GSTM1和CYP2E1基因多态性与肺癌遗传易感性关系的研究

背景与目的肺癌是中国人群恶性肿瘤死因的首位，其发病可能与肺癌人群中某些肺癌相关基因的遗传多态性有关。本研究旨在探讨细胞色素P4502E1(CYP2E1)基因RsaⅠ／PstⅠ多态性和谷胱甘肽转移酶M1(GSTM1)基因多态性与肺癌易感性之间是否存在相关性。方法应用PCR-RFLP和PCR法检测99例人非小细胞肺癌患者和66例同期住院的肺良性疾病患者CYP2E1基因的RsaⅠ／PstⅠ多态性和GSTM1基因多态性，并分析其与肺癌遗传易感性的相关性。结果(1)CYP2E1基因RsaⅠ／PstⅠ多态性的三种基因型在肺癌组和对照组的频率差异没有统计学意义(χ^2=1．374，P=0．241)。(2)肺癌组GSTM1(-)基因型频率显著高于对照组(分别为57．6％和40．9％)(χ^2=4．401，P=0．036)。(3)携带GSTM1(-)基因型的个体患肺癌的危险性显著高于GSTM1( )基因型的个体(OR=1．96，95％CI=1．042～3．689，P=0．037)。(4)与携带c1／c2或c2／c2基因型的不吸烟个体比较，携带c1／c1基因型的吸烟者患肺癌的风险显著增加(OR=3．525，95％CI=1．168～10．638，P=0．025)。(5)联合分析CYP2E1基因RsaⅠ／PstⅠ多态性和GSTM1基因多态性，携带有c1／c1和GSTM1(-)基因型的个体患肺癌的风险显著高于携带GSTM1( )和c1／c2或c2／c2基因型的个体(OR=3．449，95％CO=1．001～11．886，P=0．050)。按照吸烟因素分层，携带有GSTM1(-)和c1／c1基因型的不吸烟个体患肺癌的风险显著高于携带GSTM1( )和c1／c2或c2／c2基因型的不吸烟个体(OR=11．553，95％CI=1．068-124．944，P=0．044)，携带有GSTM1(-)和c1／c2或c2／c2基因型的不吸烟个体患肺癌的风险同样显著高于携带GSTM1( )和c1／c2或c2／c2基因型的不吸烟个体(OR=13．374，95％CI=1．258～142．166，P=0．032)。结论(1)GSTM1(-)基因型增加人群患肺癌的风险；(2)CYP2E1的c1／c1基因型和GSTM1(-)基因型的联合可增加吸烟和不吸烟人群患肺癌的风险。     

CYP1A1、GSTM1基因多态性及其联合作用与食管癌的易感性

目的探讨CYP1A1、GSTM1基因多态性及其联合作用与新疆汉族人食管癌易感性的关系。方法采用聚合酶链式反应-连接酶检测反应分析方法检测107例食管癌患者和204例非食管癌患者的CYP1A1(rs1048943、rs4646421和rs4646903)和GSTM1(缺失型和rs2071487)的基因型。结果CYP1A1基因rs1048943位点的等位基因和基因型频率在病例组和对照组之间比较,总体分布差异有统计学意义(χ² =5.52,P=0.019)。与A/A基因型相比,GG+AG基因型可增加食管癌的发病风险(OR=1.79,OR95%CI:1.10~2.92);GSTM1基因缺失型和非缺失型在病例组和对照组中的分布频率分别为68.69%、31.31%和48.39%、51.61%,在两组间的分布差异有统计学意义(χ²=10.55,P=0.001;OR=2.34,OR95%CI:1.40~3.91)。结论CYP1A1基因rs1048943位点多态性和GSTM1基因缺失型与新疆地区汉族人食管癌易感性有相关性。     

CYP2E1基因多态性与肺癌易感性关系的研究进展

肺癌是最常见的恶性肿瘤,其发生发展与吸烟、大气污染、危险因素暴露及基因变异等多种因素有关,由细胞色素P450(CYP450)基因家族所编码的细胞色素P450酶系(Cytochrome P450s)所组成的Ⅰ相酶介导氧化代谢,具有重要的解毒功能.CYP2E1是CYP450基因家族重要成员之一,大量研究表明其基因多态性与肺癌易感性密切相关,但研究结果不一致.     

Genetic Variation of GSTM1, GSTT1 and GSTP1 Genes in a South Indian Population

The glutathione S transferase (GST) family of enzymes play a vital role in the phase II biotransformation ofenvironmental carcinogens, pollutants, drugs and other xenobiotics. GSTs are polymorphic and the polymorphismsin GST genes have been associated with cancer susceptibility and prognosis. Moreover, distinct ethnic differenceshave been observed in the type and frequency of GST gene polymorphisms. Hence, the present study was aimed todetermine the frequencies of GSTM1, GSTT1 and GSTP1 polymorphisms in 255 healthy random volunteers fromSouth India. The GSTM1 and GSTT1 genotypes were determined by PCR and GSTP1 by PCR-RFLP using peripheralblood DNA.The GSTM1 and GSTT1 null genotype frequencies were found to be 22.4% and 17.6% respectively. TheGSTP1 allelic frequency was 0.78 for the Ile allele and 0.22 for the Val allele and the genotype frequency was 58.4%for Ile/Ile, 38.4% for Ile/Val, and 3.1% for Val/Val. Comparison of the frequencies of GST polymorphisms observedin the present study with other Indian and world populations revealed a distinctive nature of the South Indianpopulation with respect to polymorphims at the GST gene loci. A better understanding of carcinogen metabolizinggene distribution should contribute to risk assessment of humans exposed to environmental carcinogens.     

Genetic Polymorphisms of CYP2E1 and GSTP1 in a South Indian Population - Comparison with North Indians,Caucasians and Chinese

CYP2E1 and GSTP1 enzymes belong to phase I and phase II group of drug metabolizing enzymes respectively ‍which are involved in the metabolic activation and detoxification of various potential genotoxic compounds. The ‍functional polymorphism in these genes exhibit inter-individual variations in susceptibility towards various diseases ‍and difference in therapeutic response. The variant sequences of these genes differ considerably between ethnic ‍groups. Therefore, the objective of the study was to assess the prevalence of CYP2E1 & GSTP1 gene variants in ‍healthy volunteers of Tamilnadu, a population of South India. The genotype distribution of CYP2E1*1B A2A2, A2A1 ‍and A1A1 were 61%, 36% and 3% respectively. The distribution of CYP2E1*5B c1c1, c1c2 genotypes were 99.2%and ‍0.8%. CYP2E1*6 DD, DC and CC genotype frequencies were 72%, 25% and 3% respectively. The allele frequencies ‍of CYP2E1*1B, CYP2E1*5B and CYP2E1*6 were A2- 0.79 A1- 0.21, c1-0.996 c2 - 0.004 and D- 0.84 C- 0.16 respectively. ‍The genotypic distribution of GSTP1 (Ile/Val) were Ile/Ile - 44%, Ile/Val -47% and Val/Val- 9 % whereas, the allelic ‍frequencies were 0.67 for Ile and 0.33 for Val allele. The molecular studies in these enzymes provide basis for further ‍epidemiological investigations in the population where the functional mutations in the genes alter therapeutic response ‍and acts as susceptibility markers for various clinical conditions.     

Modification effects of GSTM1, GSTT1 and CYP2E1 polymorphisms on associations between raw salted food and incomplete intestinal metaplasia in a high-risk area of stomach cancer

Incomplete intestinal metaplasia (IM) is a precursor of stomach cancer. To identify risk factors of incomplete IM, a 2-stage survey was carried out in 1995 among 1,485 residents in Matzu, an area with highest mortality from stomach cancer in Taiwan. There were 312 study subjects including 174 men and 138 women sampled for the gastroendoscopic examination of IM. Information on personal and familial history of stomach cancer, cigarette smoking, alcohol consumption and intake frequency of various salted food items were obtained by personal interview based on a structured questionnaire. Blood samples were collected from each participant. Four biopsies per subject were taken from all subjects at gastroendoscopic examination to diagnose the status of IM pathologically. The Helicobacter pylori in biopsies was detected by the histomorphological or immunochemistry method, and antibodies against H. pylori in serum by the enzyme-linked immunosorbent assay. Plasma level of selenium was determined by atomic absorption spectrometry, plasma level of retinol, alpha-tocopherol, alpha-carotene, and beta-carotene by high performance liquid chromatography, genotypes of glutathione S-transferase (GST) M1 and T1 and cytochrome P450 (CYP) 2E1 by polymerase chain reaction. The significant association between history of stomach cancer among first-degree relatives and incomplete IM was found (odds ratio [OR] = 2.50; 95% confidence interval [CI] = 1.15-5.43). There was no association between H. pylori infection and incomplete IM. Alcohol drinkers for >20 years had an elevated risk compared to non-drinkers (OR = 3.34; 95% CI = 1.19-9.39). No associations between incomplete IM and plasma levels of selenium, retinol, alpha-tocopherol, alpha-carotene and beta-carotene were found. Salted food including salted meat, dehydrated salted vegetables and raw salted seafood consumed at ages of 相似文献   

Polymorphisms at GSTM1 and GSTP1 Gene Loci and Risk of Prostate Cancer in a South Indian Population

Inter-individual differences in cancer susceptibility may be mediated in part through polymorphic variability in ‍the bioactivation and detoxification of carcinogens. The glutathione S-transferases (GSTs), which are active in ‍detoxification of wide variety of carcinogens, have been consistently implicated as cancer susceptibility genes in this ‍context. We here assessed the association of GSTM1 and GSTP1 polymorphisms with susceptibility to prostate ‍cancer in a case-control study of 75 patients and 100 age-matched controls in a South Indian population. The ‍GSTM1 null polymorphism was detected by PCR and the GSTP1 Ile105Val polymorphism by PCR-RFLP using ‍peripheral blood DNA.There was no significant link between the null genotype of GSTM1 and risk of prostate ‍cancer (OR-1.79; 95% CI-0.78-4.11; P-0.18). However, the GSTP1 Ile/Val genotype was significantly associated with ‍a decreased risk for prostate cancer (OR-0.36; 95% CI-0.18-0.73; P<0.001). Analysis of the variant GSTM1 and ‍GSTP1 genotypes in combination did not reveal any significant difference between cases and controls, even with a ‍stratified analysis tumor grades. Thus our study indicates that the GSTP1 Ile/Val genotype may decrease risk of ‍prostate cancer in the South Indian population.     

Associations of CYP1A1, GSTM1 and GSTT1 Polymorphisms with Lung Cancer Susceptibility in a Northern Indian Population

Background: Susceptibility to lung cancer has been shown to be modulated by inheritance of polymorphicgenes encoding cytochrome P450 1A1 (CYP1A1) and glutathione S transferases (GSTM1 and GSTT1), which areinvolved in the bioactivation and detoxification of environmental toxins. This might be a factor in the variation inlung cancer incidence with ethnicity. Materials and Methods: We conducted a case-control study of 218 northernIndian lung cancer patients along with 238 healthy controls, to assess any association between CYP1A1, GSTM1and GSTT1 polymorphisms, either separately or in combination, with the likelihood of development of Lungcancer in our population. Results: We observed a significant difference in the GSTT1 null deletion frequency in thispopulation when compared with other populations (OR=1.87, 95%CI: 1.25-2.80–0.73, P=0.002). However, GSTM1null genotype was found associated with lung cancer in the non-smoking subgroup. (P=0.170). Conclusions: Ourstudy showed the GSTT1 null polymorphism to be associated with smoking-induced lung cancer and the GSTM1null polymorphism to have a link with non-smoking related lung cancer.     

淋巴瘤患者多环芳烃-DNA加合物及代谢酶基因细胞色素氧化酶P4501A1与谷胱苷肽硫转移酶M1基因多态性的研究

目的 探讨多环芳烃（PAH）-DNA加合物和代谢酶基因细胞色素氧化酶P4501A1（CYP1A1）与谷胱苷肽硫转移酶M1（GSTM1）基因多态性与淋巴瘤发病的关系.方法 通过竞争性酶联免疫吸附法测定54例淋巴瘤患者及34例对照组骨髓液中PAH-DNA加合物含量,采用限制性片段长度多态性PCR法（PCR-RFLP）测定上述标本CYP1A1、GSTM1基因多态性.结果 淋巴瘤患者骨髓液中PAH-DNA加合物含量为（2498±1 250） pg/ml,较对照组的（1 882±797） pg/ml增加,差异有统计学意义（t=0.006,P＜0.05）;淋巴瘤患者GSTM1基因型缺失占85.2％,对照组占58.8％,差异有统计学意义（x2=7.73,P＜0.05）,GSTM1基因型缺失者患淋巴瘤风险是GSTM1表达者的4.03倍（95％ CI1.51～10.76,P＜ 0.05）;CYP1A1变异型是野生型患淋巴瘤风险的1.36倍（95％CI 0.56～ 3.31,P＞ 0.05）,GSTM1缺失者PAH-DNA加合物水平≥2 200 pg/ml时患淋巴瘤的危险性增加（OR=9.53,95％CI 2.397～ 37.990,P＜ 0.05）.结论 PAH-DNA加合物可能参与淋巴瘤的发病,GSTM1缺失与淋巴瘤发生有关,并且增加患淋巴瘤的风险.     

CYP1A1 (Ile462Val), CYP1B1 (Ala119Ser and Val432Leu), GSTM1 (null), and GSTT1 (null) Polymorphisms and Bladder Cancer Risk in a Turkish Population

We aimed to investigate bladder cancer risk with reference to polymorphic variants of cytochrome p450 (CYP)1A1, CYP1B1, glutathione S-transferase (GST) M1, and GSTT1 genes in a case control study. Polymorphismswere examined in 114 bladder cancer patients and 114 age and sex-matched cancer-free subjects. Genotypes weredetermined using allele specific PCR for CYP1A1 and CYP1B1 genes, and by multiplex PCR and melting curveanalysis for GSTM1 and GSTT1 genes. Our results revealed a statistically significant increased bladder cancerrisk for GSTT1 null genotype carriers with an odds ratio of 3.06 (95% confidence interval=1.39-6.74, p=0.006).Differences of CYP1A1, CYP1B1 and GSTM1 genotype frequencies were not statistically significant betweenpatients and controls. However, the specific combination of GSTM1 null, GSTT1 null, and CYP1B1 codon 119risk allele carriers and specific combination of GSTM1 present, GSTT1 null, and CYP1B1 432 risk allele carriersexhibited increased cancer risk in the combined analysis. We did not observe any association between differentgenotype groups and prognostic tumor characteristics of bladder cancer. Our results indicate that inheritedabsence of GSTT1 gene may be associated with bladder cancer susceptibility, and specific combinations ofGSTM1, GSTT1 and CYP1B1 gene polymorphisms may modify bladder cancer risk in the Turkish population,without any association being observed for CYP1A1 gene polymorphism and bladder cancer risk.     

细胞色素P450 2E1(CYP2E1)基因多态性与胃癌易感性的Meta分析

[目的]探讨细胞色素P4502E1(CYP2E1)基因多态性与胃癌易感性的关系。[方法]检索PubMed和CNKI数据库中有关CYP2E1基因多态性与胃癌易感性关联研究的文献,对入选文献以OR为效应指标,应用RevMan4.28软件包进行Meta分析。[结果]纳入11篇文献,共1352例胃癌病例和1866例对照;Meta分析结果显示,合并OR值为0.73(95%CI=0.60￣0.91),按人群分层后,中国人群合并OR值为0.54(95%CI=0.31￣0.94),其他人群合并OR值为0.83(95%CI=0.69￣1.01)。[结论]CYP2E1突变基因型(c1c2或c2c2)是胃癌的保护因素,但这一结果有待进一步严格设计的大样本病例对照或前瞻性研究予以验证。     

CYP1A1和GSTM1基因多态性与内蒙古人群肺癌易感性的关系

背景与目的 肺癌是严重危害人类健康的恶性肿瘤之一，其发病与肺癌人群中某些肺癌相关基因的遗传多态性有关。本研究旨在探讨细胞色素P4501A1（CYP1A1）基因多态性和谷胱甘肽硫转移酶M1（GSTM1）基因多态性与内蒙古人群肺癌易感性的关系。方法 用PCR-RFLP技术分析了原发性肺癌组和住院对照组（各163例）的CYP1A1、GSTM1基因的多态性、基因型分布频率和交互作用。结果 CYP1A1突变型和GSTM1基因缺陷型EGSTM1（-）]频率分布分别为36．8％、65．0％（病例组）和19．0％、48．9％（对照组），二者经χ^2检验差异有显著性（χ^2=12．82，P=0．000；χ^2=9．78，P=0．002）。CYP1A1突变型患肺癌的风险显著增加（OR=2．48，95％CI为1．51～4．08）。GSTM1（-）者患肺癌的风险也显著增加（OR=2．03，95％CI为1．30～3．17）。基因突变的协同分析发现CYP1A1突变型／GSTM1（-）在肺癌组和对照组中的分布频率分别为28．8％和8．0％，二者经χ^2检验有显著性差异（χ^2=23．883，P=0．000）。CYP1A1突变型／GSTM1（-）患肺癌的风险显著增加（OR=4．90，95％CI为2．50～9．83）。无论是在肺癌组还是在对照组，CYP1A1突变型／GSTM1（-）和CYP1A1非突变型／GSTM1（-）在性别间分布频率的差异均无显著性（肺癌组χ^2=0．797，P=0．372；对照组χ^2=0．670，P=0．761）。吸烟与肺癌易感性的统计学分析，结果显示吸烟与肺癌易感性有关（χ^2=14．197，P=0．000），吸烟者患肺癌的风险显著增加（OR=2．33，95％CI为1.50～3．62）。CYP1A1突变型与吸烟关系的协同分析发现，携带CYP1A1突变型基因的吸烟者较携带CYP1A1突变型基因不吸烟者易患肺癌（OR=4．44，95％CI为2．40～8．32，χ^2=23．843，P=0．000）。GSTM1（-）与吸烟关系的协同分析中也发现，携带GSTM1（-）的吸烟者患肺癌的风险显著增加（OR=7．32，95％CI为3．39～15．50，χ^2=36．708，P=0．000）。结论 CYP1A1突变型和GSTM1（-）是内蒙古地区肺癌的易患因素，二者对肺癌的发生有协同作用，吸烟与肺癌的易感性也有关，CYP1A1突变型、GSTM1（-）与吸烟在肺癌的发生上也有相互促进作用。     

Polymorphisms of CYP1A1, GSTM1, GSTT1, and prostate cancer risk in Turkish population

Prostate cancer is the most common cancer among men in many countries. Although the etiology of prostate cancer largely is unknown, both genetic and environmental factors may be involved. Advanced age, androgen metabolism, and heredity-race have been reported to be possible risk factors. On the other hand, several studies indicate that genetic polymorphisms in biotransformation enzymes play a role in prostate cancer development. In this study, association of the prostate cancer risk with genotype frequencies of the Phase I (CYP1A1) and Phase II (GSTM1 and GSTT1) biotransformation enzymes was investigated in 321 Turkish individuals (152 prostate cancer patients and 169 age-matched male controls). The presence or absences of the GSTM1 and GSTT1 genes were determined by a PCR-based method. Genotypes of CYP1A1 were determined by MspI-RFLP. The prevalence of GSTM1 null genotype in the cases was 64 percent, compared to 31 percent in the control group, indicating a strong association (OR = 4.08, 95%CI = 2.50-6.69). No association was observed between either GSTT1 null genotype or CYP1A1 polymorphism and prostate cancer incidence. No statistically significant association was observed between smoking status of the patients and any of the polymorphisms studied. In conclusion, results of this study indicate that only the GSTM1 null genotype may play an important role as a risk factor for prostate cancer development in Turkish population.     

CYP1A1和GSTM1基因多态性与肺癌易感性的Meta分析

目的探讨CYP1A1和GSTM1基因多态性与个体肺癌易感性的关系。方法全面检索相关文献,应用Meta分析方法对各研究进行数据的合并与分析。结果共8篇文献入选,累计肺癌病例1067人,对照1416人,分别对CYP1A1*A和GSTM1-、CYP1A1*B/C和GSTM1+、CYP1A1*B/C和GSTM1-联合基因型进行统计分析。异质性检验χ2值分别为6.43、8.83与9.63,P>0.05,文献有同质性,各合并OR及95%CI分别为1.36(1.09~2.77)、1.65(1.26~2.15)和2.01(1.57~2.59)。结论CYP1A1和GSTM1突变基因型为罹患肺癌的易感基因型,且两者存在协同作用,在肿瘤防治方案中应加以重视从而采取相应措施达到有效预防肿瘤的目的。     

CYP1A1, GSTM1, GSTT1 and TP53 Polymorphisms and Risk of Gallbladder Cancer in Bolivians

The Plurinational State of Bolivia (Bolivia) has a high incidence rate of gallbladder cancer (GBC). However, the genetic and environmental risk factors for GBC development are not well understood. We aimed to assess whether or not cytochrome P450 (CYP1A1), glutathione S-transferase mu 1 (GSTM1), theta 1 (GSTT1) and tumor suppressor protein p53 (TP53) genetic polymorphisms modulate GBC susceptibility in Bolivians. This case-control study covered 32 patients with GBC and 86 healthy subjects. GBC was diagnosed on the basis of histological analysis of tissues at the Instituto de Gastroenterologia Boliviano Japones (IGBJ); the healthy subjects were members of the staff at the IGBJ. Distributions of the CYP1A1 rs1048943 and TP53 rs1042522 polymorphisms were assayed using PCR-restriction fragment length polymorphism assay. GSTM1 and GSTT1 deletion polymorphisms were detected by a multiplex PCR assay. The frequency of the GSTM1 null genotype was significantly higher in GBC patients than in the healthy subjects (odds ratio [OR], 2.35; 95% confidence interval [CI], 1.03-5.37; age-adjusted OR, 3.53; 95% CI, 1.29-9.66; age- and sex-adjusted OR, 3.40; 95% CI, 1.24-9.34). No significant differences were observed in the frequencies of CYP1A1, GSTT1, or TP53 polymorphisms between the two groups. The GSTM1 null genotype was associated with increased GBC risk in Bolivians. Additional studies with larger control and case populations are warranted to confirm the association between the GSTM1 deletion polymorphism and GBC risk suggested in the present study.     

CYP1A1 Polymorphisms and Risk of Lung Cancer in the Ethnic Kashmiri Population

The CYP1A1 category of enzymes plays a central role in the metabolic activation of major tobaccocarcinogens. Several polymorphisms within the CYP1A1 locus have been identified and have been shownto be associated with lung cancer risk, particularly in Asian populations. Here we focused on the influenceof three polymorphisms on lung cancer in ethnic Kashmiris, genotyping 109 lung cancer cases and 163healthy controls by PCR-RFLP methods. While no polymorphic alleles in CYP1A1m4 (exon 7 thr toasn) site were detected in our population, the allele frequency of CYP1A1m1 (Msp1) and CYP1A1m2(exon 7 ile to val) were 30.1 and 26.6 in controls and 44.5 and 38.9 in cases. The CYP1A1m1 andCYP1A1m2 variants were significantly associated with lung cancer susceptibility (ORs; 2.65, CI 95% =1.562-4.49 and 2.24,CI 95%=1.35-3.73).This risk was prominent in case of SCC compared with AC orother types of lung cancer. Stratified analysis showed a multiplicative interaction between tobaccosmoking and variant CYP1A1m1 genotype on the risk of SCC. The ORs of SCC for non-smokers were2.08 and 3.15 for smokers. When stratified by pack years, effect was stronger in the heaviest smokers(ORs=6.00,95% CI=1.672-21.532).The interaction between tobacco smoking and variant CYP1A1m2genotype followed similar pattern. Our findings thus support the conclusion that CYP1A1m1 and m2polymorphisms are associated with the smoking related lung cancer risk in Kashmiri population.     

Updated Meta-analysis of the Association Between CYP2E1 RsaI/PstI Polymorphisms and Lung Cancer Risk in Chinese Population

Background: A number of studies have reported relationships of CYP2E1 RsaI/PstI polymorphisms with susceptibility to lung cancer in Chinese population. However, the epidemiologic results have been conflictive rather than conclusive. The purpose of this study was to address the associations of CYP2E1 RsaI/PstI polymorphisms with lung cancer risk in Chinese population comprehensively. Materials and Methods: Systematic searches were conducted in the PubMed, Science Direct, Elsevier, CNKI and Chinese Biomedical Literature Databases. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of association. Results: Overall, we observed a decreased lung cancer risk among subjects carrying CYP2E1 RsaI/PstI c1/c2 and c1/c2+c2/c2 genotypes (OR=0.76, 95%CI: 0.64-0.90 and OR=0.78, 95%CI: 0.66-0.93, respectively), as compared with subjects carrying the c1/c1 genotype. In subgroup analysis, we observed a decreased lung cancer risk among c1/c2 carriers in hospital-based studies (OR=0.81, 95%CI: 0.68-0.98) and among carriers with c1/c2 and c1/c2+c2/c2 genotypes in population-based studies(OR=0.57, 95%CI: 0.42-0.79 and OR=0.58, 95%CI: 0.43-0.79, respectively), as compared with subjects carrying the c1/c1 genotype. Limiting the analysis to studies with controls in Hardy-Weinberg equilibrium (HWE), we similarly observed a decreased lung cancer risk among c1/c2 and c1/c2+c2/c2 carriers (OR=0.73, 95%CI: 0.60-0.88 and OR=0.73, 95%CI: 0.60-0.88, respectively), as compared with c1/c1. Conclusions: Our results suggested that CYP2E1 RsaI/PstI c1/c2 and c1/c2+c2/c2 variants might be a protective factor for developing lung cancer in Chinese population. Further well-designed studies with larger sample size are required to verify our findings.     

CYP2D6 and CYP2E1 Gene Polymorphisms and their Association with Cervical Cancer Susceptibility: A Hospital Based Case-Control Study from South-Western Maharashtra

Background: In last few years several studies all over the world discovered the genetic polymorphisms in different cytochrome P450 genes associated with risk of various cancers, but contradictory outcomes were evidenced in case of cervical cancer risk.  In this case-control study we aimed to see whether the polymorphism of CYP2D6 or CYP2E1 genes may or may not be associated with cervical cancer risk in women of rural Maharashtra. Methods: In this case-control study, the association of CYP2D6 and CYP2E1 gene polymorphism with cervical cancer risk was studied by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The study was conducted with 350 clinically confirmed cervical cancer patients and 350 healthy women in a population of South-Western Maharashtra. The Odds ratio (OR) with 95% confidence interval and p-value were evaluated, where p ≤0.005 was considered as statistically significant. Results: After the analysis of SNP (rs389209) of CYP2D6 and SNPs (rs2031920, rs6413432, rs6413420) of CYP2E1, we noticed that variant allele A of CYP2E1*6 showed significant increase in cervical cancer cases (OR=4.81; 95% CI: 1.57- 14.77; p=0.005). The genotypic distribution of heterozygote G/A genotype of CYP2D6*4 showed negative association with cervical cancer development when age of cancer occurrence (OR=0.41; 95% CI: 0.27- 0.61; p<0.0001) and tobacco history (OR=0.35; 95% CI: 0.20- 0.59; p=0.0001) was considered. Conclusion: The findings from this study supported that rs6413432 SNP of CYP2E1*6 increased cervical cancer risk in the studied rural women population.     

CYP1A1 Genetic Polymorphisms and Risk for Esophageal Cancer: a Case-control Study in Central China

The purpose of this study was to evaluate the associations of CYP1A1 genetic polymorphisms with the riskof developing esophageal cancer (EC). A case-control study was carried out in a Chinese population in which157 hospital based EC cases and 157 population based healthy controls with 1:1 match by age and sex wereincluded. PCR based restriction fragment length polymorphisms (PCR-RFLP) were used to detect genotypes incase and control groups. For the CYP1A1 Ile/Val polymorphism, comparing with wild genotype Ile/Ile, both theheterozygote genotype Ile/Val and the combined variant genotype Ile/Val+Val/Val increased the risk of esophagealcancer (OR: 2.05, 95%CI: 1.19-3.54, OR: 1.86, 95%CI: 1.11-3.12). No significant association was found betweenthe CYP1A1 MspI polymorphism and EC. According to analysis of combined genotypes, the TC/AG combinedgenotype which contained both variant alleles of these two polymorphisms increased the risk of developing EC(OR: 2.12, 95%CI: 1.16-3.85). Our results suggested that genetic polymorphisms of CYP1A1 may increase thesusceptibility to EC.