Genetic variation at -1878 (rs2596542) in MICA gene region is associated with chronic hepatitis B virus infection in Saudi Arabian patients

Single nucleotide polymorphism of rs2596542 and the risk of hepatocellular carcinoma development: A meta-analysis

BACKGROUND

Major histocompatibility complex class I-related chain A (MICA) is considered as a tumor antigen, and its expression is affected by its genetic polymorphisms. However, the relationship between rs2596542 polymorphisms in MICA promoter region and hepatocellular carcinoma (HCC) is not fully elucidated so far. This study aims to explore the relationship between single nucleotide polymorphism of rs2596542 and the risk of HCC development through meta-analysis.

METHODS

MEDLINE, Web of Science, and EMBASE databases were systematically searched to identify relevant studies. A meta-analysis was performed to examine the association between MICA rs2596542 polymorphism and susceptibility to HCC. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

Fourteen case-control studies involving 4,900 HCC cases and 19,519 controls were included. The MICA rs2596542C allele was significantly associated with decreased risk of HCC based on allelic contrast (OR = 0.76, 95% CI = 0.69-0.83, P < .001), homozygote comparison (OR = 0.57, 95% CI = 0.48-0.69, P < .001), and a recessive genetic model (OR = 0.77, 95% CI = 0.65-0.91, P < .001), whereas patients carrying the MICA rs2596542TT genotype had significantly higher risk of HCC than those with the CT or CC genotype (TT vs CT + CC, OR = 1.57, 95% CI = 1.36-1.81, P < .001). Subgroups analyses based on the ethnic or the source of control groups found very similar findings.

CONCLUSION

The C allele in MICA rs2596542 is a protective factor for hepatocarcinogenesis, whereas the T allele is a risk factor. Further large and well-designed studies are needed to confirm this conclusion.

Clinical significance of SNP (rs2596542) in histocompatibility complex class I-related gene A promoter region among hepatitis C virus related hepatocellular carcinoma cases

The major histocompatibility complex class I-related gene A (MICA) is an antigen induced by stress and performs an integral role in immune responses as an anti-infectious and antitumor agent. This work was designed to investigate whether (SNP) rs2596542C/T in MICA promoter region is predictive of liver cirrhosis (LC) and hepatocellular carcinoma (HCC) or not. Forty-seven healthy controls and 94 HCV-infected patients, subdivided into 47 LC and 47 HCC subjects were enrolled in this study. SNP association was studied using real time PCR and soluble serum MICA concentration was measured using ELISA. Results showed that heterozygous genotype rs2596542CT was significantly (P = 0.022) distributed between HCC and LC related CHC patients. The sMICA was significantly higher (P = 0.0001) among HCC and LC. No significant association (P = 0.56) between rs2596542CT genotypes and sMICA levels was observed. Studying SNP rs2596542C/T association with HCC and LC susceptibility revealed that statistical significant differences (P = 0.013, P = 0.027) were only observed between SNP rs2596542C/T and each of HCC and LC, respectively, versus healthy controls, indicating that the rs2596542C/T genetic variation is not a significant contributor to HCC development in LC patients. Moreover, the T allele was considered a risk factor for HCC and LC vulnerability in HCV patients (OR = 1.93 and 2.1, respectively), while the C allele contributes to decreasing HCC risk. Therefore, SNP (rs2596542C/T) in MICA promoter region and sMICA levels might be potential useful markers in the assessment of liver disease progression to LC and HCC.

Genome-wide association study: new genetic insights into HBV/HCV-related hepatocellular carcinoma genomes

Hepatocellular carcinoma (HCC) is the third common cause of cancer-related death with highest prevalence in developing countries, such as Southeast China and Saharan African. The major pathogenic factors can be categorized into environmental effects and genetic variations, and it is mostly caused by hepatitis B or C virus (HBV and HCV). The geographic prevalence of chronic hepatitis B and C (CHB and CHC) varies, with HBV heavily-infected in developing countries and HCV prevalent in developed countries. The infection of either hepatitis virus B or C causes damage to the liver cells through cellular immune attack by the mechanism of inflammation. However, how liver cell injury progresses to HCC development is still poorly understood. Along with the maturation of genome-wide association study (GWAS) technology, the specific genetic mutations responsible for the progression from CHB or CHC to HCC have been identified. Moreover, the findings of similar studies for these variants are different from each other due to diverse populations. More functional experiments are warranted to confirm the precise roles of these genetic mutations in the correlations between HBV/HCV and HCC for the future clinical application.

MICA SNPs and the NKG2D system in virus-induced HCC

Hepatocellular carcinoma (HCC) is one of the most frequent causes of cancer-related death globally. Above well-known risk factors for HCC development ranging from various toxins to diseases such as diabetes mellitus, chronic infection with hepatitis B virus and hepatitis C virus (HCV) poses the most serious threat, constituting the cause in more than 80 % of cases. In addition to the viral genes intensively investigated, the pathophysiological importance of host genetic factors has also been greatly and increasingly appreciated. Genome-wide association studies (GWAS) comprehensively search the host genome at the single-nucleotide level, and have successfully identified the genomic region associated with a whole variety of diseases. With respect to HCC, there have been reports from several groups on single nucleotide polymorphisms (SNPs) associated with hepatocarcinogenesis, among which was our GWAS discovering MHC class I polypeptide-related sequence A (MICA) as a susceptibility gene for HCV-induced HCC. MICA is a natural killer (NK) group 2D (NKG2D) ligand, whose interaction with NKG2D triggers NK cell-mediated cytotoxicity toward the target cells, and is a key molecule in tumor immune surveillance as its expression is induced on stressed cells such as transformed tumor cells for the detection by NK cells. In this review, the latest understanding of the MICA-NKG2D system in viral HCC, particularly focused on its antitumor properties and the involvement of MICA SNPs, is summarized, followed by a discussion of targets for state-of-the-art cancer immunotherapy with personalized medicine in view.

Genetic polymorphism of IL-23R influences susceptibility to HCV-related hepatocellular carcinoma

BACKGROUND

Genetic variations may play an important role in the development of HCC in HCV patients. Variants of IL23R gene were investigated for association with many diseases like chronic inflammatory disorders, RA, inflammatory bowel diseases and the susceptibility to the development of gastric cancer but no data are available concerning the association of IL23R gene (rs11209026) polymorphism with HCC development in HCV patients. Therefore the current study aimed to analyze this polymorphism within the gene to evaluate its contribution to chronic HCV susceptibility and/or HCC development in Egyptian patients.

SUBJECTS AND METHODS

One hundred and ninety-two patients with chronic HCV infection were included in this study (92 of them without HCC and 100 of them with HCC). One hundred healthy control subjects with no history of previous liver disease (HBV and HCV infection were negative) were included in the study. The IL23R polymorphism (rs11209026 G>A) were genotyped by real time PCR.

RESULTS

We found a significant lower incidence of GA and AA genotype in HCV patients with HCC compared to those without HCC (p=0.026 and 0.040 respectively) and compared to control group (p=0.008 and 0.007 respectively). While, no significant difference between control and HCV patients without HCC groups was found.

CONCLUSIONS

Our study suggests that wild type IL-23R GG serves as a risk factor for HCC and supports for the protective role of the rare variant rs11209026 (Arg381Gln) against HCV-related HCC in Egyptian patients.

The hepatitis B virus-associated tumor microenvironment in hepatocellular carcinoma

In contrast to a majority of cancer types, the initiation of hepatocellular carcinoma (HCC) is intimately associated with a chronically diseased liver tissue, with one of the most prevalent etiological factors being hepatitis B virus (HBV). Transformation of the liver in HBV-associated HCC often follows from or accompanies long-term symptoms of chronic hepatitis, inflammation and cirrhosis, and viral load is a strong predictor for both incidence and progression of HCC. Besides aiding in transformation, HBV plays a crucial role in modulating the accumulation and activation of both cellular components of the microenvironment, such as immune cells and fibroblasts, and non-cellular components of the microenvironment, such as cytokines and growth factors, markedly influencing disease progression and prognosis. This review will explore some of these components and mechanisms to demonstrate both underlying themes and the inherent complexity of these interacting systems in the initiation, progression, and metastasis of HBV-positive HCC.