Eight functional polymorphisms in the estrogen receptor 1 gene and endometrial cancer risk: a meta-analysis

Analysis of Single Nucleotide Polymorphisms (SNPs) rs2234693 and rs9340799 of the ESR1 Gene and the Risk of Breast Cancer

BACKGROUND/AIM

The aim of this study was to analyze rs2234693 and rs9340799 polymorphisms of the ESR1 gene in the context of breast cancer risk in Polish patients.

MATERIALS AND METHODS

The study involved a group of 117 patients with breast cancer and 106 controls. The analyses were carried out using the polymerase chain reaction - restriction fragments length polymorphism technique.

RESULTS

The presence of the CC genotype in rs2234693 more than doubled the risk of breast cancer (p=0.04), whereas the presence of the TT genotype in rs2234693 significantly reduced the risk of developing this type of cancer (p=0.0002). The presence of the GG genotype in rs9340799 more than doubled the risk of breast cancer (p=0.04), which was confirmed by the analysis of the recessive model (p=0.04).

CONCLUSION

The polymorphisms rs2234693 and rs9340799 of the ESR1 gene may be associated with the risk of breast cancer among Polish women.

Association of the Estrogen Receptor 1 Polymorphisms rs2046210 and rs9383590 with the Risk, Age at Onset and Prognosis of Breast Cancer

Estrogen receptor α (ERα), encoded by the ESR1 gene, is a key prognostic and predictive biomarker firmly established in routine diagnostics and as a therapeutic target of breast cancer, and it has a central function in breast cancer biology. Genetic variants at 6q25.1, containing the ESR1 gene, were found to be associated with breast cancer susceptibility. The rs2046210 and rs9383590 single nucleotide variants (SNVs) are located in the same putative enhancer region upstream of ESR1 and were separately identified as candidate causal variants responsible for these associations. Here, both SNVs were genotyped in a hospital-based case-control study of 409 female breast cancer patients and 422 female controls of a Central European (Austrian) study population. We analyzed the association of both SNVs with the risk, age at onset, clinically and molecularly relevant characteristics and prognosis of breast cancer. We also assessed the concordances between both SNVs and the associations of each SNV conditional on the other SNV. The minor alleles of both SNVs were found to be non-significantly associated with an increased breast cancer risk. Significant associations were found in specific subpopulations, particularly in patients with an age younger than 55 years. The minor homozygotes of rs2046210 and the minor homozygotes plus heterozygotes of rs9383590 exhibited a several-years-younger age at onset than the common homozygotes, which was more pronounced in ER-positive and luminal patients. Importantly, the observed associations of each SNV were not consistently nullified upon correction for the other SNV nor upon analyses in common homozygotes for the other SNV. We conclude that both SNVs remain independent candidate causal variants.

Association of ESR1 gene polymorphisms with the susceptibility to Hepatitis B virus infection and the clinical outcomes

Estrogen receptor alpha (ESR1) has been implicated in the pathological process of Hepatitis B virus (HBV) infection and is probably an important determinant for gender differences. In this study, a total of 975 subjects including 368 healthy controls, 323 hepatocellular carcinoma (HCC) patients with HBsAg positive, and 284 HBV-infected subjects without HCC were included. Three single nucleotide polymorphisms of ESR1 (rs2234693, rs2077647, rs2228480) were detected to investigate the correlation between ESR1 polymorphisms and the susceptibility to HBV persistence and the clinical outcomes. The association of ESR1 polymorphisms with HCC prognosis was investigated in our cohort enrolling 376 HBV-HCC patients. The frequency of rs2234693 C allele was lower in chronic Hepatitis B (CHB) and liver cirrhosis (LC) than that in HCC patients in the males (adjusted odds ratio [AOR] = 0.63, 95% confidence interval [CI] = 0.41-0.96). rs2228480 A allele was associated with increased risk of LC (AOR = 2.20, 95% CI = 1.06-4.56) in HBV genotype C, and significantly decreased the risk of HCC recurrence (p = 0.010) and ESR1 mRNA level in tumor tissues (p = 0.032). Haplotype C-G-G was associated with significantly increased risk of HBV persistence (OR = 1.37, 95% CI = 1.08-1.73), while it was opposite for C-A-G and T-G-G (OR = 0.41, 95% CI = 0.27-0.62; OR = 0.53, 95% CI = 0.32-0.85, respectively). These results imply that combinations of these ESR1 polymorphisms may be valuable for the prediction of HBV persistence.

Pleiotropic Functions of Cytochrome P450 Monooxygenase-Derived Eicosanoids in Cancer

Eicosanoids are a class of functionally bioactive lipid mediators derived from the metabolism of long-chain polyunsaturated fatty acids (PUFAs) mediated by multiple enzymes of three main branches, including cyclooxygenases (COXs), lipoxygenases (LOXs), and cytochrome P450s (CYPs). Recently, the role of eicosanoids derived by COXs and LOXs pathways in the control of physiological and pathological processes associated with cancer has been well documented. However, the role of CYPs-mediated eicosanoids, such as epoxyeicosatrienoic acids (EETs), epoxyoctadecenoic acids (EpOMEs), epoxyeicosatetraenoic acids (EpETEs), and epoxydocosapentaenoic acids (EDPs), as well as hydroxyeicosatetraenoic acids (HETEs), in tumorigenesis and cancer progression have not been fully elucidated yet. Here we summarized the association of polymorphisms of CYP monooxygenases with cancers and the pleiotropic functions of CYP monooxygenase-mediated eicosanoids (EETs, EpOMEs, EpETE, EDPs, and 20-HETE) in the tumorigenesis and metastasis of multiple cancers, including but not limited to colon, liver, kidney, breast and prostate cancers, which hopefully provides valuable insights into cancer therapeutics. We believe that manipulation of CYPs with or without supplement of ω-3 PUFAs to regulate eicosanoid profile is a promising strategy to prevent and/or treat cancers.

Association between MDM2 SNP309 and endometrial cancer risk: A PRISMA-compliant meta-analysis

BACKGROUND

Murine double minute 2 homolog (MDM2) plays an important role in the downregulation of P53 tumor suppressor gene. MDM2 inhibits P53 transcriptional activity and thereby results in accelerated tumor formation. Overexpression of MDM2 has been found in several cancer types including endometrial cancer. SNP309 is located in the promoter region of MDM2 and contributes to the overexpression of MDM2. The association between MDM2 SNP309 polymorphism and endometrial cancer risk has been investigated in several studies; however, the conclusion remains controversial.

OBJECTIVES

We performed the present meta-analysis to give a comprehensive conclusion of the association between MDM2 SNP309 polymorphism and endometrial cancer susceptibility.

METHODS

We conducted a literature research on PubMed, Embase, Cochrane Library, OVID, Web of Science, Wan Fang, CNKI, and CQVIP databases up to July 31, 2018. Newcastle-Ottawa scale was used to assess the quality of studies. We evaluated the strength of association by combining odds ratios (ORs) and 95% confidence intervals (CIs) in 5 different genetic models under a fixed-effect model or random-effect model. We further conducted subgroup analysis by ethnicity, source of control, histological type, clinical type, grade, and stage of tumor. Sensitivity analysis and publication bias were also performed.

RESULTS

Nine eligible studies were finally included in our meta-analysis. We found MDM2 SNP309 polymorphism increased the risk of endometrial cancer under allele model (OR: 1.23, 95% CI: 1.06-1.41, P = .005), homozygote model (OR: 1.43, 95% CI: 1.13-1.81, P = .003) and recessive model (OR: 1.55, 95% CI: 1.17-2.04, P = .002). Subgroup analysis suggested a similar elevated risk in both Asians and Caucasians. We identified a strong association of enhanced susceptibility to endometrial cancer in endometrioid group (OR: 2.13, 95% CI: 1.28-3.54, P = .004) and Type I group (OR: 1.89, 95% CI: 1.25-2.86, P = .002) under dominant model. We identified no significant publication bias according to Egger's test.

CONCLUSIONS

Our meta-analysis suggested that MDM2 SNP309 polymorphism increased the risk of endometrial cancer significantly, especially in endometrioid and Type I endometrial cancer, indicating MDM2 could serve as a potential diagnostic factor marker for endometrial cancer.

Association of PvuII and XbaI polymorphisms in estrogen receptor alpha gene with the risk of hepatitis B virus infection in the Guangxi Zhuang population

BACKGROUND AND OBJECTIVE

Available evidence has suggested that estrogen receptor alpha (ESR1) is implicated in the pathogenic process of hepatitis B infection. Therefore, we evaluated the association of PvuII (rs2234693) and XbaI (rs9340799) in ESR1 and HBV infection in Guangxi Zhuang populations.

METHODS

A total of 389 subjects were divided into four groups: 112 patients with chronic hepatitis B (CHB), 65 patients with hepatitis B virus (HBV)-related liver cirrhosis (LC), 107 patients with HBV-related hepatocellular carcinoma (HCC), and 105 healthy controls. The polymerase chain reaction-restriction fragment length polymorphism strategy was used to detect ESR1 gene PvuII and XbaI polymorphisms.

RESULTS

Compared with healthy controls, binary logistic regression analyses show that the CC genotype of PvuII was associated with a significantly increased susceptibility to CHB compared with the TT genotype (OR=1.760, 95% CI 1.316-2.831; p=0.044). The PvuII CC genotype was also associated with significantly increased risk of HBV-related LC (OR=1.921, 95% CI 1.342-2.478; p=0.043). Similarly, the subjects bearing the homozygous CC genotype of PvuII polymorphism also had more than a 1.7-fold increased risk for development of HCC (OR=1.748, 95% CI 1.313-2.787; p=0.010) compared with those bearing the TT genotype. Furthermore, the AC haplotype was associated with a significantly increased risk of HCC with an OR of 1.456 (p=0.003). In contrast, there were no significant differences in the genotype and allele of XbaI polymorphisms in the ESR1 gene between the groups of patients and healthy controls. In addition, ESR1 polymorphisms were not significantly associated with susceptibility to HBV-related HCC when using CHB and LC patients as references.

CONCLUSION

We conclude that the CC genotype of PvuII in ESR1 is associated with an increased risk of CHB, HBV-related LC and HCC in Guangxi Zhuang populations.

Estrogen receptor α gene polymorphisms and risk of Alzheimer's disease: evidence from a meta-analysis

Objective

Human estrogen receptor α (ESR1), a member of the nuclear receptor superfamily of ligand-activated transcription factors, is one of the key mediators of hormonal response in estrogen-sensitive tissues. Accumulating evidence has demonstrated that two of the most widely studied single-nucleotide polymorphisms in ESR1 – PvuII (T/C, rs223493) and Xbal (A/G, rs9340799) – are possibly associated with Alzheimer’s disease (AD). However, individual study results are still controversial.

Materials and methods

We searched PubMed, Embase, Web of Science, Science Direct, SpringerLink, and the Chinese National Knowledge Infrastructure databases for eligible studies assessing the association of ESR1 polymorphisms and AD risk (last search performed in November 2013). Thereafter, a meta-analysis of 13,192 subjects from 18 individual studies was conducted to evaluate the association between ESR1 polymorphisms and susceptibility to AD.

Results

The results indicated that a significant association was found between the ESR1 PvuII polymorphism and AD risk in Caucasian populations (CC + CT versus TT, odds ratio [OR] 1.14, 95% confidence interval [CI] 1.02–1.28, P=0.03; CT versus TT, OR 1.16, 95% CI 1.02–1.31, P=0.02), whereas no evidence of association was found in Asian populations. Nevertheless, we did not find any significant association between the ESR1 XbaI polymorphism and AD risk for any model in Caucasian and Asian populations (all P>0.05).

Conclusion

Based on this meta-analysis, we conclude that the ESR1 PvuII polymorphism might be a risk factor in AD development in Caucasian populations, not in Asian populations. Further confirmation is needed from better-designed and larger studies.

MDM2 rs2279744 polymorphism and endometrial cancer: a meta-analysis

Case-control studies on the association between mouse double minute 2 homolog (MDM2) rs2279744 polymorphism and endometrial cancer have provided either controversial or inconclusive results. To clarify the effect of MDM2 rs2279744 polymorphism on the risk of endometrial cancer, a meta-analysis of all case-control observational studies was performed. Pooled odds ratios (ORs) for various polymorphisms were estimated using random and fixed effect models. Q-statistic was used to evaluate the homogeneity, and Egger and Begg tests were used to assess publication bias. Overall, the MDM2 rs2279744 polymorphism was associated with a risk of endometrial cancer (OR = 0.76; 95% CI = 0.64-0.90 for allele contrast, p = 0.002, P(het) = 0.003). The contrast of homozygotes and the recessive and dominant models produced the same pattern of results as the allele contrast. In the analysis stratified by ethnicity, significant associations were found in the Caucasian population in all of the genetic models. Our pooled data suggest evidence for a major role of MDM2 rs2279744 polymorphism in the carcinogenesis of endometrial cancer, especially among Caucasian populations.