TP53基因多态与结直肠癌肝转移遗传易感性的相关性

目的 探讨TP53基因C-8343G、C-1863T及第72密码子(R72P)单核苷酸多态性与结直肠癌(colorectal cancer,CRC)肝转移风险的关系.方法 采用TaqMan和聚合酶链反应-限制性片段长度多态性方法,检测121例伴肝转移CRC与性别、年龄匹配的280例不伴肝转移CRC的各单核苷酸多态性的基因型分布及差异.结果 C-8343G和C-1863T基因型分布在伴和不伴肝转移的两组CRC人群间差异均无统计学意义.R72P增加CRC肝转移的发生风险:与PP基因型相比,RP基因型、RR基因型和R等位基因携带者(RP或RR基因型)的肝转移风险分别增加至2.21倍(95%CI:1.13～4.33)、2.26倍(95%CI:1.03～4.94)和2.22倍(95%CI:1.16～4.26).CRC组织中P53表达状态的分层分析结果显示:对于P53表达阳性者,72R携带者的肝转移风险与PP基因型相比进一步增加至3.28倍(95%CI:1.21～8.88);而对于P53表达阴性者,PP基因型与72R携带者的肝转移风险差异无统计学意义(比值比为1.37,95%CI:0.52～3.62).结论 TP53增加CRC,特别是P53表达阳性CRC的肝转移风险,可作为CRC肝转移高危人群的筛选指标;C-8343G和C-1863T可能均与CRC肝转移风险无关.     

E-钙黏蛋白基因多态性与上皮性卵巢癌发病风险关系的研究

目的 探讨E-钙黏蛋白基因(E-cadherin gene,CDH1)单核苷酸多态性(single nucleotide polymorphism,SN-P)与上皮性卵巢癌发病风险的关系.方法 采用聚合酶链反应-限制性片段长度多态性方法分析207例上皮性卵巢癌患者和256名健康对照的CDH1基因启动子区-160C/A、-347G/GA和3′UTR+54C/T3个SNP位点基因型频率分布;采用免疫组织化学方法检测携带3′UTR+54C/T SNP位点不同基因型的卵巢癌患者癌组织CDH1基因的表达情况.结果 CDH1基因-160C/A和-347G/GA 2个SNP位点的基因型和等位基因频率分布在患者组与健康对照组间差异无统计学意义(P＞0.05).3′UTR+54C/T SNP 位点的基因型与等位基因频率分布在患者与健康对照组间差异有统计学意义,患者组中CC基因型和C等位基因频率(65.2%,89.1%)明显高于对照组(52.7%,64.5%)(P＜0.01);CC基因型可能显著增加上皮性卵巢癌的发病风险(比值比为1.85,95%可信区间为1.27～2.69);且免疫组化研究表明CC基因型患者癌组织CDH1基因的表达明显低于T等位基因(CT+TT)携带者(P＜0.05).采用2LD软件分析显示-160C/A、-347G/GA两位点间存在连锁不平衡(D′=0.999 582),-160A/-347GA单倍型仅在患者组中检测到(5.1%),-160C/-347GA单倍型可能明显降低卵巢癌的发病风险(比值比为0.66,95%可信区间为0.45～0.96).结论 CDH1基因-160C/A、-347G/GA SNP可能与上皮性卵巢癌的发病风险无关,但两位点的单倍型可能改变上皮性卵巢癌的发病风险.3′UTR+54C/T多态CC基因型可能成为上皮性卵巢癌发病的潜在危险因素.     

胃癌中骨桥蛋白、结缔组织生长因子的表达及其意义

目的 探讨骨桥蛋白(osteopontin,OPN)和结缔组织生长因子(connective tissue growth factor,CTGF)及其联合检测在判断胃癌患者预后中的意义.方法 应用免疫组化PowerVision法检测108例胃癌组织中OPN及CTGF的表达,分析OPN、CTGF表达与患者临床病理特征、术后生存时间之间的关系.结果 TNM III/IV期患者中OPN阳性率高于Ⅰ/Ⅱ期(P<0.001),OPN阳性的患者更易发生淋巴结转移(P=0.002)和远处转移(P=0.022),并且OPN表达与肿瘤浸润深度正相关(P=0.015).CTGF高表达常见于发生淋巴结转移的病例(P=0.038).OPN阳性的患者术后5年生存率低于OPN阴性的患者(P<0.001).高表达CTGF的患者术后5年生存率低于低表达CTGF的患者(P=0.003).分析联合检测OPN和CTGF在胃癌组织中的表达发现OPN阳性/CTGF高表达组、OPN阳性/CTGF低表达或者OPN阴性/CTGF高表达组与OPN阴性/CTGF低表达组3组之间患者的术后生存率存在显著差异(4.2%、34.1%、60.5%,P<0.001).Cox回归分析结果表明TNM分期(P<0.001)、分化程度(P=0.01)和OPN/CTGF联合表达水平(P<0.001)是胃癌患者的独立预后因子.结论 组织中OPN、CTGF表达与胃癌的生物学特征密切相关,尤其是联合检测OPN/CTGF两种蛋白是指示胃癌患者预后的独立指标.     

肝细胞性肝癌中MAZ基因的表达及意义

目的探讨MAZ基因在肝细胞性肝癌(hepatocellular carcinoma,HCC)及其癌旁正常组织中的表达,分析其与HCC各临床病理特征及预后的关系。方法采用组织芯片技术和免疫组化法检测75例HCC及其对应癌旁正常组织中MAZ基因的表达,分析其与HCC临床病理特征及与患者预后的关系。结果 MAZ在HCC中的表达(48%,36/75)明显高于其癌旁正常组织(22.67%,17/75),组间比较差异有统计学意义(P0.05)。MAZ表达与HCC患者性别、年龄、病理分级、临床分期、TNM分期、是否合并肝硬化、是否合并乙肝病毒感染、是否有肝癌家族史以及血清AFP、CEA、γ-GT、ALT、AST和ALB水平、是否有淋巴结转移等均无明显相关性,而与肿瘤直径、吸烟与否、饮酒与否显著相关(P0.05)。HCC中MAZ阳性组和阴性组的累计生存率差异有显著性(P0.05),MAZ阳性组患者的术后无瘤生存时间明显低于阴性组,提示MAZ表达上调可能导致患者的预后更差。结论 MAZ基因表达上调可能与HCC的发生、发展密切相关。     

ICAM-1基因K469E与MCP-1基因-2518A/G多态性的交互作用和胃癌侵袭与转移的关系

目的:探讨细胞间黏附分子1(intercellular adhesion molecule-1,ICAM-1)基因K469E与单核细胞趋化蛋白1(monocyte chemoattractant protein-1,MCP-1)基因-2518A/G多态性的交互作用和胃癌侵袭与转移的关系。方法:依据TNM分期,选择我院2009年12月至2014年11月收治的胃癌患者4 500例,分为胃癌Ⅰ期组、Ⅱ期组、Ⅲ期组、Ⅳ期组及0期组各900例,各组在年龄、性别、民族、籍贯和生活习惯方面无显著差异,以上述各组患者的外周血白细胞为样本,利用聚合酶链反应(polymerase chain reaction,PCR)技术分析了ICAM-1基因K469E和MCP-1基因-2518A/G多态性。结果:K469E(EE)基因型和-2518A/G(GG)基因型频率在Ⅰ期组、Ⅱ期组、Ⅲ期组、Ⅳ期组与0期对照组之间有显著差异(P0.01)。K469E(EE)基因型者胃癌侵袭与转移的风险显著增加。-2518A/G(GG)基因型者胃癌侵袭与转移的风险也显著增加。基因突变的协同分析发现K469E(EE)/-2518A/G(GG)基因型者在Ⅰ期、Ⅱ期、Ⅲ期、Ⅳ期与0期对照组中的分布频率经χ2检验有显著差异(P0.01)。K469E(EE)/-2518A/G(GG)基因型者胃癌侵袭与转移的风险显著增加。K469E(EE)和-2518A/G(GG)基因型之间存在超相乘模型的交互作用。结论:K469E(EE)和-2518A/G(GG)基因型均是胃癌侵袭与转移的易患因素,基因多态性的交互作用增加了胃癌侵袭与转移风险。     

结直肠癌组织乳脂肪球表皮生长因子8蛋白表达与临床病理特征和患者生存率的关系

目的:探讨乳脂肪球表皮生长因子8(MFG-E8)蛋白在结直肠癌(CRC)组织中的表达及其与临床病理特征和患者生存率的关系。方法:留取手术切除CRC癌组织(CRC组)及相应癌旁组织(Control组)各88例,应用免疫组织化学法(SP法)检测癌组织及癌旁组织MFG-E8蛋白表达,统计分析各组MFG-E8蛋白高表达率的差异,以及CRC组中MFG-E8低表达组、阳性表达组和强阳性表达组患者临床病理因素和总生存率的差异。结果:CRC组癌组织MFG-E8蛋白高阳性表达率为73.86%(65/88),显著高于Control组28.41%(25/88)(P0.01)。MFG-E8蛋白表达强度仅与淋巴结转移有关(P0.05),而与患者年龄、临床T和M分类、临床分期及肿瘤分型无显著相关(P0.05);MFG-E8阴性表达组及强阳性表达组患者总生存率均显著低于阳性表达组(P0.01)。结论:MFG-E8在CRC患者癌组织中阴性表达及强阳性表达均可促进CRC的淋巴结转移,并提示预后较差。     

肿瘤坏死因子α和白细胞介素6基因启动子区多态性与精神分裂症的相关性研究

目的 探讨肿瘤坏死因子α(tumor necrosis factorα,TNF-α)基因启动子区-308G/A、-857C/T和-1031T/C位点,白细胞介素6(interleukin-6)基因启动子-174G/C和-572C/G多态性与精神分裂症发生的相关性.方法 采用聚合酶链反应-限制性片段长度多态性分析方法检测346例精神分裂症患者、323名健康对照各个多态性位点的基因型,采用SPSS 13.0进行统计学分析.结果 TNF-α基因-857C/T位点的基因型及等位基因频率分布在精神分裂症组与正常对照组均存在统计学意义(P＜0.05),其中,-857T的等位基因的频率在精神分裂症组均显著高于对照组(x2=9.414,P=0.002,OR=1.511,95%CI:1.160～1.969).-857C/T位点不同基因型患者之间的阳性和阴性症状量表总分及阴性症状差异存在显著性,且TT基因型的分值显著高于CC基因型(P＜0.05).结论 TNF-α基因-857C/T位点可能与精神分裂症的发病存在关联,其中,-857T等位基因可能是易感基因,并且-857C/T位点与阳性和阴性症状量表评分中阴性症状存在关联.     

上皮性钙黏蛋白G-347GA SNP单核苷酸多态性与食管癌的关系

目的:探讨CDH1基因启动子区G-347GA单核苷酸多态性(SNP)对食管鳞状细胞癌(ESCC) 发生、淋巴结转移及预后的影响.方法:采用病例-对照研究, 以聚合酶链反应-限制性片段长度多态性(PCR-RFLP)的方法, 分析218例ESCC和218名健康对照者的CDH1 G-347GA SNP分布情况.结果:ESCC组的CDH1基因启动子区G-347GA多态性基因型和等位基因型分布与健康对照组无统计学差异(P>0.05).根据吸烟状况分层分析发现, CDH1 G-347GA多态性基因型及等位基因型频率在吸烟及非吸烟的患者和健康个体中均无统计学意义.根据有无淋巴结转移进行分层分析表明, CDH1 G-347GA多态性基因多态性在有淋巴结转移组和无淋巴结转移组之间无统计学意义, 所以CDH1G-347GA 基因多态性与淋巴结转移的风险性无关.结论:CDH1G-347GA多态性基因型和等位基因型与ESCC的发生和发展及ESCC患者淋巴结转移和预后无关.     

胃癌中微小干扰RNA-20a表达与TNM分期和淋巴结转移的关系

目的 分析微小干扰RNA(miRNA)-20a在胃癌中表达与胃癌TNM分期和淋巴结转移的关系.方法 选取本院普外科于2011年10月至2013年10月收治的145例胃癌患者作为临床观察对象,利用PCR检测并对比这些患者胃癌组织与癌周正常组织的miRNA-20a表达水平,分析其与TNM分期和淋巴结转移的关系.结果 胃癌组织中miRNA-20a的表达水平明显高于癌周正常组织(2.18±0.38比0.65±0.13,P＜0.05).高TNM分期(Ⅲ+Ⅳ期)组较低TNM分期(Ⅰ+Ⅱ期)组胃癌组织中miRNA-20a的表达上调(2.84±0.45比1.37±0.24,P＜0.05).淋巴结转移阳性的患者胃癌组织中miRNA-20a的表达要明显高于淋巴结转移阴性的患者(2.65±0.63比1.88±0.54,P＜0.05).结论 胃癌组织中miRNA-20a的表达升高,其表达与胃癌的TNM分期与淋巴结转移有关.     

18F-FDG PET/CT半定量参数与乳腺癌病理特征的相关性研究

目的 分析18 F-FDG PET/CT半定量参数与乳腺癌病理特征的相关性,研究MTV、TLG预测其病理特征的价值.方法 回顾性分析40例乳腺癌患者.依据病理特征分组,独立样本t检验比较组间MTV、TLG差异,选取其中与MTV、TLG相关的病理特征分别行多重线性回归分析.结果 MTV:单因素分析示高核分级(III级)(t=2.393,P=0.022),高T分期组(T3～T4期)(t=3.546,P=0.003),有淋巴结转移(t=2.951,P=0.007),Ki-67高表达(≥20％)(t=3.267,P=0.003),HER2阳性(t=2.156,P=0.040)及三阴性乳腺癌(t=2.53,P=0.015)均与高MTV相关.多因素分析示高T分期(T3～T4期)与高MTV相关(P=0.015).TLG:单因素分析示高核分级(Ⅲ级)(t=3.091,P=0.005),高T分期(T3～T4期)(t=3.081,P=0.007),有淋巴结转移(t=3.274,P=0.002)及三阴性乳腺癌(t=2.73,P=0.009)与高TLG相关.多因素分析示高核分级(III级)、高T分期(T3～T4期)及三阴性乳腺癌与高TLG相关(P=0.04,P=0.03,P=0.021).结论 乳腺癌原发灶高MTV与高T分期(T3～T4期)相关,高TLG与高核分级(Ⅲ级)、高T分期(T3～T4期)及三阴性乳腺癌相关,18 F-FDG PET/CT半定量参数对于预测乳腺癌病理特征有重要的参考价值,有助于临床筛选三阴性乳腺癌.     

The association between heat shock protein P2/P2 genotype with Egyptian hepatocellular carcinoma patients

Polymorphism of heat shock protein 70 (HSP70) at position 1267 may influence its expression. Many studies showed the importance of this polymorphism in developing cancers and some autoimmune diseases. In this study, we investigated the association of this polymorphism with the risk of hepatocellular carcinoma (HCC) in Egyptian patients. The study included 40 cases with HCC and 20 healthy age- and sex-matched subjects as control. The cases included 31 males (77.5 %) and 9 females (22.5 %). Their ages ranged from 42 to 70 years. HSPA1B 1267 was investigated using polymerase chain reaction with restriction fragment length polymorphism cutting with PstI enzyme. The two allelic forms were designated as the P1 allele and P2 allele. Among the HCC group, 14 patients (35 %) had P2/P2 genotype, 15 patients (37.5 %) had P1/P2 genotype, and 11 patients (27.5 %) had P1/P1 genotype. The frequencies of the HSPA1B P2/P2 genotype and the HSPA1B P2 allele in HCC patients were higher than in controls (each p?=?0.0001). The risk for developing HCC in the homozygous HSPA1B P2/P2 genotype was 2.8-fold higher than that in the heterozygous P1/P2 genotype. In conclusion, polymorphism of HSP70 at position 1267 may be a risk for HCC development in Egyptians.     

Correlation of transforming growth factor beta-1 gene polymorphisms C-509T and aplastic anemia

Autoreactive cytotoxic T cells play a key role in the pathogenesis of aplastic anemia (AA) by myelosuppressive cytokines including interferon gamma, tumor necrosis factor alpha, and transforming growth factor beta. As an important cytokine that modulates the cell cycle, the involvement of transforming growth factor beta-1 (TGF-β1) in AA has been studied. The purpose of our study was to investigate the role of (TGF-β1/2509) gene polymorphisms in patients with acquired AA and to assess whether genotype was associated with higher or lower production and compare it with established control populations. Thirty-one patients with acquired aplastic anemia and 30 age- and sex-matched healthy controls were analyzed consecutively using PCR–restriction fragment length polymorphism (PCR-RFLP). TGF-β1 polymorphism C-509T was identified using PCR-RFLP. Significantly different distributions of the gene were demonstrated between the case and the control. The frequencies of ?509CT and ?509TT genotypes (74.2 versus 30 % and 16.2 versus 3.3 %, respectively) were significantly higher in cases than in controls (P?<?0.001), while the frequency of the ?509 CC genotype is higher in the control than in cases (66.7 versus 9.6 %, P?<?0.001). Our data showed a genotypic profile associated with high TGF-β production in patients with bone marrow failure and suggest that the genetic regulation of inflammatory and T cell-mediated immunological pathways could be involved in the pathogenesis of bone marrow failure, reinforcing the view that AA are organ-specific autoimmune disorders.     

CDH1基因-160(C→A) 多态与福建地区中国人群胃癌遗传易感性的关联研究

目的 上皮钙黏着蛋白（E—cadherin）的编码基因CDHI是重要的肿瘤抑制基因，本研究探讨CDH1基因-160（C→A）多态性在福建地区胃癌人群中的分布及其与福建地区胃癌发病风险的相关性。方法 采用聚合酶链反应-变性高效液相色谱分析方法对102例胃癌患者和101名正常对照者进行CDH1基因-160（C→A）多态的基因型分析，比较基因型分布和发病风险的关系；危险度OR及95％CI应用非条件Logistic回归分析计算。结果 CDH1基因-160（C→A）多态的CC、CA、AA基因型在病例组中的分印频率分别为58（56．9％）．38（37．3％），6（5．9％）；在对照组的分布频率分别为55（54．5％），41（40．6％），5（5％）；两组间分布的差异无统计学意义（P〉0．05）。AA基因型没有显著性地提高或降低胃癌的发病危险（OR=1．12；95％CI：0．32～3．95）；携带A等化基因与胃癌的临床病理特征也无关联性。结论 CDH1基因-160（C→A）多态性可能与福建地区中国人群胃癌发生的遗传易感性无关。     

Genetic variations in DNA-repair genes (XRCC1, 3, and 7) and the susceptibility to hepatocellular carcinoma in a cohort of Egyptians

Chronic hepatitis C (CHC) is a worldwide etiology of chronic hepatic insult particularly in Egypt. DNA-repair systems are responsible for maintaining genomic integrity by countering threats posed by DNA lesions. Deficiency in the repair capacity due to genetic alterations in DNA-repair genes can lead to genomic instability and increased risk of cancer development. The present work aimed at studying the possible association between XRCC1-G28152A (rs25487), XRCC3-C18067T (rs861539), and XRCC7-G6721T (rs7003908) single nucleotide polymorphisms (SNPs) and the susceptibility to hepatocellular carcinoma (HCC) in Egyptian population. The study was conducted on 100 newly diagnosed HCC patients and 100 age- and sex-matched healthy controls. Laboratory workup revealed that all HCC patients have chronic hepatitis C viral infection. Genotyping of the studied SNPs was performed by real-time PCR. The heteromutant genotype of XRCC1 (GA) conferred an almost two-fold increased risk of HCC (OR , 2.35; 95% CI, 1.33-4.04). Regarding XRCC7, the heteromutant (TG) genotype conferred a two-fold increased risk of HCC (OR , 2.17; 95% CI, 1.23-3.82). Coinheritance of the polymorphic genotypes of XRCC1 and 7 was significantly higher in HCC cases than controls and was associated with an 11-fold increased risk of HCC (OR , 11.66; 95% CI, 2.77-49.13). The frequency of XRCC3 polymorphic genotypes in HCC patients was close to that of the controls.     

细胞周期蛋白D1基因多态与人结直肠癌遗传易感性

目的探讨细胞周期蛋白D1(Cyclin D1)基因第870位点单核苷酸多态(G870A)与结直肠癌(colorectal cancer,CRC)遗传易感性的关系。方法采用聚合酶链反应限制性片段长度多态性(PCR-RFLP)方法,检测345例CRC与670名对照的G870A基因型分布及差异。结果CRC和对照两组人群的Cyclin D1 G870A基因型分布差异无统计学意义(P>0.05)。与GG基因型相比,GA、AA基因型及A等位基因携带者(GA及AA基因型)的CRC风险分别为1.08倍(95%CI=0.75～1.54)、1.01倍(95%CI=0.68～1.51)及1.06倍(95%CI=0.75～1.49)。经性别、年龄、肿瘤位置、组织学分化程度和Dukes分期等因素分层分析,结果均显示G870A与CRC发病风险无显著性相关。结论Cyclin D1 G870A多态与宁波地区人群的CRC发病风险无相关性。     

Meta-Analysis of Adiponectin Polymorphisms and Colorectal Cancer Risk

Objective The adiponectin gene (ADIPOQ) has been suggested to be associated with the pathogenesis of colorectal cancer (CRC). However, the results have been inconsistent. In this study, we performed a meta-analysis to investigate the association between adiponectin polymorphisms and CRC risk.Methods All eligible case-control studies published up to March 2013 were identified by searching PubMed, Web of Science and CNKI. Effect sizes of odds ratio (OR) and 95% confidence interval (95% CI) were calculated by using a fixed- or random-effect model.Results A total of 9 case-control studies were included, Of those studies, there were eight studies (2024 cases and 2777 controls) for rs1501299G/T polymorphism, five studies (1401 cases and 1691 controls) for rs2241766T/G polymorphism, five studies (2945 cases and 3361 controls) for rs266729C/G polymorphism, three studies (1221 cases and 1579 controls) for rs822395A/C polymorphism and three studies (1222 cases and 1575 controls) for rs822396A/G polymorphism. Overall, a significant association was observed for rs2241766T/G polymorphism under heterozygote comparison (TG vs. TT: OR=1.22, 95%CI: 1.05-1.43); while there was no significant association for rs2241766 polymorphism under other genetic models, and for other four polymorphisms under all genetic models. Besides, when stratified analyses by ethnicity, no significant association between five polymorphisms and CRC risk were observed under all genetic models among Asian, Caucasian and African-American.Conclusions This meta-analysis indicated that adiponectin rs2241766T/G rather than rs1501299G/T, rs266729C/G, rs822395A/C and rs822396A/G polymorphism was associated with the risk of colorectal cancer.     

Endothelin-Converting Enzyme-1 Promoter Polymorphisms and Susceptibility to Sporadic Late-Onset Alzheimer's Disease in a Chinese Population

Endothelin converting enzyme (ECE-1) is a candidate Alzheimer disease susceptibility gene. It was previously reported that western individuals homozygous for the C-338A polymorphism (AA) within the ECE1 gene promoter region are at reduced risk of developing late onset Alzheimer disease (LOAD). A further polymorphism, T-839G, is present within the ECE1 promoter region but a potential association with LOAD has not been studied. We therefore studied possible associations between these ECE1 polymorphisms and LOAD in a Chinese population. Subjects comprised 376 Chinese LOAD patients and 376 age- and sex-matched controls; all subjects were typed for the ECE1 C-338A and the T-839G polymorphisms. We report that the frequency of the 338A allele was decreased in LOAD patients compared to controls (adjusted OR =0.73; 95% CI=0.54–0.98; P=0.03). There was no significant association between T-839G genotype and LOAD, however the combined 839T/338A haplotype was significantly associated with decreased risk of LOAD (OR=0.73; 95% CI=0.57–0.93; P=0.01). This study argues that the ECE1 338A allele is protective against LOAD in a Chinese population.     

Polymorphism and circulating levels of the chemokine CXCL12 in colorectal cancer patients

The chemokine CXCL12, also known as stromal cell-derived factor-1 (SDF-1), is a small protein that regulates leukocyte trafficking and is variably expressed in a number of normal and cancer tissues. CXCL12 as ligand and its receptor CXCR4 have been implicated in colorectal cancer (CRC) progression including angiogenesis and metastasis. A CXCL12 gene variant CXCL12-A (CXCL12-G801A, a single nucleotide polymorphism in the 3' untranslated region) is associated with increased susceptibility to breast cancer. Based on the suggested role of CXCL12 in the pathogenesis of cancer we examined the association of the gene variant CXCL12-A with CRC. The polymorphism was analysed with PCR and RFLP methods. Furthermore, the plasma CXCL12 levels from patients with CRC were also examined. There was no significant difference in genotype distribution and allelic frequencies between CRC patients (n=151) and controls (n=141). On the other hand, we found that the carrying rate of allele CXCL12-A was higher in colon cancer patients compared with rectal cancer patients (P=0.017). Analyses by ELISA showed that CRC patients (n=63) had a lower CXCL12 plasma level compared with controls (P<0.0001). Moreover, patients with tumours classified as Dukes' stage B and C revealed lower levels than patients with tumours in Dukes' stage A. Further studies with larger samples of patients are necessary to determine whether the CXCL12 polymorphism and plasma level reflect the clinical outcome of CRC and have an impact on CRC progression.     

The E-cadherin (CDH1)--160 C/A polymorphism and prostate cancer risk: a meta-analysis

Published data on the association between E-cadherin (CDH1) -160 C/A polymorphism and prostate cancer (PCA) risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. A logistic regression approach proposed for molecular association studies was used to estimate a biological model of the gene effect. A total of 11 studies including 2637 cases and 2673 controls were involved in this meta-analysis. Logistic regression analysis indicated that the CDH1 -160 C/A genotypes were associated with PCA risk. The genetic model test indicated that the genetic model was most likely to be dominant (CA+AA vs CC). Overall, meta-analysis indicated that the -160A allele carriers (CA+AA) had a 21% elevated risk of PCA, when compared with the homozygotes (CC) (odds ratio (OR)=1.21; 95% confidence interval (CI): 0.97-1.51; P=0.090, P(heterogeneity)=0.001). In the subgroup analyses by ethnicity, significantly elevated risks were associated with -160 variant genotypes (CA+AA) in both European and Asian populations (OR=1.24; 95% CI: 1.08-1.43; P=0.003, P(heterogeneity)=0.220 and OR=1.54; 95% CI: 1.23-1.93; P<0.001, P(heterogeneity)=0.200). However, no significant associations were found in Africans (OR=0.59; 95% CI: 0.32-1.09; P=0.090, P(heterogeneity)=0.070). Although some modest bias could not be eliminated, this meta-analysis suggests that the CDH1 -160A allele is a low-penetrant risk factor for developing PCA, especially in Europeans and Asians.     

MTHFR C677T has differential influence on risk of MSI and MSS colorectal cancer

The majority of colorectal cancer (CRC) exhibiting the micosatellite instability (MSI) phenotype is due to hypermethylation of the hMLH1 gene promoter. We aimed to test the hypothesis that polymorphisms in genes coding for enzymes involved in folate metabolism play a role in altered promoter-specific hypermethylation and thus predispose to MSI CRC. Analysis of MSI was performed in 1685 CRCs, and polymorphism genotypes were determined in germline DNA for all cases and 2692 cancer-free controls. MSI was observed in 171 cancers (10.1%). Compared to homozygous wild-type individuals, those with MTHFR 677TT genotype were more likely to have MSI than microsatellite stable (MSS) CRC [odds ratio (OR) 1.90; 95% confidence interval (CI): 1.09-3.31]. When MTHFR C677T genotype frequencies in MSS CRC cases were compared to controls, individuals with homozygous variant genotype were at 19% reduced risk of cancer compared to wild type (OR = 0.81; 95% CI: 0.65-1.02). Conversely, when MSI CRC cases were compared to controls, individuals with one or two MTHFR 677T alleles were at 42% increased cancer risk (OR = 1.42; 95% CI: 1.02-1.96). Our observations indicate that MTHFR 677TT homozygous individuals are more likely to develop MSI CRC than those with wild-type genotype, and this common polymorphism has differential influences on MSI and MSS CRC risk. Stratification by MSI status should aid future studies investigating the complex relationships between genotype, environmental factors and CRC risk.