Browsing by Author "Takezaki,"
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Item Allele Frequencies of 25 Polymorphisms Pertaining to Cancer Risk for Japanese, Koreans and Chinese.(2002-01-30) Hamajima,; Takezaki,; Tajima,Allele frequencies are rather constant among different ethnic groups in many genetic polymorphisms, but some polymorphisms vary in the allele frequency depending on the time when the germ-line base exchanges occurred in the history of humans and on the adaptability of the phenotypes to given environment. This review documented the allele frequencies of polymorphisms pertaining to cancer risk for Japanese, Koreans, and Chinese. Twenty-five polymorphisms of 21 genes whose allele frequencies were available for at least two out of the three ethnic groups were selected. They were ALDH2 Glu487Lys, COMT Val158Met, CYP1A1 MspI and Val/Ile, CYP1B1 Leu432Val, CYP2E1 RsaI, CYP17 T-34C, ER C975G, GSTM1, GSTT1, GSTP1 Ile105Val, IL-1B C-511T, IL-1RN 86-bp VNTR (variable number of tandem repeats), MTHFR C677T and A1298C, NAT1, NAT2, NQO1 Pro187Ser, OGG1 Ser326Cys, p21 Ser31Arg, p53 Arg72Pro, TNF-A G-308A and G-238A, and XRCC1 Arg194Trp and Arg399Gln. The allele frequencies were found for 24 in Japanese, 16 in Koreans, and 24 in Chinese. All of the polymorphisms had similar allele frequencies for these ethnic groups, except the following polymorphisms; ALDH2 Glu487Lys whose Lys allele was more common for Japanese and Taiwanese, COMT Val158Met whose Met allele was more common for Japanese, and NAT2 rapid/slow whose slow alleles were more common for Chinese. When compared with the allele frequencies among Caucasians, the following minor alleles were more frequent among Japanese/Koreans/Chinese; ALDH2 478Lys, CYP1A1 m1 and m2, CYP2E1 c2, ER 975G, GSTT1 null, NAT1 *10, NQO1 187Ser, OGG1 326Cys, p21 31Arg, and XRCC1 194Trp, and less frequent in COMT 158Met, GST-P1 105Val, IL-1RN non-4R, MTHFR 1298C, and TNF-A -308A. The differences in genetic background may affect the impact on the lifestyle factors and/or genotypes examined in epidemiological studies. However, the influences of the variations in the allele frequency seemed to be limited among Japanese, Koreans, and Chinese. The substantial differences in the allele frequency from Caucasians could modify the influences of lifestyle factors and polymorphism genotypes, resulting in the inconsistent results of epidemiologic studies.Item Asian Pacific Cancer Prevention in the 21(st)Century: Five Rule Points from the Hospital-based Epidemiologic Research Program at Aichi Cancer Center (HERPACC).(2001-01-30) Tajima,; Hirose,; Hamajima,; Inoue,; Takezaki,; Kuroishi,Item Gene-environment Interactions and Polymorphism Studies of Cancer Risk in the Hospital-based Epidemiologic Research Program at Aichi Cancer Center II (HERPACC-II).(2001-01-30) Hamajima,; Matsuo,; Saito,; Hirose,; Inoue,; Takezaki,; Kuroishi,; Tajima,Genetic polymorphisms may modify the effects of environmental risk factors on cancer occurrence. We have recently launched a comprehensive epidemiologic project, HERPACC II (Hospital-based Epidemiologic Research Program at Aichi Cancer Center II), including both lifestyle and polymorphism data, following HERPACC-I which solely concentrated on lifestyle data. As of April 2001, about 3000 samples of DNA are being stored to conduct case-control studies. Genotyping of 46 polymorphisms has been conducted at the laboratory of the Division of Epidemiology and Prevention. Twelve case-control studies and two papers on a new PCR method, PCR-CTPP (polymerase chain reaction with confronting two-pair primers), have been accepted for publication. Significant findings in Japanese were found for 1) gene-environment interaction for esophageal cancer between heavy drinking and aldehyde dehydrogenase 2 (ALDH2), 2) malignant lymphoma risk with methylenetetrahydrofalate reductase (MTHFR) and methionine synthase (MS), 3) interactions between smoking and two polymorphisms, interleukin 1B (IL-1B) and myeloperoxidase (MPO) for Helicobacter pylori infection, and 4) smoking habits with dopamine receptor D2 (DRD2) and IL-1B. Further studies on interactions with polymorphisms will continue to be conducted for Japanese, using larger sizes of samples.Item Genotype Frequencies of Cyclooxygenease 2 (COX2) Rare Polymorphisms for Japanese with and without Colorectal Cancer.(2001-01-30) Hamajima,; Takezaki,; Matsuo,; Saito,; Inoue,; Hirai,; Kato,; Ozeki,; Tajima,Cyclooxygenase 2 (COX2) is an inducible enzyme synthesizing prostaglandins from arachidonic acid, which is thought to play an important role in colorectal carcinogenesis. Since the COX2 polymorphisms, if functional, may modify the carcinogenesis pathway, the associations between the reported polymorphisms and colorectal cancer risk were examined in a hospital-based case-control study. Six polymorphisms of the gene encoding COX2 were genotyped for 241 non-cancer individuals (controls) and 148 colorectal cancer patients (74 colon cancer, 73 rectal cancer, and 1 colorectal cancer date, 22 polymorphisms including the above six have been reported for COX2. The other polymorphisms remain to be examined.Item High Prevalence of HBV in Tibet, China.(2001-01-30) Zhao,; Li,; Lou,; Lu,; Yu,; Gao,; Hu,; Chiba,; Takezaki,; Takeshita,; Yashiki,; Fujiyoshi,; Sonoda,; Tajima,Hepatitis B virus (HBV), distributed throughout the world, is classified into seven geographically separated genotypes designated A to G. Since the prevalence of HBV infection in isolated ethnic Tibetan populations in China, and the HBV genotypes involved have been hither to remained unclear, we collected 262 blood samples from four isolated villages in the east and west regions of Tibet. The prevalence of HBV infection was estimated by EIA for HBV Ag and HBV Ab. The HBV genotypes were determined by a PCR-microwell plate hybridization method using plasma DNA. The prevalence of HBV Ag and HBV Ab positives was 19.1% (50/262 cases) and 29.0% (76/262 cases), respectively. We detected only the C genotype (20/20 cases), this being known as a predominant type of HBV among Mongoloid populations in Asia. The results revealed, for the first time, that Tibetan villagers have a high rate of infection with HBV of C genotype, in line with the available data for chronic hepatitis and liver cancer.Item The JICA Training Course, Community-based Cancer Prevention (Epidemiological Approach).(2001-01-30) Takezaki,Item Methionine Synthase Reductase Gene A66G Polymorphism is Associated with Risk of Colorectal Cancer.(2002-01-29) Matsuo,; Hamajima,; Hirai,; Kato,; Inoue,; Takezaki,; Tajima,A hospital-based case-control study was conducted to evaluate the significance of methionine and folate related polymorphisms, with 72 colon and 70 rectal cancer cases and 241 non-cancer controls. The polymorphisms examined were in the genes for methionine synthase reductase (MTRR A66G), methionine synthase (MTR A2756G) and methylenetetrahydrofolate reductase (MTHFR C677T and A1298C). An unconditional logistic regression model was applied for estimating the odds ratios (ORs) and 95% confidence intervals (CIs). The age-sex adjusted OR for the MTRR GG genotype as compared with the AA and AG genotypes was 2.77 (95% CI: 1.39-5.53, p = 0.004), whereas adjusted ORs for other polymorphisms were not statistically significant. When the ORs for environment factors (smoking, alcohol consumption, body-mass-index, and physical exercise) were calculated according to each polymorphism, no substantial difference was observed except with the MTRR polymorphism. The ORs for the MTRR GG genotype seemed to be modified by the extent of environmental exposure. In conclusion, the present study showed that the GG genotype of MTRR A66G is a risk factor for colorectal cancer in Japanese, while MTHFR and MTR polymorphisms are not. The conclusions, however, need further evaluation in terms of micronutrient status and additional confirmatory studies are required with datasets for various ethnic groups.Item A Model of Practical Cancer Prevention for Out-patients Visiting a Hospital: the Hospital-based Epidemiologic Research Program at Aichi Cancer Center (HERPACC).(2000-01-30) Tajima,; Hirose,; Inoue,; Takezaki,; Hamajima,; Kuroishi,To promote a cancer prevention program at hospital, we started the hospital-based epidemiologic research program at Aichi Cancer Center (HERPACC) in 1988. Because patients visiting hospitals are very concerned not only about their own health condition but also practical way of disease prevention, we consider outpatients, especially those free of cancer, as ideal targets to make a model program and a practical cancer prevention strategy for general people. To confirm risk and protective effects of lifestyle factors like dietary habits, smoking and drinking, and exercise on cancer in Japanese, we have been undertaking large-scale case-referent comparative studies of main cancer sites (stomach, colorectal, lung, breast and uterine cancers) using the data generated by HERPACC. The risk of respiratory tract cancer was definitely elevated by habitual smoking and that of upper digestive tract cancer by combined habitual smoking and drinking. Frequent intake of raw vegetables and/or fruit in contrast reduced the risk of lung cancer among smokers. Current obesity was positively associated with risk of post-menopausal breast cancer, recently on the increase in Japan. However, all sites of cancer were linearly decreased with frequency of exercise in both males and females. Based on these pieces of evidence and other main results obtained from the HERPACC studies, prevention trials with provision of information about protective and risk factors for main sites of cancers to outpatients have been planned in parallel to continuation of HERPACC.Item Valid Responses to ABO Blood Type Question in Self-reporting Questionnaire.(2001-01-30) Ito,; Matsuo,; Saito,; Hirose,; Inoue,; Takezaki,; Hamajima,; Kuroishi,; Tajima,This paper reports the sensitivity and specificity of self-reported ABO blood type. Subjects were 283 outpatients who participated in Helicobacter pylori eradication program at Aichi Cancer Center Hospital. Excluding seven patients, an ABO blood test was successfully conducted for 276 participants (133 males and 143 females). Only three participants answered their blood type differently from the results of the blood test; one A-type male answered to be with AB type, one B-type male with AB type, and one AB-type male with A type. Nine participants stated that they did not know their ABO blood type. The sensitivity was 98.7% (95% confidence interval, 92.8-100.0%) for 75 O-type individuals, 96.1% (90.3-98.9%) for 102 A-type individuals, 92.9% (84.1-97.6%) for 70 B-type individuals, and 93.1% (77.2-99.2%) for 29 AB-type individuals, when the nine individuals were included. The specificity was more than 99% for any blood type. These findings revealed that self-reported ABO blood type is highly valid for epidemiologic studies.