Promoter polymorphism of transforming growth factor-β1 gene and ulcerative colitis

AIM: To elucidate the possible difference in two promoter polymorphisms of the transforming growth factor-β1 (TGF-β1) gene (-800G > A, -509C > T) between ulcerative colitis (UC) patients and normal subjects.METHODS: A total of 155 patients with established ulcerative colitis and 139 normal subjects were selected as controls. Two single nucleotide polymorphisms within the promoter region of TGF-β1 gene (-509C > T and -800G > A) were genotyped using PCR-RFLP. RESULTS: There was a statistically significant difference in genotype and allele frequency distributions between UC patients and controls for the -800G > A polymorphism of the TGF-β1 gene (P < 0.05). The frequency of the TGF-β1 gene polymorphism at position -800 showed that the AA genotype and the allele A frequencies significantly differed between the patients and healthy controls (P < 0.05). At position -509, there was no statically significant difference in genotype and allele frequency between the patients and control subjects.CONCLUSION: The results of our study indicate that there is a significant difference in both allele and genotype frequency at position -800G > A of TGF-β1 gene promoter between Iranian patients with UC and normal subjects.

XRCC1 genetic polymorphism Arg399Gln and gastric cancer risk:A meta-analysis

AIM： To evaluate the association between X-ray crosscomplementing gene 1 （XRCCl） genetic polymorphism Arg399Gln and gastric cancer risk by means of metaanalysis. METHODS： We searched PubMed and NCBI up to June 1, 2008. A total of 16 clinical trials and reports were identified, but only 8 trials qualified under our selection criteria. Statistical analysis was performed with the software program Review Manage, version 4.2.8. RESULTS： Of the 8 case-control studies selected for this meta-analysis, a total of 1334 gastric cancer cases and 2194 controls were included. For Arg399GIn, the Gin/Gin genotype carriers did not have a decreased cancer risk compared with those individuals with the Arg/Arg genotype （OR = 0.92, 95% CI, 0.71-1.19; P = 0.51）. Similarly, no associations were found in the recessive and dominant modeling （Gin/Gin vs Arg/GIn ＋ Arg/Arg： OR = 0.96; 95% CI, 0.77-1.19; P = 0.70 and Gin/Gin ＋ Arg/GIn vs Arg/Arg： OR = 0.90, 95% CI, 0.77-1.05; P = 0.18）. CONCLUSION： No association is found between the XRCC1 polymorphism Arg399GIn and gastric cancer risk.

DNMT3B 579 G>T promoter polymorphism and risk of esophagus carcinoma in Chinese

AIM:To investigate the relationship between 579 G>T polymorphisms in the DNMT3B gene, which is involved in de novo methylation and associated with the risk of esophagus cancer (EC) in Chinese. METHODS:DNMT3B 579 G>T genotypes were determined by PCR-RFLP in 194 EC patients and 210 healthy controls matched for age and sex, who did not receive radiotherapy or chemotherapy for newly diagnosed and histopathologically confirmed EC. RESULTS:In control subjects, the frequency of T/T and G/T genotypes, and T and G alleles was 81.4%, 18.1%, 90.05% and 9.55%, respectively. The distribution of genotypes and allelotypes in the EC patients was not significantly different from that in the controls. When stratified by sex and age, there was still no significant association between the risks of EC and GT and GG genotypes. This study also showed a distinct difference in the distribution of DNMT3B and single nucleotide polymorphism (SNP) between Chinese and Koreans.CONCLUSION:DNMT3B 579 G>T polymorphism may not be a stratification marker to predict the susceptibility to EC, at least in Chinese. DNMT3B promoter SNP is diverse in ethnic populations.

Lack of association between UGT1A7,UGT1A9,ARP,SPINK1 and CFTR gene polymorphisms and pancreatic cancer in Italian patients

AIM： To investigate simultaneously UGT1A7, UGT1A9, ARP, SPINK and CFTR genes to verify whether genetic polymorphisms predispose to the development of pancreatic cancer （PC）.METHODS： Genomic DNA of 61 pancreatic cancer patients and 105 healthy controls （HC） were analyzed. UGT1A7 genotyping was determined by PCR-RFLP analysis. Specific PCR and sequencing were used to analyze genetic variants of UGT1A9, ARP, SPINK1 and CFTR genes.RESULTS： Four different alleles （^＊1：WT; ＂2： N129K and R131K; ＂3： N129K, R131K, and W208R; and ＂4： W208R） in UGT1A7 and three different alleles （^＊1：WT;^＊4： Y242X; and ^＊5： D256N） in UGT1A9 were detected. All UGT1A polymorphisms were observed at similar frequency in PC patients and HC. Seven different alleles in ARP were found in PC patients and HC at similar frequency. The SPINK1 mutations N34S and P55S occurred in five PC patients with a prevalence （4.1%） not significantly different from that observed （2.0%） in HC. The only CFTR AFS08 mutation was recognized in three PC patients with a prevalence （4.9%） similar to HC.CONCLUSION： UGT1A7, UGT1A9, ARP, SPINK1 and CFTR gene polymorphisms are not associated with PC in Italian patients.

CYP4F2 polymorphism as a genetic risk factor for major hemorrhagic complications in Chinese patients on warfarin therapy

Warfarin is a commonly used anticoagulant with a narrow therapeutic range and risk of hemorrhagic complications. After CYP2C9 and VKORC1, CYP4F2 was confirmed as the third principle genetic determinant of warfarin dose variability.

Genetic diversity of the hepatitis C virus: Impact and issues inthe antiviral therapy

The hepatitis C Virus (HCV) presents a high degree of genetic variability which is explained by the combination of a lack of proof reading by the RNA dependant RNA polymerase and a high level of viral replication. The re- sulting genetic polymorphism defines a classification in clades, genotypes, subtypes, isolates and quasispecies. This diversity is known to reflect the range of responses to Interferon therapy. The genotype is one of the pre- dictive parameters currently used to define the antiviral treatment strategy and the chance of therapeutic suc- cess. Studies have also reported the potential impact of the viral genetic polymorphism in the outcome of antivi- ral therapy in patients infected by the same HCV geno- type. Both structural and non structural genomic regions of HCV have been suggested to be involved in the Inter- feron pathway and the resistance to antiviral therapy. In this review, we first detail the viral basis of HCV diversity. Then, the HCV genetic regions that may be implicated in resistance to therapy are described, with a focus on the structural region encoded by the E2 gene and the non- structural genes NS3, NS5A and NS5B. Both mechanisms of the Interferon resistance and of the new antiviral drugs are described in this review.