Association of vitamin D receptor polymorphism [VDR rs 2238136] with colorectal cancer

Many studies have demonstrated that Vitamin D has an important role in cell growth and proliferation and vitamin D receptor polymorphism has significant relationship with colorectal cancer [CRC]. The aim of this study was to assess the incidence of VDR rs 2238136 polymorphism in Iranian population and to investigate the relationship between this single nucleotide polymorphism [SNP] and increased risk of CRC. In this case-control study, genotyping of vitamin D receptor gene polymorphism [VDR rs2238136] was determined in a series of 112 colorectal cancer patients and 112 controls by using polymerase chain reaction and restriction fragment length polymorphism genotyping assays [PCR-RFLP]. Statistical analysis was done through SPSS 16. VDR polymorphism [rs 2238136] had no significant relationship with CRC risk. The result of statistical analysis for the genotype AG compared with GG was OR=0. 59, CI=0.33-1.03 and for AA versus GG was OR=0.8, Ct=0.29-2.17. Incidence of mutant allele in patients and controls did not show significant difference [OR=0.74, CI=0.49 -1.13]. These findings suggest that VDR [rs 2238136] is not associated with increased risk of CRC. Moreover age, sex and smoking are not predisposing factors for increased risk of CRC

[Seroepidemiologic study of HAV infection in Tehran province: a population based study]

Hepatitis A is a viral infection which is transmitted via fecal-oral route and its prevalence is directly related to the public health standards. The prevalence rate of this infection is different in different populations. The aim of this study was to determine the prevalence of hepatitis A antibody and assess the need for vaccination against hepatitis A in Tehran Province. This descriptive analytical cross-sectional study was conducted from 2006 to 2007 in Tehran Province. 448 subjects were selected by random cluster sampling. Blood samples were collected and demographic data were recorded in a questionnaire. Anti-HAV antibodies were measured by ELISA competitive method. Chi-square test and student t-test were used for statistical analysis. This study included 287 women and 161 men. Anti-HAV antibody was positive in 405 subjects [90.4%]. There were no significant relationships between HAV seropositivity and different age groups or gender. The results of our study showed a high prevalence of antibody in this region which is compatible with those of WHO results. Our results were similar to those obtained in Zabol City and eastern parts of Golestan Province but were not compatible with the results of the studies from Isfahan and Tabriz. At the present time there is no need for vaccination in this region

[Molecular determination of Echinococcus granulosus isolated from hydatid cyst using mitoconderial atp6 gene]

Several strains of the Echinococcus granulosus have been described based on morphological characters, intermediate host specificity and/or genetic analysis of mitochondrial and nuclear DNA. The aim of this study was to characterize different E.granulosus isolates by using sequences of mitochondrial atp6 gene. In this study, Sixty infected liver and lungs of cattle, sheep and goats were collected from the abattoir of Varamin city-Iran during 2008. Protoscoleces were removed from each fertile cyst and DNA extracted. New and specific primers were designed for two existing genotypes [G1 and G6] of E. granulosus known to occur in Iran and applied in PCR reactions. The new primers selectively amplified the G1 and G6 genotypes of E. granulosus with specific bands of 708 and 705 bp respectively. The G1 genotype was identified in all fertile cyst samples. This study showed that the new primer pairs which specifically amplify portions of the mitochondrial atp6 gene of the G1 and G6 strains of Echinococcus granulosus are proper molecular marker for investigating genetic variation in a number of isolates of E. granulosus from a range of hosts [sheep, goats, cattle] in Iran. The result of sequenced samples showed that our sequences were the same as those reported previously for these strains

[Effect of interleukin-12 p40 subunit gene 3'-untranslated region polymorphism in chronic HCV infection]

Production of unusual cytokine levels in hepatitis C infection appears to be associated with progression of the disease, persistence of the virus in host, and establishment of chronic disease. Interleukin-12 as a heterodimeric immunoregulating cytokine is important in the generation of a Th1-based immune response. In this study we investigated the role of IL-12B 3'UTR polymorphism in susceptibility to chronic hepatitis C infection. A total of 126 chronic hepatitis C patients and 136 healthy blood donors were genotyped for IL12-p 40-3' UTR polymorphism. Genotyping was carried out by PCR-RFLP method. The results were confirmed by analyzing 10% of the samples by direct sequencing. We found no significant differences in genotype and allele frequencies of the 3'UTR polymorphism between chronic hepatitis C patients and healthy controls. There was no association between IL12B-3'UTR polymorphism and chronic hepatitis C infection. Our study can be useful in regard to the factors regulating IL-12 production, and its consequent impact on chronic hepatitis C infection susceptibility in Iranian population

Global genome methylation status in gastritis lesion in comparison with normal adjacent tissue and its relationship with clinicopathologic findings

To determine the role of global genome methylation in gastritis lesion and its relation with clinicopathologic finding. The study was conducted on 44 gastritis and normal adjacent specimens using a technique composed of restriction enzyme digestion and pyrosequencing known as LUMA [LUminometric Methylation Assay]. At first, DNA extracted from gastritis lesion and normal tissue was digested with HpaII [sensitive to methylation in recognition site] and MspI [insensitive]. These enzymes leave an overhang after cutting which are then filled in a polymerase extension assay with stepwise addition of dNTPs using pyrosequencing. The comparison of the height of picks obtained form both enzymes provides the possibility to evaluate and compare global genome methylation level of normal and gastritis tissues. If the target site is fully methylated, the HpaII/MspI will approach toward zero .If not, this ratio will go around one. In the other conditions the ratio varies between 0-1. According to our findings, gastritis tissue was significantly more hypomethylated [p = 0.04] than the nornal tissue and Global genome methylation had no correlation with sex, age, microsatellite instability [MSI] and gastritis severity. Global DNA hypomethylation occurs in the gastritis lesion. Presumably the process of hypomethylation keeps falling in the next steps leading to gastric cancer

Association between genetic polymorphism of methylenetetrahydrofolate reductase with non familial Colorectal Cancer in Iranian population

Methylenetetrahydrofolate reductase [MTHFR] is a key enzyme regulating folate metabolism, which affects DNA methylation and synthesis. One of the most important polymorphisms identified in the MTHFR gene is C677T. MTHFR activity is lowered in individuals with 677TT genotype. Using pyrosequencing, we analyzed the MTHFR genotypes in 118 colorectal cancer patients and 189 normal matched controls. Whereas the CC, CT and TT genotypes of MTHFR among the colorectal cancer patients were 51.7%, 28.0% and 20.3% respectively, we were able to find 47.1% of 677CC, 27.0% of 677CT and 25.9% of 677TT in normal controls. An inverse association was observed between the risk of colorectal cancer and TT genotype with the odds ratios [OR] of 1, 0.94 and 0.71 for CC, CT, and TT genotypes, respectively. This association was similar in both sexes, but in patients with high levels of folate intake. Our study corroborates previous findings of an inverse association between MTHFR 677TT genotype and colorectal cancer, especially at high levels of folate

Association between polymorphism of MTHFR gene and non-familial colorectal cancer

Colorectal cancer is one of the most common malignancies in worldwide. Because the gene 5, 10-methylene-tetrahydrofolate reductase [MTHFR] plays a key role in methylation, synthesis and repair of DNA, numerous studies have focused on evaluating the correlation between polymorphisms of this gene and sporadic colorectal cancer. This study was carried out to examine the association of MTHFR gene polymorphism, C677T, with non-familial colorectal cancer in an Iranian population. We analyzed peripheral blood samples of 118 cases of colorectal cancer and 189 controls by pyrosequencing method. Controls were subjects who had been referred to our center during the study period and had revealed normal findings on colonoscopy. We found that frequency of CC, CT and TT genotypes among the colorectal cancer patients were 51.7%, 28% and 20.3% respectively. The figures for controls were 47.1%, 27% and 25.9% respectively. Furthermore, allele frequency T in the cases was 34% and allele frequency C was 66% while allele frequency T in controls was 39% and allele frequency C was 61%. Interestingly we observed a reverse association between risk of colon cancer with 677TT genotype