Hepatocellular carcinoma in chronic hepatitis C: from bench to bedside

Hsa_circ_0007059 sponges miR-421 to repress cell growth and stemness in hepatocellular carcinoma by the PTEN-AKT/mTOR pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is a substantial health concern worldwide. Increasing studies have suggested that circle RNAs (circRNAs) function as new regulators in HCC progression. The present work explored the role of hsa_circ_0007059 (circ_0007059) in the developing process of hepatocarcinogenesis.

METHODS

The circ_0007059 level in HCC was determined by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) and northern blot. Its biological role in HCC cells was assessed using 3-(4,5-Dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT), colony formation, flow cytometry, Transwell, sphere formation and western blotting analyses. Bioinformatics analysis, luciferase reporter, and RNA immunoprecipitation (RIP) assays were used to test the regulatory mechanisms of circ_0007059.

RESULTS

Our results revealed that circ_0007059 expression was downregulated in HCC samples and cells. Moreover, circ_0007059 overexpression inhibited HCC cell proliferation, migration, invasion, and stem cell-like property, and strengthened cell apoptosis. In mechanism, circ_0007059 suppressed AKT/mTOR pathway by positively regulating phosphatase and tensin homolog (PTEN) expression. Additionally, circ_0007059 acted as a positive regulator of PTEN through controlling the availability of miR-421. Rescue assays demonstrated that PTEN knockdown or SC79 (AKT agonist) eliminated the effect of circ_0007059 on HCC cell phenotypes.

CONCLUSION

Circ_0007059 sponges miR-421 to inhibit oncogenic cellular process in HCC by mediating the PTEN-AKT/mTOR pathway.

The Effect of a Newly Synthesized Ferrocene Derivative against MCF-7 Breast Cancer Cells and Spheroid Stem Cells through ROS Production and Inhibition of JAK2/STAT3 Signaling Pathway

Background:

Breast Cancer Stem Cells (BCSCs) possess the ability of self-renewal and cellular heterogeneity, and therefore, play a key role in the initiation, propagation and clinical outcome of breast cancer. It has been shown that ferrocene complexes have remarkable potential as anticancer drugs.

Objective:

The present study was conducted to investigate the effects of a novel ferrocene complex, 1- ferrocenyl-3-(4-methylsulfonylphenyl)propen-1-one (FMSP) on MCF-7 breast cancer cell line and its derived mammospheres with cancer stem cell properties.

Methods:

Mammospheres were developed from MCF-7 cells and validated by the evaluation of CD44 and CD24 cell surface markers by flow cytometry as well as of the expression of genes that are associated with stem cell properties by real-time PCR. Cells viability was assessed by a soluble tetrazolium salt (MTS) after the treatment of cells with various concentrations of FMSP. Apoptosis was evaluated by flow cytometry analysis of annexin V and PI labeling of cells. Reactive Oxygen Species (ROS) production was measured using a cellpermeable, oxidant-sensitive fluorescence probe (carboxy-H2DCFDA). The involvement of the JAK2/STAT3 pathway was also investigated by western blotting.

Results:

FMSP could successfully prevent mammosphere formation from differentiated MCF-7 cells and significantly down-regulated the expression of genes involved in the production of the stem cell properties including Wnt1, Notch1, β -catenin, SOX2, CXCR4 and ALDH1A1. FMSP decreased cell viability in both MCF-7 cells and spheroid cells, although MCF-10A cells were unaffected by this compound. Apoptosis was also dramatically induced by FMSP, via ROS production but independent of CD95 activation. Phosphorylation levels of JAK2 and STAT3 were also found to be significantly attenuated even in the presence of IL-6, the putative activator of the JAK/STAT pathway.

Conclusion:

FMSP can effectively target BCSCs via ROS production and modulation of major signaling pathways that contribute to the stemness of breast cancer cells, and therefore, might be considered a promising anticancer agent after in vivo studies.

Co-targeting p53-R249S and CDK4 synergistically suppresses survival of hepatocellular carcinoma cells

p53-R249S (p53-RS) is frequently detected in human hepatocellular carcinoma (HCC) that is highly associated with hepatitis B infection and aflatoxin B1 exposure. Our previous study showed that CDK4/Cyclin D1 phosphorylates p53-RS at the cancer-derived Ser249 and promotes its interaction with c-Myc in the nucleus, consequently enhancing c-Myc-dependent ribosomal biogenesis and HCC cell proliferation. Here we explored the possibility of co-targeting CDK4 and p53-RS with available small molecule inhibitors as a potential combined therapy for HCC that harbor p53-RS. Indeed, co-treatment of p53-RS-containing, but not wild-type p53 or p53-null, HCC cells with PD-0332991 (PD), a CDK4/6 inhibitor, and CP-31398 (CP), a compound that can restore the intrinsic conformation and transcriptional activity of mutant p53, drastically repressed the c-Myc activation function of p53-RS. This combination of PD with CP exhibited a synergistic effect on the inhibition of HCC cell growth in a p53-RS dependent manner, especially at a lower dose. These results suggest that co-targeting CDK4 and p53-RS can serve as a potential approach for the development of an effective therapy for HCC that harbor p53-RS.

A 2-year retrospective study of viral and host-associated risk factors in Pakistani hepatocellular carcinoma patients

OBJECTIVE

Persistent chronic hepatitis C (CHC) infection is associated strongly with serious complications such as hepatitis C virus-associated liver cirrhosis (HCV-LC) and hepatitis C virus-associated hepatocellular carcinoma (HCV-HCC). The aim of this study was to assess the distribution of hepatitis C virus (HCV) genotypes among HCV-positive patients and examine the potential associations between viral and host-associated factors with the risk of developing HCV-HCC.

PATIENTS AND METHODS

HCV-positive patients (n = 300) were enrolled and divided into three groups: CHC (n = 171), HCV-LC (n = 51), and HCV-HCC (n = 78).

RESULTS

HCV genotype 3a showed the highest prevalence among HCV-positive individuals (66% of patients), followed by genotype 1a (15% of patients). The proportion of individuals infected with mixed HCV genotypes was higher among HCV-HCC patients. Interestingly, there were a significantly higher proportion of women (54/78; 69.2%) among HCV-HCC patients compared with CHC patients (89/171 or 52%; χ = 6.47; P=1 × 10). Women with HCV had two-fold higher odds of developing HCV-HCC (odds ratio = 2.07, 95% confidence interval: 1.18-3.71). In comparison with CHC patients, significantly more HCV-HCC patients were 50 years of age or older (59/78 or 75.6% of HCV-HCC patients and 61/171 or 35.7% of CHC patients; χ = 34.27; P < 0.0001), suggesting that HCV-positive patients aged 50 years or older had an ~five-fold higher risk of developing HCV-HCC (odds ratio = 5.6, 95% confidence interval: 3.02-10.01).

CONCLUSION

In summary, HCV genotype 3a had the highest prevalence in the studied HCV-positive population, and women and older patients were at a higher risk of developing HCV-LC and HCV-HCC following CHC infections.

Virus-associated human cancers in Moroccan population: From epidemiology to prospective research

Eight human viruses have been classified by the International Agency for Research on Cancer as carcinogenic or probably carcinogenic for humans. Infection with high risk human papillomaviruses, hepatitis B and C viruses, Epstein-Barr virus (EBV), human T-Cell Lymphotropic Virus Type 1 (HTLV-1), Human herpesvirus 8 (HHV-8), Merkel cell polyomavirus and human immunodeficiency virus-1 (HIV1) alone or in combination with other agents are the main etiologic factors of many cancers. This review highlights some aspects of virus-associated human cancers, potentially responsible for >14,000 malignancies per year in Morocco. Given that not all individuals infected with these viruses develop cancer, somatic alterations, genetic predisposition, and lifestyle or environmental factors obviously play potentializing roles modulating viral activity. These viral, host genetic signatures and lifestyle interactions may represent a reservoir of biomarkers for early detection, prevention of cancer and rationale-based therapy.

Profile of HBV Integration in the Plasma DNA of Hepatocellular Carcinoma Patients

Background:

Hepatitis B Viral (HBV) infection is one of the major causes of Hepatocellular Carcinoma (HCC). Mounting evidence had provided that the HBV integration might be a critical con-tributor of HCC carcinogenesis.

Objective and Methods:

To explore the profile of HBV integration in the plasma DNA, the method of next-generation sequencing, HBV capture and bioinformatics had been employed to screen for HBV in-tegration sites in the plasma samples.

Results:

In the initial experiment, a total of 87 breakpoints were detected in the 20 plasma samples. The distribution of breakpoints showed that there was significant enrichment of breakpoints in the region of intron. Furthermore, the HBV breakpoints were prone to occur in the region of X protein (1,700-2,000bp) in the plasma samples. The pathway analysis had revealed that the HBV integrations sites were specifically enriched in the cancer pathway.

Conclusion:

Altogether, our results had provided direct evidence for the HBV integration in plasma DNA, and they might be potentially useful for future HCC prognosis and diagnosis.

Epidemiology of Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) Related Hepatocellular Carcinoma

Introduction

Hepatocellular carcinoma (HCC) is one of the most prevalent primary malignant tumors and accounts for about 90% of all primary liver cancers. Its distribution varies greatly according to geographic location and it is more common in middle and low- income countries than in developed ones especially in Eastern Asia and Sub Saharan Africa (70% of all new HCCs worldwide), with incidence rates of over 20 per 100,000 individuals.

Explanation

The most important risk factors for HCC are Hepatitis B Virus (HBV) infection, Hepatitis C Virus (HCV) infection, excessive consumption of alcohol and exposition to aflatoxin B1. Its geographic variability and heterogeneity have been widely associated with the different distribution of HBV and HCV infections worldwide.Chronic HBV infection is one of the leading risk factors for HCC globally accounting for at least 50% cases of primary liver tumors worldwide. Generally, while HBV is the main causative agent in the high incidence HCC areas, HCV is the major etiological factor in low incidence HCC areas, like Western Europe and North America.

Conclusion

HBV-induced HCC is a complex, stepwise process that includes integration of HBV DNA into host DNA at multiple or single sites. On the contrary, the cancerogenesis mechanism of HCV is not completely known and it still remains controversial as to whether HCV itself plays a direct role in the development of tumorigenic progression.

Ultrasound Elastography Used for Preventive Non-Invasive Screening in Early Detection of Liver Fibrosis

Background

Early discovery of liver fibrosis is becoming more popular because of enhanced incidence of hepatocellular carcinoma. Ultrasound-based liver elastography is a method used to approve suspected liver fibrosis or cirrhosis. We assessed the clinical usefulness of acoustic radiation force impulse shear wave elasticity imaging (ARFI-SWEI) as a preventive screening method to uncover fibrosis.

Methods

We screened 382 patients by native routine sonography for abnormal liver results and divided them into six groups: group 1: normal liver, groups 2-4: fatty liver grade I-III, group 5: liver cirrhosis, and group 6: inhomogenic liver tissue. Then ARFI-SWEI was performed and the results were compared with published shear wave velocity cut-off values that were predictive of each fibrosis stage (F0-4). A control group consisted of 20 healthy volunteers.

Results

The part of liver fibrosis ≥ F2 was in groups 1-4: 20-32%, group 5: 100%, and group 6: 91%. Main causes for fibrosis stage ≥ F2 were (non)-alcoholic steatohepatitis, chronic viral or autoimmune hepatitis and chronic heart failure.

Conclusions

Screening of the liver tissue in b-mode ultrasound can underestimate possible liver fibrosis; by using ARFI-SWEI, liver fibrosis can be uncovered early. It is a suitable preventive method comparable to colonoscopy for colon cancer.

Impact of physiological, pathological and environmental factors on the expression and activity of human cytochrome P450 2D6 and implications in precision medicine

With only 1.3-4.3% in total hepatic CYP content, human CYP2D6 can metabolize more than 160 drugs. It is a highly polymorphic enzyme and subject to marked inhibition by a number of drugs, causing a large interindividual variability in drug clearance and drug response and drug-drug interactions. The expression and activity of CYP2D6 are regulated by a number of physiological, pathological and environmental factors at transcriptional, post-transcriptional, translational and epigenetic levels. DNA hypermethylation and histone modifications can repress the expression of CYP2D6. Hepatocyte nuclear factor-4α binds to a directly repeated element in the promoter of CYP2D6 and thus regulates the expression of CYP2D6. Small heterodimer partner represses hepatocyte nuclear factor-4α-mediated transactivation of CYP2D6. GW4064, a farnesoid X receptor agonist, decreases hepatic CYP2D6 expression and activity while increasing small heterodimer partner expression and its recruitment to the CYP2D6 promoter. The genotypes are key determinants of interindividual variability in CYP2D6 expression and activity. Recent genome-wide association studies have identified a large number of genes that can regulate CYP2D6. Pregnancy induces CYP2D6 via unknown mechanisms. Renal or liver diseases, smoking and alcohol use have minor to moderate effects only on CYP2D6 activity. Unlike CYP1 and 3 and other CYP2 members, CYP2D6 is resistant to typical inducers such as rifampin, phenobarbital and dexamethasone. Post-translational modifications such as phosphorylation of CYP2D6 Ser135 have been observed, but the functional impact is unknown. Further functional and validation studies are needed to clarify the role of nuclear receptors, epigenetic factors and other factors in the regulation of CYP2D6.

Hepatitis C virus markers in infection by hepatitis C virus: In the era of directly acting antivirals

About 130-170 million people are infected with the hepatitis C virus (HCV) worldwide and more than 350000 people die each year of HCV-related liver diseases. The combination of pegylated interferon (Peg-IFN) and ribavirin (RBV) was recommended as the treatment of choice for chronic hepatitis C for nearly a decade. In 2011 the directly acting antivirals (DAA) HCV NS3/4A protease inhibitors, telaprevir and boceprevir, were approved to treat HCV-genotype-1 infection, each in triple combination with Peg-IFN and RBV. These treatments allowed higher rates of SVR than the double Peg-IFN + RBV, but the low tolerability and high pill burden of these triple regimes were responsible for reduced adherence and early treatment discontinuation. The second and third wave DAAs introduced in 2013-2014 enhanced the efficacy and tolerability of anti-HCV treatment. Consequently, the traditional indicators for disease management and predictors of treatment response should be revised in light of these new therapeutic options. This review article will focus on the use of the markers of HCV infection and replication, of laboratory and instrumental data to define the stage of the disease and of predictors, if any, of response to therapy in the DAA era. The article is addressed particularly to physicians who have patients with hepatitis C in care in their everyday clinical practice.

Mitochondrial DNA Copy Number in Egyptian Patients with Hepatitis C Virus-Related Hepatocellular Carcinoma

AIM

To assess the use of mitochondrial DNA (mtDNA) content as a noninvasive molecular biomarker in hepatitis C virus-related hepatocellular carcinoma (HCV-HCC).

MATERIALS AND METHODS

A total of 135 participants were enrolled in the study. Equal numbers of subjects were enrolled in each of three clinically defined groups: those with HCV-related cirrhosis (HCV-cirrhosis), those with HCV-HCC, and a control group of age- and sex-matched healthy volunteers with no evidence of liver disease. mtDNA concentrations were determined using a quantitative real-time polymerase chain reaction (PCR) technique.

RESULTS

mtDNA content was lowest among the HCV-HCC cases. No statistically significant difference was observed between the group of HCV-cirrhosis and the control group as regards mtDNA level. HCC patients with multicentric hepatic lesions had significantly lower mtDNA content than HCC patients with less advanced disease. When a receiver operating characteristic curve analysis was used, a cutoff of 34 was assigned for mtDNA content to distinguish between HCV-HCC and HCV-cirrhosis patients who are not yet complicated by malignancy. Lower mtDNA content was associated with HCC risk when using either or both healthy controls and HCV-cirrhosis groups for reference.

CONCLUSIONS

mtDNA content analysis could serve as a noninvasive molecular biomarker that reflects tumor burden in HCV-HCC cases and could be used as a predictor of HCC risk in patients of HCV-cirrhosis. In addition, the nonsignificant difference of mtDNA level between HCV-cirrhosis patients and healthy controls could eliminate the gray zone created by the use of alpha-fetoprotein in some cirrhotic patients.

Role of genetic polymorphisms in hepatitis C virus chronic infection

AIM: To analyze the host genetics factors influencing the clinical course and the response to antiviral treatment in patients with chronic hepatitis C (CHC).

METHODS: We conducted an electronic search on the PubMed and MEDLINE (2000-2014) databases and Cochrane library (2000-2014). A total of 73 articles were retrieved and their data were extensively evaluated and discussed by the authors and then analyzed in this review article.

RESULTS: Several studies associated polymorphisms in the interleukin 28B gene on chromosome 19 (19q13.13) with a spontaneous viral clearance in acute hepatitis C and with the response to pegylated interferon (Peg-IFN)-based treatment in chronic hepatitis C patients. Other investigations demonstrated that inosine triphosphate pyrophosphatase genetic variants protect hepatitis C virus-genotype-1 CHC patients from ribavirin-induced anemia, and other studies that a polymorphism in the patatin-like phospholipase domain-containing protein 3 was associated with hepatic steatosis in CHC patients. Although not conclusive, some investigations suggested that the vitamin D-associated polymorphisms play an important role in the achievement of sustained virologic response in CHC patients treated with Peg-IFN-based antiviral therapy. Several other polymorphisms have been investigated to ascertain their possible impact on the natural history and on the response to treatment in patients with CHC, but the data are preliminary and warrant confirmation.

CONCLUSION: Several genetic polymorphisms seem to influence the clinical course and the response to antiviral treatment in patients with CHC, suggesting individualized follow up and treatment strategies.

HCV NS5A Up-Regulates COX-2 Expression via IL-8-Mediated Activation of the ERK/JNK MAPK Pathway

Chronic hepatitis C virus (HCV) infection leads to intrahepatic inflammation and liver cell injury, which are considered a risk factor for virus-associated hepatitis, cirrhosis, and hepatocellular carcinoma worldwide. Inflammatory cytokines are critical components of the immune system and influence cellular signaling, and genetic imbalances. In this study, we found that cyclooxygenase-2 (COX-2) and interleukin-8 (IL-8) were significantly induced by HCV infection and HCV NS5A expression, and induction of COX-2 correlated with HCV-induced IL-8 production. We also found that the ERK and JNK signaling pathways were involved in the regulation of IL-8-mediated COX-2 induction in response to HCV infection. Using a promoter-linked reporter assay, we identified that the C/EBP regulatory element within the COX-2 promoter was the dominant factor responsible for the induction of COX-2 by HCV. Silencing C/EBP attenuated HCV-induced COX-2 expression. Our results revealed that HCV-induced inflammation promotes viral replication, providing new insights into the involvement of IL-8-mediated COX-2 induction in HCV replication.

Hepatitis C virus prevalence and genotyping among hepatocellular carcinoma patients in Baghdad

Hepatocellular carcinoma (HCC) is the third most common cause for cancer death in the world, now being especially linked to chronic hepatitis C virus (HCV) infection. This case-control study consisting of 65 HCC patients and 82 patients with other malignant tumours as controls was conducted to determine the association of HCV markers with HCC. Serum of each participant was obtained for detection of HCV Ab and RNA by DNA enzyme immunoassay (DEIA). Twenty six per cent (26.0%) of HCC patients had positive anti-HCV which was significantly greater than the control group (p=0.001). HCC patients significantly have a risk of exposure to HCV infection almost 3 times than the control group (OR=2.87, 95% C.I=1.1-7). Anti-HCV seropositive rate was significantly (p=0.03) higher among old age HCC patients and increases with age. Males with HCC significantly showed to have more than 9 times risk of exposure to HCV infection (OR=9.375, 95 % CI=1.299-67.647) than females. HCV-RNA seropositive rate was (70.8%) significantly higher among HCC patients compared to (22.2%) the control group (p=0.019). The most prevalent genotype (as a single or mixed pattern of infection) was HCV- 1b. This study detected a significantly higher HCV seropositive rate of antibodies and RNA in HCC patients.

Infección por el virus de la hepatitis C en individuos transfundidos antes de 1994 en Antioquia, Colombia

Introducción: la infección por el virus de la hepatitis C es un problema de salud pública. Según datos de la Organización Mundial de la Salud, se estiman 184 millones de casos de infección por VHC en el mundo. El principal factor de riesgo en países en desarrollo corresponde a la transfusión de componentes sanguíneos. En Colombia, en 1993, se reglamentó el tamizaje serológico en los bancos de sangre para diferentes agentes infecciosos, incluido el VHC; sin embargo, los datos de infección por VHC en la población transfundida antes de esta fecha es limitada. Objetivo: describir la frecuencia de infección por el VHC en una población de individuos transfundidos antes de 1994 en Antioquia. Materiales y Métodos: un total de 166 individuos transfundidos antes de 1994 aceptaron participar en el estudio. A partir de las muestras de suero se realizó la detección de anticuerpos totales contra el VHC (anti-VHC) mediante prueba de ELISA y en las muestras positivas se determinó la presencia del genoma viral por RT-PCR de la región no codificante 5’. Resultados y conclusiones: en el población de estudio se encontró una frecuencia de anticuerpos anti-VHC de 6,6% (11/166) y presencia del genoma del VHC en 7/11 de las muestras; el genotipo 1 se identificó en 4 de las muestras. No se encontró asociación de otros factores de riesgo diferentes a transfusión en los individuos con marcadores de infección por el VHC. Este estudio aporta datos a la epidemiología de la infección por el VHC en Colombia.

Monoterpene (-)-citronellal affects hepatocarcinoma cell signaling via an olfactory receptor

Terpenes are the major constituents of essential oils in plants. In recent years, terpenes have become of clinical relevance due to their ability to suppress cancer development. Their effect on cellular proliferation has made them promising agents in the prevention or treatment of many types of cancer. In the present study, a subset of different monoterpenes was investigated for their molecular effects on the hepatocellular carcinoma cell line Huh7. Using fluorometric calcium imaging, acyclic monoterpene (-)-citronellal was found to induce transient Ca(2+) signals in Huh7 cells by activating a cAMP-dependent signaling pathway. Moreover, we detected the (-)-citronellal-activated human olfactory receptor OR1A2 at the mRNA and protein levels and demonstrated its potential involvement in (-)-citronellal-induced calcium signaling in Huh7 cells. Furthermore, activation of OR1A2 results in phosphorylation of p38 MAPK and reduced cell proliferation, indicating an effect on hepatocellular carcinoma progression. Here, we provide for the first time data on the molecular mechanism evoked by (-)-citronellal in human hepatocellular carcinoma cells. The identified olfactory receptor could serve as a potential therapeutic target for cancer diagnosis and treatment.

The role of cirrhosis in the etiology of hepatocellular carcinoma

Abundant evidence supports the belief of a causal relationship between cirrhosis and hepatocellular carcinoma, but one that differs between high- and low-incidence regions of the tumor. In high-incidence regions, the cirrhosis is of the macronodular variety, is typically asymptomatic, and is caused predominantly by chronic hepatitis B virus infection, whereas in low-incidence regions, the cirrhosis, although usually macronodular, may be micronodular, is commonly symptomatic and of long-standing, and is caused by chronic hepatitis C virus infection, alcohol abuse over many years, the metabolic syndrome, or hereditary hemochromatosis. In a minority of patients, hepatocellular carcinoma develops in the absence of cirrhosis, supporting a direct hepatocarcinogenic effect of some of the causal agents. Cirrhosis is the major risk factor for tumor formation in patients with chronic hepatitis C virus infection. This virus does not integrate into cellular DNA, and malignant transformation results from increased liver cell turnover induced by recurring injury and regeneration of cells in the context of persisting inflammation, oxidative DNA damage, fibrosis, cirrhosis, and changes induced by the virus at a DNA level that have yet to be fully defined. Hepatitis B virus causes malignant transformation by both direct and indirect routes. The direct route results, in part, from integration of the viral DNA into host cellular DNA; transcriptional activation of host growth regulatory genes by hepatitis B virus-encoded proteins; and effects on apoptosis, cell signaling, and DNA repair. The direct route may share some similarities with that of hepatitis C virus infection. The metabolic syndrome may cause malignant transformation by production of oxidative stress and the induction of a variety of mutations, including some in the p53 gene.

Targeting gap junction intercellular communication as a potential therapy for HCV-related carcinogenesis

ABSTRACT: 

Worldwide, at least 170 million people are infected with hepatitis C virus (HCV), which is associated with hepatocellular carcinoma (HCC). With the recent success of Sofosbuvir (and other agents) antiviral therapy may be used as a future early-stage HCC treatment; however, in the short term, a cost-effective solution is needed to treat patients with viral-associated HCC. Here, we emphasize the potential of targeting gap junction intercellular communication (GJIC) as a therapeutic approach for HCC as HCV perturbs GJIC, which is linked to cellular transformation. We review the ROCK inhibitor Y-27632 and structurally related compounds that may inhibit the carcinogenic properties of HCV.

Quantitative assessment of the effect of glutathione S-transferase genes GSTM1 and GSTT1 on hepatocellular carcinoma risk

Hepatocellular carcinoma (HCC) is one of the most serious health problems worldwide. As in many other diseases, environment and genetic factors are believed to be involved in the pathogenesis of HCC. Numerous epidemiologic investigations including case-control and cohort studies have suggested the association of glutathione S-transferase (GST) genetic polymorphisms and HCC risk. However, some studies have produced conflicting results. Therefore, we performed an updated meta-analysis to clarify this inconsistency and to establish a comprehensive picture of the association of the polymorphisms of GSTM1 and GSTT1 with HCC susceptibility. We searched PubMed, Embase, ISI Web of Science, and CNKI databases to identify eligible studies meeting the inclusion criteria up to August 30, 2013. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of association. Finally, there were a total of 33 studies with 4,232 cases and 6,601 controls included in this meta-analysis. In the pooled analysis, significantly increased HCC risks were found for null genotype of GSTM1 (OR = 1.31, 95% CI = 1.07-1.61, P = 0.010, P heterogeneity < 10(-5)) and GSTT1 (OR = 1.47, 95% CI = 1.25-1.74, P < 10(-5), P heterogeneity < 10(-5)). Potential sources of heterogeneity were explored by subgroup analysis based on ethnicity, sample size, and source of control. Significant results were found among East Asians and Indians when stratified by ethnicity, while no evidence of significant associations was observed among Caucasian and African populations. In the gene-gene interaction analysis, a statistically significant increased risk for HCC was detected for individuals with combined deletion mutations in both genes compared to those with wild genotypes (OR = 1.88, 95% CI = 1.41-2.50, P < 10(-4), P heterogeneity = 0.004). The present meta-analysis demonstrated that the GSTM1 and GSTT1 null genotype may be associated with an increased risk of HCC and that individuals having the combination of both defective GST genotypes may be more susceptible to developing HCC.

Prevention of hepatocellular carcinoma in chronic viral hepatitis B and C infection

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide, with the majority of cases associated with persistent infection from hepatitis B virus (HBV) or hepatitis C virus (HCV). Natural history studies have identified risk factors associated with HCC development among chronic HBV and HCV infection. High-risk infected individuals can now be identified by the usage of risk predictive scores. Vaccination plays a central role in the prevention of HBV-related HCC. Treatment of chronic HBV infection, especially by nucleoside analogue therapy, could also reduce the risk of HBV-related HCC. Concerning HCV infection, besides the advocation of universal precautions to reduce the rate of infection, pegylated interferon and ribavirin could also reduce the risk of HCV-related HCC among those achieving a sustained virologic response. Recently there has been mounting evidence on the role of chemopreventive agents in reducing HBV- and HCV-related HCC. The continued advances in the understanding of the molecular pathogenesis of HCC would hold promise in preventing this highly lethal cancer.

Association of GST genetic polymorphisms with the susceptibility to hepatocellular carcinoma (HCC) in Chinese population evaluated by an updated systematic meta-analysis

Background

Due to the possible involvement of Glutathione S-transferase Mu-1 (GSTM1) and Glutathione S-transferase theta-1 (GSTT1) in the detoxification of environmental carcinogens, environmental toxins, and oxidative stress products, genetic polymorphisms of these two genes may play important roles in the susceptibility of human being to hepatocellular carcinoma. However, the existing research results are not conclusive.

Methods

A systematic literature search using databases (PubMed, Scopus, Embase, Chinese Biomedical Database, Chinese National Knowledge Infrastructure, Wanfang Data, etc.) for the eligible studies meeting the inclusion criteria including case-control studies or cohort studies is evaluated using an updated systematic meta-analysis.

Results

Significant increase in the risk of HCC in the Chinese population is found in GSTM1 null genotype (OR = 1.47, 95% CI: 1.21 to 1.79, P<0.001) and GSTT1 null genotype (OR = 1.38, 95% CI: 1.14 to 1.65, P<0.001). Analysis using the random-effects model found an increased risk of HCC in GSTM1-GSTT1 dual null population (OR = 1.79, 95% CI: 1.26 to 2.53, P<0.001). In addition, subgroup analyses showed a significant increase in the association of GST genetic polymorphisms (GSTM1, GSTT1, and GSTM1-GSTT1) with HCC in southeast and central China mainland. However, available data collected by this study fail to show an association between GST genetic polymorphisms and HCC in people from the Taiwan region (for GSTM1: OR = 0.78, 95% CI: 0.60 to 1.01, P = 0.06; for GSTT1: OR = 0.94, 95% CI: 0.78 to 1.14, P = 0.546; for GSTM1-GSTT1: OR = 1.04, 95% CI: 0.81 to 1.32, P = 0.77). Sensitivity analysis and publication bias diagnostics confirmed the reliability and stability of this meta-analysis.

Conclusions

Our results indicate that both GSTM1 and GSTT1 null genotypes are associated with an increased HCC risk in Chinese population. Peoples with dual null genotypes of GSTM1-GSTT1 are more susceptible to developing HCC. In conclusion, GST genetic polymorphisms play vital roles in the development of HCC in the Chinese population.