Research progress on metabolic activation of indirect carcinogens by CYP1A1 / 中国职业医学

Cytochrome P450 enzyme 1A1 (CYP 1A1) is one of the main members of CYP1A subfamily, which participates in metabolizing and activating a variety of indirect carcinogens. CYP1A1 can induce carcinogenesis by participating in activating exogenous compounds to produce intermediates or active metabolites that bind to specific biomolecules. CYP1A1 plays a critical role in the metabolic activation of benzo(a)pyrene e ［B(a)P］, and plays a key role in activating the toxic and carcinogenic effects of B(a)P. CYP1A1 involves in the metabolic activation of 7,12-dimethyl benzanthracene and 2-amino-1-methyl-6-phenylimidazo［4,5-b］pyridine (PhIP), and plays an important role in PhIP-induced genotoxicity. CYP1A1 is the main enzyme to metabolize and activate 7H-dibenzo［c,g］carbazole (DBC), a key factor in the carcinogenic effect of DBC. CYP1A1 is also associated with metabolic activation of indirect carcinogens such as aflatoxin B1, 3-nitrobenzene, and naphthalene. Inhibition of the catalytic activity of CYP1A1 can decrease the CYP1A1-mediated activity of carcinogens, thus playing a role in the prevention and treatment of malignant tumors.

The expression of oxidative stress genes related to myocardial ischemia reperfusion injury in patients with ST-elevation myocardial infarction / 世界急诊医学杂志（英文）

@#BACKGROUND: We aimed to investigate the gene expression of myocardial ischemia/reperfusion injury (MIRI) in patients with acute ST-elevation myocardial infarction (STEMI) using stress and toxicity pathway gene chip technology and try to determine the underlying mechanism. METHODS: The mononuclear cells were separated by ficoll centrifugation, and plasma total antioxidant capacity (T-AOC) was determined by the ferric reducing ability of plasma (FRAP) assay. The expression of toxic oxidative stress genes was determined and verified by oligo gene chip and quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, gene ontology (GO) enrichment analysis was performed on DAVID website to analyze the potential mechanism further. RESULTS: The total numbers of white blood cells (WBC) and neutrophils (N) in the peripheral blood of STEMI patients (the AMI group) were significantly higher than those in the control group (WBC: 11.67±4.85 ×109/L vs. 6.41±0.72 ×109/L, P<0.05; N: 9.27±4.75 ×109/L vs. 3.89±0.81 ×109/ L, P<0.05), and WBCs were significantly associated with creatine kinase-myocardial band (CK-MB) on the first day (Y=8.945+0.018X, P<0.05). In addition, the T-AOC was significantly lower in the AMI group comparing to the control group (12.80±1.79 U/mL vs. 20.48±2.55 U/mL, P<0.05). According to the gene analysis, eight up-regulated differentially expressed genes (DEGs) included GADD45A, PRDX2, HSPD1, DNAJB1, DNAJB2, RAD50, TNFSF6, and TRADD. Four down-regulated DEGs contained CCNG1, CAT, CYP1A1, and ATM. TNFSF6 and CYP1A1 were detected by polymerase chain reaction (PCR) to verify the expression at different time points, and the results showed that TNFSF6 was up-regulated and CYP1A1 was down-regulated as the total expression. GO and kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis suggested that the oxidative stress genes mediate MIRI via various ways such as unfolded protein response (UPR) and apoptosis. CONCLUSIONS: WBCs, especially neutrophils, were the critical cells that mediating reperfusion injury. MIRI was regulated by various genes, including oxidative metabolic stress, heat shock, DNA damage and repair, and apoptosis-related genes. The underlying pathway may be associated with UPR and apoptosis, which may be the novel therapeutic target.

Influence of nicotine dependence, current smoking status and gender on CYP1A1, CYP1B1 and CYP2A6 expression in oral squamous cell carcinoma / Influência da dependência nicotínica, parâmetros de consumo de tabaco e gênero na expressão de CYP1A1, CYP1B1 e CYP2A6 em carcinoma de células escamosas oral

Objective: Tobacco smoke is composed of cancer-causing chemicals referred to as carcinogens. These carcinogens are metabolized by the enzymes of the cytochrome P450 (CYP) family. Our objective was to evaluate the correlation of tobacco consumption parameters with CYP1A1, CYP1B1 and CYP2A6 expression using qRT-PCR in samples of oral squamous cell carcinoma (OSCC). Material and Methods: The sample was divided into 2 groups: Cancer (36 subjects) and non-Cancer (12 subjects). The smokers' participants (36) were evaluated regarding their Nicotine dependence (ND) was assessed by the Fagerström test for cigarette dependence (FTCD). Questions regarding tobacco consumption like the number of cigarettes/day (CPD), duration of use, and pack-years were also evaluated. The Mann-Whitney and Spearman correlation tests were used at a significance level of 5%. Results: 48 participants were included, 32 men (66.7%), 36 smokers (75%) and 27 smokers with OSCC (56.3%). Samples of OSCC expressed more CYP1A1, CYP1B1, and CYP2A6. Especially, the CYP1B1 gene was significantly expressed in OSCC samples, regardless gender or tobacco use. No women expressed CYP2A6, as well as, non-smokers did not express the CYP1A1 and CYP2A6 genes. CYP1A1 gene was higher among men (P = 0.021). Conclusion: Lack of exposure to tobacco may justify the absence of CYP1A1 and CYP2A6 expression in non-smokers. The CYP1B1 gene was significantly expressed in the cancer presence despite gender or tobacco use. The assessment of ND and quantification of tobacco consumption are important instruments in monitoring smokers with benign oral lesions and, especially, in the presence of cancer.(AU)

Objetivo: A fumaça do tabaco é composta de substâncias químicas cancerígenas conhecidas como carcinógenos. Esses carcinógenos são metabolizados pelas enzimas da família do citocromo P450 (CYP). Nosso objetivo foi avaliar a correlação dos parâmetros do consumo de tabaco com a expressão de CYP1A1, CYP1B1 e CYP2A6 por qRT-PCR em amostras de carcinoma de células escamosas bucal (CCEB). Material e Métodos: A amostra foi dividida em 2 grupos: Câncer (36 indivíduos) e sem Câncer (12 indivíduos). Os participantes fumantes (36) foram avaliados quanto à dependência nicotínica (DN) pelo teste de Fagerström para dependência de cigarro (TFDC). Questões relacionadas ao consumo de tabaco como número de cigarros / dia (CPD), tempo de uso e anos-maço também foram avaliadas. Os testes de correlação de Mann-Whitney e Spearman foram utilizados com nível de significância de 5%. Resultados: foram incluídos 48 participantes, 32 homens (66,7%), 36 fumantes (75%) e 27 fumantes com CCEB (56,3%). Amostras de CCEB expressaram mais CYP1A1, CYP1B1 e CYP2A6. Especialmente, o gene CYP1B1 foi significativamente expresso em amostras de CCEB, apesar do sexo ou uso de tabaco. Nenhuma mulher expressou CYP2A6, assim como, não fumantes não expressaram os genes CYP1A1 e CYP2A6. O gene CYP1A1 foi maior entre os homens (P = 0,021). Conclusão: A falta de exposição pode justificar a ausência da expressão dos genes CYP1A1 e CYP2A6 entre não fumantes. O gene CYP1B1 foi significativamente expresso na presença de câncer, independentemente do sexo ou do uso de tabaco. A avaliação da DN e a quantificação do consumo de tabaco são importantes instrumentos no acompanhamento de fumantes com lesões bucais benignas e, principalmente, na presença de câncer (AU)

Association of polycyclic aromatic hydrocarbon exposure and CYP1A1 gene and enzyme activity of peripheral blood monocyte cells in coke oven workers / 中华劳动卫生职业病杂志

Objective@#To explore the association between polycyclic aromatic hydrocarbons (PAHs) exposure and cytochrome P450 CYP1A1 expression at gene and enzyme activity levels in the peripheral blood monocyte cells in coke oven workers, and to provide a certain basis for the biological monitoring of health damage in coke oven workers.@*Methods@#We surveyed 118 coke oven workers and 63 controls (energy power workers in the same company) using self-designed questionnaire, determined their post-shift urinary 1-hydroxypyrene (1-OH-Py) concentration using high performance liquid chromatography (HPLC)-fluorescence detector method. We also isolated the peripheral blood mononuclear cell (PBMC) from fasting venous blood, and detected DNA damage using comet assay, CYP1A1 mRNA level using the real-time fluorescent quantitative PCR (FQ-PCR), and EROD activity using spectrophotometry. Statistical analyses including one-way analysis of variance and multiple linear regressions were used to analyze the association of urinary 1-OH-Py and CYP1A1 mRNA level and EROD activity.@*Results@#Compared to the control group, the urinary 1-OH-Py concentration and PBMC DNA tail moment were significantly increased in coke oven workers (P<0.05), and CYP1A1 gene level and EROD activity in PBMC were significantly decreased (P<0.05). Multiple linear regression showed that a ten-fold increase of urinary 1-OH-Pycon centration was associated with a decrease of 0.77 (95%CI: -1.33--0.21) in CYP1A1 gene level, and a decline of 0.15 (95%CI: -0.76--0.16) in EROD activity of PBMC in coke oven workers (P<0.05).@*Conclusion@#Occupational PAHs exposure induced DNA damage, which was associated with the decreased level in CYP1A1 gene cavel and EROD activity in PBMC of coke oven workers.

Analysis of promoter methylation of CYP1A1 and CYP1B1 gene in thyroid cancer / 中华内分泌代谢杂志

Objective To investigate the promoter methylation of drug metabolism genes CYP1A1 and CYP1B1 in thyroid cancer and its relationship with clinical pathological characteristics. Method 201 cases of thyroid cancer and 23 cases of normal thyroid tissues were involved. Methylation-specific PCR ( MSP ) was performed to analyze promoter methylation of CYP1A1 and CYP1B1 genes in the above tissues to detect the frequency of methylation positive, compare the promoter methylation level of CYP1A1 and CYP1B1 genes in papillary thyroid carcinomas ( PTC) and the controls. Five thyroid cancer cell lines were treated with methyltransferase inhibitor 5-Aza-dC for 5 days, and real time PCR ( RT-PCR) was performed to evaluate the mRNA expression of CYP1A1 and CYP1B1 genes. Logistic regression was used to analyze the correlation between the aberrant methylation and the clinical features. Results Aberrant methylation status in promoter region of CYP1A1 and CYP1B1 genes were detected in all kinds of thyroid cancers. Compared with control tissues, the methylation in promoter regions of CYP1A1 in PTCs was significantly higher, while that in promoter regions of CYP1B1 was lower (P<0.05). In vitro, 5-Aza-dC treatment significantly increased the CYP1A1 gene mRNA expression for 6. 92 and 8. 30 times in K1 and C643 cell lines respectively and restored CYP1B1 gene mRNA expression for 7.62 times in K1 cell line. Compared with the controls, PTCs with methylation in promoter regions of CYP1B1 had decreased lymphatic metastasis rate. Conclusion The methylation in promoter regions of CYP1A1 and CYP1B1 gene may regulate their mRNA expressions. Aberrant methylation of the promoter region of CYP1B1 is associated with lymph node metastasis in PTC.

Study of genetic detection of KRAS, FCGR, CYP3A5 and CYP1A1 in predicting clinical outcomes of chemotherapy/target therapy in metastatic colorectal cancer (mCRC) / 中国医师杂志

Objective To investigate the predictive and prognostic value of genetic detection of Kirsten rat sarcoma viral oncogene homolog(KRAS),Fc gamma receptors (FCGR),cytochrome P450 3A5 (CYP3A5) and CYP1A1 in patients with metastatic colorectal cancer (mCRC) receiving C225 combined with CapeOx chemotherapy.Methods Twelve KRAS wild-type (WT) mCRC patients were selected receiving C225 (cetuximab) combined with CapeOx (capecitabine/oxaliplatin) chemotherapy.KRAS,FCGR,CYP3A5,CYP1 A1 gene mutation were detected before treatment.The expressions of phosphatase and tensin homolog deleted on chromosome ten (PTEN) were detected in colorectal cancer tissues and the corresponding adjacent tissues expression with immunohistochemical staining (SP method).The relationship between FCGR,CYP3A5,CYP1A1 mutation,and PTEN expression and survival time were analyzed.Results The mutation rates of FCGR,CYP3A5,and CYP1 A1 were 16.7％ (2/12),25％ (3/12) and 16.7％ (2/12) in 12 patients with KRAS WT,respectively.PTEN was expressed mainly in the nucleus in yellowish brown.The rates of expression in the tissue adjacent to the cancer and in the tumor tissue were 100％ (12/12) and 41.7％ (5/12),respectively.PTEN expression in tumor tissue was reduced or absent.The study indicated that the objective response rate [complete response + partial response (CR + PR)] was 80％ in patients whose KRAS,FCGR,CYP3A5,and CYP1A1 were all in wild type,the CR + PR rates in FCGR,CYP3A5,and CYP1A1 gene mutation group were 0,33.6％ and 50％.The objective response rates of patients with PTEN expression or null were 50％ and 37.5％,respectively (P ＜ 0.05).The progression free survival (PFS) with KRAS/FCGR/CYP3A5/CYP1A1 wild type or mutation were 15.56 or 8.12 months (P ＜ 0.05).The overall survival (OS) with wild type or mutation of KRAS/FCGR/CYP3A5/ CYP1A1 were 25.03 or 19.21 months(P ＜0.05).The PFSs of positive or negative expression of PTEN in patients were 9.13 or 7.87 months (P ＜0.05),and the OSs of positive or negative expression of PTEN in patients were 24.25 or 18.74 months (P ＜0.05).Conclusions FCGR,CYP3A5 and CYP1A1 mutations and PTEN expression null both have been associated with resistance to cetuximab in mCRC patients.FCGR,CYP3A5,CYP1A1 and PTEN can be served as the predictive biomarkers for the response to cetuximab.

Study on the induction of drug metabolizing enzyme CYP1 A1 activity by Ginsenoside Rc,Re,Rf and Rg1 / 中国药理学通报

Aim To investigate the induction effect of ginsenoside Rc, Re, Rf and Rg1 on CYP1A1, and further validate the role of aryl hydrocarbon receptor in CYP1A1 expression. Methods Dual luciferase re-porter gene system was performed. Four kinds of gin-senoside were screened for aryl hydrocarbon receptor activation by reporter assays, and TCDD as the positive control. Further with different concentrations of ginsen-oside Rc, Re, Rf and Rg1 treated on LS174T cells, RNA and total protein were extracted to detect the reg-ulating effect of ginsenosides on CYP1 A1 mRNA and protein expression with Real-time PCR and Western blot technology respectively. Results Reporter gene screening showed that the ginsenoside Rc, Re, Rf and Rg1 could activate AhR and had potential effects on the induction of CYP1A1 enzyme. Meanwhile, dose-de-pendent induction of the gene expression were observed in response to ginsenoside Rc, Re, Rf and Rg1 and the levels of CYP1 A1 protein expression were increased by ginsenoside Rc, Re, Rf and Rg1 in varying de-grees. Conclusion Ginsenoside Rc, Re, Rf and Rg1 can up-regulate the gene and protein expression of CYP1 A1 possibly via the AhR-mediated CYP1 A1 path-way.

Cytochrome P450 1A1 genetic polymorphisms as cancer biomarkers.

Phase I metabolic enzyme CYP1A1 plays an important role in xenobiotics metabolism and has been extensively studied as a cancer risk biomarker. CYP1A1 is polymorphic and its four variants, e.g., CYP1A1* 2 A, CYP1A1* 2C, CYP1A1* 3 and CYP1A1* 4 with trivial names m1, m2, m3, and m4 respectively, are most commonly studied for cancer link. Gene‑ gene interaction studies combining polymorphisms of this enzyme with those of phase II detoxifying enzymes, especially glutathione S‑ transferases (GSTs) revealed greater risk for cancer susceptibility. Variants of CYP1A1 have also been found to be associated with chemotherapeutic adverse‑ effects. Results of these studies, however, remained largely contradictory mainly because of lack of statistical power due to involvement of small sample size. Strongly powered experimental designs involving gene‑ gene, gene‑ environment interactions are required in order to validate CYP1A1 as reliable cancer‑ biomarker.

Association of CYP1A1 A4889G and T6235C polymorphisms with the risk of sporadic breast cancer in Brazilian women

OBJECTIVES:We examined the influence of CYP1A1 A4889G and T6235C polymorphisms on the risk of sporadic breast cancer.METHODS:DNA from 742 sporadic breast cancer patients and 742 controls was analyzed using the polymerase chain reaction, followed by the restriction fragment length polymorphism technique.RESULTS:More patients had the CYP1A1 4889AG+GG genotype compared to controls (29.0% versus 23.2%, p=0.004). The G allele carriers had a 1.50-fold increased risk (95% CI: 1.14-1.97) of sporadic breast cancer compared to the other study participants. The frequency of the 4889AG+GG genotype among the Caucasian patients was higher than in the non-Caucasian patients (30.4% versus 20.2%, p=0.03) and controls (30.4% versus 23.2%, p=0.002). Caucasians and G allele carriers had a 1.61-fold increased risk (95% CI: 1.20-2.15) of sporadic breast cancer compared to other subjects. The CYP1A1 4889AG+GG genotype was more common among patients with a younger median age at first full-term pregnancy than among controls (33.8% versus 23.2%, p=0.001) and subjects whose first full-term pregnancies occurred at an older age (33.8% versus 26.1%, p=0.03). Women with the CYP1A1 4889AG+GG genotype and earlier first full-term pregnancies had a 1.87-fold (95% CI: 1.32-2.67) increased risk of sporadic breast cancer compared to the other study participants. Excess CYP1A1 4889AG+GG (39.8% versus27.1%, p=0.01) and 6235TC+CC (48.4% versus 35.9%, p=0.02) genotypes were also observed in patients with grade I and II tumors compared to patients with grade III tumors and controls (39.8% versus 23.2%, p=0.04; 48.4% versus 38.6%, p=0.04). The G and C allele carriers had a 2.44-fold (95% CI: 1.48-4.02) and 1.67-fold (95% CI: 1.03-2.69) increased risk, respectively, of developing grade I and II tumors compared to other subjects.CONCLUSIONS:The CYP1A1 A4889G and T6235C polymorphisms may alter the risk of sporadic breast cancer in Brazilian women.

Polimorfismo CYP1A1*2A e infertilidad en hombres de la región Caribe colombiana / CYP1A1*2A polymorphism and infertility in Colombian Caribbean male subjects

Objetivo: El objetivo de este estudio fue investigar la asociación del polimorfismo CYP1A1*2A (T-C) y la infertilidad en una muestra de hombres del Caribe colombiano. Materiales y Métodos: Se analizaron características macroscópicas y microscópicas de la muestra seminal de 31 hombres infértiles y 20 fértiles. La genotipificación del polimorfismo se realizó a partir de la técnica PCR-RFLP. Resultados: Se encontraron diferencias significativas (p<0.05) en las características seminales microscópicas en ambos grupos. Además, se identificaron alteraciones en movilidad, concentración y/o morfología. Fueron identificados tres genotipos: TT, TC y CC. En los inértiles se presentaron 25 individuos con genotipo TT (80.6 %), 5 TC (16.1 %) y 1 CC (3.2 %), y en el grupo fértil 16 individuos presentaron genotipo TT (80.0 %), 4 TC (20.0 %) y 0 CC (0.0 %). La distribución genotípica se encontró en equilibrio Hardy - Weinberg en ambos grupos. El análisis de regresión logística mostró que no hubo asociación significativa entre el polimorfismo CYP1A1*2A y la infertilidad en hombres del Caribe colombiano (p>0.05). Conclusión: Estos resultados preliminares sugieren que el polimorfismo CYP1A1*2A no contribuye a la infertilidad masculina en hombres del Caribe colombiano. Sin embargo, son de gran importancia debido a que existe escasa información que asocie polimorfismos del gen CYP1A1 con la infertilidad masculina.

Objective: The aim of this study was to investigate the association of CYP1A1*2A polymorphism (T-C substitution) with male infertility in Colombian Caribbean subjects. Materials and Methods: Macroscopic and microscopic characteristics were analyzed in the semen sample of 31 infertile and 20 fertile men. The polymorphism was genotyped through PCR-RFLP. Results: Both groups evidenced significant differences in microscopic characteristics (p< 0.05), as well as alterations in sperm motility, count and morphology. Three genotypes were identified: wild type homozygous (TT), heterozygous (TC) and variant homozygous (CC). 25 TT genotype (80.6%), 5 TC genotype (16.1%) and 1 CC genotype (3.2%) in infertile men, and 16 TT genotype (80.0%), 4 TC genotype (20.0%) and 0 CC genotype (0.0%) in fertile men were identified. In both infertile and fertile men, distributions of the genotypes were in Hardy-Weinberg equilibrium. Logistic regression analysis showed no significant association between CYP1A1*2A polymorphism and male infertility in Colombian Caribbean men (p>0.05). Conclusion: These preliminary results suggest that CYP1A1*2A polymorphism do not contribute to male infertility of Colombian Caribbean men. However, they are very important because there is limited information about CYP1A1 gene polymorphisms associated with male infertility.

Association of CYP1A1z.ast;2C polymorphism with the susceptibility to childhood acute lymphoblastic leukemia: A meta-analysis / 肿瘤

Objective: To explore the contribution of cytochrome P450 (CYP) 1A1z.ast;2C polymorphism to susceptibility to acute lymphoblastic leukemia (ALL) in children. Methods: The case-control studies involving the association of CYP1A1z.ast;2C polymorphism with the susceptibility to childhood ALL were retrieved through computer-based search in PubMed, Embase, Ovid, China Journal Full-text Database, Chinese Biomedical Literature Data, China National Knowledge Infrastructure and Wanfang Database. The statistical analysis was performed by STATA 12.0 software. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated, and the subgroup ananlysis, sensitivity analysis and publication bias were also carried out. Results: A total of seven eligible case-control studies were included for analysis. The Meta analysis revealed that there was a significant association of CYP1A1z.ast;2C ploymorphism with risk of childhood ALL (C vs A: OR = 1.20, 95% CI: 1.01-1.43; GG vs AA: OR = 1.73, 95% CI: 1.1 1-2.70; GG vs AG + AA: OR = 1.68, 95% CI: 1.09-2.59). In a subgroup in which the controls were hospitalized in the same period as the cases hospitalized, there was also a significant association of CYP1A1z.ast;2C ploymorphism with risk of childhood ALL (G vs A: OR = 1.29, 95% CI: 1.04-1.59; GG vs AA: OR = 1.89, 95% CI: 1.15-3.10; GG vs AG+AA: OR = 1.83, 95% CI: 1.14-2.94). After excluding a study with high heterogeneity, the sensitivity analysis showed no significant association between CKP1A1z.ast;2C ploymorphism and childhood ALL. Conclusion: The results of this Meta analysis suggest that CYP1A1z.ast;2C polymorphism may be not significantly associated with the susceptibility to childhood ALL.

Association between CYP1A1 genetic polymorphisms and coronary artery disease in Uygur population in Xinjiang, China / 中华流行病学杂志

Objective To assess the association between human CYP1A1 gene polymorphisms and coronary artery disease (CAD) among the Uygur population of China.Methods Genotypes of CYP1A1 single nucleotide polymorphisms (SNPs:rs4886605,rs 12441817,rs4646422 and rs1048943) were detected by real-time PCR in 293 CAD patients and 408 controls.Results Among the Uygur group,distribution of genotypes and allele of rs4886605 were both significantly different between CAD and the controls (all P＜0.05).The dominant model (CC vs.CT + TT) of rs4886605 was significantly lower among CAD patients than in controls.Significant differences were retained after the adjustment was made in all the participants (OR=0.368,95％CI:0.185-0.530,P=0.018) and in men (OR=0.350,95％CI:0.235-0.568,P=0.015).Distributions of genotypes and allele of rs12441817 were both significantly different between CAD and the controls (all P＜0.05).The dominant model (TT vs.CT+CC) of rs12441817 was significantly lower among patients CAD than in controls.Significant difference were retained after the adjustment was made,in total participants (OR=0.253,95％ CI:0.231-0.546,P=0.016) and in men (OR=0.241,95％ CI:0.132-0.478,P=0.002).Conclusion Both rs4886605 and rs12441817 SNPs of the CYP1A1 gene were associated with CAD in the Uygur population of China.

Association of CYP1A1 gene polymorphism with adverse reactions of high-does methotrexate in children with acute lymphocytic leukemia / 实用医学杂志

Objective To investigate the association between CYP1A1 gene polymorphism and toxicities related to high-does methotrexate of childhood acute leukemia. Methods The SNPs were detected by reverse transcriptional (RT)-PCR-denaturing gradient gel elelctrphoresis combined with direct sequencing in 51 children with acute leukemia. Toxicities were collected thereby. Results Only one SNP,A4889G, was screened in CYP1A1. A4889G polymorphism was not associated with all the toxicities (P > 0.05). High-risk ALL children were more likely to increase the risk of thrombocytopenia compared with standard-risk ALL (P< 0.05). Conclusions CYP1A1 A4889G polymorphism may be not association with all toxicities after HD-MTX ,but the thrombocytopenia may be relevant to the risk degree of ALL children.

Relationship between MspⅠ polymorphism of CYP1A1 gene and susceptibility to breast cancer in Yi nationality in Yunnan province / 实用医学杂志

Objective To explore the relationship between MspⅠpolymorphism of CYP1A1 gene and susceptibility to breast cancer in Yi nationality in Yunnan province. Methods The gene polymorphism of restriction enzyme of 3′-terminal of CYP1A1 was detected by PCR-RFLP in 60 healthy Yi women , 51 Yi women with breast cancer, 235 healthy Han women, and 250 Han women with breast cancer. Results The distribution frequency of CYP1A1-MspⅠgenotypes was significantly higher in Yi women with breast cancer (51.0%) than in the healthy Yi women (33.3%) (P 0.05), and there were no differences in three genotype frequencies (P > 0.05). Conclusions Gene polymorphism of CYP1A1 genotypes may be associated with the risk of breast cancer in Yi nationality but not in Han nationality in Yunnan. The mutation of CYP1A1 gene may increase the incidence of breast cancer in Yi nationality.

Analysis of PAH-DNA adducts and gene polymorphisms of CYP1A1 and GSTM1 in lymphoma patients / 白血病·淋巴瘤

Objective To explore the relationship between PAH-DNA adducts and CYP1A1,GSTM1 gene polymorphisms and lymphoma.Methods PAH-DNA adducts from bone marrow of lymphoma patients and control cases were determined by competitive ELISA.The genotypes of both CYP1A1 and GSTM1 were detected by PCR-based restriction fragment length polymorphisms (PCR-RELP).Results The level of PAH-DNA adducts in lymphoma patients [(2 498±1 250) pg/ml] was significantly higher than that in control [(1 882±797) pg/ml] (t =0.006,P ＜ 0.05).CYP1A1 mutant genotype and GSTM1 null genotype had increased risk of lymphoma,with OR being 1.36 (95 ％ CI 0.56-3.31,P ＞ 0.05),4.03 (95 ％ CI 1.51-10.76,P ＜ 0.05),respectively.GSTM1 null genotype individuals with PAH-DNA level higher (or equal) than 2 200 pg/ml had increased risk of lymphoma.Conclusions The content of PAH-DNA adducts and the occurrence of lymphoma may have a certain correlation.GSTM1 null genotype may be linked to lymphoma and increase the risk.

Frecuencia de los polimorfismos CYP1A1*2A y deleción del gen GSTM1 en pacientes con carcinoma de células escamosas de laringe en relación al hábito tabáquico: estudio piloto en Chile / Frequency of CYP1A1*2A and GSTM1 gene polymorphisms in Chilean patients with squamous cell carcinoma of the larynx in relation to smoking habit: a pilot study

Introducción: Entre los factores de riesgo para cáncer laríngeo (CL) son relevantes el consumo de tabaco y alcohol. Estos xenobióticos son metabolizados por un grupo de enzimas, entre las cuales están CYP1A1 y GSTM1, cuyas variantes polimórficas se postulan como factores de riesgo para esta enfermedad. Objetivos: Describir la frecuencia de las variantes de los polimorfismos de CYP1A1 y GSTM1 en un grupo de pacientes diagnosticados con CL. Analizar la posible correlación entre las variantes genéticas de ambas enzimas y la presencia de CL. Evaluar la influencia del hábito tabáquico en el riesgo de aparición de cáncer escamoso de laringe en pacientes con genotipos de riesgo. Material y método: Se seleccionaron 35 pacientes con CL entre los años 2000 y 2010 en Servicio de Otorrinolaringología del HBLT y 124 controles reclutados en el Centro de Investigaciones Farmacológicas y Toxicológicas (IFT). A todos los individuos se les registraron datos demográficos y extrajo una muestra de sangre para analizar las variantes polimórficas de CYP1A1 y GSTM1, mediante PCR-RFLP. Resultados: De un total de 35pacientes 54,3% presentan el genotipo GSTM1 (-/-) y 17,1% el genotipo CYP1A1*2A C/C. En el grupo control (n =140) estas frecuencias fueron de 19,35°% y 10,48%o, respectivamente. Se observó una correlación entre GSTM1 y el CL, estratificado por el hábito tabáquico y alcohólico. No se encontraron relaciones estadísticamente significativas con el hábito alcohólico y/o tabáquico. No se observaron asociaciones entre la patología y la combinación de genotipos o entre genotipos y el hábito tabáquico o alcohólico. Conclusiones: Los resultados muestran una asociación estadísticamente significativa entre la deleción de GSTM1 (-/-) y el riesgo de presentar CL, lo que refleja el importante papel que juega esta enzima en la desintoxicación de compuestos cancerígenos. Sin embargo, se requiere incrementar el número de pacientes para establecer apropiadamente la relación genético-ambiental que permite adjudicar un papel relevante a estos biomarcadores.

Introduction: Tobacco and alcohol consumption are recognized risk factors for squamous cell carcinoma of the larynx. These xenobiotics are metabolized by numerous enzymes, among which, CYP1A1 and GSTM1 gene polymorphisms have been identified as risk factors for developing tobacco related cancers as lung and laryngeal carcinomas. Nevertheless, these polymorphisms have not been studied in Chilean patients with squamous cell carcinoma of the larynx. Aim: To describe, for the first time, the frequency of CYP1A1 and GSTM1 gene polymorphisms in Chilean patients with squamous cell carcinoma of the larynx. Material and method: We conducted a case-control study. The case group consisted of 35 Chilean patients with squamous cell carcinoma of the larynx; the control group was formed by 124 Chilean subjects without cancer diagnosis. Demographic data as age, sex and quantification of tobacco smoking and alcohol consumption were recorded in all individuals. CYP1A1 and GSTM1 gene polymorphisms were evaluated by polymerase chain reaction and restriction enzymes (PCR-RFLP). Results: The frequency of CYP1A1*2A C/C genotype was 54, 3°% among laryngeal cancerpatients and 17,1%% among control subjects. The frequency ofGSTM1 (-/-) genotype was 19,35 %% among laryngeal cancer patients and 10,48%% among control subjects. There were no statistically significant relationships between this gene polymorphisms and tobacco smoking or alcohol consumption. There were no associations between the presence of both gene polymorphisms in the same individual and the presence of laryngeal cancer. Interestingly we found an OR of 8.69 (CI 2.90 to 26.01) for GSTM1 (-/-) polymorphism and laryngeal cancer, stratified by tobacco smoking and alcohol consumption. Conclusions: Our work shows that the deletion of GSTM1 could be an important risk factor for squamous cell carcinoma of the larynx in Chilean patients. This finding reflects the important role that detoxification of carcinogenic compounds plays in Chilean population. However, it is necessary to increase the number of studied patients to properly establish the genetic-environmental relationship ascribed to these biomarkers.

Head and Neck Squamous Cell Carcinoma: Genetic Polymorphisms and Occurrence Risks / 한양의대학술지

Head and neck squamous cell carcinoma (HNSCC), which is the 5th most common cancer worldwide, is believed to be induced by environmental carcinogens and host genetic factors. The main etiologic environmental factors are tobacco, alcohol, viral infection, nutritional deficit, mineral inhalation and history of radiation exposure. Accumulating evidence has shown that genetic polymorphisms influence the risk of environmental carcinogenesis, and that genetic susceptibility plays an important role in the development of HNSCC. Genetic susceptibility to HNSCC may be due to genetic polymorphisms in genes controlling both carcinogen metabolism and repair of DNA damage. We analyzed the associations between genetic polymorphisms in the xenobiotics metabolizing gene, alcohol metabolizing gene and DNA repair genes and the risk of HNSCC in an at-risk Korean population. In conclusion, ADH1B +3170A>G His48Arg and XRCC1 R194W (C>T) polymorphism are associated with an increased risk of HNSCC, and these genotypes could be useful biomarkers for identifying Koreans with a greater risk of HNSCC.

Relationship between CYP1A1 polymorphisms and invasion and metastasis of breast cancer

OBJECTIVE@#To investigate the relationship between CYP1A1 genetic polymorphisms and the invasion and metastasis of breast cancer.@*METHODS@#The CYP1A1 gene polymorphism (an T-C transversion at nucleotide position 3801) was detected by the polymerase chain reaction and restriction fragment length polymorphism in 80 cases with breast cancer and 60 samples of normal breast tissue. The difference in genotypic distribution frequency between the groups, the correlation between the genotypes and the factors related to prognosis were analyzed.@*RESULTS@#The incidence of homozygous and variant genotypes had no difference between the breast cancer group and controls group (P=0.746). The proportion of variant genotype increased as clinical stage (P=0.006) advanced, as well as with increased numbers of lymph node metastases (P=0.010).@*CONCLUSIONS@#In patients with breast cancer there is a correlation between the CYP1A1 CC allele and some factors indicating poor prognosis, including more lymph node metastases as well as a more advanced clinical stage.

Mete analysis of colorectal cancer risk and CYP1A1 polymorphism / 肿瘤研究与临床

Objective To evaluate the association between CYP1A1 polymorphism and colorectal cancer risk.Methods PubMed,Embase and Web of Science databases were searched using the search terms as ‘Cytochrome P4501Al’,‘CYP1A1’,‘polymorphism’ and ‘colorectal cancer’.A meta-analysis was performed by STATA 10.0 software to assess the data included.Results By using 6768 cases and 7973 controls from 15 studies,significantly elevated colorectal cancer risks were associated with CYP1A1 2454A＞G in the following models (G vs A:pooled OR =1.19,95 ％ CI =1.03-1.37; GG vs AA:OR =1.40,95 ％ CI =1.12-1.75; GG vs AG+AA:OR =1.43,95 ％ CI =1.15-1.78).Conclusion CYP1A1 2454A＞G may cause an increased risk of colorectal cancer.

Role of CYP1A1 haplotypes in modulating susceptibility to coronary artery disease.

To investigate the role of cytochrome P450 1A1 (CYP1A1) haplotypes in modulating susceptibility to coronary artery disease (CAD), a case-control study was conducted by enrolling 352 CAD cases and 282 healthy controls. PCR-RFLP, multiplex PCR, competitive ELISA techniques were employed for the analysis of CYP1A1 [m1 (T→C), m2 (A→G) and m4 (C→A)] haplotypes, glutathione-S-transferase (GST)T1/GSTM1 null variants and plasma 8-oxo-2’deoxyguanosine (8-oxodG) respectively. Two CYP1A1 haplotypes, i.e. CAC and TGC showed independent association with CAD risk, while all-wild CYP1A1 haplotype i.e. TAC showed reduced risk for CAD. All the three variants showed mild linkage disequilibrium (D’: 0.05 to 0.17). GSTT1 null variant also exerted independent association with CAD risk (OR: 2.53, 95% CI 1.55–4.12). Among the conventional risk factors, smoking showed synergetic interaction with CAC haplotype of CYP1A1 and GSTT1 null genotype in inflating CAD risk. High risk alleles of this pathway showed dose-dependent association with percentage of stenosis and number of vessels affected. Elevated 8-oxodG levels were observed in subjects with CYP1A1 CAC haplotype and GSTT1 null variant. Multiple linear regression model of these xenobiotic variants explained 36% variability in 8-oxodG levels. This study demonstrated the association of CYP1A1 haplotypes and GSTT1 null variant with CAD risk and this association was attributed to increased oxidative DNA damage.