Mdm2-SNP309 polymorphism in prostate cancer: no evidence for association with increased risk or histopathological tumour characteristics

Association between MDM2 SNP309, p53 Arg72Pro, and hepatocellular carcinoma risk: A MOOSE-compliant meta-analysis

Epidemiological studies have determined the associations between polymorphisms on the promoter of MDM2 (SNP309) and the codon 72 on exon 4 of p53 (p53 Arg72Pro) and the risk of hepatocellular carcinoma (HCC); however, the results were not always consistent. The aim of the present meta-analysis was to evaluate the overall associations between these 2 variants and HCC risk.The MEDLINE, Web of science, EMBASE, Cochrane Library, and CNKI databases were searched for eligibility studies and the data were synthesized under the fixed- or random-effects model. Heterogeneity among the studies was evaluated with the Cochrane test Q and I statistic.For MDM2 SNP309, the pooled odds ratio (OR) from 15 independent studies with a total of 4038 cases and 5491 controls suggested a significant association for the variant with HCC risk [allele model, G vs T: pooled OR = 1.48, 95% confidence interval (95% CI) = 1.26-1.73; pooled OR = 1.53, 95% CI = 1.26-1.81, for G/T vs T/T; pooled OR = 2.04, 95% CI = 1.54-2.71 for G/G vs T/T]. For p53 Arg72Pro, a total of 21 studies with 7285 cases and 9710 controls suggested that the variant was also associated with HCC risk under common genetic model (allele Pro vs Arg, pooled OR = 1.13, 95% CI = 1.02-1.25; Pro/Pro vs Arg/Arg, pooled OR = 1.32, 95% CI =1.06-1.64). No publication bias was found for all the meta-analysis as suggested by the Begg funnel plot and Egger tests.These results suggested that variants MDM2 SNP309 and p53 Arg72Pro are susceptibility factors for HCC; however, more studies are warranted to validate the results.

Murine Double Minute 2 SNP T309G Polymorphism and Urinary Tract Cancer Risk: A Meta-Analysis

Urinary tract cancer is a common cause of cancer-related death. The etiology and pathogenesis of urinary tract cancer remain unclear, with genetic and epigenetic factors playing an important role. Studies of the polymorphism of murine double minute 2 (MDM2) have shown inconclusive trends in the risk of urinary tract cancer.To clarify this inconsistency, we conducted updated meta-analyses to evaluate the role of MDM2 T309G polymorphism in urinary tract cancer susceptibility.Data sources were Pubmed (1966-May 2015), Chinese biomedicine literature database (1978-May 2015), and hand searching of the reference lists of included studies:(1) research categories case-control study or a nested case-control study; (2) information evaluating the association between the MDM2 SNP309 and urinary tract cancer risk; (3) studies with sufficient data to perform a meta-analysis.It included the use of odds ratios (ORs) to assess the strength of the association, and 95% confidence intervals (CIs) give a sense of the precision of the estimate. We used I for the assessment of between-study heterogeneity, and publication bias was assessed using the funnel plot and the Egger test. Statistical analyses were performed by Review Manage, version 5.0 and Stata 11.0.A total of 18 studies met the eligibility criteria and were included in our analyses. Overall, there was no statistical association between MDM2 SNP309 and prostate cancer risk for the allele contrast, the GG genotype, the recessive genetic model, the dominant genetic model, and prostate cancer risk in all subjects (OR = 0.96, 95% CI 0.87-1.05, P = 0.36; OR = 0.93, 95% CI 0.75-1.15, P = 0.50; OR = 1.00, 95% CI 0.87-1.15, P = 0.99; OR = 0.93, 95% CI 0.80-1.07, P = 0.30), and between MDM2 SNP309 and bladder cancer risk (the allele contrast: OR = 1.06, 95% CI 0.89-1.27, P = 0.50; the GG genotype: OR = 1.12, 95% CI 0.79-1.61, P = 0.52; the dominant genetic model: OR = 1.03, 95% CI 0.83-1.28, P = 0.78; the recessive genetic model: OR = 1.12, 95% CI 0.84-1.49, P = 0.45). However, there was positive association between MDM2 SNP309 and kidney cancer risk for the allele contrast (OR = 1.24, 95% CI 1.05-1.46, P = 0.01), the GG genotype (OR = 1.57, 95% CI 1.11-2.20, P = 0.01), dominant model contrast (OR = 1.30, 95% CI 1.00-1.68, P = 0.05), the recessive genetic model (OR = 1.37, 95% CI 1.02-1.83, P = 0.04).First, only the data of published studies were included in this meta-analysis. Unpublished studies tend to show more negative results; therefore, publication bias may be present. Second, because of the lack of the original data, we did not perform stratification analysis by age, hormone levels, dietary habit, or other variables. This might have caused confounding bias. Third, because the number of studies was relatively small for kidney cancer, the results might not have enough statistical power for us to investigate the association of the polymorphism with kidney cancer susceptibility, and we could not perform subgroup analyses. Finally, there were no studies about Africans in this meta-analysis.In summary, the results of our meta-analysis suggest an increased risk role of the MDM2 SNP T309G in renal cancer. However, there was no association between the MDM2 SNP T309G and prostate cancer risk or between the MDM2 SNP T309G and bladder cancer risk. Moreover, well-designed studies should estimate different ethnicities, degree of malignancy and clinical progression on the association between MDM2 SNP309 and urinary cancer risk in the future.

The T309G murine double minute 2 gene polymorphism is an independent prognostic factor for patients with renal cell carcinoma

The purpose of this study was to evaluate the association of the T309G MDM2 gene polymorphism with renal cell carcinoma (RCC) risk, pathology, and cancer-specific survival (CSS). T309G MDM2 was genotyped in 449 Caucasians, including 240 with RCC and 209 cancer-free controls. The T309G MDM2 genotype was TT in 174 (38.8%), GT in 214 (47.7%), and GG in 61 (13.6%) subjects, without any significant differences between cases and controls on both univariable (p=0.58) and multivariable logistic regression (each p>0.25). Furthermore, T309G MDM2 was not linked with T stage (p=0.75), N stage (p=0.37), M stage (p=0.94), grade (p=0.21), and subtype (p=0.55). There was, however, a statistically significant association of T309G MDM2 with CSS (p=0.022): patients with TT had significantly worse survival than GG/GT (p=0.009), while those with GT and GG had similar outcomes (p=0.92). The 5-year survival rate for patients with TT, GT, and GG was 69.5%, 84.5%, and 89.7%, respectively. On the multivariable analysis, T309G was identified as an independent prognostic factor. The T309G MDM2 polymorphism is an independent prognostic factor for patients with RCC, with the TT genotype being associated with worse prognosis. In this study, there were no significant associations with RCC risk and pathology.

Meta-analysis of associations between the MDM2-T309G polymorphism and prostate cancer risk

The mouse double minute 2 (MDM2) gene plays a key role in the p53 pathway, and the SNP 309T/G single- nucleotide polymorphism in the promoter region of MDM2 has been shown to be associated with increased risk of cancer. However, no consistent results were found concerning the relationships between the polymorphism and prostate cancer risk. This meta-analysis, covering 4 independent case-control studies, was conducted to better understand the association between MDM2-SNP T309G and prostate cancer risk focusing on overall and subgroup aspects. The analysis revealed, no matter what kind of genetic model was used, no significant association between MDM2-SNP T309G and prostate cancer risk in overall analysis (GT/TT: OR = 0.84, 95%CI = 0.60-1.19; GG/TT: OR = 0.69, 95%CI = 0.43-1.11; dominant model: OR = 0.81, 95%CI= 0.58-1.13; recessive model: OR = 1.23, 95%CI = 0.95-1.59). In subgroup analysis, the polymorphism seemed more likely to be a protective factor in Europeans (GG/TT: OR = 0.52, 95%CI = 0.31-0.87; recessive model: OR = 0.58, 95%CI = 0.36-0.95) than in Asian populations, and a protective effect of the polymorphism was also seen in hospital-based studies in all models (GT/TT: OR = 0.74, 95%CI = 0.57-0.97; GG/TT: OR = 0.55, 95%CI = 0.38-0.79; dominant model: OR = 0.69, 95%CI = 0.54-0.89; recessive model: OR = 0.70, 95%CI = 0.51-0.97). However, more primary studies with a larger number of samples are required to confirm our findings.

The risks, degree of malignancy and clinical progression of prostate cancer associated with the MDM2 T309G polymorphism: a meta-analysis

To determine the risk, malignant degree and clinical progression of prostate cancer (PCa) associated with mouse double-minute 2 protein (MDM2) T309G variants, a meta-analysis was performed on all eligible published studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess these associations in seven studies that included 5151 cases and 1003 controls. In the overall analysis, the 309G allele was significantly associated with a decreased PCa risk (OR=0.85, 95% CI: 0.74-0.97); this was also the case for the homozygous comparison (OR=0.72, 95% CI: 0.55-0.95) and the dominant genetic model (OR=0.79, 95% CI: 0.65-0.96). The 309G allele was also found to be significantly associated with lower degrees of PCa malignancy (OR=0.85, 95% CI: 0.75-0.96) in the overall analysis, as well as in the heterozygous comparison (OR=0.79, 95% CI: 0.65-0.96), homozygous comparison (OR=0.76, 95% CI: 0.58-0.98) and dominant genetic model (OR=0.81, 95% CI: 0.68-0.96). Furthermore, grouping analysis showed that the 309G allele in Caucasians was significantly correlated with a decreased PCa risk (OR=0.77, 95% CI: 0.61-0.96); this was also the case in the homozygous comparison (OR=0.51, 95% CI: 0.31-0.86). The grouping analysis also showed that the 309G variant in Caucasians was significantly associated with a lower degree of PCa malignancy in all of the genetic models. In addition, we found that the 309G variant in Caucasians was significantly associated with a slower PCa clinical progression in all of the genetic models. In summary, our meta-analysis showed that the MDM2 309G variant was significantly associated with a decreased PCa risk, lower malignant degree and slower clinical progression in Caucasians, but there was no obvious association in the Asian population.

Murine double minute 2 promoter SNP309 polymorphism and prostate cancer risk: a meta-analysis

OBJECTIVE

The murine double minute 2 gene encodes a negative regulator of the tumor protein p53. A single nucleotide polymorphism in murine double minute 2 promoter, SNP309 T>G, has been reported to alter murine double minute 2 protein expression and to accelerate tumor formation in humans. We carried out a meta-analysis to explore the association between this polymorphism and prostate cancer risk.

METHODS

All eligible studies were searched in PubMed. Crude odds ratios, with 95% confidence intervals, were assessed for the association using fixed- and random-effects models.

RESULTS

Overall, five case-control studies (872 cases, 1005 controls) were included in the meta-analysis. A significant association between murine double minute 2 SNP309 and prostate cancer risk was observed for homozygote genetic model GG versus TT (odds ratio 0.72, 95% confidence interval 0.55-0.95, P < 0.05, P = 0.130 for heterogeneity), and for dominant model TG + GG versus TT (odds ratio 0.79, 95% confidence interval 0.65-0.96, P < 0.05, P = 0.119 for heterogeneity). The stratified analysis based on ethnicity showed a significant effect of the polymorphism on prostate cancer risk in Caucasians for GG versus TT.

CONCLUSIONS

Findings of the present meta-analysis suggest that the murine double minute 2 309 G allele might be associated with a reduced risk of prostate cancer. The effect of murine double minute 2 309 G allele on tumorigenesis might be influenced by sex and hormonal status.

SNP285C modulates oestrogen receptor/Sp1 binding to the MDM2 promoter and reduces the risk of endometrial but not prostatic cancer

INTRODUCTION

The MDM2 promoter polymorphism (SNP309T > G) extends a binding site for the transcription factor Sp1 and has been linked to elevated cancer risk and/or young age at cancer diagnosis, especially in females. Recently, we reported an adjacent polymorphism (SNP285G > C). SNP285C antagonises the effect of SNP309G by reducing Sp1 binding and lowers the risk of breast and ovarian cancer.

METHODS

We assessed the potential gender specificity in the effect of this polymorphism. We performed in silico predictions of transcription factor binding sites in the MDM2 promoter and analysed MDM2 SNP285 and SNP309 status in two independent cohorts of endometrial (n = 438 and 472) and 666 prostatic cancer patients, and compared to 3.140 healthy controls.

RESULTS

We identified three oestrogen-receptor binding elements (EREs) within the MDM2 intronic promoter, one of which overlapping the Sp1 binding-site harbouring SNP285. The SNP285C/309G haplotype was associated with a reduced Odds Ratio (OR) for endometrial cancer (OR1: 0.55; Confidence Interval (CI) 0.32-0.97; OR2: 0.65; CI 0.40-1.08, especially for ER+ tumours; OR: 0.48; CI 0.28-0.87) but not for prostatic cancer among SNP309TG heterozygotes. SNP309G (SNP309TG or SNP309GG genotype) was associated with a moderately increased risk of endometrial cancer (OR: 1.17; CI 1.00-1.37) compared to SNP309TT homozygotes. Removing individuals harbouring the SNP309G-counteracting SNP285C polymorphism from the analysis strengthened this association (OR: 1.20; CI 1.02-1.41).

CONCLUSION

The finding of an ERE overlapping with the Sp1-binding site affected by SNP285, taken together with the significant impact of SNP285 on the risk of breast, ovarian and now endometrial cancer but not prostatic cancer, suggests a gender specific effect of SNP285C on cancer risk.

MDM2 SNP309 contributes to tumor susceptibility: a meta-analysis

The potentially functional polymorphism, SNP309, in the promoter region of MDM2 gene has been implicated in cancer risk, but individual published studies showed inconclusive results. To obtain a more precise estimate of the association between MDM2 SNP309 and risk of cancer, we performed a meta-analysis of 70 individual studies in 59 publications that included 26,160 cases with different types of tumors and 33,046 controls. Summary odds ratios (OR) and corresponding 95% confidence intervals (CIs) were estimated using fixed- and random-effects models when appropriate. Overall, the variant genotypes were associated with a significantly increased cancer risk for all cancer types in different genetic models (GG vs. TT: OR, 1.123; 95% CI, 1.056-1.193; GG/GT vs. TT: OR, 1.028; 95% CI, 1.006-1.050). In the stratified analyses, the increased risk remained for the studies of most types of cancers, Asian populations, and hospital- /population-based studies in different genetic models, whereas significantly decreased risk was found in prostate cancer (GG vs. TT: OR, 0.606; 95% CI, 0.407-0.903; GG/GT vs. TT: OR, 0.748; 95% CI, 0.579-0.968). In conclusion, the data of meta-analysis suggests that MDM2 SNP309 is a potential biomarker for cancer risk.

MDM2 SNP309, gene-gene interaction, and tumor susceptibility: an updated meta-analysis

Background

The tumor suppressor gene p53 is involved in multiple cellular pathways including apoptosis, transcriptional control, and cell cycle regulation. In the last decade it has been demonstrated that the single nucleotide polymorphism (SNP) at codon 72 of the p53 gene is associated with the risk for development of various neoplasms. MDM2 SNP309 is a single nucleotide T to G polymorphism located in the MDM2 gene promoter. From the time that this well-characterized functional polymorphism was identified, a variety of case-control studies have been published that investigate the possible association between MDM2 SNP309 and cancer risk. However, the results of the published studies, as well as the subsequent meta-analyses, remain contradictory.

Methods

To investigate whether currently published epidemiological studies can clarify the potential interaction between MDM2 SNP309 and the functional genetic variant in p53 codon72 (Arg72Pro) and p53 mutation status, we performed a meta-analysis of the risk estimate on 27,813 cases with various tumor types and 30,295 controls.

Results

The data we reviewed indicated that variant homozygote 309GG and heterozygote 309TG were associated with a significant increased risk of all tumor types (homozygote comparison: odds ratio (OR) = 1.25, 95% confidence interval (CI) = 1.13-1.37; heterozygote comparison: OR = 1.10, 95% CI = 1.03-1.17). We also found that the combination of GG and Pro/Pro, TG and Pro/Pro, GG and Arg/Arg significantly increased the risk of cancer (OR = 3.38, 95% CI = 1.77-6.47; OR = 1.88, 95% CI = 1.26-2.81; OR = 1.96, 95% CI = 1.01-3.78, respectively). In a stratified analysis by tumor location, we also found a significant increased risk in brain, liver, stomach and uterus cancer (OR = 1.47, 95% CI = 1.06-2.03; OR = 2.24, 95%CI = 1.57-3.18; OR = 1.54, 95%CI = 1.04-2.29; OR = 1.34, 95%CI = 1.07-1.29, respectively). However, no association was seen between MDM2 SNP309 and tumor susceptibility in the stratified analysis by p53 mutation status (GG vs TT: OR = 1.17, 95% CI = 0.75-1.82 and TG vs TT: OR = 1.09, 95% CI = 0.89-1.34 for positive p53 mutation status; GG vs TT: OR = 0.95, 95% CI = 0.72-1.25 and TG vs TT: OR = 1.06, 95% CI = 0.85-1.30 for negative p53 mutation status).

Conclusions

The analyses indicate that MDM2 SNP309 serves as a tumor susceptibility marker, and that there is an association between MDM2 SNP309 and p53 Arg72Pro regarding tumor susceptibility. Further studies that take into consideration environmental stresses and functional genetic variants in the p53-MDM2-related genes are warranted.

Association between polymorphisms of TP53 and MDM2 and prostate cancer risk in southern Chinese

Alterations in the TP53 and MDM2 genes appear to be important in the development of many human tumors, but evidence is conflicting on associations between polymorphisms in these genes and risk of prostate cancer (PCa). The influence of TP53 codon 72, MDM2 SNP309, and MDM2 C1797G polymorphisms in southern Chinese PCa patients was investigated. In the comparison of genotype distributions of TP53 codon 72 between cases and controls, the adjusted odds ratios for PCa associated with the Pro/Pro, Arg/Pro, and Arg/Arg genotypes were 1.00, 1.89 (95% CI = 1.20-2.97), and 2.01 (95% CI = 1.11-3.64), respectively; however, MDM2 SNP309 and C1797G did not show any significant difference between cases and controls. When TP53 and MDM2 polymorphisms were combined based on the numbers of variant risk alleles (i.e., G-allele of TP53 codon 72, G-allele of MDM2 SNP309, and G-allele of MDM2 C1797G), individuals with 3-5 variants had a 1.56-fold greater risk of PCa than those with 0-2 variants (95% CI = 1.07-2.26). Moreover, subjects with 0-2 variants had 33.3% positive p53 expression, whereas subjects with 3-5 variants had 23.3% p53 expression (P = 0.39). These findings suggest that TP53 and MDM2 polymorphisms play a role in PCa susceptibility in southern Chinese Han population.

Single-nucleotide polymorphisms in p53 pathway and aggressiveness of prostate cancer in a Caucasian population

PURPOSE

The tumor suppressor p53 plays a crucial role in maintaining genomic stability and tumor prevention. Mdm2, Mdm4, and Hausp are all critical regulators of the p53 protein. Despite the importance of the p53 pathway in prostate cancer development and progression, little is known about the association of functional single-nucleotide polymorphisms (SNP) in the p53 pathway genes and prostate cancer aggressiveness.

EXPERIMENTAL DESIGN

In this study, we analyze the association of SNPs in p53, Mdm2, Mdm4, and Hausp genes with prostate cancer clinicopathologic variables in a large hospital-based Caucasian prostate cancer cohort (N = 4,073).

RESULTS

We found that the Mdm2 SNP309 T allele was associated with earlier onset prostate cancer (P = 0.004), higher Gleason scores (P = 0.004), and higher stages in men undergoing a radical prostatectomy (P = 0.011). Both the Mdm4 and Hausp SNPs (rs1380576 and rs1529916) were found to be associated with higher D'Amico risk prostate cancer category at the time of diagnosis (P = 0.023 and P = 0.046, respectively). Mdm4 SNP was also found to be associated with higher Gleason score at radical prostatectomy (P = 0.047). We did not observe any statistically significant association between the p53 Arg72Pro polymorphism and prostate cancer aggressiveness or pathologic variables.

CONCLUSIONS

These results suggested the importance of these p53 regulators in prostate cancer development and progression.

Are cell cycle and apoptosis genes associated with prostate cancer risk in North Indian population?

OBJECTIVE

Prostate cancer (CaP) is a heterogeneous, multifactorial, and multifocal disease. Therefore, the search for a combination of functional polymorphisms using cell cycle and apoptotic genes as tumor markers is fundamental for a more precise and reliable diagnosis. In the present study, we investigated the diagnostic value of 3 different genes associated with CaP carcinogenesis, encoding for cell cycle (MDM2, CCND1) and apoptotic (Fas) genes that are differentially expressed in CaP.

METHODS

In a hospital-based case control study of northern India, blood samples were obtained from 192 CaP patients and 224 cancer-free age matched unrelated healthy controls of similar ethnicity. They were genotyped for MDM2 G309T, CCND1 G870A, Fas A670G, and G1377A polymorphisms using polymerase chain restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

MDM2 309GG variant was at reduced risk for developing CaP (P = 0.041; OR, 0.59). Whereas CCND1 AA genotype demonstrated increased risk (P = 0.018; OR, 1.86). The diplotype analysis of Fas G670A and G1377A (G-A) was observed to be associated with a significant increase in CaP risk (P = 0.024; OR, 1.63).

CONCLUSION

Findings based on current sample size our results suggested a positive association of CCND1AA genotype and diplotype analysis of Fas G670A and G1377A (G-A) to be associated with CaP risk that could influence the pathophysiology, thereby modulating the risk of CaP.

No evidence for association of the MDM2-309 T/G promoter polymorphism with prostate cancer outcomes

OBJECTIVES

Mouse double-minute 2 (MDM2) SNP309 polymorphism (T>G) has been correlated with an increased risk of cancer in multiple tumor types. MDM2 overexpression has shown to be weakly associated with distant tumor metastases, and down-regulation of MDM2 via antisense oligonucleotides in vitro has resulted in the radiosensitization of prostate cancer cell lines. Based on these results, we decided to evaluate the role of MDM2 SNP309 in the context of histopathologic parameters and clinical outcomes in prostate cancer tumors.

MATERIALS AND METHODS

The population consisted of 212 consecutive prostate cancer patients who underwent radical prostatectomy between 1997 and 1999 at Vanderbilt University Medical Center. Two hundred eight of the samples were successfully genotyped for the MDM2 SNP309 polymorphism. Correlations between the polymorphism, recurrence, and survival data were analyzed using univariate and multivariate genetic models.

RESULTS

The only prognostic factor predictive of overall survival in our study was Gleason score (P<0.005). Using χ(2) analysis, we determined that the MDM2 SNP309 polymorphism had no significant association with race (P=0.7512), patient's age at diagnosis (P=0.6820), pre-prostatectomy PSA level (P=0.8606), Gleason's score (P=0.4839), surgical margin status (P=1.0000), extracapsular extension (P=0 .6175), and disease stage (P=0.4945). In addition, there was no significant difference in 3-year recurrence-free survival (P=0.218), or 8-year overall survival (P=0.376).

CONCLUSIONS

Our study finds no evidence for association of the MDM2 SNP309 polymorphism with clinicopathologic variables, recurrence risk, and overall survival outcome in prostate cancer.

MDM2 expression and regulation in prostate cancer racial disparity

MDM2 is a key negative regulator of tumor suppressor p53. A single nucleotide polymorphism in the MDM2 promoter, SNP309, enhances transcriptional activation of MDM2 and has been associated with early onset of several types of cancer. In this study, we attempted to determine if the MDM2 SNP309 polymorphism plays a role in the aggressive phenotype seen in African American (AA) prostate cancer by examining the association between MDM2 SNP309 and MDM2 protein levels in prostate cancer (PCa) patients of different racial backgrounds. Prospectively enrolled PCa patients (AA=51, CA=50) were evaluated for MDM2 SNP309 and MDM2 protein expression. MDM2 overexpression, defined as >10% of tumor cells in three tissue cores, was assessed using immunohistochemistry on tissue microarray. MDM2 protein expression was significantly greater in CA than AA patients (78% versus 45% respectively, p=0.0007). Germline DNA was analyzed by PCR-RFLP then confirmed by DNA sequencing. MDM2 SNP309 genotype frequencies did not differ significantly between AA and CA PCa patients (AA: TT 68.6%, TG 25.5%, GG 5.9%; CA: TT 62.0%, TG 20.0%, GG 18.0%; p=0.16), suggesting that the MDM2 SNP309 allele does not play a significant role in the observed overexpression.