Myeloperoxidase G-463A polymorphism and the risk of gastric cancer: a case-control study

Several epidemiological studies have shown that the myeloperoxidase (MPO) G-463A polymorphism may influence the risk of many cancers, including lung, breast, bladder and laryngeal cancer. However, there is no study concerning the MPO polymorphism and gastric cancer risk. In this hospital-based, case-control study, we used polymerase chain reaction-restriction fragment length polymorphism protocols to examine the prevalence of MPO G-463A polymorphism in gastric cancer. A significantly different distribution of the MPO -463G/A genotype was demonstrated among the cases and controls (chi2=7.42, P=0.03). Subjects with the variant genotypes (the sum of GA and AA) had a 44% reduced risk of gastric cancer relative to those with GG [adjusted odds ratio (OR)=0.56; 95% CI: 0.32-0.97]. Stratified analyses revealed that the protective effect of A allele was significant in male (adjusted OR=0.51; 95% CI: 0.26-0.98) or younger subjects (age<58 years) (adjusted OR=0.42; 95% CI: 0.18-0.94), but not in female or older subjects. In addition, there was also a significantly reduced risk in subjects residing in rural areas (adjusted OR=0.41; 95% CI: 0.18-0.95) but not in urban areas. The interaction between the MPO G-463A polymorphism and smoking status was not observed in this study. Tumor differentiation was also not found to be associated with the MPO genotype. In conclusion, our results showed that the MPO -463 G to A variant may be associated with the decreased risk of gastric cancer in Chinese population.     

Associations of ERCC4 rs1800067 Polymorphism with Cancer Risk: an Updated Meta-analysis

Background: Results from previous studies concerning the association of ERCC4 rs1800067 polymorphismwith risk of cancer were inconsistent. To explore the exact relation with susceptibility, we conducted the presentmeta-analysis. Materials and Methods: Literature of electronic databases including PubMed, Web of Science,EMBASE, Wanfang and Chinese National Knowledge Infrastructure (CNKI) were systematically searched. ORsand their 95%CIs were used to assess the strength of associations between ERCC4 polymorphism and cancerrisk. Results: There was no significant association between ERCC4 rs1800067 AA or AG genotypes and overallrisk of cancer (AA vs. GG: OR=0.998, 95%CI=0.670-1.486, P=0.992; AG vs. GG: OR=0.970, 95%CI=0.888-1.061, P=0.508). A dominant genetic model also did not demonstrate significant association of (AA+AG)genotype carriers with altered risk of overall cancer (OR=0.985, 95%CI=0.909-1.068, P=0.719). In addition,no significant association was observed between A allele of ERCC4 rs1800067 A/G polymorphism and alteredcancer risk compared with G allele (OR=0.952, 95%CI=0.851-1.063, P=0.381). Subgroup analysis suggestedthat AA genotype carriers were significantly associated with decreased risk of glioma compared with wild-typeGG genotype individuals (OR=0.523, 95%CI=0.275-0.993, P=0.048). For subgroup of lung cancer, A allele ofERCC4 rs1800067 A/G polymorphism was significantly associated with decreased risk of lung cancer comparedwith G allele (OR=0.806, 95%CI=0.697-0.931, P=0.003). Conclusions: This meta-analysis indicated that ERCC4rs1800067 A/G polymorphism might not be associated with risk of overall cancer. However, individuals with theAA genotype were associated with significantly reduced risk of glioma compared with wild-type GG genotype;The A allele was associated with significantly reduced risk of lung cancer compared with G allele. Future largescalestudies performed in multiple populations are warranted to confirm our results.     

Genetic polymorphism in myeloperoxidase but not GSTM1 is associated with risk of lung squamous cell carcinoma in a Chinese population

Myeloperoxidase (MPO), an enzyme derived from neutrophils, metabolically activates a wide range of carcinogens, whereas glutathione S-transferase M1 (GSTM1) detoxifies various electrophilic metabolites. A -463G-->A polymorphism in the promoter region of the MPO gene diminishes the expression of MPO and has been consistently shown to be associated with reduced risk of lung cancer in different ethnic populations. In our study, we have assessed the role of this polymorphism in lung cancer risk in a Chinese population. Genotypes of MPO and GSTM1 were determined by PCR-SSCP and multiplex PCR in 314 patients with lung cancer and 320 frequency-matched controls. The allele frequency for MPO -463A was found to be 0.155 in controls and 0.114 in cases. Subjects with the MPO -463GG genotype were at an increased risk of squamous cell carcinoma (SCC) of the lung compared to those having at least one -463A variant allele (adjusted odds ratio [OR] 2.35; 95% confidence interval [CI] 1.40-3.94). Stratified analysis suggested an interaction between heavy smoking (> or =26 pack-years) and the MPO-463GG genotype. The adjusted OR of lung SCC for those having MPO-463GG genotype and smoked > or =26 pack-years was 20.50 (95% CI 5.58-75.33) compared to 6.22 (95% CI 1.72-22.47) for those smoked > or =26 pack-years but having at least one variant A allele (p = 0.023, test for homogeneity). This effect of the MPO polymorphism was not observed in lung adenocarcinoma. GSTM1 deletion was quite common in both controls (49.4%) and cases (50.3%) but was not associated with risk of lung cancer alone or in combination with the MPO polymorphism. Our results confirm the previous reports showing that the variant A allele of MPO has a protective effect against risk of lung cancer.     

CYP3A4*1B polymorphism and cancer risk: A HuGE review and meta-analysis

CYP450 3A4 (CYP3A4), encoded by the CYP3A4 gene, is a major enzyme catalyzing the metabolism of both endogenous and exogenous agents that may play a role in the etiology of carcinogenesis. Several potentially functional polymorphisms of the CYP3A4 gene have been implicated in cancer risk, but individually published studies have shown inconclusive results. The aim of this Human Genome Epidemiology (HuGE) review and meta-analysis was to investigate the association between CYP3A4*1B (rs2740574 A?>?G) polymorphism and cancer risk. Eleven studies were included with a total of 3,810 cancer patients and 3,173 healthy controls. We found that the G allele and GG genotype of CYP3A4*1B polymorphism were associated with increased risk of cancers using the fixed effects model (allele model: odds ratio (OR)?=?1.24, 95 %CI: 1.09–1.42, P?=?0.001; recessive model: OR?=?1.77, 95 %CI: 1.30–2.41, P?<?0.001; homozygous model: OR?=?1.72, 95 %CI: 1.19–2.47, P?=?0.004). Subgroup analyses by cancer type showed that the G allele and G carrier (AG?+?GG) of CYP3A4*1B polymorphism had significant associations with increased risk of prostate cancer, but not with breast cancer, leukemia, or other cancers. With further subgroup analysis based on different ethnicities, the results indicated that the GG genotype of CYP3A4*1B polymorphism might increase the risk of cancer among African populations. However, similar associations were not observed among Caucasian and Asian populations. Results from the current meta-analysis indicate that the G allele and GG genotype of CYP3A4*1B polymorphism might be associated with increased cancer risk, especially for prostate cancer among African populations.     

Genetic variation in C-reactive protein in relation to colon and rectal cancer risk and survival

C-reactive protein (CRP), a biomarker of inflammation, has been shown to be influenced by genetic variation in the CRP gene. In this study, we test the hypothesis that genetic variation in CRP influences both the risk of developing colon and rectal cancer and survival. Two population-based studies of colon cancer (n = 1,574 cases, 1,970 controls) and rectal (n = 791 cases, 999 controls) were conducted. We evaluated four CRP tagSNPs: rs1205 (G > A, 3' UTR); rs1417938 (T > A, intron); rs1800947 (G > C, L184L); and rs3093075 (C > A, 3' flanking). The CRP rs1205 AA genotype was associated with an increased risk of colon cancer (OR 1.3, 95%CI 1.1-1.7), whereas the rs3093075 A allele was associated with a reduced risk of rectal cancer (OR 0.7, 95%CI 0.5-0.9). The strongest association for the rs1205 polymorphism and colon cancer was observed among those with KRAS2 mutations (OR 1.5, 95%CI 1.1-2.0). The CRP rs1205 AA genotype also was associated with an increased risk of CIMP+ rectal tumors (OR 2.5, 95%CI 1.2-5.3); conversely, the rs1417938 A allele was associated with a reduced risk of CIMP+ rectal tumors (OR 0.5, 95%CI 0.3-0.9). We observed interactions between CRP rs1800947 and BMI and family history of CRC in modifying risk of both colon and rectal cancer. These data suggest that genetic variation in the CRP gene influences risk of both colon and rectal cancer development.     

Association of a Pre-miR-27a Polymorphism with Cancer Risk: an Updated Meta-analysis

MicroRNA-27a is highly expressed in cancers and has been identified as an oncogenic microRNA. A geneticvariant in pre-miR-27a (rs895819) with a transition of A to G has been demonstrated to be associated with cancerrisk; however, the results of these studies remain conflicting rather than conclusive. Therefore, we performed ameta-analysis to derive a more precise estimation. Through searching PubMed or other databases up to March2014 using the following MeSH terms and keywords, “miR-27a”, “polymorphism” and “cancer”, seventeencase-control studies were identified in this meta-analysis, including 7,813 cases and 9,602. Crude odds ratios(ORs) and corresponding 95% confidence intervals (CIs) were calculated to investigate the association strengthbetween rs895819 and the susceptibility of cancer. The results of the overall meta-analysis did not suggest anyassociation between rs895819 polymorphism and cancer susceptibility, and this remained in Asians as a subgroup.In Caucasians, however, the rs895819 was associated with a reduced cancer risk in heterozygous (OR,0.83; 95%CI, 0.75-0.93) and dominant models (OR, 0.84; 95%CI, 0.76-0.93), and the [G] allele of rs895819showed a protective effect (OR, 0.90, 95%CI, 0.84-0.97). Further studies showed a significant association betweenthe [G] allele of rs895819 and decreased risk of breast cancer (0.91; 95%CI, 0.85-0.98), and stratified analysesindicated a protective effect of the [G] allele in Caucasians (OR, 0.89; 95%CI, 0.82-0.98), younger breast cancercases (OR, 0.87; 95%CI, 0.79-0.96), and in the group of unilateral breast cancer patients (OR, 0.90; 95%CI,0.83-0.97). These findings suggest an association between pre-miR-27a polymorphism rs895819 and cancer riskin Caucasians. The protective effect of rs895819 [G] allele in younger breast cancer and in the group of unilateralbreast cancer patients await further confirmation since the included studies in this meta-analysis were limited.     

Association between the HSPA1B ±1267A/G Polymorphism and Cancer Risk: a Meta-analysis of 14 Case-Control Studies

Background: Previous epidemiological studies have suggested a potential role of the HSPA1B±1267A/G polymorphism in risk of developing cancer. However, the results were inconsistent. Therefore, we performed this meta-analysis to summarize the possible association with cancer risk. Materials and Methods: We retrieved relevant articles from PubMed, EMBASE, ISI Web of Science, Chinese Biomedical Literature and Chinese National Knowledge Infrastructure. Studies were selected using specific criteria. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess those associations. All analyses were performed using STATA software. Results: Fourteen case-control studies, including 1, 834 cancer cases and 2, 028 controls were included in this meta-analysis. Overall, the results indicated that the G allele of HSPA1B gene ±1267A/G was significantly associated with an increased cancer risk in all genetic models (G vs A: OR=1.51, 95%CI 1.17-1.95, p=0.001; GG vs AA: OR=2.93, 95%CI 1.50-5.74, p=0.002; AG vs AA: OR=1.48, 95%CI 1.10-1.98, p=0.009; GG/AG vs AA: OR=1.69, 95%CI 1.22-2.33, p=0.001; GG vs AG/AA: OR=2.31, 95%CI 1.24-4.32, p=0.009). In the subgroup analysis stratified by ethnicity, a significant association was identified in Caucasians (G vs A: OR=1.35, 95%CI 1.08-1.69, p=0.008; GG/AG vs AA: OR=1.36, 95%CI 1.09-1.70, p=0.007), but not in Asians. In the stratified analysis by cancer types, individuals with the G allele showed an increased risk of hepatocellular carcinoma compared with carriers of the A allele (OR=2.40, 95%CI 1.47-3.91, p< 0.001). Inversely, individuals with the GG genotype showed a decreased risk of gastric cancer compared with carriers of the AG/GG genotypes (GG vs AG/AA: OR=0.39, 95%CI 0.20-0.70, p=0.007). Conclusions: This meta-analysis suggests associations between the HSPA1B ±1267A/G polymorphism and risk of cancer. However, this association might be Caucasian-specific and the G allele of this polymorphism probably increases risk of hepatocellular carcinoma while decreasing risk of gastric cancer. Further well-designed studies based on larger sample sizes are needed to validate these findings.     

A polymorphism in the CYP17 gene is associated with prostate cancer risk

CYP17 encodes the enzyme cytochrome P-450c17 alpha, which mediates both 17 alpha-hydroxylase and 17,20-lyase in the steroid biosynthesis pathway. A polymorphism in the 5; promoter region of the CYP17 gene has been described. Steroid hormones, especially androgens, are believed to play a key role in the etiology of prostate cancer. Therefore, polymorphisms in genes involved in the androgen metabolism may affect the risk of prostate cancer. We conducted a case-control study of 63 patients with untreated histologically proven prostate cancer and 126 age-matched control men with benign prostatic hyperplasia (BPH) to determine whether a polymorphism in the CYP17 gene is associated with prostate cancer risk. This polymorphism was investigated by PCR/RFLP using DNA from lymphocytes. The transition (T-->C) in the risk allele (A2) creates a new recognition site for the restriction enzyme MspAI, which permits designation of the wildtype (A1) and the risk allele (A2). The prevalence of the A2/A2 genotype was significantly higher (P = 0.03) in the cancer group (23.8%) than in the BPH control group (9.5%). We found an increased risk in men carrying 2 A2 alleles (OR = 2.80, 95%CI = 1.02-77.76). For carrier with at least 1 A2 allele, the OR was 0.90 (95%CI = 0.43-1.89). After stratification by median age (66 years) at time of diagnosis, a marked increased risk was found in carriers of the A2/A2 genotype older than 66 years (OR = 8.93, 95%CI = 1.78-49.19, P = 0.01). Although the sample size is rather small and the controls are BPH patients, our results suggest that the CYP17A2/A2 genotype may be a biomarker for prostate cancer risk, especially for older men.     

2q35 rs13387042和8q24 rs13281615单核苷酸多态性与中国东北汉族绝经前妇女乳腺癌风险关系

背景与目的：乳腺癌作为中国女性最常见的恶性肿瘤,每年的新发数量和死亡数量分别占全世界的12.2%和9.6%,但与中国乳腺癌患者明显相关的基因多态位点至今尚不清楚。本研究旨在探讨2q35 rs13387042和8q24 rs13281615单核苷酸多态性与中国北方汉族绝经前妇女乳腺癌风险关系,为预防和治疗乳腺癌提供循证依据。方法：采用多重单碱基延伸单核苷酸多态性分型技术(SNaPshot)分析方法,检测了280例绝经前乳腺癌患者和287例绝经前正常对照者2q35 rs13387042和8q24 rs13281615多态性位点基因型,并比较不同基因型和等位基因与乳腺癌风险的关系。结果：2q35 rs13387042多态性位点基因型频率在乳腺癌和对照样本之间差异有统计学意义(P=0.017);8q24 rs13281615多态性位点基因型频率在乳腺癌和对照样本之间差异无统计学意义(P=0.967)。Logistic回归分析结果显示,对于2q35 rs13387042位点,与GG相比,GA和GA+AA基因型携带者显著增加乳腺癌的患病风险(OR=1.793,95%CI：1.177～2.733,P=0.007;OR=1.691,95%CI：1.122～2.550,P=0.012),而AA携带者与乳腺癌的患病风险无关(OR=0.572,95%CI：0.104～3.153,P=0.521);与G等位基因相比,A等位基因显著增加乳腺癌的患病风险(OR=1.505,95%CI：1.033～2.193,P=0.033)。对于8q24rs13281615位点,与AA相比,AG、GG和AG+GG基因型携带者与乳腺癌的患病风险无关(OR=0.992,95%CI：0.660～1.490,P=0.968;OR=1.047,95%CI：0.642～1.708,P=0.853;OR=1.007,95%CI：0.682～1.487,P=0.971);与A等位基因相比,G等位基因不增加乳腺癌患病风险(OR=1.021,95%CI：0.809～1.288,P=0.863)。结论：本实验证实2q35 rs13387042多态性位点能够增加中国北方汉族绝经前妇女乳腺癌易感风险,而8q24 rs13281615多态性位点与中国北方汉族绝经前妇女乳腺癌易感性无明显相关性。     

髓过氧化物酶基因-463G/A多态与中国人肺癌遗传易感性

目的 研究髓过氧化物酶（MPO）基因－463G→A单核苷酸多态与肺癌易感性的关系。方法 以PCR－单链构像多态（SSCP）技术,分析了314例肺癌患者和320例正常对照者MPO基因启动子区第－463位核苷酸多态基因型分布,及其与肺癌风险的关系。结果 正常对照组中G和A等位基因频率分别为85.0%和15.0%,而肺癌患者分别为89.0%和11.0%。携带MPO－463GG基因型的个体患肺癌风险比携带GA和AA基因型个体高1.7倍（校正的OR为1.7;95%CI为1.2-2.5）,且此种风险增高只限于肺鳞癌（OR为2.4;95%CI为1.4-3.9）,而与肺腺癌无关（OR为1.3;95%CI为0.8-2.1）。分层分析结果表明,与GA和AA基因型比较,GG基因型并不增加非吸烟者和累积吸烟量＜26包年者患肺癌的风险,但在累积吸烟量≥26包年的吸烟者中,GG基因型发生肺鳞癌的风险比GA和AA基因型高3.3倍。结论 MPO－463 A等位基因显著降低中国人发生吸烟相关性肺鳞癌的风险。     

Angiotensin-converting enzyme insertion/deletion polymorphism and the risk of prostate cancer in the Han population of China

As a main effector in the renin-angiotensin system, the angiotensin II plays a critical role in cell proliferation and angiogenesis. The change between angiotensin II and its precursor is conducted by the angiotensin-converting enzyme. The association between angiotensin-converting enzyme insertion/deletion polymorphism and the activity of angiotensin-converting enzyme was testified. Furthermore, previous researches proved the association between angiotensin-converting enzyme activity and the risk of prostate cancer. Therefore, we conducted a case-control study in the Han population of China to elaborate the relation between the angiotensin-converting enzyme insertion/deletion polymorphism and prostate cancer. DNA was extracted from blood samples collected from 189 pathologically diagnosed prostate cancer patients and 290 cancer-free subjects. The angiotensin-converting enzyme insertion/deletion genotype was determined by polymerase chain reaction analysis. Stratified analyses on age (<71 or ≥ 71), cancer stage (localized or advanced), Gleason score (<7 or ≥ 7) and PSA level (<20 ng/ml or ≥ 20 ng/ml) were performed. We found the II genotype (OR = 0.304 95%CI (0.180,0.515), P < 0.001) and I allele (OR = 0.547 95%CI(0.421,0.711), P < 0.001) were associated with a decreased risk of prostate cancer compared with the DD genotype and D allele. The DD genotype was related to patients with aggressive stage of prostate cancer (OR = 2.214 95%CI(1.169, 4.194), P = 0.014) and patients diagnosed of prostate cancer at a relatively early age (OR = 0.513 95%CI(0.272, 0.965), P = 0.037). The results of our experiment supported the hypothesis that the angiotensin-converting enzyme insertion/deletion polymorphism, a potential risk factor in carcinogenesis, played an important role in the Han population of China.     

Myeloperoxidase G463A polymorphism and risk of lung cancer

Myeloperoxidase (MPO) is a phase I enzyme playing a crucial role in metabolically activating a wide range of procarcinogens, such as polycyclic aromatic hydrocarbons and aromatic amines. The G463A polymorphism in the promoter region of the MPO gene has been indicated in lung cancer risk. To investigate the precise association of MPO G463A polymorphism with the lung cancer risk, we performed this comprehensive meta-analysis with large available data published to date. The included 24 individual studies involving a total of 8,313 cases and 8,728 controls were identified by searching the PubMed, Embase, and Wanfang databases. The crude odds ratios (ORs) and the corresponding 95 % confidence intervals (CIs) were calculated to estimate the association. Stratified analyses by ethnicity, source of controls, smoking status, and histological types were also conducted. Overall, the MPO G463A polymorphism was negatively related to the development of lung cancer in the following genetic models (A vs. G, OR?=?0.90, 95 % CI?=?0.82–0.99, P _OR?=?0.029; GA vs. GG, OR?=?0.89, 95 % CI?=?0.80–0.98, P _OR?=?0.022; AA?+?GA vs. GG, OR?=?0.89, 95 % CI?=?0.81–0.98, P _OR?=?0.023). Stratified analyses by ethnicity indicated that the variant genotype of MPO G463A was associated with a decreased risk of lung cancer in Asians and Caucasians. Similar findings were observed among the smokers and population-based case–control studies. The MPO G463A polymorphism seemed to exert no effect on lung adenocarcinoma and squamous cell carcinoma. The comprehensive meta-analysis shows that the polymorphism of MPO G463A is a protective factor for lung cancer, particularly among the populations of Asians, Caucasians, and smokers.     

Counterpoint: the myeloperoxidase -463G-->a polymorphism does not decrease lung cancer susceptibility in Caucasians.

The myeloperoxidase (MPO) G-to-A substitution polymorphism in the promoter region of the MPO gene has been associated with a 40-70% reduction in lung cancer risk in several studies, although a recent nested case-control study disputes these findings. MPO is involved in the activation of a number of procarcinogens, including benzo(a)pyrene. The variant A allele has been shown to reduce MPO mRNA expression, thus potentially decreasing carcinogen activation. To confirm results from smaller studies, we evaluated this MPO polymorphism in 988 incident Caucasian lung cancer cases and 1128 controls. Logistic regression evaluated the association between MPO genotype and lung cancer risk, adjusting for age, gender, smoking status, time since quitting smoking, and pack-years of smoking. In the controls, the A allele frequency was 21%, and genotype distribution was in the Hardy-Weinberg equilibrium. Compared with the wild-type G/G genotype, the adjusted odds ratios for the A/A and A/G genotypes were 1.15 (95% confidence interval 0.7-1.9, P > 0.2) and 1.03 (95% confidence interval 0.8-1.3, P > 0.20), respectively. A similar lack of association was seen in analyses stratified by smoking status, median age, a number of smoking variables, disease stage, tumor grade, and histological subtype. These findings are in contrast with earlier studies suggesting a protective effect of carrying the variant A allele.     

Association of the XRCC1 c.1178G>A Genetic Polymorphism with Lung Cancer Risk in Chinese

The X-ray repair cross-complementing group 1 protein (XRCC1) plays important roles in the DNA baseexcision repair pathway which may influence the development of lung cancer. This study aimed to evaluatethe potential association of the XRCC1 c.1178G>A genetic polymorphism with lung cancer risk. The createdrestriction site-polymerase chain reaction (CRS-PCR) and DNA sequencing methods were utilized to evaluatethe XRCC1 c.1178G>A genetic polymorphism among 376 lung cancer patients and 379 controls. Associationsbetween the genetic polymorphism and lung cancer risk were determined with an unconditional logistic regressionmodel. Our data suggested that the distribution of allele and genotype in lung cancer patients was significantlydifferent from that of controls. The XRCC1 c.1178G>A genetic polymorphism was associated with an increasedrisk of lung cancer (AA vs GG: OR=2.91, 95%CI 1.70-4.98, p<0.001; A vs G: OR=1.52, 95%CI 1.22-1.90, p<0.001).The allele A and genotype AA may contribute to risk of lung cancer. These preliminary results suggested thatthe XRCC1 c.1178G>A genetic polymorphism is statistically associated with lung cancer risk in the Chinesepopulation.     

Myeloperoxidase and superoxide dismutase polymorphisms are associated with an increased risk of developing pancreatic adenocarcinoma

BACKGROUND: Pancreatic cancer risk has been linked to chronic pancreatitis and periodontitis, suggesting a role for inflammation in disease etiology. Myeloperoxidase (MPO) and superoxide dismutase (SOD2) are enzymes that regulate reactive oxygen species and contain recognized single nucleotide polymorphisms (SNPs) that confer altered enzyme activity. METHODS: One hundred twenty-two patients with pancreatic cancer and 331 age- and sex-matched controls were analyzed for polymorphisms of the MPO - guanine 463 adenine (-G463A) and the SOD2 alanine (Ala)-to-valine (Val) polymorphism at codon 16 (Ala16Val) genes. Cases and controls were analyzed for associations between these polymorphisms, adjusting for sex, age, history of alcohol use and smoking history. RESULTS: The variant A allele of MPO -G463A was associated with a lower risk of pancreatic cancer (adjusted odds ratio [OR] for pancreatic cancer, 0.57; 95% confidence interval [95% CI], 0.4-0.9; P = .02). The SOD2 homozygous variant genotype (Val/Val) was associated with a greater risk of pancreatic cancer (adjusted OR, 1.96; 95% CI, 1.0-3.8; P = .04). Compared with individuals who carried both low-risk alleles (A/- and Ala/-), significantly more cases than controls carried both high-risk genotypes (G/G and Val/Val; adjusted OR, 4.31; 95% CI, 1.8-10; P = .001), or 1 high-risk genotype (adjusted OR, 1.96; 95% CI, 1.1-3.4; P = .01). CONCLUSIONS: Polymorphisms of the inflammatory pathway genes MPO -G463A and SOD2 Ala16Val are associated with elevated pancreatic cancer risk. Oxidative stress may play an important role in pancreatic cancer carcinogenesis.     

髓过氧化物酶基因多态性与肺癌遗传易感性的研究

背景与目的:髓过氧化物酶(myeloperoxidase,MPO)基因启动子区域-463bp处存在G/A多态位点,国外研究表明此位点与肺癌遗传易感性有关,但中国人MPO基因型与肺癌易感性关系尚未见报道,本研究拟对此问题作一探讨。方法:采用病例-对照分子流行病学方法,以PCR-RFLP技术检测98例原发性肺癌和112名健康对照MPO基因型,通过比较不同基因型者的比值比(oddsratio,OR)及其95%可信区间(confidenceinterval,CI)分析基因多态性与中国人肺癌易感性的关系。结果:正常人群G/G、G/A、A/A基因型频率分别为47.3%、42.9%和9.8%,肺癌病例组分别为63.3%、33.7%和3.0%,杂合子G/A在两组人群中分布无显著性差异(P>0.05),但病例组A/A基因型频率显著低于对照组(P<0.025)。携带至少一个等位基因A者患肺癌的风险是基因型为G/G者的52.0%(95%CI0.29～0.93)。在吸烟人群中,等位基因A对肺癌易感性的保护作用有显著性意义(OR=0.41,P<0.025),而在非吸烟人群,这种保护作用无显著性意义(P>0.25)。结论:本研究人群MPO基因多态与肺癌遗传易感性相关,等位基因A对吸烟人群的肺癌易感性有保护作用。