MDM2启动子309位点多态性与乳腺癌易感性关系的Meta分析

[目的]综合评价MDM2（routine double minute2）基因启动子309位点多态性与乳腺癌易感性的关系。[方法]检索中国医学文献数据库和PubMed中MDM2基因SNP309与乳腺癌易感性关系的病例对照研究,并用Meta分析的方法合并SNP309与乳腺癌易感性OR值。然后进行其中有家族史的乳腺癌亚组分析,敏感性分析和文献的发表偏倚检验。[结果]Meta分析共纳入10篇文献,乳腺癌家族史组有3篇;累计病例7535例,对照8272例,G等位基因相对于T等位基因0R值为1．01（95％CI：0．96～1．06）。乳腺癌家族史组G等位基因相对于T等位基因OR值为1．06（95％CI：0．94～1．19）。[结论]MDM2基因309T〉G多态与乳腺癌易感性无统计学意义。     

PALB2基因遗传多态性在早发性乳腺癌中的作用

背景与目的:PALB2基因是新近发现的乳腺痛易感基因,其多个遗传单核苷酸多态性(SNP)可能与乳腺癌发病风险有关,本研究探讨PALB2基因rs249954、rs447529及rs16940342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124例早发性乳腺癌患者(年龄≤35岁)和101例健康女性进行PALB2基因rs249954、rs447529及rs16940342 PCR扩增,并采用基质辅助激光解吸电离飞行时间质谱分析(MALDI-TOF-MS)法鉴定其基因型,比较各基因型分布和发病风险的关系;应用非条件Logistic回归分析计算危险度(OR)及95%CI.结果:PALB2基因rs249954、rs447529及rs16940342多态性基因型在病例组中的分布频率与对照组的分布频率均未见明显差异(P＞0.05).Logistic回归分析表明,在早发性乳腺癌人群中,以rs249954的CC基因型、rs447529 CC基因型及rs16940342 AA基因型为参照,各基因多态性位点的其他基因型,均未能显著改变乳腺癌的发病危险(P＞0.05).各基因型风险比分别为1.061(rs249954 TT vs CC),0.793(rs447529 GG vs CC)以及0.921(rs16940342 GG vs AA).结论:PALB2基因rs249954、rs447529及rs16940342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,作为低外显率的乳腺癌易感基因位点和未来临床基因筛查的候选指标尚需谨慎.     

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-SNP309 G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 GG等位基因型显著高于淋巴转移阴性组 （31.8% vs 11.5%, 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SNP309 GG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 T309G基因多态性与前列腺癌的相关性

目的:探讨鼠双微体基因2(MDM2) T309G基因多态性与前列腺癌相关性。方法:用酚氯法提取全基因组DNA,应用聚合酶链反应、限制性内切酶的方法检测100例前列腺癌患者和100例健康男性的MDM2 T309G基因多态性。结果:病例组中G、T等位基因型频率分别为52.5%、47.5%,对照组中G、T等位基因型频率分别为40.5%、59.5%,MDM2 T309G基因型在两组的分布有显著性差异,TT基因型在对照组分布频率明显增高（P＜0.05）。结论:MDM2 T309G基因型在病例组和对照组的分布存在明显差异,G等位基因与前列腺癌发病增加相关。     

CLOCK基因单核苷酸多态性与乳腺癌易感性的病例对照研究

目的：探讨生物钟CLOCK基因的单核苷酸多态性与乳腺癌易感性的关系。方法：采用应用聚合酶链式反应-限制性片断长度多态性（PCR-RFLP）技术检测1 499例中国汉族女性乳腺癌患者和1 592例正常女性对照者CLOCK基因rs3805151位点的基因型,采用SPSS 16.0软件进行数据处理。结果：CLOCK基因CC型、CT型和TT型在病例组和对照组间的分布差异有统计学意义（χ2=9.712,P=0.008）,与CC型相比,杂合型CT可以显著增加乳腺癌的发病风险 （OR=1.41,95% CI：1.07～1.87）,携带T等位基因（CT/TT）的个体乳腺癌风险增加35%（OR=1.35,95% CI：1.04～1.76）。分层分析显示,携带T等位基因绝经后、无肿瘤家族史者、无乳腺良性病史的个体患乳腺癌风险增加。结论：CLOCK基因rs3805151 C>T可增加乳腺癌发病风险,这一结论有待于进一步通过不同种族人群的关联研究以及功能学研究的证实。     

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基因多态性与NSCLC辐射敏感性及易感性的相关性

研究表明鼠双微体2（murine double minute 2,MDM2）基因的扩增和（或）过度表达可见于多种肿瘤，如淋巴瘤，乳腺癌和睾丸精子细胞肿瘤，MDM2在肺癌中的表达是一个常见现象。因此，MDM2在非小细胞肺癌（NSCLC）易感性及辐射敏感性中的作用是值得肿瘤学家们探讨的问题，笔者采用PCR-RFLP方法检测80例NSCLC及82例正常人MDM2基因单核苷酸多态性（SNP），旨在探讨MDM2基因多态性与NSCLC易感性及辐射敏感性是否存在相关性。     

MDM2基因多态性与肝细胞肝癌易感性的关系研究

目的:探讨小鼠双微体基因(murine double minute 2,MDM2)单核苷酸多态性(SNP)与肝细胞肝癌易感性及生物学行为的关系。方法:对166例肝癌病例和157例健康对照病例的外周血标本,利用SYBRGREEN PCR溶解曲线法分析MDM2基因型。结果:实验组等位基因的发生率(T,0.49;G,0.51)与对照组基因的发生率(T,0.59;G,0.41)(P=0.015)有统计学差异。肝癌患者中GG基因型的发生率(22.29%)高于健康人群(13.38%)(P=0.010)。结论:与TT基因型相比,携带G等位基因或GG型与肝癌发生的相关性较大。     

微小RNA基因多态与乳腺癌易感性的关系

目的：探讨微小RNA（ miRNA）基因序列的单核苷酸多态（ SNP ）位点与乳腺癌患病风险之间的关系,以期分析可用于易感人群筛查的分子标志物。方法选取经病理证实的乳腺癌患者（病例组）384例,选取与病例组患者年龄匹配的正常健康对照（对照组）192例,均为汉族、女性,均经5年以上随诊证实无恶性肿瘤病史。根据美国国立生物技术信息中心和microRNA Base公共数据库信息,选择已知汉族人群中全部miRNA最小等位基因频率＞0．05的SNP位点,最终入选22条miRNA基因的23个位点。采用高通量的MassARRAY时间飞行质谱生物芯片系统分析候选位点的基因型。采用非条件Logistic回归模型评估候选位点与乳腺癌患病风险的关系。结果全组研究对象年龄21～81岁,中位年龄48岁。病例组患者的年龄分布、吸烟状态与对照组比较,差异均无统计学意义（均P＞0．05）。病例组和对照组伴有乳腺癌或卵巢癌家族史者所占比例分别为9．1％和1．6％,初潮年龄≤14岁所占比例分别为53．1％和37．5％,未绝经者所占比例分别为61．2％和50．0％,差异均有统计学意义（均P＜0．05）。病例组miRNA基因SNP位点各基因型的分布频率与对照组比较,差异无统计学意义（ P＞0．05）。结论存在于miRNA基因序列的SNP与汉族、女性乳腺癌患病风险无明显相关性。     

环氧化酶-2基因多态性与肿瘤遗传易感性研究进展

环氧化酶-2（cyclooxygenase-2,COX-2）是前列腺素（prostaglandins,PGs）合成过程中的关键限速酶之一,可将花生四烯酸代谢成各种PGs产物,从而维持机体的病理生理过程,参与炎症反应,疼痛反应,与肿瘤的发生、发展密切相关。因此,COX-2基因成为近年来研究的热点。最近国内外众多关于COX-2基因多态性与肿瘤易感性相关的病例对照研究,均表明COX-2单核苷酸多态性与多个肿瘤的易感性相关。这对肿瘤的个体化治疗有一定的指导作用。     

MDM2 SNP309 polymorphism contributes to endometrial cancer susceptibility: evidence from a meta-analysis

Objective

The SNP309 polymorphism (T-G) in the promoter of MDM2 gene has been reported to be associated with enhanced MDM2 expression and tumor development. Studies investigating the association between MDM2 SNP309 polymorphism and endometrial cancer risk reported conflicting results. We performed a meta-analysis of all available studies to explore this association.

Methods

All studies published up to August 2013 on the association between MDM2 SNP309 polymorphism and endometrial cancer risk were identified by searching electronic databases PubMed, Web of Science, EMBASE, and Chinese Biomedical Literature database (CBM). The association between the MDM2 SNP309 polymorphism and endometrial cancer risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs).

Results

Eight case–control studies with 2069 endometrial cancer cases and 4546 controls were identified. Overall, significant increase of endometrial cancer risk was found when all studies were pooled in the meta-analysis (GG vs. TT: OR = 1.464, 95% CI 1.246–1.721, P < 0.001; GG vs. TG + TT: OR = 1.726, 95% CI 1.251–2.380, P = 0.001; GG + TG vs. TT: OR = 1.169, 95% CI 1.048–1.304, P = 0.005). In subgroup analysis by ethnicity and HWE in controls, significant increase of endometrial cancer risks were observed in Caucasians and studies consistent with HWE. In subgroup analysis according to study quality, significant associations were observed in both high quality studies and low quality studies.

Conclusions

This meta-analysis suggests that MDM2 SNP309 polymorphism contributes to endometrial cancer susceptibility, especially in Caucasian populations. Further large and well-designed studies are needed to confirm this association.     

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.     

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 SNP309 contributes to non-small cell lung cancer survival in Chinese

Murine double minute 2 (MDM2) is a negative regulator of the tumor suppressor gene p53. Single nucleotide polymorphisms in MDM2 and p53 can affect patient's response to chemotherapy as well as overall survival of many cancers. This study aimed to assess the associations between polymorphisms in MDM2 and p53 and survival of non‐small cell lung cancer (NSCLC) patients in Chinese. We selected and genotyped both potentially functional SNPs and tagging SNPs in MDM2 and p53 using Illumina Golden Gate platform in a cohort of 568 NSCLC patients. Associations between genotypes and NSCLC median survival time (MST) were assessed using the Kaplan–Meier method. Cox proportional hazard models were performed with the adjustment for age, stage, smoking, histology, surgical operation, and chemo‐ or radiotherapy status. We found that the MDM2 SNP309 (rs2279744) GT/TT genotypes were associated with a significantly worse survival (MST: 23.0 mo for GT/TT vs. 33.0 mo for GG; log‐rank P = 0.028). In the multivariate Cox regression analyses, the MDM2 SNP309GT/TT genotypes were associated with a 1.42‐fold [HR = 1.42, 95% confidence interval (CI), 1.09–1.84] increased risk of death of NSCLC, compared with SNP309GG genotype. MDM2 SNP309 may be used as one of the candidate biomarkers to predict NSCLC survival. © 2011 Wiley‐Liss, Inc.     

Effects of p53 Codon 72 and MDM2 SNP309 Polymorphisms on Gastric Cancer Risk among the Iranian Population

Background: Development of gastric cancer (GC) is a multistep process that requires alterations in the expression of oncogenes and tumor suppressor genes, occurring over several decades. The p53 tumor suppressor protein is involved in cell-cycle control, apoptosis and DNA repair. One of the most important regulators of p53 is MDM2, which acts as a negative regulator in the p53 pathway. Based on the key role of p53 and MDM2 in tumor suppression, polymorphisms that cause change in their function might affect cancer risk. We therefore elevated associations of the polymorphisms of p53 (R72P) and MDM2 (SNP309) with GC in Iran. Materials and Methods: A total of 104 patients with gastric cancer and 100 controls were recruited. Genomic DNA was extracted from fresh gastric samples. Genotyping of the p53 and MDM2 genes was performed using allele specific PCR(AS-PCR). Results: There was no significant difference between the p53 codon 72 polymorphism distribution in control and patient groups (p=0.54), but the G allele of MDM2 was found to be over-represented in patients (p=0. 01, Odds Ratio=2. 08, 95% Confidence Interval= 1.37-4.34). Conclusions: The p53 R72P seems not to be a potential risk factor for development of GC among Iranian patients, but our data suggest that MDM2 SNP309 might modify the risk related to GC.     

Genetic Polymorphism of MDM2 SNP309 in Patients with Helicobacter Pylori-Associated Gastritis

Background: Helicobacter pylori plays an important role in gastric cancer, which has a relatively low inciduencein Thailand. MDM2 is a major negative regulator of p53, the key tumor suppressor involved in tumorigenesis ofthe majority of human cancers. Whether its expression might explain the relative lack of gastric cancer in Thailandwas assessed here. Materials and Methods: This single-center study was conducted in the northeast region ofThailand. Gastric mucosa from 100 patients with Helicobacter pylori associated gastritis was analyzed for MDM2SNP309 using real-time PCR hybridization (light-cycler) probes. Results: In the total 100 Helicobacter pyloriassociated gastritis cases the incidence of SNP 309 T/T homozygous was 78 % with SNP309 G/T heterozygousfound in 19% and SNP309 G/G homozygous in 3%. The result show SNP 309 T/T and SNP 309 G/T to be rathercommon in the Thai population. Conclusions: Our study indicates that the MDM2 SNP309 G/G homozygousgenotype might be a risk factor for gastric cancer in Thailand and the fact that it is infrequent could explain tosome extent the low incidence of gastric cancer in the Thai population.