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Aim: Our study aimed to screen the genotype frequencies of very important pharmacogenomic (VIP) mutations and identify their differences between Bai and other populations. Materials & methods: We selected 66 VIP variants from PharmGKB (www.pharmgkb.org/) for genotyping. χ2 test was used to identify differences in loci between these populations and FST values of Bai and the other 26 populations were analyzed. Results: Our study showed that the frequencies of SNPs of CYP3A5 , ACE , PTGS2  and NAT2 differed significantly from those of the other 26 populations. At the same time, we found that some VIP variants may affect the metabolism of drugs and the genetic relationship between the Bai population and East Asian populations was found to be the closest. Conclusion: By comparing the genotype frequencies of different populations, the loci with significant differences were identified and discussed, providing a theoretical basis for individualized drug use in the Bai ethnic population.

Purpose: This study investigated the effect of 1 g genistein daily for 14 days on caffeine-based metrics of cytochrome P4501A2 (CYP1A2), cytochrome P4502A6 (CYP2A6), N-acetyltransferase 2 (NAT2), and xanthine oxidase (XO). Methods: A single dose of 100 mg caffeine was administered once before and once on the last day of a 14-day treatment regime with 1 g genistein once daily to 18 healthy female volunteers. Urine and blood samples were collected up to 12 and 24 h, respectively, after each caffeine dose. Using high-performance liquid chromatography (HPLC), caffeine and 1,7-dimethylxanthine (17X) were quantified in plasma, whereas 17X, 1,7-dimethylurate (17U), 1-methylxanthine (1X), 1-methylurate (1U), and 5-acetylamino-6-formylamine-3-methyluracil (AFMU) were quantified in urine. Urinary metabolite ratios were calculated to assess enzyme activities and compared between administrations using analysis of variance (ANOVA). Results: Genistein decreased the urinary caffeine metabolite ratio used to assess CYP1A2 activity by 41% [90% confidence interval (CI) 28-51%). The urinary ratio indicating XO activity decreased by 29% (90% CI 24-32%), whereas urinary ratio for CYP2A6 activity increased by 47% (90% CI 29-66%) after 2 weeks of genistein. The NAT2 urinary caffeine metabolite ratio did not change significantly. Conclusions: Two weeks of intake of 1 g genistein daily led to decreases in CYP1A2 and XO activity and an increase in CYP2A6 activity, whereas NAT2 activity did not change in healthy Chinese female volunteers. Pharmacokinetics of other substrates of the enzymes investigated here may be influenced in a similar manner. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To explore the association of polymorphisms in N-acetyltransferase 2 (NAT2), glutathione S-transferase (GST), cytochrome P450 (CYP) 2A6, and CYP 2A13 genes with susceptibility and clinicopathologic characteristics of bladder cancer in a Chinese population. Methods: In a hospital-based case-control study of 208 cases and 212 controls matched on age and gender, genotypes were determined by PCR-based methods. Risks were evaluated by unconditional logistic regression analysis. Results: It was found that significant associations of the NAT2 slow-acetylator genotype (odds ratio, OR: 2.42; 95% confidence interval, CI: 1.47–3.99), GSTM1 null genotype (OR: 1.64; 95% CI: 1.11–2.42) and GSTM1/GSTT1-double null genotype (OR: 1.72; 95% CI: 1.00–2.95) with increased risk of bladder cancer. Conversely, carriers with at least one CYP2A6*4 allele showed lower risk than the non-carriers (OR: 0.47; 95% CI: 0.28–0.79). The adjusted ORs (95% CI) for smokers with NAT2 slow-acetylator, GSTM1 null, GSTM1/GSTT1-double null genotype, and variant CYP2A6 genotypes were 2.99 (1.44–6.25), 1.98 (1.13–3.48), 2.66 (1.22–5.81) and 0.41 (0.20–0.86), respectively. Furthermore, NAT2 slow-acetylator, GSTM1 null, and GSTM1/GSTT1-double null genotypes were associated with higher tumor grade (P =0.001, 0.022, and 0.036, respectively), and only NAT2 slow-acetylator genotype was associated with higher tumor stage (P =0.007). CYP2A13 was not associated with risk or tumor characteristics. Conclusion: It is suggested that NAT2 slow-acetylator, GSTM1 null, GSTM1/GSTT1-double null, and variant CYP2A6 genotypes may play important roles in the development of bladder cancer in Henan area, China. [Copyright &y& Elsevier]

2,4,6-Trinitrotoluene (TNT) is an important occupational and environmental pollutant. In TNT-exposed humans, notable toxic manifestations have included aplastic anaemia, toxic hepatitis, cataracts, hepatomegaly, and liver cancer. Therefore, methods were developed to biomonitor workers exposed to TNT. The workers were employed in a typical ammunition factory in China. The external dose (air levels and skin exposure), the internal dose (urinary metabolites), the biologically effective dose (haemoglobin adducts, urinary mutagenicity), biological effects (chromosomal aberrations and health effects), and individual susceptibility (genotypes of xenobiotic-metabolizing enzymes) were determined. Haemoglobin-adducts of TNT, 4-amino-2,6-dinitrotoluene (4ADNT) and 2-amino-4,6-dinitrotoluene (2ADNT), and the urinary metabolites of TNT, 4ADNT and 2ADNT, were found in all workers and in some controls. The levels of the haemoglobin-adducts or the urinary metabolites correlated weakly with the skin or air levels of TNT. The urinary mutagenicity determined in a subset of workers correlated strongly with the levels of 4ADNT and 2ADNT in urine. The haemoglobin-adducts correlated moderately with the urinary metabolites and with the urinary mutagenicity. The genotypes of glutathione S-transferases (GSTM1, GSTT1, GSTP1) and N-acetyltransferases (NAT1, NAT2) were determined. In general, the genotypes did not significantly influence the haemoglobin-adduct levels and the urine metabolite levels. However, TNT-exposed workers who carried the NAT1 rapid acetylator genotype showed an increase in urinary mutagenicity and chromosomal aberrations as compared with slow acetylators. The haemoglobin adduct 4ADNT was significantly associated with a risk of hepatomegaly, splenomegaly and cataract; urine metabolites and genotypes were not associated with health effects. These results indicate that a set of well-selected biomarkers may be more informative regarding exposure and effect than routinely performed chemical measurements of pollutants in the air or on the skin. [ABSTRACT FROM AUTHOR]

A case-control study was conducted for analyzing the genetic polymorphisms of phase II metabolic enzymes in 97 patients with lung cancer and 197 healthy subjects from Han ethnic group of Hunan Province located in Central South China. The results showed that the frequencies of glutathione S-transferase (GST) M1-null (GSTM1-) or GSTT1-null (GSTT1-) genotype alone, or combined form of both in lung cancer patients were significantly higher than those of the controls. Genotypes of combining GSTP1 mutant/GSTM1(-) or GSTP1 mutant/GSTT1(-) led to high risk of lung cancer. Individuals carrying any two or all three of GSTM1(-), GSTT1(-) and GSTP1 mutant genotypes have a distinctly increased risk of lung cancer when compared to those with GSTM1 present (GSTM1+: GSTM1+/+ or GSTM1+/-), GSTT1 present (GSTT1+: GSTT1+/+ or GSTT1+/-) and GSTP1 wild genotypes. Furthermore, individuals possessing combined genotypes of N-acetyltransferase 2 (NAT2) rapid acetylator, GSTP1 mutant and both GSTT1(-) and GSTM1(-) have a remarkably higher lung cancer risk than those carrying combined NAT2 slow acetylator genotype, GSTP1 wild genotype and both GSTT1(+) and GSTM1(+) genotypes. All these findings suggest that the genetic polymorphisms of phase II metabolic enzymes affect the susceptibility of lung cancer in the Han ethnic group of Central South China. [ABSTRACT FROM AUTHOR]

Background: Anti-tuberculosis drug-induced hepatotoxicity (ATDH) is a serious adverse drug reaction. The slow acetylator status of N-acetyl transferase 2 (NAT2) is a well-established risk factor for ATDH. One novel tagging single nucleotide polymorphism (tagging SNP), rs1495741, in NAT2 has been found to be highly predictive of the NAT2 phenotype. The present study aimed to validate the relationships between tagging SNP rs1495741 and ATDH in a Chinese Han population., Methods: A 1:2 matched case-control study was conducted using 235 ATDH cases and 470 controls. Conditional or unconditional logistic regression analysis was used to estimate the association between genotypes and the risk of ATDH according to the odds ratio (OR) with a 95% confidence interval (CI)., Results: Patients carrying the AA genotype of tagging SNP rs1495741 were at higher risk of ATDH than those carrying the GG genotype (OR = 1.653, 95% CI = 1.050-2.601; p = 0.030). Subgroup analysis suggested that the AA genotype was a risk factor for ATDH in patients aged older than 50 years (OR = 2.486, 95% CI = 1.313-4.706; p = 0.005), weighing over 50 kg (OR = 1.757, 95% CI = 1.016-3.038; p = 0.044) or using a hepatoprotectant (OR = 1.611, 95% CI = 1.009-2.572; p = 0.046). Tagging SNP rs1495741 was not a significant risk factor for moderate and severe hepatotoxicity but appears to be relevant to risk of mild hepatotoxicity specifically., Conclusions: The present study is the first to validate the relationships between the tagging SNP rs1495741 and ATDH in a Chinese population. Based on this case-control study, the NAT2 rs1495741 polymorphism is a risk factor for mild but not more severe ATDH in Chinese Han patients., (© 2019 John Wiley & Sons, Ltd.)

Background: N-acetyltransferase 2 (NAT2) is involved in both carcinogen detoxification through hepatic N-acetylation and carcinogen activation through local O-acetylation. NAT2 slow acetylation status is significantly associated with increased bladder cancer risk among European populations, but its association in Asian populations is inconclusive., Methods: NAT2 acetylation status was determined by both single nucleotide polymorphisms (SNPs) and caffeine metabolic ratio (CMR), in a population-based study of 494 bladder cancer patients and 507 control subjects in Shanghai, China., Results: The CMR, a functional measure of hepatic N-acetylation, was significantly reduced in a dose-dependent manner among both cases and controls possessing the SNP-inferred NAT2 slow acetylation status (all P-values<5.0×10-10). The CMR-determined slow N-acetylation status (CMR<0.34) was significantly associated with a 50% increased risk of bladder cancer (odds ratio = 1.50, 95% confidence interval = 1.10-2.06) whereas the SNP-inferred slow acetylation statuses were significantly associated with an approximately 50% decreased risk of bladder cancer. The genotype-disease association was strengthened after the adjustment for CMR and was primarily observed among never smokers., Conclusions: The apparent differential associations for phenotypic and genetic measures of acetylation statuses with bladder cancer risk may reflect dual functions of NAT2 in bladder carcinogenesis because the former only measures the capacity of carcinogen detoxification pathway while the latter represents both carcinogen activation and detoxification pathways. Future studies are warranted to ascertain the specific role of N- and O-acetylation in bladder carcinogenesis, particularly in populations exposed to different types of bladder carcinogens., Competing Interests: The authors declare no competing interests.