CYP1A1、CYP2D6基因多态性对白血病发生的影响

目的 分析细胞色素P450 CYP1A1和CYP2D6的多态性基因型在湖南地区白血病患者和健康人群中的分布及其对白血病发生的影响.方法 采用PCR及PCR-RFLP技术分析多态性基因型频率.结果 CYP1A1和CYP2D6基因的野生型、杂合突变型及纯合突变型的分布频率在急性淋巴细胞性白血病、急性非淋巴细胞性白血病、慢性粒细胞性白血病患者组与健康对照组之间无显著性差异;携带一个突变等位基因型的个体患白血病的风险与相应野生型携带者比较均无显著性差异;急性非淋巴细胞性白血病患者组的CYP1A1杂合突变型与CYP2D6杂合突变型的联合基因型频率高于健康对照组.结论 单独的CYP1A1或CYP2D6基因的多态性变异与白血病易感性不相关;CYP1A1杂合突变与CYP2D6杂合突变的联合基因型增加患急性非淋巴细胞性白血病的风险.     

Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not involved in the risk of recurrent pregnancy loss

The etiology of recurrent pregnancy loss (RPL) remains unclear, but it may be related to a possible genetic predisposition together with involvement of environmental factors. We examined the relation between RPL and polymorphisms in four genes, human aryl hydrocarbon (Ah) receptor, cytochrome P450 (CYP) 1A1, CYP1A2 and CYP1B1, which are involved in the metabolism of a wide range of environmental toxins and carcinogens. All cases and controls were women resident in Sapporo, Japan and the surrounding area. The Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotypes were assessed in 113 Japanese women with recurrent pregnancy loss (RPL) and 203 ethnically matched women experiencing at least one live birth and no spontaneous abortion (control). No significant differences in Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotype frequencies were found between the women with RPL and the controls [Ah receptor: Arg/Arg (reference); Arg/Lys and Lys/Lys, odds ratio (OR)=0.67; 95% confidence interval (CI)=0.40-1.11, CYP1A1: m1m1 (reference); m1m2 and m2m2, OR = 0.86; 95% CI = 0.53-1.40, CYP1A2: C/C and C/A (reference); A/A, OR = 1.16; 95% CI = 0.71-1.88, CYP1B1: Leu/Leu (reference); Leu/Val and Val/Val, OR = 1.18; 95% CI = 0.68-2.02]. The present study suggests that the Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not major genetic regulators in RPL.     

兔抗人细胞色素P450 1A2多克隆抗体的制备及鉴定

目的：制备兔抗人细胞色素P4501A2（CYP1A2）抗体及其特性鉴定。方法：利用生物信息学方法分析CYP1A2蛋白的序列，根据亲水性、抗原性、柔韧性及表面性等指标选择多肽序列，合成CYP1A2多肽，与载体蛋白钥孔戚血蓝素（Keyhole limpet hemocyanin，KLH）偶联，免疫日本大耳白兔制备抗CYP1A2抗体。辛酸-硫酸铵法纯化抗体，间接ELISA法测定抗体的效价及相对亲和力常数，Western blot鉴定其特异性，免疫组化进行定位。结果：获得针对小分子CYP1A2的抗体。该抗体效价为1∶16000；相对亲和力常数在10^5-10^6/M，具有实用价值；可与CYP1A2合成肽及天然CYP1A2出现特异性反应；可识别正常人肝脏组织CYP1A2；Western blot的结果显示，该抗体识别的相应抗原的相对分子质量为58000。结论：合成的多肽-KLH复合物具有免疫原性，可用于制备相应的抗体。制备的兔抗CYP1A2合成肽抗体可应用于酶联免疫吸附试验、免疫印迹、免疫组化实验。     

小鼠抗人细胞色素P450 1A2合成肽抗血清的制备与鉴定

目的：制备小鼠抗人细胞色素P450 1A2（CYP1A2）抗体及其特性鉴定。方法：利用生物信息学方法分析CYP1A2蛋白的序列,根据4个指标（亲水性、柔韧性、抗原性及表面性）选择欲合成的多肽序列,设计、合成CYP1A2多肽。将其与载体蛋白钥孔戚血蓝素（keyhole limpet hemocyanin,KLH）偶联,免疫BALB/c雌性小鼠制备抗CYP1A2抗体。用间接ELISA法测定抗体的效价,Western blot鉴定其特异性。结果：成功地获得针对小分子CYP1A2的抗体。该抗体效价为1∶16000,可与CYP1A2合成肽及天然CYP1A2出现特异性反应。Western blot的结果显示,该抗体识别的相应抗原的相对分子质量（Mr）为58000。结论：合成的多肽-KLH复合物具有免疫原性,可用于制备相应的抗体。制备的小鼠抗CYP1A2合成肽抗体的效价高及特异性良好。     

Transcriptional activation of cytochrome P450 1A1 with α-tocopherol

Peroral administration of α-tocopherol in a daily dose of 150 mg/kg for 1, 4, 8, and 12 days leads to induction of cytochromes P450 1A in male rats. Activity of CYP1A1 and CYP1A2 increased most significantly one day after α-tocopherol administration (by 2.6 and 2.7 times, respectively). CYP1A1 was immunohistochemically detected in rat liver microsomes during this period. The content ofCYP1A1 mRNA significantly increased in the liver. The amount ofCYP1A2 mRNA and regulatory proteins for signal activation of CYP1A1 (AhR andArnt) remained unchanged after treatment with α-tocopherol. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 138, No. 9, pp. 264–267, September, 2004     

Analysis of human CYP1A1 and CYP1A2 genes and their shared bidirectional promoter in eight world populations

The human CYP1A1_CYP1A2 locus comprises the CYP1A1 (5,988 bp) and CYP1A2 (7,759 bp) transcribed regions, oriented head‐to‐head, sharing a bidirectional promoter of 23,306 bp. The older CYP1A1 gene appears more conserved and responsible for critical life function(s), whereas the younger CYP1A2 gene might have evolved more rapidly due to environmental (dietary) pressures. A population genetics study might confirm this premise. We combined 60 CYP1A1_CYP1A2 SNPs found in the present study (eight New Guinea Highlanders, eight Samoans, four Dogrib, four Teribe, four Pehuenche, and one Caucasian) with those found in a previous study (six West Africans, four Han Chinese, six Germans, four Samoans, and four Dogrib), yielding a total of 106 SNPs in 106 chromosomes. Resequencing of Oceanians plus Amerindians in the present study yielded 21 New World SNPs (～20%), of which 17 are not previously reported in any SNP database. Various tests revealed selective pressures for both genes and both haploblocks; unfortunately, differences in rates of evolution between the two genes were undetectable. Fay & Wu's H test revealed a “hitchhiking event” centered around four SNPs in the CYP1A1 3′‐UTR; a study in silico identified different microRNA‐binding patterns in the hitchhiked region, when the mutations were present compared with the mutations absent. Hum Mutat 30:1–14, 2009. © 2009 Wiley‐Liss, Inc.     

CYP1A1基因I462V多态与非小细胞肺癌的相关性

目的 探讨CYP1A1基因1462V多态性与非小细胞肺癌的相关性.方法 采用病例对照研究,应用聚合酶链反应-限制性片段长度多态性对72例非小细胞肺癌患者(病例组)和90例正常对照(对照组)CYP1A1基因I462V多态进行检测,分析基因型频率和等位基因频率在病例组和对照组的分布,比较不同基因型与非小细胞肺癌患病风险的关...     

Polymorphisms in the VKORC1 gene are strongly associated with warfarin dosage requirements in patients receiving anticoagulation

Background

Warfarin is a mainstay of therapy for conditions associated with an increased risk of thromboembolic events. However, the use of this common agent is fraught with complications and little is known regarding inter‐individual variation in warfarin response.

Objective

We tested for association between single nucleotide polymorphisms (SNPs) in VKORC1 and CYP2C9 and average weekly warfarin dose required to maintain patients at their desired anticoagulation target.

Methods

The sample consisted of 93 European‐American patients from anticoagulation clinics at the University of North Carolina at Chapel Hill. Data on mean weekly warfarin dose were collected over a mean treatment period of 20.6 months. ANCOVA models were used and haplotype analysis was performed.

Results

Three of six VKORC1 SNPs were found to be very strongly associated with the average warfarin dose required to achieve the target international normalised ratio (INR; p<0.0001). The mean weekly dose by genotype ranged from approximately 27 to 47 mg. There was no evidence for an association between either of the two CYP2C9 polymorphisms studied, CYP2C9*2 and CYP2C9*3. CYP2C9*3 was significantly (p = 0.05) associated with average warfarin dosage after adjustment for VKORC1*1173.

Conclusions

These results are of considerable clinical interest and confirm recently published results regarding the role of these two genes in modifying warfarin metabolism and maintenance dosage. The consistent findings regarding the role of VKORC1 and CYP2C9 in warfarin metabolism and maintenance dosage represent a clinically useful proof of principal for the use of pharmacogenomic information in medicine and may lead to improved understanding of warfarin''s actions.     

Haplotypes in the 5′‐untranslated region of the CYP1A2gene are inversely associated with lung cancer risk but do not correlate with caffeine metabolism

In this study, we analyzed the influence of CYP1A2 genetic variation and enzyme activity on lung cancer risk in a high‐incidence area. A total of 95 lung cancer patients and 196 controls were genotyped for the ?3860G/A, ?3113A/G, ?2467T/delT, ?739T/G, and ?163C/A polymorphisms in the 5′‐untranslated region of the gene. In addition, a subset of 70 patients and 115 controls were phenotyped by high‐performance liquid chromatography determination of the caffeine metabolic ratio (CMR). The ?2467T/delT polymorphism and the CYP1A2*1V haplotype (‐163C>A, ?2467T>delT) were inversely associated with lung cancer risk (odds ratio [OR] = 0.47 [0.2–0.9]; P = 0.02 and OR = 0.13 [0.02‐1.0]; P = 0.04; respectively). In addition, the CYP*1A/*1V and *1F (‐163C>A)/*1D (?163C>A, ?2467T>delT) diplotypes were absent in the patients group, whereas accounting for 7.1% (P = 0.017) and 5.6% (P = 0.037) of controls, respectively. Mean CMR was significantly higher in patients than in controls (10.50 ± 17.31 vs. 6.52 ± 6.26, P = 0.01) but regression analyses did not yield significant ORs for the association with lung cancer risk. Similarly, no significant correlations were found between any genetic variant and enzyme activity. Several CYP1A2 haplotypes and diplotypes containing the ?2467delT variant were associated with lower lung cancer risk; however, they did not correlate with significant changes in CYP1A2 metabolic activity toward caffeine. Environ. Mol. Mutagen., 2013. © 2012 Wiley Periodicals, Inc.     

Effect of triphenyldioxane on phase I xenobiotic metabolism enzymes in the liver of rats and rabbits

We studied the effect of triphenyldioxane on phase I xenobiotic metabolism enzymes in the liver of rats and rabbits. Total cytochrome P450 content, protein concentration, and catalytic activity of CYP2B, CYP3A, and CYP2C isoforms were measured. Triphenyldioxane significantly increases specific activity of CYP2B and CYP2C in the liver of rats and rabbits, respectively. Immunoblotting analysis of microsomal enzymes in the liver of animals showed that the increase in specific activity of CYP is related to high content of apoenzymes. We showed for the first time that rats and rabbits are characterized by interspecies differences in the induction of cytochrome P450 isoforms under the influence of triphenyldioxane. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 141, No. 6, pp. 646–648, June, 2006     

山东人群华法林稳定剂量预测模型的准确性验证

目的比较5种华法林稳定剂量预测模型以及经验给药方式(2.5 mg/day)对山东人群预测的准确性。方法招募正在或曾经服用华法林并已达到稳定剂量的患者,检测重要的华法林药物代谢基因的型别,收集患者的临床信息,采用预测百分比及绝对误差均值法评价各模型预测的准确性。结果在入组的125例患者中,CYP2C9*1/*1、CYP2C9*1/*3和CYP2C9*1/*2基因型分别占92.00%、7.20%和0.80%。VKORC1-1639 AA、AG、GG基因型分别占82.40%、15.20%、2.40%;CYP4F2*1/*1、*1/*3,*3/*3基因型分别占50.40%、39.20%、10.40%。在其他位点型别固定的情况下,CYP2C9*1/*3和CYP2C9*1/*2基因型个体与CYP2C9*1/*1相比华法林剂量明显降低。VKORC1-1639 AG型与AA型相比华法林稳定剂量增加45%~50%(P<0.05)。CYP4F2*1/*3与CYP4F2*1/*1基因型个体相比,华法林稳定剂量增加约5.9%(P=0.02);CYP4F2*3/*3与CYP4F2*1/*1基因型个体相比华法林剂量增加约13.0%(P=0.129)。预测效果较好的模型包括IWPC(59.20%)、Huang(57.60%)、Ohno(52.80%),绝对误差均值分别为0.35(95%CI:0.11~0.49)、0.15(95%CI:0.10~0.32)、0.39(95%CI:0.12~0.51)。结论CYP2C9、VKORC1、CYP4F2等3个基因的多态性对山东人群的华法林稳定剂量存在影响。IWPC模型更适用于山东人群。     

韩国人CYP450 1A1、CYP450 2E1和GSTM1、GSTT1、GSTP1基因座遗传多态性分析

目的 调查代谢相关的CYP4501A1、CYP4502E1和GSTM1、GSIT1、GSTP1基因座在韩国人群中的遗传多态性分布状况。方法 采用多重聚合酶链式反应、聚合酶链式反应-限制性片段长度多态性技术，分析300名韩国健康大学生的CYP1A1基因3′端限制性内切酶Msp Ⅰ位点、CYP2E1基因5′端转录调节区Pst Ⅰ位点和GSTM1、GSTT1缺失与存在、GSTP1基因第5外显子BsmA Ⅰ位点的基因型，计算基因型和基因频率。结果 CYP1A1基因型频率为ml／ml型39．7％、ml／m2型49．7％、m2／m2型10．7％，基因频率为ml 0．645、m2 0．355。CYP2E1基因型频率为cl／cl型66．7％、cl／c2型30％、c2／c2型3．3％，基因频率为C1 0．818、C2 0．182。GSTM1基因缺失型频率为53．3％。GSTT1基因缺失型频率为54．7％。GSTP1基因型频率为Ile／Ile型62％、Ile／Val型34．3％、VaL／Val型3．7％，基因频率为Ile 0．792、Val 0．208。基因分布符合Hardy-Weirtberg平衡定律。结论 韩国人CYP1A1、CYP2E1、GSTM1、GSTT1基因分布与我国人群较为相近，半数以上人缺乏GSTM1和GSTT1基因，纯合缺失型频率超过印度人的3倍。     

Immunohistochemical localization of cytochrome P450 2E1 in human pulmonary carcinoma and normal bronchial tissue

Cytochrome P450 2E1 (CYP2E1) is a major xenobiotic-metabolizing enzyme but data concerning its extrahepatic expression are few. CYP2E1 can metabolically activate many procarcinogens and therefore its presence in the lung might play a role in bioactivation of procarcinogens, so we studied the expression and localization of CYP2E1 in primary pulmonary carcinomas and surrounding normal bronchial tissue from 28 patients. Seromucous glands showed expression of CYP2E1 in 19 and bronchial epithelium in 18 of the 28 samples of normal bronchial tissue. Thirteen of the corresponding cases of primary pulmonary carcinoma showed staining for CYP2E1. In 11 of these 13 cases, CYP2E1 was also present in normal bronchial tissue. There was no statistically significant difference in the expression of CYP2E1 between adenocarcinomas and squamous cell carcinomas. No association was observed between the expression of CYP2E1 in tumour tissue and normal bronchial tissue. However, there was a significant correlation between the expression of CYP2E1 in seromucous glands and bronchial epithelium (r=0.61, P<0.01) of normal tissue. We conclude that CYP2E1 can be present in both normal and neoplastic bronchial tissue.     

Dose- and Time-Dependent Effects of Menadione on Enzymes of Xenobiotic Metabolism in Rat Liver

We studied the effect of synthetic vitamin K analogue menadione on enzymes of xenobiotic metabolism in rat liver (total content of cytochrome P450 and catalytic activities of CYP1A1/2, CYP2B1, CYP2C, NADPH-cytochrome P450 reductase, and glutathione S-transferase). Menadione induced phase I and II enzymes for metabolism of xenobiotics, drugs, and procarcinogens. The effect of menadione depended on its dose and duration of treatment.     

湖北地区房颤患者VKORC1、CYP2C9基因多态性及其对华法林用量的影响

目的:检测房颤患者维生素K环氧化物还原酶复合物1基因(VKORC1)和细胞色素P450酶2C9基因(CYP2C9)多态性及其对临床使用华法林用量的影响。方法:选择口服华法林抗凝治疗的房颤患者94例,采用PCR扩增和DNA直接测序技术检测患者VKORC1和CYP2C9基因型,同时记录不同基因型患者华法林日用量,比较不同基因型房颤患者华法林日用量的统计学差异。结果:94例房颤患者检出VKORC1 AA型84例,VKORC1AG型10例,CYP2C9*1/*1型88例,CYP2C9*1/*3型6例。不同VKORC1、CYP2C9基因型房颤患者华法林用量不同,VKORC1AA型并CYP2C9*1/*1型和VKORC1AG型并CYP2C9*1/*1型患者华法林日用量均高于VKORC1AA型并CYP2C9*1/*3型患者,VKORC1AA型并CYP2C9*1/*1型患者华法林用量又高于VKORC1AG型并CYP2C9*1/*1型患者。结论:湖北地区房颤患者基因型主要为VKORC1AA型与CYP2C9*1/*1型,少量VKORC1AG型与CYP2C9*1/*3型。VKORC1、CYP2C9基因型是华法林用量的重要影响因素。     

CYP Gene Polymorphisms and Early Menarche

Early age at menarche is a risk factor for breast cancer. A previous study reported a significant positive association between the CYP3A4*1B variant allele and early puberty. We investigated whether polymorphisms of the CYP3A4, CYP17, CYP1B1, and CYP1A2 genes predict the age at onset of menarche. Five hundred eighty-three nulliparous women between ages 17 and 35, of various ethnic backgrounds, completed a questionnaire that included information about menstrual history. Samples of DNA were provided and used to genotype these women for polymorphic variants in the four genes. There was no significant difference in mean age at menarche between women who carried two variant CYP17 A2 alleles (12.5 years) and women who carried one or no variant allele (12.5 years) (P = 0.8, adjusted for ethnic group and year of birth). Similar results were found for the CYP1B1*3 variant allele and for the CYP1A2*1F variant allele. Women who carried two variant CYP3A4*1B alleles had an earlier mean age at menarche (12.0 years) than women who carried one or no variant allele (12.6 years) (P = 0.02). However, after adjusting for ethnic group and year of birth, no significant differences in mean age at menarche were found. The polymorphic variants of the CYP3A4, CYP17, CYP1B1, and CYP1A2 genes are unlikely to influence age of menarche.     

Toward the evaluation of function in genetic variability: characterizing human SNP frequencies and establishing BAC-transgenic mice carrying the human CYP1A1_CYP1A2 locus

Interindividual differences in human CYP1A1 and CYP1A2 expression appear to be associated with variability in risk toward various types of environmental toxicity and cancer. These two genes are oriented head-to-head on human chromosome 15; the 23.3-kb spacer region might contain distinct regulatory regions for CYP1A1 and distinct regulatory regions for CYP1A2, or the regulatory regions for the two genes might overlap one another. From 24 unrelated subjects of five major, geographically-isolated subgroups, we resequenced both genes (all exons and all introns) plus some 3' flanking sequences and the entire spacer region (39.6 kb total); 85 SNPs were found, 49 of which were not currently in the National Center for Biotechnology Information (NCBI) database. Of the 57 double-hit SNPs, we carried out SNP-typing in 94 Africans, 96 Asians, and 83 Caucasians and found striking ethnic differences in SNP frequencies and haplotype evolution; the two CYP1A1 SNPs and the one CYP1A2 SNP that are most commonly used in epidemiological studies were shown not to be representative haplotype tag SNPs across these three human subgroups. Four BAC-transgenic mouse lines, carrying the human CYP1A2 and 15,190 bp of 5' flank, expressed only negligible basal or inducible CYP1A2 mRNA. A fifth BAC-transgenic mouse line, carrying both the human CYP1A1 and CYP1A2 genes and ample amounts of 3' flanking sequences, plus all of the spacer region--in the absence of the mouse Cyp1a1 or Cyp1a2 genes--expressed the human CYP1A1 and CYP1A2 mRNA, protein and enzyme activities in liver and nonhepatic tissues very similar to that of the mouse. Comparison of this hCYP1A1_1A2 transgenic line with hCYP1A1_1A2 lines carrying other common human haplotypes will enable us to evaluate function in human CYP1A1_CYP1A2 locus variability, with regard to toxicity and cancer caused by combustion products.     

The high prevalence of the poor and ultrarapid metabolite alleles of CYP2D6, CYP2C9, CYP2C19, CYP3A4, and CYP3A5 in Taiwanese population

Genetic polymorphisms of drug metabolizing enzymes, such as cytochromes P450 (CYPs), play major roles in the variations of drug responsiveness in human. The aim of this study is to identify the high prevalence (minor allele frequencies >1%) of the abnormal metabolite alleles of CYP2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5 in the Taiwanese population. The genotyping of the functional single nucleotide polymorphisms (SNPs) of CYPs were conducted by direct exon sequencing in 180 Taiwanese volunteers. Twenty-one unique SNPs including three newly identified SNPs were detected in the Taiwanese population. Six of the 21 SNPs in five genes showed frequencies more than 1%. The results indicated that it could be very useful and important in developing an inexpensive, convenient, and precise genotyping method for the high prevalence of CYPs metabolizing abnormal alleles in the Taiwanese population.     

The Inhibition of Superoxide Production in EL4 Lymphoma Cells Overexpressing Growth Hormone

A substantial body of research exists to support the production of growth hormone by cells of the immune system. However, the function and mechanism of action of lymphocyte-derived growth hormone remain largely unelucidated. Since, it has been found that exogenous growth hormone (GH) primes neutrophils for the production of reactive oxygen intermediates (ROI) and in particular superoxide (O₂   ^-), we investigated the role of GH on the production of O₂   ^- in T cells. Furthermore, we examined whether endogenous and exogenous GH act similarly. Our studies show that overexpression of GH in EL4, a T-cell lymphoma cell line, results in a decrease in the production of O₂   ^- compared to control cells, as detected using the fluorescent dye, dihydroethidium. O₂   ^- production in control cells was not affected by treatment with inhibitors of xanthine oxidase or a non-specific NADPH-oxidase inhibitor. However, treatment with diallyl sulfide, an inhibitor of cytochrome P450 2E1 mimicked the reduction in O₂   ^- production seen in cells overexpressing GH. Although no significant change could be detected in CYP2E1 protein levels, CYP2E1 activity was found to be greater in control EL4 than in cells overexpressing GH. Both the decrease in O₂   ^- production and the lower CYP2E1 activity in GH overexpressing cells could be abrogated by treatment with N^G-monomethyl-L-arginine, an inhibitor of nitric oxide synthase. The overexpression of GH protects cells from apoptosis induced by isoniazid, a CYP2E1 inducer, suggesting a role for nitric oxide as a mediator in the regulation of xenobiotic metabolism and apoptosis-protection by lymphocyte GH.     

AhR途径,CYP1A1、CYP1B1,雌激素代谢及作用过程中的调节

多环芳烃和多卤化烃是环境中广泛分布的有害物质,可通过与细胞芳烃受体结合,从而影响外来化合物代谢酶系如细胞色素氧化酶P450 1A1、1B1的表达,并通过这些酶的催化作用调控雌激素的代谢及作用,进而部分决定了雌激素对机体的作用效应。上述复杂的过程可受到多种因素的影响。