p73和MDM2基因多态性与卵巢上皮性癌发病风险的相关性

目的:探讨p73和鼠双微基因2(murine double minute 2, MDM2)启动子区单核苷酸多态性(single nucleotide polymorphisms, SNPs)与卵巢上皮性癌发病风险的关系.方法:采用聚合酶链反应-限制性片段长度多态性方法检测257例卵巢上皮性癌患者和257例健康志愿者妇女(对照组)的p73 G4C14/A4T14、MDM2 309T/G和MDM2 Del1518+/-这3个SNPs位点的基因型频率分布情况.结果:p73 G4C14/A4T14多态的等位基因和基因型频率在卵巢癌组和对照组中的分布差异无统计学意义(P=0.55,P=0.20);病例组中MDM2 309T/G SNP的G等位基因频率(46.7%)明显低于对照组(54.7%),2组比较差异有统计学意义(P=0.01),2组间基因型频率差异也有统计学意义(P=0.046);与MDM2 309T/G SNP的T/T基因型相比,T/G+G/G基因型可明显降低卵巢上皮性癌的发病风险[比值比(odds ratio,OR)=0.65, 95%可信区间(confidence interval,CI):0.44～0.97].进一步的分层分析显示,G等位基因携带者主要降低内膜样癌、Ⅲ～Ⅳ期卵巢癌和50岁以上卵巢癌的发病风险(OR=0.53, 95%CI:0.31～0.90; OR=0.62,95%CI:0.40～0.97; OR=0.59,95%CI:0.38～0.92).MDM2 Del1518+/- SNP的基因型和等位基因频率在卵巢癌组和对照组中的分布差异无统计学意义;分层分析显示,携带MDM2 Del1518+/+基因型会增加黏液性卵巢癌和Ⅰ～Ⅱ期卵巢癌的发病风险 (OR=2.01, 95%CI:0.93～4.37; OR=1.64, 95%CI:0.99～2.72).似然比检验发现,p73 G4C14/A4T14和MDM2 309T/G SNPs之间有明显的交互作用(P=0.03).结论:MDM2基因启动子区309T/G多态的G等位基因可能是卵巢上皮性癌发病风险的一个保护因素,且可能与p73 G4C14/A4T14多态间存在交互作用.     

MDM2 启动子区309 位点基因多态性与乳腺癌风险的关系*

目的:采用病例- 对照研究检测MDM2 启动子区309 位点T>G 单核苷酸多态（SNP 309）在中国女性人群中的频率分布,分析其与中国女性乳腺癌发病风险的关系。方法:提取病例组698 例原发性乳腺癌患者及对照组525 例健康人的外周血单核细胞DNA,采用聚合酶链反应- 限制性片段长度多态性（PCR-RFLP ）分析法,检测MDM2 启动子区309 位点基因多态性,确定此位点三种基因型,即T/T、T/G、G/G 基因型。统计分析病例组和对照组人群MDM2 SNP 309 各基因型频率分布,及各基因型与乳腺癌发病风险的相关性。结果:在研究的病例组与对照组整体人群中,经年龄、月经状态、家族史及生育史等因素校正后,与MDM2 SNP 309 T/T基因型比较,T/G 型及G/G 型与乳腺癌的发病风险无显著相关性（T/G,adjusted OR= 1.2,95%CI:0.8～1.6,P=0.30;G/G,adjusted OR= 1.0,95%CI:0.7～1.5,P=0.88）。 进一步分层分析后显示:在绝经后人群中,与T/T基因型比较,T/G 基因型及G/G 基因型显著增加乳腺癌的发病风险（T/G,adjusted OR= 1.8,95%CI:1.2～3.0,P=0.011;G/G,adjusted OR= 1.9,95%CI:1.2～3.3,P=0.014）。 提示绝经后人群携带T/G 型、G/G 型者比携带T/T基因型者患乳腺癌的风险分别升高约1.8、1.9 倍。在绝经前人群中,各基因型与乳腺癌的发病风险无显著相关性（P>0.05）。 结论:MDM2 启动子309 位点突变型G 等位基因携带者显著增加绝经后女性乳腺癌的发病风险。      

MDM2基因SNP309可能与早发性乳腺癌易感性无关:福建病例-对照研究

背景与目的:MDM2基因是p53基因的负性调控因子,其SNP309遗传多态性可能与乳腺癌发病风险有关,本研究探讨SNP309多态性在福建早发性乳腺癌人群中的分布及其与乳腺癌发病风险的相关性.方法:对123例早发性乳腺癌患者(发病年龄≤35岁)和101例正常对照者进行MDM2基因SNP309(T>G,rs2279744)的PCR扩增,并采用时间飞行质谱分析(MALDI-TOF-MS)法鉴定多态性的基因型,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:MDM2基因SNP309多态性基因型在正常对照组和病例组中的分布频率分别为TT:28(27.7%)/26(21.1%),TG:50(49.5%)/61(49.6%),GG:23(22.8%)/36(29.3%);两组间分布频率差异无统计学意义(P>0.05).Logistic回归分析表明,在早发性乳腺癌人群中,以rs2279744的TT基因型为参照,含G基因型(TG,GG)未显著性地提高乳腺癌的发病危险,OR=1.358(95%CI:0.706～2.614,P>0.05).结论:MDM2基因SNP309(T>G,rs2279744)多态性可能与福建地区汉族人群早发性乳腺癌的遗传易感性无关,其作为低外显率的乳腺癌易感基因位点尚不明确,作为未来临床基因筛查的候选指标还需谨慎.     

MDM2基因SNP309多态性与宫颈癌的相关性研究

目的:研究汉族妇女中MDM2基因SNP309多态性与宫颈癌易感性及临床病理学参数之间的关系.方法:用DNA抽提试剂盒从研究对象的外周血标本中抽提基因组DNA,其中宫颈癌患者105例,正常对照组140例;用聚合酶链式反应-限制性片段长度多态(PCR-RFLP)和直接测序方法测定MDM2-SNP309单核苷酸多态基因型.结果:宫颈癌患者的MDM-SNP309G等位基因频率显著高于对照组(60.0% vs 48.6%,P=0.012;OR=1.59,95%CI=1.11～2.28);宫颈癌与对照组之间的GG、TG和TT等位基因型的分布差异有统计学意义,其中GG等位基因型在宫颈细胞癌中的频率显著高于对照组(36.2%vs 18.6%,P=0.016;OR=2.58,95%CI=1.19～5.61).在宫颈癌组中,淋巴转移阳性组MDM2-SNP309 CG等位基因型显著高于淋巴转移阴性组(31.8% vs11.5%,P＜0.05),SNP309单核苷酸多态性分布与肿瘤组织学类型、病理分级及肿瘤大小无关.结论:MDM2基因SNP309GG基因型是宫颈癌发生的遗传易感因素,与宫颈癌的淋巴转移发生有相关性.     

MDM2基因多态性与食管鳞癌、贲门腺癌易感性的关系

目的：研究MDM2启动子区SNP309和Dell 518基因多态性与中国河北省高发区人群食管鳞状细胞癌（esophageal squamous cell carcinoma，ESCC）和贲门腺癌（gastric cardiac adenocarcinoma，GCA）易感性的关系。方法：应用引物引入限制性内切酶分析-聚合酶链反应（primer-introduced restriction analysis-polymerase chain reaction，PIRA-PCR）方法，分别检测了351例ESCC患者、212例GCA患者和642例健康对照组人群的MDM2启动子区SNP309和Dell518的基因型。应用EH和2LD软件分析两个多态性位点的相互关系。结果：MDM2基因型分布在总体ESCC患者组和健康对照组间无显著性差异（P〉0．05），而在总体GCA患者组与健康对照组间存在的差异有统计学意义（P〈0．05）。单体型分析显示，MDM2单体型分布在ESCC患者组与健康对照组间差异无统计学意义（P=0．198），而在GCA患者组与健康对照组间有显著性差异（P=0．000）。与SNP309G／Dell518＋单体型相比，检出SNP309T／Dell518-单体型组可显著降低GCA的发病风险（OR=0．51，95％CI=0．38～0．70）。结论：MDM2的SNP309和Dell518多态性与ESCC的发病风险可能无关；携带MDM2SNP309T等位基因的基因型（G／T与T／T）和携带Dell518-等位基因的基因型（＋／-与-／-）可分别降低GCA的发病风险：MDM2SNP309T／Dell518-单体型组可以降低GCA的发病风险。     

潮汕地区食管癌患者O6-甲基鸟嘌呤-DNA甲基转移酶基因多态性的分析

背景与目的初步研究中国食管癌高发区之一潮汕地区食管癌患者和正常人群O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)基因编码84、143及160位密码子的单核苷酸多态性(Single nucleotide polymorphism,SNP)。材料与方法应用双色荧光杂交微阵列技术分别检测潮汕地区100例食管鳞状细胞癌患者及65例健康对照外周血MGMT基因84位密码子(C2740214T)单核苷酸多态性;用同样的方法检测76例食管鳞状细胞癌患者和50例健康对照MGMT基因143位密码子(A2798995G)、160位密码子(G2799046A)单核苷酸多态性。结果基因型分布符合Hardy-Weinberg定律。统计分析显示食管鳞状细胞癌组与对照组84位密码子2740214C和2740214T等位基因频率差异无统计学意义(P=0.402),2740214CT基因型在病例组和对照组中所占的比例分别为16%和12.3%,2740214TT基因型在病例组中所占的比例是2%。食管鳞状细胞癌组变异基因型拥有者(CT TT)高于对照组,但差异无统计学意义(P=0.327),2740214TT基因型仅见于个别肿瘤患者,而在正常对照中未发现。143位密码子A2798995G位点仅在对照组中发现一例杂合子,其余均为野生型纯合子,病例组与对照组基因型和等位基因频率差异均无统计学意义。160位密码子G2799046A位点检测在所有的病人和对照中均为野生型纯合子。结论潮汕地区食管鳞状细胞癌患者和正常人群中存在MGMT基因多态性,84位密码子C2740214T位点的突变型纯合子仅见于肿瘤患者,可能与食管鳞状细胞癌有关。     

TNF-α 基因308 位点单核苷酸多态性与原发性肺癌相关性研究*

目的:肿瘤坏死因子- α（tumor necrosis factor- α ,TNF-α）基因启动子单核苷酸多态性与某些炎性疾病、肿瘤的发生有关。本研究就TNF-α - 308G/A 位点基因多态性与中国人群原发性肺癌易感性进行探讨。方法:应用高通量TaqMan-MGB 探针技术对TNF-α - 308G/A 位点,即rs 1800629 位点进行基因分型,分析比较447 例健康对照者和250 例原发性肺癌患者的基因类型。采用SPSS18.0 软件对数据资料进行统计分析。结果:TNF-α - 308G/A 位点GG基因型在病例组和对照组中的频率分别为73.2%和90.8% 。A/G 基因型在病例组和对照组中频率分别为26.8% 和8.7% 。基因型A/G+AA频率分别为26.8% 和9.2% ,该位点多态性在病例组和对照组中的分布频率差异具有统计学意义（P < 0.05）。 此外,A/G 基因型在男性、吸烟、小细胞肺癌或非小细胞肺癌患者相对于GG型均为危险因素,但在女性中无统计学意义（P > 0.05）。 结论:TNF-α - 308G/A 位点基因多态性与中国原发性肺癌发病易感性显著相关。      

中国人肺癌易感性与Cyclin D1(A870G)遗传多态性的研究

目的研究中国北方人对肺癌的易感性与Cyclin D1基因第870位核苷酸A/G(A870G)多态性的关系.方法应用PCR-SSCP方法,检测93例肺癌及122例健康对照外周血白细胞Cyclin D1(A870G)的遗传多态性.结果肺癌组与对照组Cyclin D1(A870G)A/G的等位基因频率分别为60.75%、39.25%及51.64%、48.36%,两组间分布无显著性差异(P=0.06).肺癌组与对照组的A/A、A/G及G/G基因型频率分别为38.71%、44.09%、17.20%及23.77%、55.74%、20.49%.两组间A/G及G/G基因型频率无显著性差异(P＞0.05),而肺癌组A/A基因型频率明显高于对照组(P=0.018).肺癌组与对照组A/A基因型频率的分布差异与肺癌的病理类型有关.肺鳞癌组的A/A基因型频率与对照组无显著性差异(P=0.403),而肺腺癌组的A/A基因型频率明显高于对照组(P=0.017).与A/G及G/G基因型携带者之和相比,A/A基因型携带者患肺腺癌的校正相对风险度(OR)为2.43,95%CI=1.74～4.77.结论Cyclin D1(A870G)A/A基因型是中国北方人患肺腺癌的危险因素,而肺鳞癌的易感性与Cyclin D1(A870G)多态性无关.     

FGFR2基因多态性与乳腺癌的相关性研究

目的:探讨成纤维细胞生长因子受体2基因(FGFR2)第二内含子单核苷酸多态性在女性群体中的频率分布及其与女性乳腺癌易感性之间的相关性.方法:运用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法结合琼脂糖凝胶电泳技术,对106例女性乳腺癌患者(乳腺癌组)和116例正常女性(对照组)对照进行检测,分析两组贵州地区人群FGFR2基因第二内含子的两个单核苷酸多态性位点rs2420946和rs2981579的基因及基因型的分布情况.结果:乳腺癌组FGFR2基因单核苷酸多态性位点rs2420946的基因型(AA,AG.CG)频率分别为15.09%、48.11%、36.79%,对照组为18.10%、43.97%、37.93%;乳腺癌组与对照组A等位基因频率分别为39.15%和40.09%,G等位基因频率分别为60.85%和59.91%;两组人群分别进行比较,基因型及等位基因频率分布的差异均无统计学意义(P>0.05);FGFR2基因rs2981579的基因型(CC,CT,TT)频率在乳腺癌组分别为30.19%、45.28%、24.53%,对照组为27.59%、48.28%、24.14%;乳腺癌组与对照组c等位基因频率分别为52.83%和51.72%,T等位基因频率分别为47.17%和48.28%;两组人群分别进行比较,基因型频率与等位基因频率分布的差异均无统计学意义(P>0.05).结论:FGFR2基因第二内含子的两个单核苷酸多态性位点rs2420946及rs2981579在乳腺癌及对照人群中基因型频率与等位基因频率分布差异均无统计学意义,提示两个位点的多态性与乳腺癌无明显相关性.     

贵州汉族人群乳腺癌与FGFR2 rs1219648多态性相关性研究*

目的:探讨贵州汉族人群成纤维细胞生长因子受体2（fibroblast growth factor receptor 2,FGFR2）基因单核苷酸多态性与女性乳腺癌易感性之间的相关性。方法:运用聚合酶链反应- 序列特异性引物（PCR-SSP ）方法分析106 例女性乳腺癌患者和116 例正常对照女性FGFR2 基因内含子5 rs 1219648 多态性的分布情况。结果:乳腺癌组FGFR2 基因单核苷酸多态性位点rs 1219648 的基因型（TT,TC,CC）频率分别为50.00% 、25.47% 和24.53% ,对照组分别为29.31% 、48.28% 和22.41% ,乳腺癌组与对照组T 等位基因频率分别为62.74% 和53.45% ,C 等位基因频率分别为37.26% 和46.55% ,FGFR2 rs 1219648 基因型频率及等位基因频率在乳腺癌组与对照组中的分布差异均有统计学意义（P<0.05）。 结论:FGFR2 基因内含子5 的单核苷酸位点rs 1219648 多态性与乳腺癌可能具有相关性。携带FGFR2 rs 1219648 的TT等位基因型的人群可能更易患乳腺癌。      

Significant Association of the MDM2 T309G Polymorphism with Breast Cancer Risk in a Turkish Population

Background: Breast cancer is a leading cause of death in women worldwide. Genetic polymorphisms have beenreported to be important etiological factors. Murine double minute 2 (MDM2) T309G interacts with p53 and mutationsin p53 are present in approximately 50% of all cancers. However, it has been reported that effect of the polymorphismon breast cancer risk may vary in different populations. Here, we therefore investigated whether there is an associationbetween MDM2 T309G (rs2279744) polymorphism and breast cancer in a Turkish population. Materials and Methods:We analysed 110 patients with breast cancer and 138 matched? controls. For genotyping, polymerase chain reactionand restriction length fragment polymorphism methods were used. Results: A significant difference was observedbetween case and control groups with regard to the distribution of the MDM2 T309G polymorphism (p<0.05). Therewas a significantly higher frequency of the TT genotype in the control group (p=0.028; OR, 2.42; 95% CI, 1.09-5.37).However, we did not find any relationships among tumor grade and metastasis status and this polymorphism. Conclusion:This study indicates that the MDM2 T309G polymorphism GG genotype and the TG+GG combination may be riskfactors for breast cancer in our Turkish population.     

MDM2 SNP309 modifies the prognostic significance of the p53 mutational status in patients with ovarian cancer

A single nucleotide polymorphism (SNP309) of MDM2 causes elevated MDM2 levels and an attenuation of p53 function. The aim of the present study was to examine the clinical relevance of the MDM2 SNP309 in ovarian cancer.MDM2 SNP309 genotype was analyzed in 198 patients with primary ovarian cancer. MDM2 expression was investigated using immunohistochemistry. A functional yeast-based assay and subsequent sequencing were performed to determine p53 mutational status. Of the patients, 44.4% (88 of 198) exhibited the common variant (T/T), 40.9% (81 of 198) the heterozygous variant (T/G) and 14.7% (29 of 198) the homozygous variant (G/G) MDM2 SNP309 genotype. MDM2 SNP309 was not associated with p53 mutational status, MDM2 expression, clinicopathological parameters or prognosis. In patients with the T allele (T/T and T/G genotype), p53 wild type carcinomas were associated with significantly improved recurrence-free (p<0.001) and overall survival (p<0.001) as compared to p53 mutant carcinomas. In contrast, p53 mutational status did not possess prognostic relevance in G/G carriers. A possible functional impairment of the p53 pathway caused by the G/G genotype of the MDM2 SNP309 may modify the association between p53 mutational status and prognosis in ovarian cancer.     

No association of the MDM2 SNP309 polymorphism with risk of breast or ovarian cancer

A functional T to G germline polymorphism in the promoter region of MDM2 (SNP309) has been reported to profoundly accelerate tumor formation suggesting that it may also represent a powerful cancer predisposing allele. To investigate the role of SNP309 in cancer predisposition we undertook a case-control study of this polymorphism among 351 women diagnosed with breast cancer, 302 women diagnosed with ovarian and 258 female controls from a British population. The GG genotype was not associated with either breast cancer (OR 1.04, 95% CI 0.67–1.60) or ovarian cancer (OR 0.86, 95% CI 0.53–1.37). This study has found no evidence that the GG genotype of the MDM2 SNP309 polymorphism is associated with early onset or familial breast cancer or with ovarian cancer.     

MDM2 309T>G polymorphism and risk of lung cancer in a Korean population

BACKGROUND: The MDM2 protein plays an important role in regulating cell proliferation and apoptosis by interaction with multiple proteins including p53 and Rb. A polymorphism (309T>G) in the MDM2 promoter has been shown to result in higher levels of MDM2 RNA and protein. In order to evaluate the association of the MDM2 309T>G polymorphism and lung cancer risk, we carried out a case-control study in a Korean population. METHODS: The MDM2 genotypes were determined in 582 lung cancer patients and in 582 healthy control subjects who were frequency matched for age and gender. RESULTS: The distribution of the MDM2 309T>G genotypes was not significantly different between overall lung cancer cases and controls. However, when the cases were categorized by tumor histology, the 309GG genotype was associated with a significantly increased risk of adenocarcinoma (adjusted OR=1.91, 95% CI=1.16-3.14, P=0.01) compared to the 309TT genotype. In addition, the risk of adenocarcinoma increased as the number of 309G alleles increased (P(trend)=0.01). CONCLUSION: Our findings suggest that the MDM2 309T>G polymorphism may be used as a marker for genetic susceptibility to adenocarcinoma of the lung.     

MDM2 promoter polymorphism and pancreatic cancer risk and prognosis.

PURPOSE: The mouse double minute 2 homologue (MDM2) -309T/G promoter polymorphism has been associated recently with the development and prognosis of a variety of tumors. The G allele is associated with increased affinity for Sp1 binding and higher MDM2 mRNA and protein levels, leading to diminished tumor suppressor activity of the p53 pathway. We hypothesized that the G allele is also associated with increased risk and worse outcome in pancreatic cancer. EXPERIMENTAL DESIGN: We evaluated the association between MDM2 309T/G and the risk of histologically confirmed pancreatic adenocarcinoma at Massachusetts General Hospital using unconditional logistic regression (123 cases and 372 controls). Complete overall survival and progression-free survival data were also available for 109 newly diagnosed patients. RESULTS: The adjusted odds ratios (95% confidence intervals) of pancreatic cancer associated with the MDM2 T/G and G/G genotypes compared with TT were 1.89 (1.20-2.99) and 2.07 (1.03-4.16), respectively (adjusting for age, gender, smoking status, and pack-years of smoking). In Cox proportional hazards model with the wild-type T/T genotype as the reference category and adjusting for stage, treatment, and performance status, both the heterozygous T/G and the homozygous G/G genotypes were associated with decreased progression-free survival [adjusted hazard ratio (95% confidence interval), 1.67 (0.98-2.84) for T/G and 2.28 (1.11-4.71) for G/G] and overall survival [2.64 (1.23-5.67) for T/G and 3.12 (1.22-7.91) for G/G]. CONCLUSIONS: The G allele of the MDM2 -309T/G polymorphism is associated with 2- to 3-fold increase risk and progression of pancreatic adenocarcinoma and a corresponding decrease in survival.     

MDM2 promoter SNP309 is associated with an increased susceptibility to chronic lymphocytic leukemia and correlates with MDM2 mRNA expression in Chinese patients with CLL

A single nucleotide polymorphism (SNP) at position 309 in the promoter region of MDM2 leading to increased expression of MDM2 and attenuated function of p53 has recently been suggested as an unfavorable prognostic marker in chronic lymphocytic leukemia (CLL) although this has been questioned. The MDM2 SNP309 genotypes in 173 CLL patients and 260 healthy controls were detected by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, which was confirmed by direct DNA sequencing. Compared with the T/T genotype, the SNP309 G/G genotype instead of T/G heterozygote was associated with a significantly increased risk of CLL (OR = 2.84; 95% CI 1.61-5.03; p < 0.001). Age at onset of CLL was similar irrespective of MDM2 status. MDM2 mRNA expression within CLL of G/G genotype was significantly higher than that in T/G (p = 0.009) and T/T genotypes (p < 0.001). Excluding patients with p53 deletions or mutations enhanced the significance of the findings (G/G vs. T/T, p < 0.001; G/G vs. T/G p = 0.001), which prompted us to study the role of the polymorphism in p53 wild-type individuals. In the p53 wild-type groups, survival analysis showed that the patients with MDM2 SNP309 G/G and T/G genotypes both had significantly shorter treatment-free survival (TFS) than SNP309 T/T genotype. Notably, univariate and multivariate analyses showed that MDM2 SNP309 genotypes were associated with TFS. These data show that MDM2 309G polymorphisms contribute to the risk of developing CLL. The unfavorable MDM2 SNP309 G/G genotype was associated with an increase of MDM2 mRNA expression. MDM2 SNP309 was found to be associated with TFS in p53 wild-type Chinese CLL populations.     

The MDM2 SNP309T>G Polymorphism Increases Bladder Cancer Risk among Caucasians: a Meta-analysis

Published studies have evaluated associations between the MDM2 SNP309T>G polymorphism and bladder cancer susceptibility. However, these generated inconsistent results. The aim of the present investigation was to quantify the strength of association between MDM2 SNP309T>G polymorphism and bladder cancer risk by conducting a meta-analysis. We searched PubMed and Embase for related studies that had been published in English before April 1, 2014 and associations were assessed by summarizing the odds ratios (ORs) with thecorresponding 95% confidence intervals (CIs). Five case-control studies with a total of 972 cases and 1,012 controls were finally identified to be eligible for the meta-analysis. Overall, the results indicated that there was no significant association between the MDM2 SNP309T>G polymorphism and bladder cancer risk (for the allele model G vs. T: OR=1.08, 95% CI 0.85-1.36, p=0.54; for the co-dominant model GG vs. TT: OR=1.20, 95% CI 0.74-1.93, p=0.46; for the dominant model GG+GT vs. TT: OR=0.98, 95% CI 0.80-1.20, p=0.83; for the recessive model GG vs. GT+TT: OR=1.20, 95% CI 0.83-1.74, p=0.33). However, on subgroup analysis by ethnicity, significant associations were found in Caucasians in three models (for the allele model G vs. T: OR=1.41, 95% CI 1.10-1.81, p=0.006; for the co-dominant model GG vs. TT: OR=2.16, 95% CI 1.28-3.63, p=0.004; for therecessive model GG vs. GT+TT: OR=2.06, 95% CI 1.31-3.22, p=0.002). In summary, the present meta-analysis provides evidence that the genotype for the MDM2 SNP309T>G polymorphism may be associated with genetic susceptibility to bladder cancer among Caucasians.     

No association between SNP309 promoter polymorphism in the MDM2 and cervical cancer in a study from northeastern Brazil

Background: A functional variant in the MDM2 promoter (a T/G substitution, SNP309) was found to be associated with increased expression of MDM2 gene products and at significantly earlier age onset of tumors in both hereditary Li-Fraumeni individuals and sporadic cancer patients. We tested the hypothesis that this functional variant was associated with either risk or early age diagnosis of cervical cancer in a Brazilian population. Methods: A primer-introduced restriction analysis PCR assay was used to genotype the MDM2 SNP309 of 72 cervical carcinoma patients and 100 healthy women. Results: No statistically significant association was observed between SNP309 and cervical cancer. We did not find allele or genotype frequency differences between the group of patients with cancer diagnosis at an early age (younger than 40 years old) and the group of older patients. Conclusions: Our findings suggest that SNP309 MDM2 may not be a risk factor for cervical cancer.     

Role of the MDM2 Promoter Polymorphism (-309T>G) in Acute Myeloid Leukemia Development

Background: The human homologue of the mouse double minute 2 (MDM2) gene is a negative regulator ofTp53. MDM2-309T>G a functional promoter polymorphism was found to be associated with overexpressionthereby attenuation of Tp53 stress response and increased cancer susceptibility. We have planned to evaluate thepossible role of MDM2-309T>G polymorphism with risk and response to chemotherapy in AML. Materials andMethods: A total of 223 de novo AML cases and 304 age and sex matched healthy controls were genotyped for theMDM2-309T>G polymorphism through the tetra-primer amplification refractory mutation system (ARMS)-PCRmethod. In order to assess the functional relationship of -309T>G SNP with MDM2 expression level, we quantifiedMDM2 mRNA in 30 primary AML blood samples through quantitative RT-PCR. Both the (-309T>G) genotypesand the MDM2 expression were correlated with disease free survival (DFS) rates among patients who haveachieved complete remission (CR) after first induction chemotherapy. Results: MDM2-309T>G polymorphismwas significantly associated with AML development (p<0.0001). The presence of either GG genotype or G alleleat MDM2-309 confered 1.79 (95% CI: 1.12-2.86; p<0.001) and 1.46 fold (95%CI: 1.14-1.86; p= 0.003) increasedAML risk. Survival analysis revealed that CR+ve cases with GG genotype had significantly increased DFS rates(16months, p=0.05) compared to CR+ve TT (11 months) and TG (9 months) genotype groups. Further, MDM2expression was also found to be significantly elevated in GG genotype patients (p=0.0039) and among CR+vecases (p=0.0036). Conclusions: The MDM2-309T>G polymorphism might be involved in AML development andalso serve as a good prognostic indicator.