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Biomedical subjects

Hideo Kunitoh

Publications and source records attributed to Hideo Kunitoh.

39 records · Page 3Linked to original sources

Three novel single nucleotide polymorphisms in UGT1A10.

Three novel single nucleotide polymorphisms (SNPs) were found in the UDP-glucuronosyltransferase (UGT) 1A10 gene from 24 Japanese patients with various cancers who were administered the anti-tumor drug, irinotecan (CPT-11). The detected SNPs were as follows: 1) SNP, MPJ6_U1A003; GENE NAME, UGT1A10; ACCESSION NUMBER, AF297093; LENGTH, 25 bases; 5'-CAGATGCCATGAC/TTTTCAAGGAGAG-3'. 2) SNP, MPJ6_U1A004; GENE NAME, UGT1A10; ACCESSION NUMBER, AF297093; LENGTH, 25 bases; 5'-CCTAGAAATAGCC/TTCTGAAATTCTC-3'. 3) SNP, MPJ6_U1A030; GENE NAME, UGT1A10; ACCESSION NUMBER, AF297093; LENGTH, 25 bases; 5'-GGTTGTAGTCATG/ACCAGAGGTGAGT-3' All the three SNPs were located in exon 1 and their frequencies were all 0.021. Among these SNPs, MPJ6_U1A003 and U1A030 resulted in amino acid alterations, T202I and M59I, respectively. The third SNP, MPJ6_U1A004, introduced a synonymous amino acid change (A231A).

Journal Article↗

Contribution of the NQO1 and GSTT1 polymorphisms to lung adenocarcinoma susceptibility.

Lung adenocarcinoma has replaced squamous cell lung carcinoma as the most frequent histological subtype in lung cancers. However, genetic factors that affect cancer susceptibility are much less understood in adenocarcinoma than in squamous cell carcinoma. In this study, polymorphisms in five genes involved in the metabolism of carcinogens or in the repair of damaged DNA in lung cells, NQO1-Pro187Ser, GSTT1-positive/null, GSTM1-positive/null, CYP1A1-Ile462Val, and OGG1-Ser326Cys, were examined for association with lung adenocarcinoma risk in a case-control study of 198 patients and 152 control subjects. The NQO1 and GSTT1 polymorphisms were associated with lung adenocarcinoma risk with adjusted odds ratio of 2.15 for the NQO1-Pro/Pro genotype versus the Ser/Ser genotype and adjusted odds ratio of 1.61 for the GSTT1-null genotype versus the positive genotype, respectively. Furthermore, individuals with the combined genotype of NQO1-Pro/Pro and GSTT1-null showed greater risk compared with those of NQO1-Ser/Ser and GSTT1-positive. In contrast, significant association was not observed for the GSTM1, CYP1A1, and OGG1 polymorphisms with lung adenocarcinoma risk, although several studies have shown their implication in the risk for squamous cell lung carcinoma. The result indicates that the NQO1-Pro/Pro and GSTT1-null genotypes are risk factors for lung adenocarcinoma development, and that the genetic factors for susceptibility to adenocarcinoma are different from those to squamous cell carcinoma. The enhanced risk of the NQO1-Pro/Pro genotype combined with the GSTT1-null genotype was more evident in smokers than in nonsmokers. Therefore, carcinogens in tobacco smoke, which are activated by NQO1 and detoxified by GSTT1, could have a role in lung adenocarcinoma development.

Adenocarcinoma↗

Genetic polymorphism of CYP2A6 gene and tobacco-induced lung cancer risk in male smokers.

Cytochrome P450 2A6 (CYP2A6) is the principal enzyme involved in the metabolic activation of tobacco-specific nitrosamines to their ultimate carcinogenic forms and metabolism of nicotine. We investigated the effects of the CYP2A6*4, an entire CYP2A6 gene deletion-type polymorphism, on lung cancer risk and daily cigarette consumption in Japanese male smokers via a hospital-based case control study. The frequency of the CYP2A6*4 variant was compared in 370 lung cancer patients and 380 control smokers. A markedly reduced adjusted odds ratio for lung cancer risk, 0.23 [95% confidence interval, 0.08-0.67], was seen in the group with homozygous deletion (*4/*4) when the odds ratio for a group with homozygous wild (*1A/*1A) was defined to be 1.00 by logistic regression. The subjects with lung cancer were additionally divided into three groups according to the histological classification of the cancer and examined for an association with the CYP2A6 polymorphism. The *4/*4 genotype was not found in patients with squamous cell carcinoma (0 of 105) or small cell carcinoma (0 of 44), indicating that subjects with the *4/*4 genotype have low risk for lung cancers, particularly those caused by tobacco smoke. Furthermore, a significant reduction of daily cigarette consumption was observed in smokers with the *4/*4 genotype, suggesting a possibility that complete lack of CYP2A6 appeared to affect the smoking behavior. These data suggest that male smokers possessing the *1A/*1A genotype have higher risk for tobacco-induced lung cancers.

Adult↗