP 70), upregulated the levels of miRNA‑137 and inhibited epidermal growth factor receptor (EGFR) activation. In addition, we observed that aspirin suppressed cell proliferation partially through the miRNA‑137/EGFR pathway. Our in vivo results showed that aspirin reduced the growth of xenograft tumors in nude mice. In conclusion, aspirin was able to inhibit the growth of HCC cells by cell cycle arrest, apoptosis, and alteration of miRNA levels in in vitro and in vivo models.

Role of microRNA-210-3p in hepatitis B virus-related hepatocellular carcinoma

Hepatitis B virus (HBV)-related hepatocarcinogenesis is not necessarily associated with the liver fibrotic stage and is occasionally seen at early fibrotic stages. MicroRNAs (miRNAs) are essentially 18- to 22-nucleotide-long endogenous noncoding RNAs. Aberrant miRNA expression is a common feature of various human cancers. The aberrant expression of specific miRNAs has been shown in hepatocellular carcinoma (HCC) tissue compared with nontumor tissue. Thus, we examined targetable miRNAs as a potential new biomarker related to the high risk of HBV-related hepatocarcinogenesis, toward the prevention of cancer-related deaths. HCC tissue samples from 29 patients who underwent hepatectomy at our hospital in 2002-2013 were obtained. We extracted the total RNA and analyzed it by microRNA array, real-time RT-PCR, and three comparisons: 1) HBV-related HCC and adjacent nontumor tissue, 2) HCV-related HCC and adjacent nontumor tissue, and 3) non-HBV-, non-HCV-related HCC and adjacent nontumor tissue. We also performed a functional analysis of miRNAs specific for HBV-related HCC by using HBV-positive HCC cell lines. MiR-210-3p expression was significantly increased only in the HBV-related HCC tissue samples. MiR-210-3p expression was upregulated, and the levels of its target genes were reduced in the HBV-positive HCC cells. The inhibition of miR-210-3p enhanced its target gene expression in the HBV-positive HCC cells. In addition, miR-210-3p regulated the HBx expression in HBV-infected Huh7/NTCP cells. The enhanced expression of miR-210-3p was detected specifically in HBV-related HCC and regulated various target genes, including HBx in the HBV-positive HCC cells. MiR-210-3p might, thus, be a new biomarker for the risk of HBV-related HCC.NEW & NOTEWORTHY Our present study demonstrated that miR-210-3p is the only microRNA with enhanced expression in HBV-related HCC, and the enhanced expression of miR-210-3p upregulates HBx expression. Therefore, miR-210-3p might be a pivotal biomarker of HBV-related hepatocarcinogenesis, and the inhibition of miR-210-3p could prevent inducing hepatocarcinogenesis related to HBV infection.

MiR-23a-3p promoted G1/S cell cycle transition by targeting protocadherin17 in hepatocellular carcinoma

MiR-23a-3p has been shown to promote liver cancer cell growth and metastasis and regulate that of chemosensitivity. Protocadherin17 (PCDH17) is a tumor suppressor gene and plays an essential part in cell cycle of hepatocellular carcinoma (HCC). This study aimed at evaluating the effects of miR-23a-3p and PCDH17 on HCC cell cycle and underlining the mechanism. The level of miR-23a-3p was up-regulated, while PCDH17 level was down-regulated in HCC tissues compared to adjacent tissues. For the in vitro studies, high expression of miR-23a-3p down-regulated PCDH17 level; increased cell viability; promoted G1/S cell cycle transition; up-regulated cyclin D1, cyclin E, CDK2, CDK4, p-p27, and p-RB levels; and down-regulated the expression of p27. Dual luciferase reporter assay suggested PCDH17 was a target gene of miR-23a-3p. MiR-23a-3p inhibitor and PCDH17 siRNA led to an increase in cell viability and the number of cells in the S phase and up-regulated cyclin D1 and cyclin E levels, compared with miR-23a-3p inhibitor and NC siRNA group. For the in vivo experiments, high expression of miR-23a-3p promoted tumor growth and reduced PCDH17 level in the cytoplasm. These results indicated that high expression of miR-23a-3p might promote G1/S cell cycle transition by targeting PCDH17 in HCC cells. The miR-23a-3p could be considered as a molecular target for HCC detection.

Role of miR-182-5p overexpression in trichloroethylene-induced abnormal cell cycle functions in human HepG2 cells

Trichloroethylene (TCE), a widely used industrial solvent, occurs frequently in the global environment. TCE was found to induce hepatocarcinogenesis in mice and one of the underlying mechanisms was reported to involve miR-182-5p overexpression. Subsequently, miR-182-5p overexpression was shown to contribute to chemical-induced enhanced cell proliferation in mouse liver cells by targeting the gene Cited2. The aim of this study was to compare our findings in mice with those in a human hepatoma cell line HepG2. Data demonstrated that TCE at 0.1mM exerted no marked effect on human hepatoma cell line HepG2 cell migration, cell cycle, apoptosis, and DNA damage, but significantly stimulated cell proliferation rate and increased mRNA expression levels of proliferating cell nuclear antigen (PCNA), a cell proliferation biomarker. In addition, TCE enhanced miR-182-5p expression levels but lowered Cited2 mRNA expression. In summary, data showed that similar to mouse liver cells, TCE exposure also upregulated cells miR-182-5p expression and inhibited Cited2 expression in human hepatoma cell line HepG2. Our results suggest that the TCE-mediated alterations in the observed cellular functions involve interaction with miR-182-5p. It is of interest that utilization of liver cancer tissues from the Cancer Genome Atlas (TCGA) database also demonstrated that upregulated miR-182-5p expression and reduced Cited2 mRNA expression was detected suggesting that TCE-induced hepatocarcinogenesis involved processes similar to those in humans.

MicroRNA-215 as a Diagnostic Marker in Egyptian Patients with Hepatocellular Carcinoma

Background: MicroRNAs are mentioned as a small non-coding RNAs groups and aberrant miRNA expression was found in hepatocellular carcinoma (HCC) patients. Aim: To evaluate role of plasma MicroRNA-215 as a diagnostic tool in HCC patients. Methods: A prospective study included 195 subjects: healthy controls (group I), cirrhotic patients (group II), and patients with HCC (group III). Clinical examination, radiological and laboratory investigations which included quantification of miR-215 by Real-time qPCR were done for all cases. Results: Spearman’s rank correlation revealed that in HCC group, there was a negative correlation between MiRNA-215 and serum AFP levels and focal size lesion (cm) (rs = -0.72, - 0.94 respectively, p<0.001). Receiver operating characteristics analysis for discrimination between cirrhosis and HCC groups regarding microRNA-215 displayed 78.3% sensitivity, 88.0% specificity at cutoff value of ≤ 1.90. Area under the curve (AUC) was 0.87 (p< 0.001). As regards AFP, it had a sensitivity of 81.7%, a specificity of 66.7 at cutoff value of ≥ 11.50 (ng/mL). Conclusions: Plasma level of miR-215 may be a promising biomarker in HCC diagnosis. Moreover, if miR-215 combined with AFP, it can be used as a diagnostic biomarker, for early detection of HCC.

Telmisartan Inhibits Cell Proliferation and Tumor Growth of Esophageal Squamous Cell Carcinoma by Inducing S-Phase Arrest In Vitro and In Vivo

Esophageal squamous cell carcinoma (ESCC) is the most common primary esophageal malignancy. Telmisartan, an angiotensin II type 1 (AT1) receptor blocker (ARB) and a widely used antihypertensive, has been shown to inhibit proliferation of various cancer types. This study evaluated the effects of telmisartan on human ESCC cell proliferation in vitro and in vivo and sought to identify the microRNAs (miRNAs) involved in these antitumor effects. We examined the effects of telmisartan on three human ESCC cell lines (KYSE150, KYSE180, and KYSE850). Telmisartan inhibited proliferation of these three cell lines by inducing S-phase arrest, which was accompanied by decreased expression of cyclin A2, cyclin-dependent kinase 2, and other cell cycle-related proteins. Additionally, telmisartan reduced levels of phosphorylated ErbB3 and thrombospondin-1 in KYSE180 cells. Furthermore, expression of miRNAs was remarkably altered by telmisartan in vitro. Telmisartan also inhibited tumor growth in vivo in a xenograft mouse model. In conclusion, telmisartan inhibited cell proliferation and tumor growth in ESCC cells by inducing cell-cycle arrest.

Galectin-9 Induces Mitochondria-Mediated Apoptosis of Esophageal Cancer In Vitro and In Vivo in a Xenograft Mouse Model

Galectin-9 (Gal-9) enhances tumor immunity mediated by T cells, macrophages, and dendritic cells. Its expression level in various cancers correlates with prognosis. Furthermore, Gal-9 directly induces apoptosis in various cancers; however, its mechanism of action and bioactivity has not been clarified. We evaluated Gal-9 antitumor effect against esophageal squamous cell carcinoma (ESCC) to analyze the dynamics of apoptosis-related molecules, elucidate its mechanism of action, and identify relevant changes in miRNA expressions. KYSE-150 and KYSE-180 cells were treated with Gal-9 and their proliferation was evaluated. Gal-9 inhibited cell proliferation in a concentration-dependent manner. The xenograft mouse model established with KYSE-150 cells was administered with Gal-9 and significant suppression in the tumor growth observed. Gal-9 treatment of KYSE-150 cells increased the number of Annexin V-positive cells, activation of caspase-3, and collapse of mitochondrial potential, indicating apoptosis induction. c-Jun NH₂-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38) phosphorylation were activated and could be involved in apoptosis. Therefore, Gal-9 induces mitochondria-mediated apoptosis of ESCC and inhibits cell proliferation in vitro and in vivo with JNK and p38 activation.

miR-99b-3p promotes hepatocellular carcinoma metastasis and proliferation by targeting protocadherin 19

Hepatocellular carcinoma (HCC) is one of the most common cancers in the world, with characteristics of high morbidity and mortality. Identifying clinically practical targets and uncovering the potential mechanism for HCC were urgent for us. Though aberrantly expressed miR-99b-3p has been reported in several cancers, the expression and roles of miR-99b-3p in HCC remain uncovered. In the present study, we demonstrated for the first time that miR-99b-3p was overexpressed in HCC by our findings and data from GEO datasets. Statistical analysis revealed that highly expressed miR-99b-3p was closely related to malignant clinicopathological characteristics and poorer prognosis of HCC patients. Furthermore, results from Wound healing assay, Transwell assays, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)assay and 5-ethynyl-2'-deoxyuridine (EdU) assay revealed that miR-99b-3p played a promoting role in migration, invasion and proliferation of HCC cells. Then, by bioinformatics tools, luciferase reporter gene assay, integrative database analysis, and Pearson correlation analysis and so on, protocadherin 19 (PCDH19) was identified as the target of miR-99b-3p in HCC cells. Furthermore, rescue experiments were conducted to confirm the mediator role of PCDH19 for miR-99b-3p. Collectively, we demonstrate that miR-99b-3p promotes HCC metastasis and proliferation by directly targeting PCDH19. MiR-99b-3p may become a potential therapy target for HCC.

Long noncoding RNA DLX6-AS1 promotes liver cancer by increasing the expression of WEE1 via targeting miR-424-5p

Long noncoding RNAs (lncRNAs) played an important role in tumorigenesis and development of hepatocellular carcinoma (HCC). In this study, we first demonstrated that lncRNA DLX6 antisense RNA 1 (DLX6‐AS1) was upregulated in cancer tissues and cells lines compared with normal adjacent and cell line. Knock‐down DLX6‐AS1 by transfection with small interfering RNA (siRNA) suppressed cell proliferation, migration, and invasion of HCC cells. Cell cycle analysis showed that cells transfected with siRNA were arrested in G0/G1 phase. Then, we performed dual‐luciferase reporter assay and RNA immunoprecipitation (RIP) assay to show that DLX6‐AS1 could bind with miR‐424‐5p. And cotransfection inhibitor of miR‐424‐5p with siRNA of DLX6‐AS1 could abolish the inhibitory effect of siRNA of DLX6‐AS1 on cell proliferation, migration, and invasion. Moreover, we further demonstrated that the oncogene WEE1 G2 checkpoint kinase (WEE1) was the target of miR‐424‐5p and expression levels of WEE1 were positive correlation with that of DLX6‐AS1. Taken together, these results suggested that upregulated DLX6‐AS1 promoted cell proliferation, migration, and invasion of HCC through increasing expression of WEE1 via targeting miR‐424‐5p.

Overexpression of miR-21 Is Associated With Recurrence in Patients With Hepatitis B Virus-Mediated Hepatocellular Carcinoma Undergoing Liver Transplantation

Liver transplantation (LT) is the best treatment option for hepatitis B virus (HBV)-mediated hepatocellular carcinoma (HCC). Nevertheless, recurrence is the most important issue after LT. The aims of the present study were to evaluate the relation of dysregulated expression of microRNAs (miRNAs) in recurrence formation in HBV-mediated HCC cases. A total of 42 HBV-mediated HCC patients were evaluated in this study. Among 21 miRNAs, the expression level of miR-106a and miR-21 were higher and miR-143 and miR145 were lower in patients with HCC compared with noncancerous liver tissues (P = .0388, P = .0214, P = .0321, and P = .002, respectively). Compared with nonrecurrent patients, the expression level of miR-21 was 3.54-fold higher and miR-145 was 2.42-fold lower in patients with recurrence during the 5-year follow-up (P = .004 and P = .032; respectively). In addition, according to multivariate Cox regression analysis, the overexpression of miR-21 was found to be a prognostic indicator in HBV-mediated HCC patients (P = .002). In conclusion, we show a significant association between high expression of miR-21 and recurrence in HBV-mediated HCC. Therefore, up-regulation of miR-21 could serve as a promising prognostic marker for HCC.

miR‑498 inhibits the growth and metastasis of liver cancer by targeting ZEB2

MicroRNAs (miRNAs) play critical roles in the growth, metastasis and therapeutic resistance of liver cancer. Accumulating evidence suggests that miR-498 is aberrantly expressed in several human malignancies. However, the role and underlying mechanism of miR-498 in liver cancer remain unclear. In the present study, we investigated the potential roles and clinical value of miR-498 in liver cancer. We found that the miR-498 expression level was significantly lower in liver cancer patient tissues than that in healthy control tissues. The expression of miR-498 was also decreased in liver cancer cell lines compared to that noted in a normal human normal liver cell line. miR-498 overexpression markedly inhibited liver cancer cell proliferation, migration and invasion. miR-498 overexpression induced cell cycle arrest and apoptosis while it suppressed epithelial-mesenchymal transition (EMT) in liver cancer cells. Bioinformatic analysis and luciferase reporter assay further identified zinc finger E-box binding homeobox 2 (ZEB2) as a novel target of miR-498. Furthermore, ZEB2 knockdown recapitulated the inhibitory effects of miR-498 overexpression in liver cancer cells. ZEB2 overexpression rescued the inhibition of liver cancer cell proliferation, migration, and invasion by miR-498, indicating that ZEB2 acts as a downstream effector of miR-498 in liver cancer cells. Thus, we demonstrated that miR-498 suppresses the growth and metastasis of liver cancer cells, partly at least, by directly targeting ZEB2, suggesting that miR-498 may serve as a potential biomarker for the diagnosis and therapy of liver cancer.

The long noncoding RNA NORAD enhances the TGF-β pathway to promote hepatocellular carcinoma progression by targeting miR-202-5p

Hepatocellular carcinoma (HCC) is one of the most fatal cancers with common features of invasion and metastasis. Recent evidence indicate that the long noncoding RNA NORAD is a potential oncogene and is significantly upregulated in several cancers. However, the general biological role and clinical value of NORAD in HCC remains unknown. Here, NORAD expression was measured in 29 paired tumor and paratumor tissues via quantitative real-time polymerase chain reaction (qPCR). The effects of NORAD on HCC cell malignant potential were investigated via NORAD overexpression and knockdown both in vitro and in vivo. The mechanism of competitive endogenous RNAs (ceRNAs) was acquired and identified by bioinformatics analyses and luciferase assays. Moreover, the impact of NORAD level on the transforming growth factor β (TGF-β) pathway was further determined by qPCR. We found that HCC tissues had a high level of NORAD compared with the paratumor tissues, and NORAD upregulation was associated with the shorter overall survival of patients with HCC. Furthermore, NORAD overexpression was demonstrated to promote HCC cell migration and invasion. Mechanically, NORAD might function as a ceRNA to regulate miR-202-5p, which served as a tumor-suppressing microRNA via the TGF-β pathway. We address that NORAD has a tumor-promoting effect in HCC and describes a novel mechanism whereby NORAD regulates the TGF-β pathway as a ceRNA of Homo sapiens (hsa)-miR-202-5p.

microRNAs: Key players in virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is known as one of the major health problems worldwide. Pathological analysis indicated that a variety of risk factors including genetical (i.e., alteration of tumor suppressors and oncogenes) and environmental factors (i.e., viruses) are involved in beginning and development of HCC. The understanding of these risk factors could guide scientists and clinicians to design effective therapeutic options in HCC treatment. Various viruses such as hepatitis B virus (HBV) and hepatitis C virus (HCV) via targeting several cellular and molecular pathways involved in HCC pathogenesis. Among various cellular and molecular targets, microRNAs (miRNAs) have appeared as key players in HCC progression. miRNAs are short noncoding RNAs which could play important roles as oncogenes or tumor suppressors in several malignancies such as HCC. Deregulation of many miRNAs (i.e., miR-222, miR-25, miR-92a, miR-1, let-7f, and miR-21) could be associated with different stages of HCC. Besides miRNAs, exosomes are other particles which are involved in HCC pathogenesis via targeting different cargos, such as DNAs, RNAs, miRNAs, and proteins. In this review, we summarize the current knowledge of the role of miRNAs and exosomes as important players in HCC pathogenesis. Moreover, we highlighted HCV- and HBV-related miRNAs which led to HCC progression.

Synergistic and independent action of endogenous microRNAs 122a and 199a for post-transcriptional liver detargeting of gene vectors

In hepatocellular carcinoma (HCC), which usually develops in a cirrhotic liver, treatments preserving normal liver function and viability are vitally important. Here, we utilise the differential expression of miRNAs 122a and 199a between normal hepatocytes and HCC to generate vectors harbouring their binding sites for hepatocyte detargeting. Using a reporter gene, we observed a synergistic detargeting of cells expressing both miRNAs as well as cells expressing either of the miRNAs; while expression was retained in HCC cells negative for both miRNA122a and miRNA199a. Mimics and inhibitors for individual miRNAs were used to confirm these results. Furthermore, suicide gene therapy with cytosine deaminase (CD)/5-fluorocytosine system resulted in limited killing of cells expressing either of the two miRNAs. Finally, we report feasibility of using adeno associated virus (AAV) based vectors for delivery of this dual regulated gene delivery system. These results present a novel dual targeted system whereby miRNA122a and miRNA199a act either synergistically or independently in regulating transgene expression with vectors harbouring binding sites of both miRNAs and have implications in detargeting vectors from multiple cell types in the liver.

Transcriptional Regulatory Networks in Hepatitis C Virus-induced Hepatocellular Carcinoma

Understanding the transcriptional regulatory elements that influence the progression of liver disease in the presence of hepatitis C virus (HCV) infection is critical for the development of diagnostic and therapeutic approaches. Systems biology provides a roadmap by which these elements may be integrated. In this study, a previously published dataset of 124 microarray samples was analyzed in order to determine differentially expressed genes across four tissue types/conditions (normal, cirrhosis, cirrhosis HCC, and HCC). Differentially expressed genes were assessed for their functional clustering and those genes were annotated with their potential transcription factors and miRNAs. Transcriptional regulatory networks were constructed for each pairwise comparison between the 4 tissue types/conditions. Based on our analysis, it is predicted that the disruption in the regulation of transcription factors such as AP-1, PPARγ, and NF-κB could contribute to the liver progression from cirrhosis to steatosis and eventually to HCC. Whereas the condition of the liver digresses, the downregulation of miRNAs' (such as miR-27, Let-7, and miR-106a) expression makes the transition of the liver through each pathological stage more apparent. This preliminary data can be used to guide future experimental work. An understanding of the transcriptional regulatory attributes acts as a road map to help design interference strategies in order to target the key regulators of progression of HCV induced HCC.

Serum miRNAs Predicting Sustained HBs Antigen Reduction 48 Weeks after Pegylated Interferon Therapy in HBe Antigen-Negative Patients

The therapeutic goal for hepatitis B virus (HBV) infection is HBs antigen (HBsAg) seroclearance, which is achieved through 48-week pegylated interferon (Peg-IFN) therapy. This study aimed to identify predictive biomarkers for sustained HBsAg reduction by analyzing serum microRNAs. Twenty-two consecutive chronic HBV infection patients negative for HBe antigen (HBeAg) with HBV-DNA levels <5 log copies/mL, alanine aminotransferase (ALT) <100 U/L, and compensated liver functions, were enrolled. The patients were subcutaneously injected with Peg-IFNα-2a weekly for 48 weeks (treatment period), followed by the 48-week observation period. HBsAg 1-log drop relative to baseline levels recorded at the end of the observation period was considered effective. Sera were obtained at weeks 0 and 24 during the treatment period analyzed for microRNAs. The microRNA (miRNA) antiviral activity was evaluated in vitro using Huh7/sodium taurocholate cotransporting polypeptide (NTCP) cells. As a result, six patients achieved the HBsAg 1-log drop after the observation periods. Comparison of serum microRNA levels demonstrated that high miR-6126 levels at week 24 predicted HBsAg 1-log drop. Furthermore, miR-6126 reduced HBsAg in culture medium supernatants and intracellular HBV-DNA quantities in Huh7/NTCP cells. In conclusion, high serum miR-6126 levels during Peg-IFN therapy predicted the HBsAg 1-log drop 48 weeks after the completion of therapy. In vitro assays revealed that miR-6126 was able to suppress HBsAg production and HBV replication.

MicroRNA-1277 Inhibits Proliferation and Migration of Hepatocellular Carcinoma HepG2 Cells by Targeting and Suppressing BMP4 Expression and Reflects the Significant Indicative Role in Hepatocellular Carcinoma Pathology and Diagnosis After Magnetic Resonance Imaging Assessment

Our study aimed to investigate the roles and possible regulatory mechanism of miR-1277 in the development of hepatocellular carcinoma (HCC). HCC patients were identified from patients who were diagnosed with focal liver lesions using magnetic resonance imaging (MRI). The expression levels of miR-1277 in the serum of HCC patients and HepG2 cells were measured. Then miR-1277 mimic, miR-1277 inhibitor, or scramble RNA was transfected into HepG2 cells. The effects of miR-1277 overexpression and suppression on HepG2 cell proliferation, migration, and invasion were then investigated. Additionally, the expression levels of epithelial–mesenchymal transition (EMT)-related markers, including E-cadherin, β-catenin, and vimentin, were detected. Target prediction and luciferase reporter assay were performed to explore the potential target of miR-1277. miR-1277 was significantly downregulated in the serum of HCC patients and HepG2 cells. Suppression of miR-1277 promoted HepG2 cell proliferation, migration, and invasion, whereas overexpression of miR-1277 had opposite effects. In addition, after miR-1277 was suppressed, the expressions of E-cadherin and β-catenin were significantly increased, while the expressions of vimentin were markedly decreased. Bone morphogenetic protein 4 (BMP4) was identified as the direct target of miR-1277. Knockdown of BMP4 reversed the effects of miR-1277 suppression on HepG2 cell migration and invasion, as well as the expressions of E-cadherin, β-catenin, and vimentin. Our results indicate that downregulation of miR-1277 may promote the migration and invasion of HepG2 cells by targeting BMP4 to induce EMT. Combination of MRI and miR-1277 level will facilitate the diagnosis and treatment of HCC.

MicroRNA-125b expression and intrahepatic metastasis are predictors for early recurrence after hepatocellular carcinoma resection

AIM

Early hepatocellular carcinoma (HCC) recurrence after curative resection is a known poor prognostic factor. We aimed to identify microRNAs associated with recurrence after curative HCC resection.

METHODS

To identify risk factors for early recurrence and metastasis, 694 patients who underwent primary curative HCC resection were analyzed. We evaluated microRNA expression in cancerous and non-cancerous tissues by microarray and quantitative PCR analyses using 16 HCC samples. We defined patients who had a recurrence within 1 year of resection as the early recurrence (ER) group, patients who had a recurrence within 1-5 years as the late recurrence (LR) group, and patients who did not recur during the 5-year observation period as the no recurrence (NR) group. We examined the relationship between microRNA expression and clinical features.

RESULTS

Multivariate analysis revealed that α-fetoprotein >31 ng/mL, tumor size >4 cm, and intrahepatic metastasis (IM) were significant factors. Afterwards, microarray analyses revealed that microRNA (miR)-125b-5p and miR-148a-3p were significantly downregulated in recurrent cases. The ratio of miR-125b-5p expression in cancerous versus non-cancerous tissue (miR-125b ratio), but not miR-148a-3p, was significantly lower in the ER group. Early recurrence was associated with reduced overall survival compared with the LR and NR group. The miR-125b ratio was significantly lower in the ER group than in the LR and NR groups. Multivariate analysis showed that a low miR-125b ratio and IM were independently associated with ER and disease-free survival.

CONCLUSIONS

Assessing tissue miR-125b-5p expression and IM is useful for stratifying patients at risk of early HCC recurrence after curative resection.

The angiotensin II type 1 receptor antagonist telmisartan inhibits cell proliferation and tumor growth of esophageal adenocarcinoma via the AMPKα/mTOR pathway in vitro and in vivo

Telmisartan, a widely used antihypertensive drug, is an angiotensin II type 1 (AT1) receptor blocker (ARB). This drug inhibits cancer cell proliferation, but the underlying mechanisms in various cancers, including esophageal cancer, remain unknown. The aim of the present study was to evaluate the effects of telmisartan on human esophageal cancer cell proliferation in vitro and in vivo. We assessed the effects of telmisartan on human esophageal adenocarcinoma (EAC) cells using the cell lines OE19, OE33, and SKGT-4. Telmisartan inhibited the proliferation of these three cell lines via blockade of the G₀ to G₁ cell cycle transition. This blockade was accompanied by a strong decrease in cyclin D1, cyclin E, and other cell cycle-related proteins. Notably, the AMP-activated protein kinase (AMPK) pathway, a fuel sensor signaling pathway, was enhanced by telmisartan. Compound C, which inhibits the two catalytic subunits of AMPK, enhanced the expression of cyclin E, leading to G₀/G₁ arrest in human EAC cells. In addition, telmisartan reduced the phosphorylation of epidermal growth factor receptor (p-EGFR) and ERBB2 in vitro. In our in vivo study, intraperitoneal injection of telmisartan led to a 73.2% reduction in tumor growth in mice bearing xenografts derived from OE19 cells. Furthermore, miRNA expression was significantly altered by telmisartan in vitro and in vivo. In conclusion, telmisartan suppressed human EAC cell proliferation and tumor growth by inducing cell cycle arrest via the AMPK/mTOR pathway.

Investigating the mechanism of hepatocellular carcinoma progression by constructing genetic and epigenetic networks using NGS data identification and big database mining method

The mechanisms leading to the development and progression of hepatocellular carcinoma (HCC) are complicated and regulated genetically and epigenetically. The recent advancement in high-throughput sequencing has facilitated investigations into the role of genetic and epigenetic regulations in hepatocarcinogenesis. Therefore, we used systems biology and big database mining to construct genetic and epigenetic networks (GENs) using the information about mRNA, miRNA, and methylation profiles of HCC patients. Our approach involves analyzing gene regulatory networks (GRNs), protein-protein networks (PPINs), and epigenetic networks at different stages of hepatocarcinogenesis. The core GENs, influencing each stage of HCC, were extracted via principal network projection (PNP). The pathways during different stages of HCC were compared. We observed that extracellular signals were further transduced to transcription factors (TFs), resulting in the aberrant regulation of their target genes, in turn inducing mechanisms that are responsible for HCC progression, including cell proliferation, anti-apoptosis, aberrant cell cycle, cell survival, and metastasis. We also selected potential multiple drugs specific to prominent epigenetic network markers of each stage of HCC: lestaurtinib, dinaciclib, and perifosine against the NTRK2, MYC, and AKT1 markers influencing HCC progression from stage I to stage II; celecoxib, axitinib, and vinblastine against the DDIT3, PDGFB, and JUN markers influencing HCC progression from stage II to stage III; and atiprimod, celastrol, and bortezomib against STAT3, IL1B, and NFKB1 markers influencing HCC progression from stage III to stage IV.

miR-200c targets nuclear factor IA to suppress HBV replication and gene expression via repressing HBV Enhancer I activity

BACKGROUND

Hepatitis B virus (HBV) chronic infection is a health problem in the worldwide, with a underlying higher risk of liver cirrhosis and hepaticocellular carcinoma. A number of studies indicate that microRNAs (miRNAs) play vital roles in HBV replication. This study was designed to explore the potential molecular mechanism of miR-200c in HBV replication.

METHODS

The expression of miR-200c, nuclear factor IA (NFIA) mRNA, HBV DNA, and HBV RNA (pregenomic RNA (pgRNA), and total RNA) were measured by qRCR. The levels of HBsAg and HBeAg were detected by ELISA. NFIA expression at protein level was measured by western blot. The direct interaction between miR-200c and NFIA were identified by Targetscan software and Dual-Luciferase reporter analysis. Enhance I activity were detected by Dual-Luciferase reporter assay.

RESULTS

miR-200c expression was prominently reduced in pHBV1.3-tranfected Huh7 and in stable HBV-producing cell line (HepG2.2.15). The enforced expression of miR-200c significantly suppressed HBV replication, as demonstrated by the reduced levels of HBV protein (HBsAg and HBeAg) and, DNA and RNA (pgRNA and total RNA) levels. NFIA was proved to be a target of miR-200c and NFIA overexpression notably stimulated HBV replication. In addition, the inhibitory effect of miR-200c on HBV Enhance I activity was abolished following restoration of NFIA.

CONCLUSIONS

miR-200c repressed HBV replication by directly targeting NFIA, which might provide a novel therapeutic target for HBV infection.

Circulating microRNA's as a diagnostic tool for hepatocellular carcinoma in a hyper endemic HIV setting, KwaZulu-Natal, South Africa: a case control study protocol focusing on viral etiology

Background

A wide range of studies has investigated the diagnostic proficiency of extracellular microRNAs (miRNAs) in hepatocellular cancer (HCC). HCC is expected to increase in Sub-Saharan Africa (SSA), due to endemic levels of viral infection (HBV/HIV), ageing and changing lifestyles. This unique aetiological background provides an opportunity for investigating potentially novel circulating miRNAs as biomarkers for HCC in a prospective study in South Africa.

Methods

This study will recruit HCC patients from two South African cancer hospitals, situated in Durban and Pietermaritzburg in the province of KwaZulu-Natal. These cases will include both HBV mono-infected and HBV/HIV co-infected HCC cases. The control group will consist of two (2) age and sex-matched healthy population controls per HCC case randomly selected from a Durban based laboratory. The controls will exclude patients if they have any evidence of chronic liver disease. A standardised reporting approach will be adopted to detect, quantify and normalize the level of circulating miRNAs in the blood sera of HCC cases and their controls. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) will be employed to quantity extracellular miRNAs. Differences in concentration of relevant miRNA by case/control status will be assessed using the Wilcoxon rank-sum (Mann-Whitney U) test. Adjustment for multiple testing (Bonferroni correction), receiver operating curves (ROC) and optimal breakpoint analyses will be employed to identify potential thresholds for the differentiation of miRNA levels of HCC cases and their controls.

Discussion

Although there is a growing base of literature regarding the role of circulating miRNAs as biomarkers, this promising field remains a ‘work in progress’. The aetiology of HBV infection in HCC is well understood, as well as it’s role in miRNA deregulation, however, the mediating role of HIV infection is unknown. HCC incidence in SSA, including South Africa, is expected to increase significantly in the next decade. A combination of factors, therefore, offers a unique opportunity to identify candidate circulating miRNAs as potential biomarkers for HBV/HIV infected HCC.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3915-z) contains supplementary material, which is available to authorized users.