Estrogen receptor-alpha polymorphism in a Taiwanese clinical breast cancer population: a case-control study

Evaluation of Serum Fructosamine as Diagnostic Marker of Postoperative Recurrence in the Patients with Breast Cancer

Objectives

A series of laboratory parameters were screened to identify the proper serum markers that could be used to predict breast cancer recurrence at an early stage.

Methods

A case-control retrospective study on 224 patients without postoperative recurrence and 43 patients with postoperative recurrence of breast cancer was performed. The edgeR software package was used to identify the test indicators expressed differently between the two groups. Univariate analysis was used to screen for diagnostic marker that could predict postoperative recurrence of breast cancer. In addition, the differential test indicators at different time points from surgery to recurrence were collected in patients with postoperative recurrence of breast cancer as a verification database.

Results

We screened out three test indicators (TBA, GSP, and URBC) for differential expression, which were all expressed downregulated in the postoperative recurrence group of breast cancer. Univariate analysis suggested that only the difference in GSP levels between the two groups was statistically significant (P = 0.001). ROC curve analysis showed that the area under the curve of GSP was 0.662, while the area under the curve of GSP+AFP+CEA+CA125+CA153+age was increased to 0.828. In addition, serum GSP levels were significantly reduced after recurrence compared with before recurrence in breast cancer patients (P < 0.01).

Conclusions

In summary, GSP could be used for early diagnosis of breast cancer recurrence after surgery, and the predicted value of combining GSP, tumor markers, and age was better than that of individual indicators.

Synonymous Variants: Necessary Nuance in our Understanding of Cancer Drivers and Treatment Outcomes

Once called "silent mutations" and assumed to have no effect on protein structure and function, synonymous variants are now recognized to be drivers for some cancers. There have been significant advances in our understanding of the numerous mechanisms by which synonymous single nucleotide variants (sSNVs) can affect protein structure and function by affecting pre-mRNA splicing, mRNA expression, stability, folding, miRNA binding, translation kinetics, and co-translational folding. This review highlights the need for considering sSNVs in cancer biology to gain a better understanding of the genetic determinants of human cancers and to improve their diagnosis and treatment. We surveyed the literature for reports of sSNVs in cancer and found numerous studies on the consequences of sSNVs on gene function with supporting in vitro evidence. We also found reports of sSNVs that have statistically significant associations with specific cancer types but for which in vitro studies are lacking to support the reported associations. Additionally, we found reports of germline and somatic sSNVs that were observed in numerous clinical studies and for which in silico analysis predicts possible effects on gene function. We provide a review of these investigations and discuss necessary future studies to elucidate the mechanisms by which sSNVs disrupt protein function and are play a role in tumorigeneses, cancer progression, and treatment efficacy. As splicing dysregulation is one of the most well recognized mechanisms by which sSNVs impact protein function, we also include our own in silico analysis for predicting which sSNVs may disrupt pre-mRNA splicing.

ESR1 gene variants, haplotypes and diplotypes may influence the risk of breast cancer and mammographic density

Breast cancer as the most common cancer worldwide is influenced by genetic and physiological factors. Based on some evidence indicating the role of estrogen receptor 1 gene (ESR1) in breast cancer development, in this study, the association of three common variations in ESR1 gene with breast cancer and density in an Iranian population was evaluated. In a case-control study, 400 blood samples were collected for DNA extraction and genotyping. Breast density was assessed using mammography. ESR1 rs6915267 (G/A), rs2077647 (C/T) and rs1801132 (C/G) were genotyped using ARMS-PCR method. PHASE program was used to estimate the haplotypes frequencies. Our data analysis showed rs6915267 GA genotype in the heterozygous (GA) as well as co-dominant models was associated with lower mammographic density. None of the three variations were associated with the breast cancer risk. Haplotype analysis indicated G-T-C haplotype of rs6915267, rs2077647 and rs1801132 [OR = 0.54, 95% CI (0.31-0.92), p = 0.025] and G-T/G-T diplotype of rs6915267-rs2077647 [OR = 0.38, 95% CI (0.17-0.86), p = 0.019] were associated with a decreased risk of breast cancer. ESR1 may affect density of the breast and its haplotypes may modulate breast cancer risk.

No Association between Estrogen Receptor-Β Rs4986938 and Cancer Risk: A Systematic Review and Meta-Analysis

BACKGROUND

The association between estrogen receptor-β (ESR2) rs4986938 polymorphism and the risk of various types of cancer have been investigated in previous studies. However, the results remained disputable. Here, we conducted a meta-analysis to investigate the association between ESR2 rs4986938 polymorphism and the risk of cancer.

METHODS

We searched for relevant articles collected by the PubMed, EMBASE, and Cochrane library up to March 30, 2018. The association was assessed using Odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The meta-analysis involved a total of 23 studies in 20 papers, including 24,334 cases and 31,707 controls. No significant association was detected between the rs4986938 polymorphism and cancer risk in the additive model (A compared with G: OR=0.97, 95% CI=0.92-1.02, P=0.20), dominant model (AA+AG compared with GG: OR=0.96, 95% CI=0.93-1.03, P=1.00), recessive model (AA compared with AG + GG: OR=0.94, 95% CI=0.86-1.03, P=0.18), heterozygous model (AG compared with GG: OR=0.97, 95% CI=0.94-1.01, P=0.14), and homozygous model (AA compared with GG: OR=0.96, 95% CI=0.87-1.06, P=0.39). Results of subgroup analysis stratified by ethnicity and cancer types further validated the results.

CONCLUSION

We found no evidence of an association between rs4986938 and the risk of overall cancer.

Variants of estrogen receptor alpha and beta genes modify the severity of sporadic breast cancer

INTRODUCTION

Reproductive factors pose a risk for sporadic breast cancer (BC) development owing to the lifetime exposure to estrogen, a hormone responsible for cell proliferation in the breast. Because variants of the estrogen receptor (ER) alpha and beta genes have been associated with BC risk in numerous populations, the objective of the study was to determine whether the risk and severity of sporadic BC was associated with the rs2228480 (ESR1) and rs4986938 (ESR2) variants in a Brazilian population.

METHODS

A total of 253 DNA samples from sporadic BC patients and 257 DNA samples from healthy controls were studied. The samples were genotyped by PCR-RFLP. Epidemiological, clinical, and reproductive factors were analyzed. Statistical tests conducted included the χ² test, Fisher's exact test, and Mann-Whitney and Kruskal-Wallis tests or their parametric equivalents.

RESULTS

There was a high frequency of the rs2228480*GG genotype among the ER-positive tumors (OR=2.13; 95% CI=1.189-3.816) and it showed minor association with clinical stage 0 (OR=0.324; 95% CI=0.116-0.904). The rs2228480*GA genotype was associated with minor ER expression, whereas rs2228480*GG was associated with high expression of the progesterone receptor (PR). The frequency of rs4986938*GA was high among women who breastfed (OR=2.11; 95% CI=1.203-3.702), and it showed high association with clinical stage 0 (OR=4.383; 95% CI=1.606-11.96) whereas it had minor association with systemic arterial hypertension (OR=0.53; 95% CI=0.319-0.880). The rs2228480*GG/rs4986938*GG haplotype occurred at a low frequency among women who breastfed (OR=0.525; 95% CI=0.298-0.924) but it was associated with a high expression of PR.

CONCLUSION

The rs2228480 and rs4986938 variants did not alter sporadic BC risk, but they did modulate the BC severity.

A Meta-Analysis of the Association between ESR1 Genetic Variants and the Risk of Breast Cancer

Background

Single nucleotide polymorphisms (SNPs) in the estrogen receptor gene (ESR1) play critical roles in breast cancer (BC) susceptibility. Genome-wide association studies have reported that SNPs in ESR1 are associated with BC susceptibility; however, the results of recent studies have been inconsistent. Therefore, we performed this meta-analysis to obtain more accurate and credible results.

Methods

We pooled published literature from PubMed, EMBASE, and Web of Science and calculated odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of associations using fixed effects models and random effects models. Twenty relevant case-control and cohort studies of the 3 related SNPs were identified.

Results

Three SNPs of the ESR1 gene, rs2077647:T>C, rs2228480:G>A and rs3798577:T>C, were not associated with increased BC risk in our overall meta-analysis. Stratified analysis by ethnicity showed that in Caucasians, the rs2228480 AA genotype was associated with a 26% decreased risk of BC compared with the GG genotype (OR = 0.740, 95% CI: 0.555–0.987). The C allele of the rs3798577:T>C variant was associated with decreased BC risk in Asians (OR = 0.828, 95% CI: 0.730–0.939), while Caucasians with this allele were found to experience significantly increased BC risk (OR = 1.551, 95% CI: 1.037–2.321). A non-significant association between rs2077647 and BC risk was identified in all of the evaluated ethnic populations.

Conclusion

Rs3798577 was associated with an increased risk of BC in Caucasian populations but a decreased risk in Asians. Rs2228480 had a large protective effect in Caucasians, while rs2077647 was not associated with BC risk.

Association of genetic variants in estrogen receptor α with HCV infection susceptibility and viral clearance in a high-risk Chinese population

The purpose of this study was to test the hypothesis that genetic variants of estrogen receptor α (ERα) are associated with the outcomes of hepatitis C virus (HCV) infection. We genotyped the seven single nucleotide polymorphisms (SNPs) (rs2077647, rs9340799, rs2234693, rs1801132, rs9322354, rs2228480 and rs3798577) of ERα and conducted a case-control study in a high-risk Chinese population, including 429 HCV spontaneous clearance cases, 880 persistent infection cases and 1,174 uninfected controls. The C allele of rs2234693 was significantly associated with increased susceptibility to HCV infection [dominant model: adjusted odds ratio (OR) = 1.377, 95% confidence interval (CI) =1.126-1.778], and the risk effect remained significant among the younger (≤55 years) and hemodialysis subjects (all P < 0.007). The other three SNPs variant genotypes also showed significant correlation with elevated risk of HCV infection in different strata (rs2077647 in males; rs9340799 in blood donors; rs1801132 in younger subjects; all P < 0.007). It was also discovered that carriage of rs2228480 A allele was more prone to develop persistent HCV infection (dominant model: adjusted OR = 1.203, 95% CI = 1.154-1.552), and the risk effect was more evident in females and blood donors (all P < 0.007). Haplotype analyses (rs2077647, rs9340799 and rs2234693) showed that, compared with the most frequent haplotype TAT, CAC played a risk effect in subgroups of younger (P = 3.24 × 10(-3)) and male (P = 5.51 × 10(-4)), whereas CAT expressed a protective effect in females (P = 2.27 × 10(-4)) for HCV infection susceptibility. We first report that these SNPs (rs2077647, rs9340799, rs2234693, rs1801132 and rs2228480) in ERα can influence the outcomes of HCV infection in a high-risk Chinese population.

The dyslipidemia-associated SNP on the APOA1/C3/A5 gene cluster predicts post-surgery poor outcome in Taiwanese breast cancer patients: a 10-year follow-up study

Background

Post-surgery therapies are given to early-stage breast cancer patients due to the possibility of residual micrometastasis, and optimized by clincopathological parameters such as tumor stage, and hormone receptor/lymph node status. However, current efficacy of post-surgery therapies is unsatisfactory, and may be varied according to unidentified patient genetic factors. Increases of breast cancer occurrence and recurrence have been associated with dyslipidemia, which can attribute to other known risk factors of breast cancer including obesity, diabetes and metabolic syndrome. Thus we reasoned that dyslipidemia-associated nucleotide polymorphisms (SNPs) on the APOA1/C3/A5 gene cluster may predict breast cancer risk and tumor progression.

Methods

We analyzed the distribution of 5 selected APOA1/C3/A5 SNPs in recruited Taiwanese breast cancer patients (n=223) and healthy controls (n=162). The association of SNP (APOA1 rs670) showing correlation with breast cancer with baseline and follow-up parameters was further examined.

Results

APOA1 rs670 A allele carriage was higher in breast cancer patients than controls (59.64% vs. 48.77%, p=0.038). The rs670 A allele carrying patients showed less favorable baseline phenotype with positive lymph nodes (G/A: OR=3.32, 95% CI=1.77-6.20, p<0.001; A/A: OR=2.58, 95% CI=1.05-6.32, p=0.039) and negative hormone receptor expression (A/A: OR=4.85, 95%CI=1.83-12.83, p=0.001) in comparison to G/G carriers. Moreover, rs670 A/A carrying patients had higher risks in both tumor recurrence (HR=3.12, 95% CI=1.29-7.56, p=0.012) and mortality (HR=4.36, 95% CI=1.52-12.47, p=0.006) than patients with no A alleles after adjustments for associated baseline parameters. Furthermore, the prognostic effect of rs670 A/A carriage was most evident in lymph node-negative patients, conferring to the highest risks of recurrence (HR=4.98, 95% CI=1.40-17.70, p=0.013) and mortality (HR=9.87, 95%CI=1.60-60.81, p=0.014) than patients with no A alleles.

Conclusions

APOA1 rs670 A/A carriage showed poor post-surgery prognosis in Taiwanese lymph node-negative breast cancer patients, whose prognosis were considered better and adjuvant treatment might be less stringent according to currently available assessment protocols. Our findings suggest that APOA1 rs670 indicate a post-surgery risk of breast cancer disease progression, and that carriers of this SNP may benefit from more advanced disease monitoring and therapy regimens than the current regular standards. Furthermore, control of lipid homeostasis might protect APOA1 rs670 minor allele carriers from breast cancer occurrence and progression.

Estrogen receptor genes variations and breast cancer risk in Iran

Evidence suggests that alterations in estrogen signaling pathways, including estrogen receptor α (ER-α) and estrogen receptor β (ER-β) occur during breast cancer development. ER-α and ER-β genes polymorphisms have been found to be associated with breast cancer and clinical features of the disease in the western countries. In the current study, we evaluated the hypothesis that certain sequence variants of the ER-α and ER-β genes are associated with an additively increased risk for breast cancer in Iranian women breast cancer patients. The genes were scanned in 150 Iranian patients with newly diagnosed invasive breast tumors and in healthy control individuals by PCR single-strand conformation polymorphism (SSCP) method. Three single nucleotide polymorphisms (SNPs) in codon10 (TCT→TCC), codon 352 (CCG→CCC) and codon 594 (ACG→ACA) in ER-α gene and one SNP codon 392 (CTC→CTG) in ER-β were revealed have additive effects in developing breast cancer and LN metastases. Also, SNP in codon 392 of estrogen receptor-β gene is more effective (threefold) than those SNPs in codons 10, 325, 594 of estrogen receptor-α gene in developing LN metastases in breast cancer patients. SNPs in estrogen receptor α and β have additive effects in increasing risk for developing breast cancer with LN metastases among Iranian women breast cancer patients.

Cancer in the Sudan: an overview of the current status of knowledge on tumor patterns and risk factors

The Sudan, the largest and most diverse country in Africa, is experiencing a growing cancer problem, but little is presently known on tumor patterns, cancer epidemiology and ethnic or environmental cancer risk factors. We review here the current status of knowledge, summarizing data from local and international publications as well as primary information from the only two cancer hospitals of the country, both located in Central Sudan (Khartoum and Wad Medani). We provide frequencies reported for cancers detected in adults and children, and summarize studies on specific cancer types, as well as information on risk factors that most likely impact on tumor patterns.

Estrogen receptor alpha polymorphisms and the risk of malignancies

Estrogens represent risk factors for endocrine-related cancers and play also an important role in the development and progression of other malignancies. In order to analyze the associations between estrogen receptor gene alpha polymorphisms and cancers susceptibility, we genotyped six single nucleotide polymorphisms (SNPs) in 163 Caucasian cancer patients--103 breast cancers and 60 other malignancies (colorectal, bladder, hepatocellular carcinoma and acute myeloid leukemia)--and 114 healthy controls using hybridization probes. We performed Armitage`s association trend-test to evaluate the risk. Linkage disequilibrium (LD) was assessed for each pair of markers. The genotypes CC and CT of rs3798577 were significantly associated with the cancers risk (p-trend breast = 4 × 10(-5); p-trend cancers = 1 × 10(-5)); in discrepancy with breast cancer where the C-allele represented the risk allele, for bladder, hepatocellular carcinomas and leukemia, the T allele seems to confer susceptibility. The minor G allele of rs1801132 was protective in our cases (p = 1 × 10(-4)); for rs2228480, the heterozygous frequency was higher for cancer groups (p = 0.03); the SNP pairs rs2228480&rs3798577 and rs2234693&rs9340799 were in low LD; the haplotypes T-A of rs2234693&rs9340799 and G-C of rs2228480&rs3798577 showed a trend to be higher represented in breast cancers; T allele of rs2234693 was higher expressed in breast, colon cancers and leukemia; rs2077647 was associated with colon (p = 0.008, C-risk allele) and bladder (p = 0.01, T-risk allele) cancers. We concluded that ESR1 polymorphisms may have distinct impact in carcinogenesis and further genotyping will establish whether these findings remain significant in larger cohorts.

Gene expression patterns distinguish breast carcinomas from normal breast tissues: the Malaysian context

Genomic and transcriptomic alterations that affect cellular processes, such as cell proliferation, differentiation, apoptosis and invasion, commonly occur in breast oncogenesis. Epidemiological evidence has proven that the risk of breast cancer predisposition varies among different ethnicities. This study aims to identify the transcriptome changes that commonly occur during the transition of normal breast epithelium to carcinoma in three local ethnic groups (Malays, Chinese and Indians). The gene expression patterns of 43 breast carcinomas with 43 patient-matched normal breast tissues were investigated using Affymetrix U133A GeneChip (containing 22,283 probe sets targeting approximately 18,400 different transcripts) and analyzed with GeneSpring GX10. Our findings revealed a total of 33 significantly differentially expressed genes, which showed>2-fold change at a 99.9% confidence interval level (p<0.001). The significantly differentially expressed genes included CD24, CD36, CD9, TACSTD1, TACSTD2, HBB, LEP, LPL, AKR1C1, AKR1C2 and AKR1C3. Our results indicate that the vast majority of gene expression changes, from normal breast epithelial to carcinoma, found in our three major ethnic populations are similar to those in the Caucasian population. Further study of the differentially expressed genes identified in our present study is needed to search for potential breast tumor biomarkers. This will eventually help to improve the therapeutic and treatment strategies for breast cancer patients in the future.

Association of polymorphisms in estrogen and thyroid hormone receptors with thyroid cancer risk

The receptors for thyroid hormone (THR) and oestrogen (ESR) are prototypes of nuclear transcription factors that regulate the expression of target genes. Genetic alterations in the genes of these receptors were found to be involved in cancer development. In this study we investigated the association of one SNP (rs2228480, T594T) and one microsatellite marker (D6S440) within the ESR1 gene and a dinucleotide repeat (D17S2189) within the THRA gene, with thyroid cancer risk. A case-control association study was conducted with 299 healthy individuals and 106 patients with thyroid cancer. Genotypic and allelic frequencies for the dinucleotide repeat in the ESR1 gene were similar between thyroid cancer patients and controls. For the AC repeat in the THRA gene, a slightly significant difference was found for the genotype 18/20 between the two groups (P = 0.034), which suggests that alleles with less than 20 repeats might have a protective effect in thyroid cancer risk. For the SNP T594T, the A allele was much more prevalent in patients than in controls and was highly associated with the risk of thyroid cancer (OR: 4,56; IC: 3.23-6.44; P < 10(-18)) and seems to have an additive mode of action. In conclusion, our data suggest that the SNP T594T but not the D6S440 and D17S189 is associated with thyroid cancer risk.

Genetic polymorphisms in the EGFR (R521K) and estrogen receptor (T594T) genes, EGFR and ErbB-2 protein expression, and breast cancer risk in Tunisia

We evaluated the association of epidermal growth factor receptor (EGFR) 142285G>A (R521K) and estrogen receptor alpha (ESR1) 2014G>A (T594T) single nucleotide polymorphisms with breast cancer risk and prognosis in Tunisian patients. EGFR 142285G>A and ESR1 2014G>A were genotyped in a sample of 148 Tunisian breast cancer patients and 303 controls using PCR-RFLP method. Immunohistochemitsry was used to evaluate the expression levels of EGFR, HER2, ESR1, progesterone receptor and BCL2 in tumors. We found no evidence for an association between EGFR R521K polymorphism and breast cancer risk. However, we found that the homozygous GG (Arg) genotype was more prevalent in patients with lymph node metastasis (P = .03) and high grade tumors (P = .011). The ESR1 2014G allele showed significant association with breast cancer risk (P = .025). The GG genotype was associated with HER2 overexpression and this association withstood univariate and multivariate analyses (P = .009; P = .021, resp.). These data suggest that the R521K might be a prognostic factor, because it correlates with both tumor grade and nodule status. The higher expression of HER2 in ESR1 T594T GG patients suggests the possibility that ESR1 gene polymorphisms accompanied by HER2 expression might influence the pathogenesis of breast cancers.

Estrogen receptor alpha gene polymorphism and breast cancer

Estrogen and estrogen receptors play important roles in the proliferation and development of breast cancer. Several genetic alterations identified in the estrogen receptor alpha gene (ESR1) are thought to influence the expression or function of this protein, and many have been evaluated for their role in breast cancer predisposition. The aim of this study was to evaluate the role of the C325G single nucleotide polymorphism (SNP) in the ESR1 in predisposition to breast cancer. The candidate SNP C325G in ESR1, exon 4 was genotyped in breast cancer patients and in healthy controls that were age and sex matched. Genotyping was performed using both single-stranded conformational polymorphism (SSCP) and a higher throughput allelic discrimination method using real-time PCR. Data on clinical features and demographic details were collected. Significant association of breast cancer risk was shown in the subgroup of women 50 years and younger who had the C allele (OR: 2.28, 95% CI: 1.10-4.72) (P= 0.03). However, the overall susceptibility to breast cancer was not significant, although all estimates were in the direction of a higher risk in women with CC genotypes. This study found significant evidence that polymorphism within the low penetrance ESR1 is associated with breast cancer susceptibility in women of 50 years or younger. There is also an indication that G allele is protective (compared to C allele).

Comparison and identification of estrogen-receptor related gene expression profiles in breast cancer of different ethnic origins

The interactions between genetic variants in estrogen receptor (ER) have been identified to be associated with an increased risk of breast cancer. Available evidence indicates that genetic variance within a population plays a crucial role in the occurrence of breast cancer. Thus, the comparison and identification of ER-related gene expression profiles in breast cancer of different ethnic origins could be useful for the development of genetic variant cancer therapy. In this study, we performed microarray experiment to measure the gene expression profiles of 59 Taiwanese breast cancer patients; and through comparative bioinformatics analysis against published U.K. datasets, we revealed estrogen-receptor (ER) related gene expression between Taiwanese and British patients. In addition, SNP databases and statistical analysis were used to elucidate the SNPs associated with ER status. Our microarray results indicate that the expression pattern of the 65 genes in ER+ patients was dissimilar from that of the ER- patients. Seventeen mutually exclusive genes in ER-related breast cancer of the two populations with more than one statistically significant SNP in genotype and allele frequency were identified. These 17 genes and their related SNPs may be important in population-specific ER regulation of breast cancer. This study provides a global and feasible approach to study population-unique SNPs in breast cancer of different ethnic origins.

Norsolorinic acid from Aspergillus nidulans inhibits the proliferation of human breast adenocarcinoma MCF-7 cells via Fas-mediated pathway

Norsolorinic acid, isolated from the Aspergillus nidulans, was investigated for its antiproliferative activity in human breast adenocarcinoma MCF-7 cells. To identity the anticancer mechanism of norsolorinic acid, we assayed its effect on apoptosis, cell cycle distribution, and levels of p53, p21/WAF1, Fas/APO-1 receptor and Fas ligand. The results showed that norsolorinic acid induced apoptosis of MCF-7 cells without mediation of p53 and p21/WAF1. We suggest that Fas/Fas ligand apoptotic system is the main pathway of norsolorinic acid-mediated apoptosis of MCF-7 cells. Our study reports here for the first time that the activity of the Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of norsolorinic acid in MCF-7 cells.

Nuclear receptor coregulators and human disease

Nuclear receptor (NR) coregulators (coactivators and corepressors) are essential elements in regulating nuclear receptor-mediated transcription. In a little more than a decade since their discovery, these proteins have been studied mechanistically and reveal that the regulation of transcription is a highly controlled and complex process. Because of their central role in regulating NR-mediated transcription and in coordinating intercompartmental metabolic processes, disruptions in coregulator biology can lead to pathological states. To date, the extent to which they are involved in human disease has not been widely appreciated. In a complete literature survey, we have identified nearly 300 distinct coregulators, revealing that a great variety of enzymatic and regulatory capabilities exist for NRs to regulate transcription and other cellular events. Here, we substantiate that coregulators are broadly implicated in human pathological states and will be of growing future interest in clinical medicine.

Association of progesterone receptor with migraine-associated vertigo

While migraine has been demonstrated to be familial and have genetic contributions, genome-wide linkage analyses and candidate gene studies have highlighted that migraine is genetically complex. Despite substantial efforts, no consistent replication of linkage or association has been reported for common migraine syndromes. Among the candidate genes tested for association with migraine by several groups were female sex hormone genes based on the observation of a much higher incidence of migraine in females. Migraine-associated vertigo (MAV) is a migraine syndrome also much more common in females than males. Because MAV is less common in the general population than migraine or migraine with aura, it may be a better migraine syndrome to detect susceptibility alleles. In this study, we tested the association of two female hormonal genes, progesterone receptor (PGR) and estrogen receptor (ESR1), which were previously reported to be associated with migraine in women. We typed 150 MAV subjects and 145 genomic matched control subjects. One SNP (rs1042838) within PGR, which is in high linkage disequilibrium with the functional PROGINS variant, was significantly associated with MAV (p = 0.0007). Two SNPs (rs2228480 and rs1801132) within ESR1 demonstrated no significant association. No synergistic effect between ESR1 variants and PGR variants was identified.

Glutathione S-transferase polymorphisms associated with risk of breast cancer in southern Taiwan

In this study, the genetic polymorphisms associated with breast cancer in southern Taiwan were investigated. Two categories of genes were analyzed: (1) BRCA1, BRCA2, and Rad51, the DNA repair factors involved in homologous recombinational repair; and (2) CYP1A1, COMT, GST, and NAT2, the xenobiotic-metabolizing enzymes (XME) involved in estrogen metabolism. We found that the number of deletions and/or mutations in the GST genes was highly correlated with the occurrence of breast cancer. These data suggest that the GST enzymes, which detoxify the catechol estrogen quinones, are important target molecules for screening in populations at high risk of breast cancer.

Genetic determinants of bone mass do not relate with breast cancer risk in US white and African-American women

INTRODUCTION

The association between high bone mass and increased breast cancer risk has been established. Identification of polymorphisms and the resultant variant receptors suggests the possibility of differential effects on hormone responsive genes when complexed with the hormones. Both estrogen receptor-alpha (ER) and vitamin D receptor (VDR) polymorphisms have been associated with bone density. Thus, we examined these polymorphisms for association with increased breast cancer risk among US African-American and white women.

METHODS

A case-control study was conducted to measure ER and VDR polymorphisms and radial bone mineral density (BMD) in African-American and white women, and to examine the association between polymorphisms, bone density and breast cancer risk. Genotypes and bone density were obtained from 412 women (220 cases and 192 controls, with equal distribution between the two ethnic groups).

RESULTS

We found no evidence for an association between either the ER or VDR genotypes and breast cancer risk. Also, there was no difference in the risk of breast cancer by genotypes after adjusting for ethnicity. The addition of age, sex and ethnicity-specific BMD (Z-scores) did not significantly change the odds ratio for breast cancer.

CONCLUSIONS

Our data suggest that the polymorphisms investigated had no effect on risk of breast cancer in this population. Thus, we found no evidence to support our hypothesis that breast cancer cases and controls would have a different distribution of ER and VDR genotypes. Furthermore, the polymorphisms were not associated with differences in bone mass and its relationship with breast cancer risk.

No role for estrogen receptor 1 gene intron 1 Pvu II and exon 4 C325G polymorphisms in migraine susceptibility

Background

We have previously reported an association between the estrogen receptor 1 (ESR1) gene exon 8 G594A polymorphism and migraine susceptibility in two independent Australian cohorts. In this paper we report results of analysis of two further single nucleotide polymorphisms (SNPs) in the ESR1 gene in the same study group, the T/C Pvu II SNP in intron 1 and the C325G SNP in exon 4, as well as results of linkage disequilibrium (LD) analysis on these markers.

Methods

We investigated these variants by case-control association analysis in a cohort of 240 migraineurs and 240 matched controls. The SNPs were genotyped using specific restriction enzyme assays. Results were analysed using contingency table methods incorporating the chi-squared statistic. LD results are presented as D' statistics with associated P values.

Results

We found no evidence for association of the Pvu II T/C polymorphism and the C325G polymorphism and migraine susceptibility and no evidence for LD between these two SNPs and the previously implicated exon 8 G594A marker.

Conclusion

We have found no role for the polymorphisms in intron 1 and exon 4 with migraine susceptibility. To further investigate our previously implicated exon 8 marker, we suggest the need for studies with a high density of polymorphisms be undertaken, with particular focus on markers in LD with the exon 8 marker.

Estrogen and progesterone receptor gene polymorphisms and sporadic breast cancer risk: A Spanish case-control study

Estrogens, and to a lesser extent progesterones, influence the proliferation, differentiation and physiology of breast tissue as well as the development and progression of breast cancer. Genetic variants in the steroid hormone receptor genes ESR1 and PGR (belonging to the nuclear receptor superfamily) could therefore modify sporadic breast cancer susceptibility. Two studies have shown a protective effect associated with variants in ESR1 in 2 distinct populations. We studied 4 single nucleotide polymorphisms (SNPs) in ESR1 and 4 in PGR in 550 consecutive and unrelated sporadic Spanish breast cancer patients and 564 healthy Spanish controls. We observed a dominant protective effect for the S10S variant in ESR1, with an estimated odds ratio (OR) of 0.75 (95% CI = 0.58-0.97; p = 0.03) although functional studies did not show changes in the RNA stability. A small subset of individuals carried a haplotype combination that corroborates this protection. No other SNP considered in either gene was found to be associated with sporadic breast cancer. Our results obtained in a European population confirm the protective role of the S10S variant in ESR1, previously reported in an Asian and a European-American population.

Estrogen receptor alpha gene polymorphism and systemic lupus erythematosus: a possible risk?

Estrogens and their receptors may play a role in the pathogenesis of systemic lupus erythematosus. Genetic alterations in the exon 8-coding region of the estrogen receptor alpha alter the intracellular signalling of estrogens, leading in enhanced or diminished activity. We investigated whether genetic alterations in exon 8 of ERalpha gene are associated with the occurrence and clinical features of lupus disease. The coding region of ERalpha exon 8 was subjected to mutation analysis using the polymerase chain reaction, denaturing gradient gel electrophoresis and sequence analysis, using DNA isolated from whole blood of 36 female patients and 38 healthy females. Clinical and laboratory parameters were available from the patients' files. We identified the codon 594 polymorphism either in homozygous for the wild type gene (ACG/ACG) or heterozygous (ACG/ACA), both in patients and healthy females. Statistical analysis of the genotype and allele distribution revealed that there was a significant difference (chi2 test, P = 0.02 and P = 0.04, respectively) between patients and healthy women. Odds ratio estimate revealed that carriers of ACG/ACA genotype have three-fold higher risk of developing lupus disease (OR = 3.129, 95% CI 1.181-8.292). Moreover, in patients the heterozygous genotype was associated with rash, mouth ulcers and serositis (Fisher's exact test, P = 0.055, P = 0.083, P = 0.065, respectively). The heterozygous patients were associated significantly with an early age at disease onset (ANOVA test, P < 0.05). We conclude that estrogen receptor alpha codon 594 genotype may influence the development of systemic lupus erythematosus at a younger age, as well as a certain disease clinical pattern.

Putranjivain A from Euphorbia jolkini inhibits proliferation of human breast adenocarcinoma MCF-7 cells via blocking cell cycle progression and inducing apoptosis

Putranjivain A, isolated from the whole plant of Euphorbia jolkini Bioss (Euphorbiaceae), was investigated for its antiproliferative activity in human breast adenocarcinoma MCF-7 cells. The results showed that putranjivain A inhibited the proliferation of MCF-7 by blocking cell cycle progression in the G0/G1 phase and inducing apoptosis. Enzyme-linked immunosorbent assay showed that putranjivain A increased the expression of p21/WAF1 concomitantly as MCF-7 cell underwent G0/G1 arrest. An enhancement in Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), might be responsible for the apoptotic effect induced by putranjivain A. Our study reports here for the first time that the induction of p21/WAF1 and the activity of Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of putranjivain A in MCF-7 cells.