FAS promoter polymorphisms correlate with activity grade in hepatitis C patients

Genetic Polymorphisms of Fas/FasL Promoter Associated with Hepatitis C cirrhosis and HCC

Aim:

The present study was performed to determine any associations of genetic polymorphisms of Fas/FasL promoter regions, at Fas670 and Fas1377 and FasL844, with hepatitis C cirrhosis and HCC, with a focus on severity of disease.

Methods:

Totals of 120 patients with cirrhosis and 101 with hepatocellular carcinoma (HCC) were enrolled. All had chronic HCV infection as indicated by positive anti-HCV antibodies and positive HCV RNA on real time PCR. One hundred healthy control subjects were also included in the study. Patients were subjected to full clinical, radiological and histopathological examinations. In addition to routine laboratory tests for liver function tests, Fas670 and Fas1377 and FasL844 genetic polymorphisms of Fas/FasL promoter regions were assessed by RFLP-PCR (restriction fragment length polymorphism with polymerase chain reaction).

Results:

Significant higher levels of the AG genotype in Fas670 and Fas1773 were observed in patients with cirrhosis and HCC (P=0.0001) as compared to control subjects. In addition, the CC genotype in FASL844 was also more common in patients (P=0.01). Furtehrmore, there was a significant association of substitution of A by G alleles in Fas670 and Fas1773 with advanced BCA staging (P=0.02, P=0.0001 respectively) and larger tumor size >5cm (P=0.01, P=0.0001 respectively) and in Fas670 with advanced pathological grading (P=0.0001). Moreover the CC genotype of FASL844 was significantly linked with advanced BCA, large tumor size >5cm and advanced pathological grading (P=0.0001).

Conclusion:

The findings of the present study highlight associations of genetic polymorphisms of promoter regions in Fas and Fas L with cirrhosis and HCC associated with chronic HCV. Support was also obtained for the conclusion that single nucleotide polymorphisms of the Fas/ FasL system impact on clinical and histopathological grading of HCCs. Further large scale studies are recommended for confirmation.

P53 rs1042522 and CD95 rs1800682 genetic variations in HCV-4a response to antiviral therapy

Current estimates indicate that the hepatitis C (HCV) is the leading cause of mortality around the world, with infection rates steadily increasing in Egypt. The dual therapy for this silent epidemic with pegylated-interferon-α2b/ribavirin has markedly improved the success rates in genotype-4 patients. It was reported that apoptosis plays a vital mechanistic role in limiting viral replication. P53, a key regulator of apoptosis, induces CD95 gene expression and subsequently initiates apoptotic cascade to be activated. The current study examined the impact of P53 rs1042522 and CD95 rs1800682 polymorphisms on the treatment response. Three groups of 240 volunteers were enrolled in this study; 86 in sustained virological responders group, 74 in non-responders group, and 80 in control group. All patients had HCV genotype-4a and were interferon treatment naïve. Quantizations of HCV-RNA by qRT-PCR and histological scores were performed for all patients. In addition, genotyping of HCV-RNA, P53 rs1042522 Arg/Pro and CD95 rs1800682 A/G polymorphisms were investigated in all subjects. It was resulted that P53 Pro/Pro homozygous genotype has high significant increase, while CD95 A/A homozygous genotype has high significant decrease when comparing non-responders with responders. Finally, it was concluded that Pro variant of P53 rs1042522 may be used as a genetic predictor for non-responsiveness, while A/A variant of CD95 rs1800682 may be used as a sensitive biomarker for responsiveness to antiviral therapy of HCV genotype-4a infection. In addition, low prolactin, high total testosterone, and high GH levels may provide promising biomarkers for early prediction of the response when associated with these genetic polymorphisms.

The potential impact of P53 and APO-1 genetic polymorphisms on hepatitis C genotype 4a susceptibility

The hepatitis C virus (HCV), the main cause of morbidity and mortality, is endemic worldwide. HCV causes cirrhosis and other complications that often lead to death. HCV is most common in underdeveloped nations, with the highest prevalence rates in Egypt. Tumor suppressor gene (P53) induces the expression of apoptotic antigen-1 gene (APO-1) by binding to its promoter for mediating apoptosis; an important mechanism for limiting viral replication. This study aims at investigating the impact of P53 72 Arg/Pro and APO-1 -670 A/G polymorphisms on HCV genotype 4a susceptibility. Two hundred and forty volunteers were enrolled in this study and divided into two major groups; 160 HCV infected patient group and 80 healthy control group. HCV patients were classified according to Metavir scoring system into two subgroups; 72 patients in F0/1-HCV subgroup (patients with no or mild fibrotic stages) and 38 patients in F3/4-HCV subgroup (patients with advanced fibrotic stages). Quantification of HCV-RNA by qRT-PCR and fibrotic scores as well as genotyping of HCV-RNA, P53 at 72 Arg/Pro, and APO-1 at -670 A/G were performed for all subjects. It was resulted that F0/1-HCV patients have significant differences of P53 at 72 (Pro/Pro and Arg/Arg) genotypes and dominant/recessive genetic models as well as APO-1 -670 A/A genotype and dominant genetic model as compared to F3/4-HCV patients. Moreover, HCV patients have significant differences of P53 at 72 (Pro/Pro) genotype and recessive genetic model as well as APO-1 -670 A/A genotype and dominant genetic model as compared to those of healthy individuals. Finally, it was concluded that P53 rs 1042522 (Pro/Pro and Arg/Arg) genotypes and APO-1 rs 1800682 A/A genotype may be potentially used as sensitive genetic markers for HCV genotype 4a susceptibility.

Hepatocellular carcinoma: towards personalized medicine

Over the past several years, the success of genome-wide association studies (GWAS) and pharmacogenomics has gradually begun to enable personalized medicine in some fields. In the field of liver diseases, host genetic factors are now very useful in clinical practice for predicting treatment outcome and adverse reactions for pegylated interferon plus ribavirin combination therapy against chronic hepatitis C virus (HCV) infection. Recently, three virus-related hepatocellular carcinoma (HCC) GWAS were reported from Asia. One study examined hepatitis B virus-related HCC in China, where hepatitis B is very prevalent, and the other two examined HCV-related HCC in Japan. We identified a common variant in the DEPDC5 locus associated with HCV-related HCC, and another group identified an association involving the MICA locus. In this review, we compare the results of these GWAS and earlier candidate gene studies. Further research is needed to determine the role of these single nucleotide polymorphisms on HCC risk, but identification of these markers could make it possible to assess the magnitude of the risk of cancer based on each patient's genetic background. Consideration of the genetic background of the patients will likely play a role in personalized medicine for HCC, and understanding the mechanism underlying the association could suggest novel promising therapeutic targets in the future.

Explanted liver inflammatory grade predicts fibrosis progression in hepatitis C recurrence

Factors present prior to liver transplantation (LT) that predict fibrosis progression in recurrent hepatitis C infection (HCV) after LT would be important to identify. This study sought to determine if histologic grade of HCV in the explant predicts fibrosis progression in recurrent HCV. The clinical and histologic data of all 159 patients undergoing their first LT for HCV at our center from 1998 to 2001 were retrospectively reviewed with follow-up through June 2008. Twenty-five cases were excluded for: non-HCV-related graft loss <90 days (19), recidivism (4), or unavailable explant or follow-up biopsies (2). A single pathologist scored (Ishak) explants in a blinded fashion. Patients were grouped by explant inflammatory grade ≤ 4 (group1) and >4 (group 2). Prospectively scored liver biopsies (protocol months 1 and 4, annually, and as indicated clinically) were reviewed for development of advanced fibrosis (bridging or cirrhosis). Cox proportional hazard regression was used to analyze the association of explant grade, donor, viral and LT factors with progression to advanced fibrosis. The groups were well-matched for patient, viral, donor, and transplant factors. Five-year advanced fibrosis-free survival in group 1 versus group 2 was 63% versus 28%, P < 0.001. Explant grade >4 was associated with increased HCV-related graft loss at 1 (6% versus 3%) and 5 (36% versus 14%) years post-LT (P = 0.003). On univariate and multivariate Cox regression analysis, predictors of advanced fibrosis were explant grade >4 (hazard ratio [HR] = 3.3, 95% confidence interval [CI] = 1.9-5.6, P < 0.001) donor age >50 (HR = 3.3, 95% CI = 1.9-5.7, P < 0.001) and viral load at LT of >158,730 IU/mL (HR = 1.8, 95% CI = 1.05-3.1, P = 0.03).

CONCLUSION

Explant histologic grade can identify patients requiring more aggressive monitoring and intervention for HCV recurrence post-LT.

Association of interferon regulatory factor-7 gene polymorphism with liver cirrhosis in chronic hepatitis C patients

BACKGROUND AND AIMS

Interferon (IFN) regulatory factor 7 (IRF-7) has been shown to play an essential role in the transcriptional activation of virus-inducible cellular genes, especially IFN genes. Polymorphisms of the IRF-7 gene may probably affect both the quality and the quantity of IRF-7. We investigated the role of IRF-7 polymorphisms in Japanese patients with chronic hepatitis C virus (HCV) infection.

METHODS

We studied a total of nine polymorphisms of the IRF-7 gene including SNP1047A/G (Lys/Glu) and SNP2157A/G (Gln/Arg) using the Taqman allelic discrimination and sequencing techniques in 406 Japanese patients with chronic HCV infection. We further performed functional analysis of SNP1047 and SNP2157 by transcriptional activation of the IFNA promoter.

RESULTS

We found that SNP1047AG and SNP2157AG genotypes were in complete linkage disequilibrium and were present in a significantly higher proportion in HCV-infected patients with cirrhosis (5.6%) than in those without cirrhosis (1.7%) (P=0.03). Multivariate analysis also revealed that SNP1047 and SNP2157 were independently associated with cirrhosis at an odds ratio of 2.5. Functional analysis revealed that SNP1047G and SNP2157G alleles increased IFNA expression.

CONCLUSION

SNP1047AG and SNP2157AG genotypes were strongly associated with cirrhosis. SNP1047G and SNP2157G alleles might be used as markers of host factors associated with a higher risk of cirrhosis in Japanese patients with chronic HCV infection.

Exploratory analysis of Fas gene polymorphisms in pediatric osteosarcoma patients

Defective apoptosis signaling by the Fas pathway has carcinogenic implications. We analyzed 123 pediatric patients with osteosarcoma for Fas single nucleotide polymorphisms: 2 of the promoter region (-1377 G>A and -670 A>G) and 2 of the coding region (exon 3 18272 A>G and exon 7 22628 C>T). As a comparison group, we used 510 adults without a history of cancer. We found an increased risk of osteosarcoma associated with the heterozygous genotype Fas exon 3 AG (genotype frequency 19.5% in cases vs. 12.0% in controls, P=0.028; adjusted odds ratio=1.6, 95% confidence interval=0.9-2.7], and this association was more pronounced in non-Hispanic whites (20.6% in cases vs. 10.1% in controls, P=0.014; adjusted odds ratio=2.3, 95% confidence interval=1.2-4.6). Additionally, the frequency of the variant allele (exon 3 G) was significantly higher in cases than in controls for both the entire group and non-Hispanic whites (P=0.046 and P=0.030, respectively). We found no significant association between osteosarcoma risk and the other Fas polymorphisms. This study suggests an association between the Fas exon 3 A>G polymorphism and osteosarcoma risk; however, further study is needed with pediatric controls and a larger sample size.

MDM2 promoter SNP309 is associated with the risk of hepatocellular carcinoma in patients with chronic hepatitis C

PURPOSE

A single nucleotide polymorphism (SNP) in the promoter region of MDM2 gene, SNP309, has recently been shown to be associated with accelerated tumor formation in both hereditary and sporadic cancers in humans. However, the association of SNP309 with hepatocellular carcinoma is unknown. We evaluated the association of SNP309 with the risk of hepatocellular carcinoma development among Japanese patients with chronic hepatitis C virus infection.

EXPERIMENTAL DESIGN

We genotyped the SNP309 at the MDM2 promoter in 435 Japanese patients with chronic hepatitis C virus infection, including 187 patients with hepatocellular carcinoma and 48 healthy subjects, using a fluorogenic PCR. Presence of SNP was also confirmed by direct sequencing of the MDM2 promoter region.

RESULTS

The proportion of G/G genotype of the SNP309 in patients with hepatocellular carcinoma (33%) was significantly higher than that in patients without hepatocellular carcinoma (23%), with an odds ratio (95% confidence interval) of 2.28 (1.30-3.98). A multivariate analysis revealed that MDM2 SNP309 (G/G versus T/T), age >60 years, male gender, presence of cirrhosis, serum alpha-fetoprotein >20 mug/L, and serum albumin <3.2 g/dL were independently associated with the hepatocellular carcinoma development at odds ratio of 2.27, 2.46, 3.08, 4.15, 4.87, and 6.33, respectively.

CONCLUSIONS

The MDM2 promoter SNP309 is associated with the presence of hepatocellular carcinoma in Japanese patients with chronic hepatitis C.