Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.5.7.1 (methylenetetrahydrofolate reductase)
 2,116 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Race-related differences in the frequency distribution of genetic polymorphisms in the CYP1A1 and CYP1B1 genes were studied in 39 Japanese and 45 Caucasians. 2. Four types of CYP1A1 polymorphism, namely m1 (a nucleotide change at T6235C in the 3'-flanking region), m2 (A4889G at exon 7), m3 (T5639C in the 3'-flanking region) and m4 (C4887A at exon 7), and three types of CYP1B1 genetic polymorphism, namely m1 (C488G and G701T leading to Arg48Gly and Ala119Ser exchanges respectively), m2 (C1294G leading to a Leu432Val exchange) and m3 (A1358G leading to an Asn453Ser exchange) were studied. 3. The distribution of the m1-, m2-, m3-, and m4-types of CYP1A1 polymorphism in the Japanese population was 30.8, 17.9, 0 and 0% respectively; those in Caucasians were 3.3, 6.7, 0 and 2.2% respectively. Two types (m1, and m2) of CYP1B1 polymorphism were expressed at 14.1 and 21.8% respectively in the Japanese, and by 28.9 and 37.5% respectively in the Caucasian. Ethnic differences were also noted in the m3-type CYP1B1 polymorphism in which the incidence in Caucasians was 23.9%, whereas no cases in the 39 Japanese subjects were observed. 4. No apparent association was found in the incidence in each of the genetic polymorphisms of CYP1A1 and CYP1B1 genes, nor in methylenetetrahydrofolate reductase gene, except that the occurrence of the m2-type of CYP1A1 genetic polymorphism was related to that of the m1-type CYP1A1 polymorphism in the Japanese population. 5. These results suggest that there are race-related differences in the occurrence of genetic polymorphisms in both CYP1A1 and CYP1B1 genes in Japanese and Caucasian populations and that these differences in P450 genetic polymorphisms may, in part, cause differences in the occurrence of lung and breast cancers in these ethnic groups.
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PMID:Ethnic-related differences in the frequency distribution of genetic polymorphisms in the CYP1A1 and CYP1B1 genes in Japanese and Caucasian populations. 1075 43

Susceptibility to colorectal cancer, one of the most common forms of cancer in the Western world, has been associated with several environmental and dietary risk factors. Dietary exposure to food derived heterocyclic amine carcinogens and polycyclic aromatic hydrocarbons have been proposed as specific risk factors. Many polymorphic Phase I and Phase II drug metabolizing enzymes are responsible for the metabolism and disposition of these compounds and it is therefore possible that inheritance of specific allelic variants of these enzymes may influence colorectal cancer susceptibility. In a multicenter case-control study, 490 colorectal cancer patients and 593 controls (433 matched case-control pairs) were genotyped for common polymorphisms in the cytochrome P450 (CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2C9, CYP2C19 and CYP2D6), glutathione S-transferase (GSTM1, GSTP1 and GSTT1), sulfotransferase (SULT1A1 and SULT1A2), N-acetyl transferase 2 (NAT2), NAD(P)H:quinone oxidoreductase (NQO1), methylenetetrahydrofolate reductase (MTHFR), and microsomal epoxide hydrolase (EPHX1) genes. Matched case-control analysis identified alleles associated with higher colorectal cancer risk as carriage of CYP1A1*2C (OR = 2.15, 95% CI 1.36-3.39) and homozygosity for GSTM1*2/*2 (OR = 1.53, 95% CI 1.16-2.02). In contrast, inheritance of the CYP2A6*2 (OR = 0.51, 95% CI 0.28-1.06), CYP2C19*2 (OR = 0.72, 95% CI 0.52-0.98) and the EPHX1(His113) alleles were associated with reduced cancer risk. We found no association with colorectal cancer risk with NAT2 genotype or any of the other polymorphic genes associated with the metabolism and disposition of heterocyclic amine carcinogens. This data suggests that heterocyclic amines do not play an important role in the aetiology of colorectal cancer but that exposure to other carcinogens such as polycyclic aromatic hydrocarbons may be important determinants of cancer risk.
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PMID:A pharmacogenetic study to investigate the role of dietary carcinogens in the etiology of colorectal cancer. 1241 32