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IntroductionThe p53 gene is frequently mutated in various forms of human cancers. The p53 signaling pathway isactivated by endogenous and exogenous stress signals and induces growth arrest, cellular senescenceand apoptosis. A common polymorphism occurs at codon 72 of the p53 has been demonstrated that itmight be associated with bladder cancer risk. However, results of researches related to this topic werecontroversial and more investigations and samples size needed.GoalTo evaluate TP53 Arg72Pro polymorphism in Mongolian patients with bladder cancer.Materials and MethodWe evaluated TP53 Arg72Pro polymorphism in DNA samples from 82 patients with bladder cancerand 82 age and gender matched healthy subjects using polymerase chain reaction-based restrictionfragment length polymorphism. All enrolments of this study were Mongolians. The association betweeneach genotype of TP53 Arg72Pro and bladder cancer risk was examined by the odds ratio and 95%confi dence interval, using logistic regression analysis. The early age onset of bladder cancer patientswas also evaluated among different genotypes of TP53 Arg72Pro.ResultsThe proportion of the polymorphism of TP53 Arg72Pro were RR 53.7% (n=44); PR 34.1% (n=28); andPP 12.2% (n=10) in the bladder cancer patients, whereas RR 52.4% (n=43); PR 28% (n=23); and PP19.6% (n=16) in healthy controls. The PR genotype increased the risk of bladder cancer (OR1.189;95% CI 0.42-0.75; p=0.997) in Mongolian people, whereas PP genotype protected from the cancer(OR=0.610; 95% CI 0.22-0.44, p=0.998) compared to the RR, respectively, however signifi cance isweak. Moreover, there was no association between each genotype of TP53 Arg72Pro (RR=52; PR=54;PP=58) and early onset of bladder cancer in the Mongolian population.Conclusion: Our result indicates that the PR genotype tends to increase the risk of bladder canceramong Mongolians. RR genotype of TP53 Arg72Pro is more prevalent among Mongolians.
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BACKGROUND: Bladder cancer is a cancer of significant morbidity and mortality in the worldwide. It is the second most common urological cancer in Mongolia. It is important to understand the risk factors of bladder cancer.We evaluated the association of smoking, alcohol intake, body mass index and other potential risk factors with bladder cancer incidence in Mongolians.MATERIALS AND METHODS: We analyzed data from a case-control study (116 histologically confirmed bladder cancer cases and 300 cancer-free healthy, age, gender-matched controls). All participants signed the consent form andfilled out the structured questionnaire including cigarette smoking, BMI, chronic urinary disease andalcohol drinking etc. Using logistic regression we estimated the covariate-adjusted odds ratio (OR) and95% confidence interval (CI) of the associations.RESULTS: Mean age of the patients with bladder cancer was 56±10.5 years and 79.3% male and 20.7% female.Cigarette smoking, history of urinary tract diseases and body mass index were associated with an increased risk of bladder cancer OR 6, 48 (95% CI 1, 61-1, 70), OR 80 (95% CI 1, 48-1, 93) and OR=9.8 (95% CI 2.32-2.91) respectively but not alcohol drinking OR 0, 26 (95% CI 1, 56-1, 66).CONCLUSIONS: The results suggest that cigarette smoking, history of urinary tract diseases and body mass indexincreased risk of bladder cancer in Mongolian patients.
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BACKGROUND:The mouse double minute 2 (MDM2) is a negative regulator of the p53 tumor suppressor protein.Overexpression of MDM2 is associated with poor survival and is a useful predictive factor for poor prognosisin various cancers in human. Studies revealed a genetic polymorphism located in intron 1 of the MDM2gene, MDM2-SNP309, (a change from T to G) is main functional polymorphism and important to developtumors. However, inconsistent associations between the MDM2-SNP309 and the risk or early onset ageof human different cancers have been reported worldwide. These conflicting results may have dependedon different patient subgroups and ethnicities studies. We studied the association of the MDM2-SNP309polymorphism andbladder cancer in Mongolian patients for the first time.OBJECTIVE:To investigate association between MDM2-SNP309 and the risk bladder cancer or early onset age of thecancer in Mongolian patients.MATERIALS AND METHODS:We genotyped MDM2-SNP309 in 44 patients with bladder cancer and 44 age and gender matched healthycontrols among Mongolian people.Genomic DNA was extracted from whole blood samples by the standardmethod of Qiagen mini blood DNA extraction kit (Qiagen Inc., Valencia, CA) and PCR amplification wasperformed using 100 ng genomic DNA template according to manufacturer’s protocol (Invitrogen, Carlsbad,CA). MDM2 SNP309 genotyping was carried out by restriction fragment length polymorphism assay.RESULTS: The allele frequencies of MDM2 SNP309 in the 44 bladder cancer patients were wild-type (T/T) 27.3%,homozygous (G/G) 34.1% and heterozygous (T/G) 38.6% whereas in the control cases were wild-type(T/T) 29.5%, homozygous (G/G) 20.5% and heterozygous (T/G) 50.0%. The proportion of homozygous(G/G) genotype was higher for bladder cancer cases than for healthy controls. Compared to the low-risk(wild type) genotype, an increased risk association with bladder cancer was shown for the GG genotype(OR=2.0, 95% CI=1.03-1.84). There is also a significant difference in median age onset of bladder cancerbetween GG low and high risk genotypes T/T and T/G (p=0,003)( p=0.0001), respectively (Figure2).CONCLUTION: The current sample data suggests that MDM2 SNP309 GG genotype may be associated withthe risk of bladder cancer as well as an earlier age onset in Mongolian patients with bladder cancer.