Genetic Polymorphisms of the CYP19A1 Gene and Breast Cancer Survival

Evaluation of novel synthesized thiazole derivatives as potential aromatase inhibitors against breast cancer

Background: 4-Methylacetophenone is used in the preparation of starting materials, 4-methylphenacyle bromide (2) and 4-methylacetophenone thiosemicarbazole (3). Results: Several novel 2,4-disubstituted-1,3-thiazole analogues were obtained via the treatment of starting materials with 4-methylphenacyl bromide, acetyl chloride, aromatic aldehydes and bromination providing thiazole derivatives 5-8 respectively. Conclusion: Compounds 5-8 were investigated for their cytotoxic activity on MCF-7 and normal breast cells. Active compounds were found and in contrast to staurosporine, compound 8 displayed the most potent cytotoxic action that showed a strong inhibitory effect (aromatase) and (protein tyrosine kinase) enzymes, proving that the novel thiazole derivatives promoted the effective anticancer drug candidates.

Association of CYP19A1 Gene, Plasma Zinc, and Urinary Zinc with the Risk of Type 2 Diabetes Mellitus in a Chinese Population

To explore the effects of CYP19A1 gene polymorphisms, plasma zinc, and urinary zinc levels and their interactions on type 2 diabetes mellitus (T2DM) in residents of Gongcheng County, Guangxi, China. The case-control study was used for the investing. The MassARRAY System was applied to genotype the CYP19A1 genes rs752760, rs10046, rs10459592, and rs700518 in 540 study subjects. Plasma and urinary zinc concentrations were measured by inductively coupled plasma mass spectrometry (ICP-MS). Conditional logistic regression showed that rs752760 and plasma zinc were associated with T2DM risks with ORs of 0.593 (95% CI: 0.371-0.948) and 0.563 (95% CI: 0.356-0.889), respectively. Unconditional logistic regression analysis showed an association between urinary zinc levels and the risk of T2DM as well, with an OR of 0.352 (95% CI: 0.212-0.585). The results of the multiplicative interaction model showed that the rs752760 T allele was associated with a significantly reduced risk of T2DM with moderate/low plasma zinc levels, with ORs of 0.340 (95% CI: 0.161-0.715) and 0.583 (95% CI: 0.346-0.981), respectively, and the rs752760 T allele was also associated with a significantly decreased risk of T2DM with moderate/low urinary zinc levels, with ORs of 0.358 (95% CI: 0.201-0.635) and 0.321 (95% CI: 0.183-0.562), respectively. CYP19A1 rs752760 T allele and moderate/low plasma/urinary zinc levels reduce the risk of T2DM.

A Novel Attention-Mechanism Based Cox Survival Model by Exploiting Pan-Cancer Empirical Genomic Information

Cancer prognosis is an essential goal for early diagnosis, biomarker selection, and medical therapy. In the past decade, deep learning has successfully solved a variety of biomedical problems. However, due to the high dimensional limitation of human cancer transcriptome data and the small number of training samples, there is still no mature deep learning-based survival analysis model that can completely solve problems in the training process like overfitting and accurate prognosis. Given these problems, we introduced a novel framework called SAVAE-Cox for survival analysis of high-dimensional transcriptome data. This model adopts a novel attention mechanism and takes full advantage of the adversarial transfer learning strategy. We trained the model on 16 types of TCGA cancer RNA-seq data sets. Experiments show that our module outperformed state-of-the-art survival analysis models such as the Cox proportional hazard model (Cox-ph), Cox-lasso, Cox-ridge, Cox-nnet, and VAECox on the concordance index. In addition, we carry out some feature analysis experiments. Based on the experimental results, we concluded that our model is helpful for revealing cancer-related genes and biological functions.

The CYP19A1 rs700519 Polymorphism and Breast Cancer Susceptibility in China: A Case-Control Study and Updated Meta-Analysis

Objective: Breast cancer (BC), the most prevalent cancer in women, has been associated with several genetic factors, including the CYP19A1 rs700519 polymorphism; however, the conclusions have not been consistent. This case-control study and meta-analysis aimed to further assess the relationship between the CYP19A1 rs700519 polymorphism and BC susceptibility. Materials and Methods: We conducted a case-control study to assess the relationship of the CYP19A1 rs700519 polymorphism with the risk and prognosis of BC. Subsequently, we performed a meta-analysis of the case-control studies. Results: In the case-control study, we found a significant negative relationship between the rs700519 AA genotype and risk (χ² = 7.503, p < 0.01) and disease-free survival rates (hazard rate = 0.400, 95% confidence interval [CI] = 0.181-0.883, p < 0.01) of patients with BC, especially in postmenopausal hormone receptor-positive (HR⁺) patients. Nine case-control studies were included in the meta-analysis. The CYP19A1 rs700519 polymorphism was significantly associated with BC susceptibility in the dominant (odds ratio [OR] = 0.95, 95% CI = 0.90-1.00, p = 0.05) and allelic models (OR = 0.84, 95% CI = 0.75-0.93, p < 0.01), but not in the recessive model. Sensitivity analysis revealed that the study results were stable, whereas the funnel plot revealed some publication bias. Conclusions: The CYP19A1 rs700519 polymorphism is related to breast tumorigenesis.

The impact of CYP19A1 variants and haplotypes on breast cancer risk, clinicopathological features and prognosis

Background

Different genetic variants in hormone‐regulating pathways have been identified to influence the risk of breast cancer. This study aimed to evaluate the association of CYP19A1 rs10046 and rs700519 polymorphisms with the risk, clinicopathological factors and prognosis of breast cancer.

Methods

In a case‐control study, rs10046 and rs700519 polymorphisms were genotyped using ARMS‐PCR and high‐resolution melting (HRM), respectively, in a total of 702 females. Statistical analysis and evaluation of haplotypes and linkage disequilibrium were performed using SPSS v16, PHASE and 2LD.

Results

Although no association of rs700519 with breast cancer was observed, rs10046 in different genetic models as well as C‐C/C‐T and C‐C/C‐C diplotypes, revealed the association with the risk of breast cancer (p < 0.05). Moreover, the rs700519‐C allele was shown to be associated with longer overall survival. In contrast, the T‐T haplotype conferred s a shorter overall survival. rs700519‐C allele was also significantly associated with menarche age.

Conclusion

Based on the identified independent association between CYP19A1 diplotypes and rs700519‐C allele with the risk and prognosis of the disease, the gene region and its genetic variants may have a diagnostic and prognostic role in breast cancer development. Further confirmation using other variants in this locus can validate these findings.

Network pharmacology-based analysis for unraveling potential cancer-related molecular targets of Egyptian propolis phytoconstituents accompanied with molecular docking and in vitro studies

Cancer is one of the predominant causes of death worldwide. The new trend nowadays is to exploit natural products with the hope of developing new anticancer agents with fewer side effects. Propolis is one of these natural products which showed effectiveness in cancer treatment. The aim of this study is to understand the multi-level mechanism of action of propolis constituents in cancer treatment using an integrated approach of network pharmacology-based analysis, molecular docking and in vitro cytotoxicity testing. An inhouse database of chemical constituents from Egyptian propolis was compiled and assessed for its ADME properties using the QikProp module in the Schrodinger software. STITCH, UniProt, STRING, KEGG and DAVID databases were used for construction of constituent-target gene, gene-pathway, and constituent-target gene-pathway networks with the aid of Cytoscape 3.8.2. The network pharmacology-based analysis showed that the hit propolis constituents related to cancer targets were genistein, luteolin, benzoic acid, quercetin and vanillic acid, whereas the main cancer-associated targets were CYP1A1, CYP19A1, ESR1, NOS3, CASP3 and AKT1. Twenty-four cancer-related pathways were recognized where the most enriched ones were pathways in cancer and estrogen signaling pathway. The most enriched biological processes involved in the mechanism of action of propolis constituents in cancer treatment were negative regulation of the apoptotic process and the metabolic process and negative regulation of cellular glucuronidation. Molecular docking analysis of the top hit compounds against the most enriched target proteins in the constructed networks was carried out using the Maestro interface of the Schrodinger software. Among hit compounds, quercetin and genistein exhibited the most stabilized interaction. Finally, confirmation of the potential anticancer activity of propolis was assured by in vitro cytotoxicity testing of propolis extract on human prostate cancer (DU-145), breast adenocarcinoma (MCF-7) and colorectal adenocarcinoma (Caco-2) cell lines. This study presents deeper insights about propolis molecular mechanisms of action in cancer for the first time using an integrated approach of network pharmacology, molecular docking and in vitro testing.

MassARRAY analysis of twelve cancer related SNPs in esophageal squamous cell carcinoma in J&K, India

Background

MassARRAY (Agena Bioscience™) combines competitive PCR with MALDI-TOF mass spectrometry (MS) analysis that gives highly accurate, sensitive, and high-throughput methods for the quantitative analysis of variation of gene expression in multiple samples. SNPs (Single Nucleotide Polymorphisms) have a very high potential of discovering disease-gene relationships. SNP-genotyping through MassARRAY is not only a cost-effective genotyping method but also provides a platform to validate variants observed through a high-throughput Next-generation sequencing (NGS).

Methods

In the present study, we have incorporated the use of matrix-assisted laser desorption/ionization-time of flight, mass spectrometry (MALDI-TOF) as a tool for differentiating genotypes based on the mass of variant. We have performed multiplex PCR and genotyped 12 SNPs in 758 samples (166 cases and 592 controls). The 12 studied SNPs were chosen with a rationale for their association with multiple cancers in literature.

Results

This is the first study to explore these SNPs with esophageal cancer within the J&K population. Out of 12 SNPs, two SNPs rs12190287 of TCF21 and rs10046 of CYP19A1 were significantly associated with esophageal cancer with Odds Ratio (OR) 1.412 (1.09–1.8 at 95% CI, p = 0.008) and 1.54 (1.21–2.072 at 95% CI, p = 0.0007) within the population of Jammu and Kashmir.

Conclusion

We explored 12 SNPs that were found to be associated with multiple cancers in literature with esophageal cancer within the population of J&K. This is the first study to find the relation of these SNPs with ESCC within the studied population. This study explores the relation of genetic and environmental factors with the ESCC susceptibility.

Associations between polymorphisms in genes related to estrogen metabolism and function and prostate cancer risk: results from the Prostate Cancer Prevention Trial

Substantial preclinical data suggest estrogen's carcinogenic role in prostate cancer development; however, epidemiological evidence based on circulating estrogen levels is largely null. Compared with circulating estrogen, the intraprostatic estrogen milieu may play a more important role in prostate carcinogenesis. Using a nested case-control design in the Prostate Cancer Prevention Trial (PCPT), we examined associations of genetic variants of genes that are involved in estrogen synthesis, metabolism and function with prostate cancer risk. A total of 25 potentially functional single nucleotide polymorphisms (SNPs) in 13 genes (PGR, ESR1, ESR2, CYP17A1, HSD17B1, CYP19A1, CYP1A1, CYP1B1, COMT, UGT1A6, UGT1A10, UGT2B7, UGT2B15) were examined in whites only. Controls (n = 1380) were frequency matched to cases on age, PCPT treatment arm, and family history (n = 1506). Logistic regression models adjusted for age and family history were used to estimate odds ratios (OR) and 95% confidence intervals (CI) separately in the placebo and finasteride arms. SNPs associated with prostate cancer risk differed by treatment arm. The associations appeared to be modified by circulating estrogen and androgen levels. CYP19A1 was the only gene harboring SNPs that were significantly associated with risk in both the placebo and finasteride arms. Haplotype analysis with all three CYP19A1 SNPs genotyped (rs700518, rs2445765, rs700519) showed that risk-allele haplotypes are associated with the increased prostate cancer risk in both arms when comparing with the non-risk allele haplotype. In conclusion, associations between SNPs in estrogen-related genes and prostate cancer risk are complex and may be modified by circulating hormone levels and finasteride treatment.

Elevated Aromatase (CYP19A1) Expression Is Associated with a Poor Survival of Patients with Estrogen Receptor Positive Breast Cancer

Genetic variants in CYP19A1, the gene encoding aromatase, have been reported to be associated with circulating estrogen concentrations, a key risk factor for breast cancer. The mechanism underlying this association is still unclear; it has been suggested that some of these variants may alter the expression and/or activity of aromatase. Here we analyzed the expression of intra-tumoral CYP19A1 messenger RNA (mRNA) and the genotypes of rs10046, a well-characterized single nucleotide polymorphism in CYP19A1, in 138 breast cancer patients and 15 breast cancer cell lines. The genotype TT was detected in 36 patients and six cell lines, genotype CT in 55 patients and five cell lines, and genotype CC in 28 patients and four cell lines. We found no evidence for a significant association of CYP19A1 levels with rs10046 genotypes, although expression tended to be higher in tumors and cell lines with the homozygous risk genotype TT. We also found no evidence for a significant association of rs10046 genotypes with breast cancer prognosis. In contrast, high CYP19A1 expression was highly significantly associated with a poor overall, disease-free, and metastasis-free survival in estrogen receptor-positive but not negative breast cancer patients. Moreover, CYP19A1 mRNA was significantly elevated in postmenopausal patients and in patients older than 50 years, and a trend towards a positive correlation with ER status and ESR1 mRNA expression was observed. These findings highlight the key role of aromatase in estrogen receptor-positive breast cancer biology.

Rs1008805 polymorphism of CYP19A1 gene is associated with the efficacy of hormone therapy in stage I-II and operable stage III breast cancer

It has been hypothesized that single nucleotide polymorphisms in CYP19A1 gene may alter aromatase activity and circulating steroid hormone levels in females. Therefore, it is biologically reasonable that CYP19A1 rs1008805 (A/G) polymorphism may be associated with the clinical outcome of hormone therapy. Genotyping for the CYP19A1 rs1008805 polymorphism was performed for 287 females with hormone receptor (HR)-positive early breast cancer, and potential associations were evaluated between CYP19A1 rs1008805 genotypes and disease-free survival (DFS). Based on the analysis of the whole cohort, no significant differences were observed between rs1008805 genotypes and DFS. However, in postmenopausal females, rs1008805 variants were significantly associated with DFS (AA vs. AG vs. GG, 89.2 vs. 58.2 vs. 32.7 months; P=0.019). In addition, when the population was divided into two cohorts, females with the GG variant exhibited a significantly poorer DFS [GG vs. AA or AG, 32.7 vs. 70.6 months; hazard ratio (HR), 3.613; 95% confidence interval (CI), 1.380-9.457; P=0.005]. Furthermore, when adjusted for other patient features in multivariate analyses, GG genotype remained an independent prognostic marker for DFS (HR, 3.439; 95% CI, 1.251-9.456; P=0.017). However, there were no significant differences in DFS between patients harboring the minor allele and those with the homozygous common allele (AG or GG vs. AA, 52.4 vs. 89.2 months; HR, 1.288; 95% CI, 0.705-2.353; P=0.408). There were also no associations between rs1008805 polymorphism and DFS for premenopausal females. In conclusion, the homozygous minor allele (GG) of CYP19A1 rs1008805 was identified to be significantly associated with an inferior clinical outcome of hormone therapy in postmenopausal hormone receptor-positive patients with early breast cancer. If confirmed by further study, genotyping for CYP19A1 rs1008805 polymorphism may provide predictive information to improve the selection of endocrine treatment.

Ancestry as a potential modifier of gene expression in breast tumors from Colombian women

Background

Hispanic/Latino populations are a genetically admixed and heterogeneous group, with variable fractions of European, Indigenous American and African ancestries. The molecular profile of breast cancer has been widely described in non-Hispanic Whites but equivalent knowledge is lacking in Hispanic/Latinas. We have previously reported that the most prevalent breast cancer intrinsic subtype in Colombian women was Luminal B as defined by St. Gallen 2013 criteria. In this study we explored ancestry-associated differences in molecular profiles of Luminal B tumors among these highly admixed women.

Methods

We performed whole-transcriptome RNA-seq analysis in 42 Luminal tumors (21 Luminal A and 21 Luminal B) from Colombian women. Genetic ancestry was estimated from a panel of 80 ancestry-informative markers (AIM). We categorized patients according to Luminal subtype and to the proportion of European and Indigenous American ancestry and performed differential expression analysis comparing Luminal B against Luminal A tumors according to the assigned ancestry groups.

Results

We found 5 genes potentially modulated by genetic ancestry: ERBB2 (log2FC = 2.367, padj<0.01), GRB7 (log2FC = 2.327, padj<0.01), GSDMB (log2FC = 1.723, padj<0.01, MIEN1 (log2FC = 2.195, padj<0.01 and ONECUT2 (log2FC = 2.204, padj<0.01). In the replication set we found a statistical significant association between ERBB2 expression with Indigenous American ancestry (p = 0.02, B = 3.11). This association was not biased by the distribution of HER2+ tumors among the groups analyzed.

Conclusions

Our results suggest that genetic ancestry in Hispanic/Latina women might modify ERBB2 gene expression in Luminal tumors. Further analyses are needed to confirm these findings and explore their prognostic value.

CYP1A2--a novel genetic marker for early aromatase inhibitor response in the treatment of breast cancer patients

Background

Endocrine resistance is a major obstacle to optimal treatment effect in breast cancer. Some genetic markers have been proposed to predict response to aromatase inhibitors (AIs) but the data is insufficient. The aim of the study was to find new genetic treatment predictive markers of AIs.

Methods

The ongoing population-based BC-blood study in Lund, Sweden includes women with primary breast cancer. This paper is based on AI-treated patients with estrogen receptor positive tumors who underwent breast cancer surgery in 2002–2008. First, an exploratory analysis of 1931 SNPs in 227 genes involved in absorption, distribution, metabolism, and elimination of multiple medications, using DMET™ chips, was conducted in a subset of the cohort with last follow-up in December 31^st 2011 (13 cases, 11 controls). Second, selected SNPs from the first analysis were re-analyzed concerning risk for early breast cancer events in the extended cohort of 201 AI-treated with last follow-up in June 30^th 2014. Clinical data were obtained from medical records and population registries.

Results

Only CYP1A2 rs762551 C-allele was significantly associated with increased risk for early events in the 24 patients (P = 0.0007) and in the extended cohort, adjusted Hazard ratio (HR) 2.22 (95 % CI 1.03–4.80). However, the main prognostic impact was found within five years, adjusted HR 7.88 (95 % CI 2.13–29.19). The impact of the CYP1A2 rs762551 C-allele was modified by a functional polymorphism in the regulator gene AhR Arg554Lys (G > A). Compared to patients who were homozygous for the major allele in both genes (CYP1A2 A/A and AhR G/G), a 9-fold risk for early events was found in patients who had at least one minor allele in both genes, adjusted HR 8.95 (95 % CI 2.55–31.35), whereas patients with at least one minor allele in either but not both genes had a 3-fold risk for early events, adjusted HR 2.81 (95 % CI 1.07–7.33). The impact of CYP1A2 rs762551 C-allele was also modified by the CYP19A1 rs4646 C/C, adjusted HR 3.39 (95 % CI 1.60–7.16) for this combination. This association was strongest within the first five years, adjusted HR 10.42 (95 % CI 3.45–31.51).

Conclusion

CYP1A2 rs762551 was identified as a new potential predictive marker for early breast cancer events in AI-treated breast cancer patients. Moreover, combined genotypes of CYP1A2 rs762551 and CYP19A1 rs4646 or AhR Arg554Lys could further improve prediction of early AI-treatment response. If confirmed, these results may provide a way to more personalized medicine.

No associations between aromatase gene polymorphisms and breast cancer risk in Saudi patients

Background

Cytochrome P450 (CYP)19A1 encodes aromatase, the enzyme responsible for the conversion of androgens to estrogens, and may play a role in variation in outcomes among women with breast cancer. The aim of this study was to analyze the genetic association of rs4646 (A > C) and rs700518 (Val > Val) in the CYP19A1 gene with the risk of breast cancer.

Methods

These two single nucleotide polymorphisms (SNPs) were analyzed in a primary study group of breast cancer patients and healthy control subjects. Genotypes were determined by the TaqMan SNP analysis technique. The study data were analyzed using the chi-square or t-test and logistic regression analysis by Statistical Package for the Social Sciences version 16 software.

Results

rs4646 and rs700518 had no association with susceptibility to breast cancer. There was no significant association for either of these SNPs overall in breast cancer samples when compared with healthy control samples. Our data do not support a relationship between the CYP19A1 rs4646 and rs700518 SNPs and risk of breast cancer. It may be that there are ethnic differences with regard to this relationship.

Conclusion

This study demonstrated that CYP19A1 rs4646 and rs700518 SNPs may not be involved in the etiology of breast cancer in the Saudi population. Confirmation of our findings in larger populations of other ethnicities could provide evidence for the role of the CYP19A1 gene in breast carcinomas.

Common germline polymorphisms associated with breast cancer-specific survival

INTRODUCTION

Previous studies have identified common germline variants nominally associated with breast cancer survival. These associations have not been widely replicated in further studies. The purpose of this study was to evaluate the association of previously reported SNPs with breast cancer-specific survival using data from a pooled analysis of eight breast cancer survival genome-wide association studies (GWAS) from the Breast Cancer Association Consortium.

METHODS

A literature review was conducted of all previously published associations between common germline variants and three survival outcomes: breast cancer-specific survival, overall survival and disease-free survival. All associations that reached the nominal significance level of P value <0.05 were included. Single nucleotide polymorphisms that had been previously reported as nominally associated with at least one survival outcome were evaluated in the pooled analysis of over 37,000 breast cancer cases for association with breast cancer-specific survival. Previous associations were evaluated using a one-sided test based on the reported direction of effect.

RESULTS

Fifty-six variants from 45 previous publications were evaluated in the meta-analysis. Fifty-four of these were evaluated in the full set of 37,954 breast cancer cases with 2,900 events and the two additional variants were evaluated in a reduced sample size of 30,000 samples in order to ensure independence from the previously published studies. Five variants reached nominal significance (P <0.05) in the pooled GWAS data compared to 2.8 expected under the null hypothesis. Seven additional variants were associated (P <0.05) with ER-positive disease.

CONCLUSIONS

Although no variants reached genome-wide significance (P <5 x 10(-8)), these results suggest that there is some evidence of association between candidate common germline variants and breast cancer prognosis. Larger studies from multinational collaborations are necessary to increase the power to detect associations, between common variants and prognosis, at more stringent significance levels.

Genetic polymorphisms in estrogen-related genes and the risk of breast cancer among Han Chinese women

Exposure to high levels of estrogen is considered an important risk factor for susceptibility to breast cancer. Common polymorphisms in genes that affect estrogen levels may be associated with breast cancer risk, but no comprehensive study has been performed among Han Chinese women. In the present study, 32 single-nucleotide polymorphisms (SNPs) in estrogen-related genes were genotyped using the MassARRAY IPLEX platform in 1076 Han Chinese women. Genotypic and allelic frequencies were compared between case and control groups. Unconditional logistic regression was used to assess the effects of SNPs on breast cancer risk. Associations were also evaluated for breast cancer subtypes stratified by estrogen receptor (ER) and progesterone receptor (PR) status. Case-control analysis showed a significant relation between heterozygous genotypes of rs700519 and rs2069522 and breast cancer risk (OR = 0.723, 95% CI = 0.541-0.965, p = 0.028 and OR = 1.500, 95% CI = 1.078-2.087, p = 0.016, respectively). Subgroup comparisons revealed that rs2446405 and rs17268974 were related to ER status, and rs130021 was associated with PR status. Our findings suggest that rs700519 and rs2069522 are associated with susceptibility to breast cancer among the Han Chinese population and have a cumulative effect with three other identified SNPs. Further genetic and functional studies are needed to identify additional SNPs, and to elucidate the underlying molecular mechanisms.

A potentially functional variant in the serotonin transporter gene is associated with premenopausal and perimenopausal hot flashes

OBJECTIVE

An increase in the use of selective serotonin reuptake inhibitors (SSRIs) and/or serotonin-norepinephrine reuptake inhibitors (SNRIs) to relieve menopausal hot flashes (HFs) has been observed recently. However, response to them has been heterogeneous. We hypothesized that this heterogeneity might be partially attributed to genetic variations in genes encoding the serotonin and/or norepinephrine transporters (SLC6A4 and SLC6A2). As a first step in testing the role of genetics in response to SSRIs/SNRIs, we examined the association between HFs and genetic variants within these two genes.

METHODS

We tested 29 haplotype-tagging single nucleotide polymorphisms within SLC6A4 and SLC6A2 for their association with HFs separately for European-American (396 cases and 392 controls) and African-American (125 cases and 81 controls) premenopausal and perimenopausal women.

RESULTS

We found that the minor allele of SLC6A4_rs11080121 was associated with protection against HFs (odds ratio, 0.75; 95% CI, 0.60-0.94) only in European-American women. Bioinformatics analyses indicated that rs11080121 is fully correlated with rs1042173 in the 3' untranslated region of SLC6A4. The minor allele of rs1042173 seems to disrupt a conserved binding site for hsa-miR-590-3p microRNA.

CONCLUSIONS

Disruption of a microRNA binding site leads to higher expression of SLC6A4, higher expression of SLC6A4 leads to depletion of serotonin in synaptic clefts, and depletion of serotonin triggers the presynaptic autoreceptor feedback mechanism to produce more serotonin, which is protective against HFs. This is the first study to test the association between HFs in both European-American and African-American premenopausal and perimenopausal women and genetic variants in two neurotransmitter transporter genes, SLC6A2 and SLC6A4. This information can be used in tailoring the pharmaceutical use of SSRIs/SNRIs for HF relief.

Associations between CYP19A1 polymorphisms, Native American ancestry, and breast cancer risk and mortality: the Breast Cancer Health Disparities Study

The cytochrome p450 family 19 gene (CYP19A1) encodes for aromatase, which catalyzes the final step in estrogen biosynthesis and conversion of androgens to estrogens. Genetic variation in CYP19A1 is linked to higher circulating estrogen levels and increased aromatase expression. Using data from the Breast Cancer Health Disparities Study, a consortium of three population-based case-control studies in the United States (n = 3,030 non-Hispanic Whites; n = 2,893 Hispanic/Native Americans (H/NA) and Mexico (n = 1,810), we examined influence of 25 CYP19A1 tagging single-nucleotide polymorphisms (SNPs) on breast cancer risk and mortality, considering NA ancestry. Odds ratios (ORs) and 95 % confidence intervals (CIs) and hazard ratios estimated breast cancer risk and mortality. After multiple comparison adjustment, none of the SNPs were significantly associated with breast cancer risk or mortality. Two SNPs remained significantly associated with increased breast cancer risk in women of moderate to high NA ancestry (≥29 %): rs700518, ORGG 1.36, 95 % CI 1.11-1.67 and rs11856927, ORGG 1.35, 95 % CI 1.05-1.72. A significant interaction was observed for rs2470144 and menopausal status (p adj = 0.03); risk was increased in postmenopausal (ORAA 1.22, 95 % CI 1.05-1.14), but not premenopausal (ORAA 0.78, 95 % CI 0.64-0.95) women. The absence of an overall association with CYP19A1 and breast cancer risk is similar to previous literature. However, this analysis provides support that variation in CYP19A1 may influence breast cancer risk differently in women with moderate to high NA ancestry. Additional research is warranted to investigate the how variation in an estrogen-regulating gene contributes to racial/ethnic disparities in breast cancer.

Genetic polymorphisms of ESR1, ESR2, CYP17A1, and CYP19A1 and the risk of breast cancer: a case control study from North India

Estrogen is a key driver of breast cancer and genes involved in its signaling and biosynthesis are crucial in breast cancer progression. In this study, we investigated the role of estrogen signaling and synthesis related genes polymorphism in susceptibility to breast cancer risk in North India population in a case-control approach. We examined the association of single nucleotide polymorphism (SNP) in estrogen receptors, ESR1 (rs2234693) and ESR2 (rs2987983); estrogen biosynthesis enzymes, CYP17A1 (rs743572); and aromatase, CYP19A1 (rs700519) with breast cancer risk. Cases (n = 360) were matched to controls (n = 360) by age, sex, ethnicity, and geographical location. Results provided evidence that all the genetic variants were significantly associated with breast cancer risk among North Indian women. Furthermore, on performing stratified analysis between breast cancer risk and different clinicopathological characteristics, we observed strong associations for menopausal status, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) status, clinical stage, and histological grade. Our results suggest that these genes could be used as molecular markers to assess breast cancer susceptibility and predicting prognosis in North India population.

Analysis of the rs10046 polymorphism of aromatase (CYP19) in premenopausal onset of human breast cancer

The CYP19 gene encodes aromatase, an enzyme catalyzing the conversion of androgens to estrogens. Studies analyzing associations between single nucleotide polymorphisms in CYP19 and breast cancer risk have shown inconsistent results. The rs10046 polymorphism is located in the 3′ untranslated region of the CYP19 gene, but the influence of this polymorphism on breast cancer risk is unclear. In this study, we investigated the impact of rs10046 SNP on breast cancer risk, age at onset and association with clinical characteristics in an Austrian population of 274 breast cancer patients and 253 controls. The results show that a significantly increased fraction of patients with the TT genotype of rs10046 develop breast cancer under the age of 50 (41.8% of TT patients, compared to 26.6% of C carriers; p = 0.018, Chi-square test). No rs10046 genotypes were significantly associated with increased breast cancer risk or patient characteristics other than age at onset. These results suggest that the rs10046 polymorphism in the CYP19 gene may have an effect on breast cancer susceptibility at an age under 50 in the investigated population.

Genetic ancestry and risk of mortality among U.S. Latinas with breast cancer

Multiple studies have reported that Latina women in the United States are diagnosed with breast cancer at more advanced stages and have poorer survival than non-Latina White women. However, Latinas are a heterogeneous group with individuals having different proportions of European, Indigenous American, and African genetic ancestry. In this study, we evaluated the association between genetic ancestry and survival after breast cancer diagnosis among 899 Latina women from the San Francisco Bay area. Genetic ancestry was estimated from single-nucleotide polymorphisms from an Affymetrix 6.0 array and we used Cox proportional hazards models to evaluate the association between genetic ancestry and breast cancer-specific mortality (tests were two-sided). Women were followed for an average of 9 years during which 75 died from breast cancer. Our results showed that Individuals with higher Indigenous American ancestry had increased risk of breast cancer-specific mortality [HR: 1.57 per 25% increase in Indigenous American ancestry; 95% confidence interval (CI): 1.08-2.29]. Adjustment for demographic factors, tumor characteristics, and some treatment information did not explain the observed association (HR: 1.75; 95%CI, 1.12-2.74). In an analysis in which ancestry was dichotomized, the hazard of mortality showed a two-fold increase when comparing women with less than 50% Indigenous American ancestry to women with 50% or more [HR, 1.89, 95%CI, 1.10-3.24]. This was also reflected by Kaplan-Meier survival estimates (P for log-rank test of 0.003). Overall, results suggest that genetic factors and/or unmeasured differences in treatment or access to care should be further explored to understand and reduce ethnic disparities in breast cancer outcomes.

CYP19 genetic polymorphism haplotype AASA is associated with a poor prognosis in premenopausal women with lymph node-negative, hormone receptor-positive breast cancer

Given the critical role of CYP19 in estrogen synthesis, we investigated the influence of CYP19 gene polymorphisms on the clinical outcome of lymph node- (LN-) negative, hormone receptor- (HR-) positive early breast cancers. Genotyping for the CYP19 polymorphisms rs4646 (A/C), rs1065779 (A/C), CYP19 (TTTA)n (short allele/long (S/L) allele using the 7 TTTA repeat polymorphism as the cut-off), and rs1870050 (A/C) was performed on 296 patients with LN-negative, HR-positive breast cancers. All patients received adjuvant hormonal therapy. Associations were examined between these 4 genotypes and 6 common haplotypes of CYP19 and distant disease-free survival (DDFS), disease-free survival (DFS), and overall survival (OS). Patients were divided into the 6 subhaplotypes of CCLA (41.1%), AASA (17.1%), CASA (11.9%), CCLC (8.9%), CCSA (7.5%), AASC (8.9%), and others (4.6%). In premenopausal patients, haplotype AASA was significantly associated with a poor DDFS (adjusted hazard ratio (aHR), 3.3; P = 0.001), DFS (aHR, 2.5; P = 0.0008), and OS (aHR, 2.9; P = 0.0004) after adjusting for age, tumor size, tumor grade, estrogen receptor status, progesterone receptor status, chemotherapy, pathology, adjuvant hormone therapy, menopausal status, and radiotherapy. Furthermore, haplotype AASA remained a negative prognostic factor for premenopausal patients receiving adjuvant chemotherapy in terms of DDFS (aHR, 4.5; P = 0.0005), DFS (HR, 3.2; P = 0.003), and OS (HR, 6.4; P = 0.0009). However, in postmenopausal patients, haplotype AASA was not associated with a poor prognosis, whereas the AASC haplotype was significantly associated with a poor DFS (aHR, 3.1; P = 0.03) and OS (aHR, 4.4; P = 0.01). Our results indicate that, in patients with LN-negative, HR-positive breast cancers, genetic polymorphism haplotype AASA is associated with poor survival of premenopausal women but does not affect survival of postmenopausal women.

A polymorphism at the 3'-UTR region of the aromatase gene is associated with the efficacy of the aromatase inhibitor, anastrozole, in metastatic breast carcinoma

Estrogen-related genes and the fat mass and obesity-associated (FTO) gene play a critical role in estrogen metabolism, and those polymorphisms are associated with a poor prognosis in breast cancer. However, little is known about the association between these polymorphisms and the efficacy of anastrozole. The aim was to investigate the impact of the genetic polymorphisms, CYP19A1, 17-β-HSD-1 and FTO, on the response to anastrozole in metastatic breast carcinoma (MBC) and to evaluate the impact of those polymorphisms on various clinicopathologic features. Two-hundred seventy-two women with hormone receptor-positive MBC treated with anastrozole were identified retrospectively. DNA was extracted from peripheral blood and genotyped for five variants in three candidate genes. Time to progression was improved in patients carrying the variant alleles of rs4646 when compared to patients with the wild-type allele (16.40 months versus 13.52 months; p = 0.049). The rs4646 variant alleles were significantly associated with longer overall survival (37.3 months versus 31.6 months; p = 0.007). This relationship was not observed with the rs10046, rs2830, rs9926298 and rs9939609 polymorphisms. The findings of this study indicate that rs4646 polymorphism in the CYP19A1 gene may serve as a prognostic maker of the response to anastrozole in patients with MBC who are treated with anastrozole.

The relationship between eight GWAS-identified single-nucleotide polymorphisms and primary breast cancer outcomes

BACKGROUND

Several single-nucleotide polymorphisms (SNPs) associated with breast cancer risk have been identified through genome-wide association studies (GWAS). We investigated whether eight risk SNPs identified in GWAS were associated with breast cancer disease-free survival (DFS) and overall survival (OS) rates.

PATIENTS AND METHODS

A cohort of 739 white women with early-stage breast cancer was genotyped for eight GWAS-identified SNPs (rs2981582, rs1219648 [FGFR2], rs3803662, rs12443621, rs8051542 [TOX3], rs999737 [RAD51L1], rs6504950 [17q23], and rs4973768 [3p24]). Relationships between SNPs and breast cancer outcomes were evaluated using Cox proportional hazard regression models. The cumulative effects of SNPs on breast cancer outcomes were assessed by computing the number of at-risk genotypes.

RESULTS

At a median follow-up of 121 months (range: 188-231 months) for survivors, 237 deaths (32%) and 186 breast cancer events (25%) were identified among the 739 patients. After adjusting for age, clinical stage, and treatment, rs12443621 (16q12; p = .03) and rs6504950 (17q23; p = .008) were prognostic for OS but not DFS. A higher risk for death was also found in the multivariable analysis of patients harboring three or four at-risk genotypes of the GWAS SNPs compared to patients carrying two or less at-risk genotypes (hazard ratio: 1.60, 95% confidence interval: 1.23-2.24; p = .0008).

CONCLUSION

The study results suggest that previously identified breast cancer risk susceptibility loci, rs12443621 (16q12) and rs6504950 (17q23), may influence breast cancer prognosis or comorbid conditions associated with overall survival. The precise molecular mechanisms through which these risk SNPs, as well as others that were not included in the analysis, influence clinical outcomes remain to be determined.

Associations between aromatase CYP19 rs10046 polymorphism and breast cancer risk: from a case-control to a meta-analysis of 20,098 subjects

Lifetime exposure to estrogen is a factor that plays an important role in the pathogenesis and progression of breast cancer. Genetic variants in genes of the biosynthesis and metabolism of estrogen have been associated with breast cancer risk. Among them, the CYP19 gene encodes for aromatase, the enzyme that catalyzes the conversion of androgens to estrogens. The rs10046 polymorphism on the CYP19 gene has been related to levels of circulating estradiol and to the estradiol/testosterone ratio. To date, epidemiological studies of rs10046 have been performed in different populations with contradictory results. In the present study, we have conducted a case-control analysis (522 cases and 1221 controls) in a Spanish population. Furthermore, we have performed a meta-analysis including 20,098 subjects (7,998 cases and 12,100 controls) to summarize the data available for rs10046 and breast cancer risk. An odds ratio (OR) with a 95% confidence interval (CI) was applied to assess the association. The results of our case-control study show an association between the carriers of at least one C allele (dominant model) and breast cancer risk (OR = 1.29, 95% CI 1.01-1.66, p-value = 0.038). The meta-analysis shows no significant association with breast cancer risk in any of the genetic models tested. The analysis by ethnic subgroups also failed to produce associations. The evaluation of heterogeneity, influence analysis, and publication bias confirms the reliability of the analysis. We can conclude that the rs10046 polymorphism on CYP19 by itself does not constitute breast cancer risk. We cannot, however, reject the possibility that it could contribute (interact), together with other genetic variants, to modify the circulating levels of estradiol.

Pharmacogenetics of aromatase inhibitors

Aromatase inhibitors (AIs) are an important class of endocrine drugs used in the treatment of early and advanced breast cancer in postmenopausal women. A number of studies have taken candidate approaches to assess the role of variants in genes encoding enzymes important in AI metabolism, notably CYP19A1 (aromatase), in AI response. These studies have shown conflicting, but interesting, results suggesting that CYP19A1 variants may be important in both the efficacy and toxicity of AIs. A recent genome-wide association study has identified a variant, creating an estrogen response element in TCL1A, which is associated with an increased risk of the musculoskeletal side effects associated with AI use. As breast cancer incidence increases, predictive biomarkers of response to AIs will become more important to ensure the most effective use of endocrine treatments.

Polymorphisms of CYP19A1 and response to aromatase inhibitors in metastatic breast cancer patients

Single nucleotide polymorphisms (SNPs) in the gene encoding aromatase (CYP19A1) have been associated with differential benefit from letrozole treatment in metastatic breast cancer (mBC) patients, but validation is lacking. The aim was to investigate whether polymorphic variation of CYP19A1 and enzymes involved in estrogen and aromatase inhibitors (AIs) metabolism are associated with efficacy of AIs. 308 Women with estrogen-receptor-positive metastatic mBC treated with a third-generation AI were identified retrospectively. DNA was extracted from archival formalin-fixed paraffin embedded tumors and genotyped for 71 variants in 16 candidate genes, including CYP19A1. Time to treatment failure (TTF) was significantly improved in patients carrying the minor (T) allele of rs4775936 when compared to patients with the reference allele [HR = 0.79 per T allele (0.66-0.95); P = 0.012]. Patients with >7 TTTA repeats on either allele of CYP19A1 intron 4 had a lower risk of failure than those with a smaller repeat size [HR = 0.84 per >7 TTTA repeats (0.7-0.99); P = 0.04]. However, importantly in multivariate analysis, adjusting for the number of disease sites; disease-free interval from diagnosis to first recurrence, grade at diagnosis and first recurrence type neither variant maintained independent predictive significance. None of the 56 SNPs analyzed as an exploratory set showed significant association with TTF. Variants in CYP19A1 or other selected genes associated with AI metabolism were not independently associated with improved AI efficacy and emphasize the importance in pharmacogenetic studies of considering genetic biomarkers in the context of relevant prognostic factors.

Positive association of polymorphisms in estrogen biosynthesis gene, CYP19A1, and metabolism, GST, in breast cancer susceptibility

PURPOSE

This case-control study was conducted in order to evaluate the potential role of polymorphic genes encoding enzymes involved in estrogen biosynthesis (CYP19A1) and metabolism (GSTM1, GSTT1, and GSTP1), and their action in modulating individual susceptibility to breast cancer.

METHODS

Genomic DNA was extracted from blood samples of 101 patients with histological diagnosis of breast cancer and 121 healthy women. Genotyping analyses of CYP19A1 codon 39 Trp/Arg (T/C), GSTM1 and GSTT1 homozygous deletions, and GSTP1 codon 105 Ile/Val (A/G) were performed by polymerase chain reaction-based methods.

RESULTS

Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated by unconditional logistic regression. Significant statistical association of the TC/CC genotypes combined with breast cancer risk was found, with reference to TT genotype (OR=1.770; 95% CI=1.036-3.024; p=0.036). Also, CYP19A1 arginine allele in homozygosity or heterozygosity (TC/CC) was associated with a significant increased risk for breast cancer when associated to GSTM1 null genotype (OR=6.158; 95% CI=2.676-14.171; p<0.001) and GSTT1 null genotype (OR=4.870; 95% CI=2.216-10.700; p<0.001). The three-way combination of CYP19A1 TC/CC, GSTM1 null, and GSTT1 null polymorphism was related with significant increased risk for breast cancer (OR=11.429; 95% CI=3.590-36.385; p<0.001). Valine alleles compared with isoleucine alleles in codon 105 in GSTP1, in combination with CYP19A1 genotypes, were not associated with an increase of breast cancer development.

CONCLUSIONS

Our results suggest that the effect of CYP19A1 T/C polymorphism in susceptibility to breast cancer development can be modulated by the presence of GSTM1 and GSTT1, but not GSTP1.

A non-synonymous coding change in the CYP19A1 gene Arg264Cys (rs700519) does not affect circulating estradiol, bone structure or fracture

Background

The biosynthesis of estrogens from androgens is catalyzed by aromatase P450 enzyme, coded by the CYP19A1 gene on chromosome 15q21.2. Genetic variation within the CYP19A1 gene sequence has been shown to alter the function of the enzyme. The aim of this study is to investigate whether a non-synonymous Arg264Cys (rs700519) single nucleotide polymorphism (SNP) is associated with altered levels of circulating estradiol, areal bone mineral density or fracture.

Methods

This population- based study of 1,022 elderly Caucasian women (mean age 74.95 ± 2.60 years) was genotyped for the rs700519 SNP were analyzed to detect any association with endocrine and bone phenotypes.

Results

The genotype frequencies were 997 wildtype (97.6%), 24 heterozygous (2.3%) and 1 homozygous (0.1%). When individuals were grouped by genotype, there was no association between the polymorphism and serum estradiol (wildtype 27.5 ± 16.0; variants 31.2 ± 18.4, P = 0.27). There was also no association seen on hip bone mineral density (wildtype 0.81 ± 0.12; 0.84 ± 0.14 for variants, P = 0.48) or femoral neck bone mineral density (0.69 ± 0.10 for wildtype; 0.70 ± 0.12 for variants, P = 0.54) before or after correction of the data with age, height, weight and calcium therapy. There were also no associations with quantitative ultrasound measures of bone structure (broadband ultrasound attenuation, speed of sound and average stiffness).

Conclusions

In a cohort of 1,022 elderly Western Australian women, the presence of Arg264Cys (rs700519) polymorphism was not found to be associated with serum estradiol, bone structure or phenotypes.

Single nucleotide polymorphisms of CYP19A1 predict clinical outcomes and adverse events associated with letrozole in patients with metastatic breast cancer

PURPOSE

The CYP19A1 gene encodes the aromatase enzyme involved in the peripheral conversion of androgen to estrogen. We evaluated the efficacy of the aromatase inhibitor letrozole in patients with metastatic breast cancer (MBC) as related to DNA polymorphisms of CYP19A1.

PATIENTS AND METHODS

One hundred and nine patients with hormone receptor-positive MBC were treated with letrozole alone or in combination with a GnRH agonist. DNA was isolated from peripheral blood and genotyped for 46 single nucleotide polymorphisms (SNPs) of CYP19A1.

RESULTS

Among 46 SNPs examined, rs700518, rs10459592, and rs4775936 were significantly associated with higher clinical benefit rate (CBR, CR + PR + SD ≥ 6 months) (OR = 2.61 [95% CI; 1.13-6.03], P = 0.025; OR = 2.45 [95% CI; 1.06-5.65], P = 0.036; OR = 2.60 [95% CI; 1.12-6.02], P = 0.026, respectively). Median time to progression (TTP) was improved without statistical significance in patients having an over-dominant form of rs700518. In haplotype analysis, the specific haplotypes M_1_3 and M_2_1 showed a strong association with CBR (OR = 3.37 [95% CI 1.43-7.90], P = 0.005; OR = 5.33 [95% CI 1.63-17.45], P = 0.006, respectively). There was a statistically significant difference in TTP in patients with haplotype M_1_3 (5.61 months [95% CI 0.00-11.45] vs. 11.08 months [95% CI 6.75-15.42], P = 0.040) and M_2_1 (7.31 months [95% CI 4.63-9.99] vs. 12.95 months [95% CI 9.27-16.63], P = 0.038). Haplotypes M_3_5 (OR = 11.25 [95% CI 1.17-108.28], P = 0.01) and M_5_3 (OR = 4.12, [95% CI 1.09-15.61], P = 0.03) were associated with side effects of arthralgia and hot flash, respectively.

CONCLUSION

The genetic variations of CYP19A1 were significantly associated with clinical efficacy, suggesting potential predictive markers for letrozole treatment in patients with metastatic breast cancer.

A polymorphism at the 3'-UTR region of the aromatase gene defines a subgroup of postmenopausal breast cancer patients with poor response to neoadjuvant letrozole

BACKGROUND

Aromatase (CYP19A1) regulates estrogen biosynthesis. Polymorphisms in CYP19A1 have been related to the pathogenesis of breast cancer (BC). Inhibition of aromatase with letrozole constitutes the best option for treating estrogen-dependent BC in postmenopausal women. We evaluate a series of polymorphisms of CYP19A1 and their effect on response to neoadjuvant letrozole in early BC.

METHODS

We analyzed 95 consecutive postmenopausal women with stage II-III ER/PgR [+] BC treated with neoadjuvant letrozole. Response to treatment was measured by radiology at 4th month by World Health Organization (WHO) criteria. Three polymorphisms of CYP19A1, one in exon 7 (rs700519) and two in the 3'-UTR region (rs10046 and rs4646) were evaluated on DNA obtained from peripheral blood.

RESULTS

Thirty-five women (36.8%) achieved a radiological response to letrozole. The histopathological and immunohistochemical parameters, including hormonal receptor status, were not associated with the response to letrozole. Only the genetic variants (AC/AA) of the rs4646 polymorphism were associated with poor response to letrozole (p = 0.03). Eighteen patients (18.9%) reported a progression of the disease. Those patients carrying the genetic variants (AC/AA) of rs4646 presented a lower progression-free survival than the patients homozygous for the reference variant (p = 0.0686). This effect was especially significant in the group of elderly patients not operated after letrozole induction (p = 0.009).

CONCLUSIONS

Our study reveals that the rs4646 polymorphism identifies a subgroup of stage II-III ER/PgR [+] BC patients with poor response to neoadjuvant letrozole and poor prognosis. Testing for the rs4646 polymorphism could be a useful tool in order to orientate the treatment in elderly BC patients.

Common germline polymorphisms in COMT, CYP19A1, ESR1, PGR, SULT1E1 and STS and survival after a diagnosis of breast cancer

Although preliminary evidence suggests that germline variation in genes involved in steroid hormone metabolism may alter breast cancer prognosis, this has not been systematically evaluated. We examined associations between germline polymorphisms in 6 genes involved in the steroid hormone metabolism and signaling pathway (COMT, CYP19A1, ESR1, PGR, SULT1E1, STS) and survival among women with breast cancer participating in SEARCH, a population-based case-control study. Blood samples from up to 4,470 women were genotyped for 4 possible functional SNPs in CYP19A1 and 106 SNPs tagging the common variation in the remainder of the genes. The genotypes of each polymorphism were tested for association with survival after breast cancer diagnosis using Cox regression analysis. Significant evidence of an association was observed for a COMT polymorphism (rs4818 p = 0.016) under the codominant model. This SNP appeared to fit a dominant model better (HR = 0.80 95% CI: 0.69-0.95, p = 0.009); however, the result was only marginally significant after permutation analysis adjustment for multiple hypothesis tests (p = 0.047). To further evaluate this finding, somatic expression microarray data from 8 publicly available datasets were used to test the association between survival and tumor COMT gene expression; no statistically significant associations were observed. A correlated SNP in COMT, rs4860, has recently been associated with breast cancer prognosis in Chinese women in a dominant model. These results suggest that COMT rs4818, or a variant it tags, is associated with breast cancer prognosis. Further study of COMT and its putative association with breast cancer prognosis is warranted.

Association of genetic variations in aromatase gene with serum estrogen and estrogen/testosterone ratio in Chinese elderly men

BACKGROUND

Single nucleotide polymorphism (SNP) rs2470152 of the gene CYP19A1 is associated with serum estradiol (E2) levels in Caucasian men. However, it remains to be verified if rs2470152 is the sole determinant accounting for the association. We determined whether 2 CYP19A1 SNPs tagging different haploblocks (rs2470152 and rs2899470) are associated with sex steroid levels in Chinese men.

METHOD

Serum sex steroid level including E2, estrone (E1) and testosterone (T), of 1402 Chinese men aged > or = 65 years were analyzed. Genotyping of the two CYP19A1 SNPs was performed using Tm-shift allele-specific PCR.

RESULTS

SNP rs2899470 was significantly associated with serum E2, E1 levels and E2/T ratio (p<0.001). However, SNP rs2470152 was only modestly associated with E2/T ratio (p=0.023). Analysis of haplotype showed a significant association between C-G, T-T haplotype with serum E2/T ratio (p=0.019 and p=1 x 10(-5), respectively). Similarly, E2 levels was also associated the T-T and T-G haplotypes (p=1 x 10(-5)).

CONCLUSION

The genetic variation of CYP19A1 was associated with circulating estrogen levels in Chinese elderly men. In addition, it revealed that haplotype of rs2899470 and rs2470152, rather than rs2899470 alone, was a better indicator for the serum E2/T ratio and E2 levels.

NAD(P)H:quinone oxidoreductase 1 Arg139Trp and Pro187Ser polymorphisms imbalance estrogen metabolism towards DNA adduct formation in human mammary epithelial cells

Estrogens (estrone, E(1); estradiol, E(2)) are oxidized in the breast first to catechols and then to form two ortho-quinones (E(1/2)-3,4-Q) that react with DNA to form depurinating adducts, which lead to mutations associated with breast cancer. NAD(P)H:quinone oxidoreductase 1 (NQO1) reduces these quinones back to catechols, and thus may protect against this mechanism. We examined whether the inheritance of two polymorphic variants of NQO1 (Pro187Ser or Arg139Trp) would result in poor reduction of E(1/2)-3,4-Q in normal human mammary epithelial cells (MCF-10F) and increased depurinating adduct formation. An isogenic set of stably transfected normal human breast epithelial cells (MCF-10F) that express a truncated (135Stop), the wild-type, the 139Trp variant or the 187Ser variant of human NQO1 cDNA was constructed. MCF-10F cells showed a low endogenous NQO1 activity. NQO1 expression was examined by RT-PCR and Western blotting, and catalytic activity of reducing E(2)-3,4-Q to 4-hydroxyE(1/2) and associated changes in the levels of quinone conjugates (4-methoxyE(1/2), 4-OHE(1/2)-2-glutathione, 4-OHE(1/2)-2-Cys and 4-OHE(1/2)-2-N-acetylcysteine) and depurinating DNA adducts (4-OHE(1/2)-1-N3Ade and 4-OHE(1/2)-1-N7Gua) were examined by HPLC with electrochemical detection, as well as by ultra-performance liquid chromatography with tandem mass spectrometry. The polymorphic variants transcribed comparably to the wild-type NQO1, but produced approximately 2-fold lower levels of the protein, suggesting that the variant proteins may become degraded. E(1/2)-3,4-Q toxicity to MCF-10F cells (IC50=24.74 microM) was increased (IC50=3.7 microM) by Ro41-0960 (3 microM), a catechol-O-methyltransferase inhibitor. Cells expressing polymorphic NQO1 treated with E(2)-3,4-Q with or without added Ro41-0960, showed lower ability to reduce the quinone ( approximately 50% lower levels of the free catechols and approximately 3-fold lower levels of methylated catechols) compared to the wild-type enzyme. The increased availability of the quinones in these cells did not result in greater glutathione conjugation. Instead, there was increased (2.5-fold) formation of the depurinating DNA adducts. Addition of Ro41-0960 increased the amounts of free catechols, quinone conjugates and depurinating DNA adducts. NQO1 polymorphic variants (Arg139Trp and Pro187Ser) were poor reducers of estrogen-3,4-quinones, which caused increased formation of estrogen-DNA adduct formation in MCF-10F cells. Therefore, the inheritance of these NQO1 polymorphisms may favor the estrogen genotoxic mechanism of breast cancer.

Sex steroid metabolism polymorphisms and mammographic density in pre- and early perimenopausal women

Introduction

We examined the association between mammographic density and single-nucleotide polymorphisms (SNPs) in genes encoding CYP1A1, CYP1B1, aromatase, 17β-HSD, ESR1, and ESR2 in pre- and early perimenopausal white, African-American, Chinese, and Japanese women.

Methods

The Study of Women's Health Across the Nation is a longitudinal community-based cohort study. We analyzed data from 451 pre- and early perimenopausal participants of the ancillary SWAN Mammographic Density study for whom we had complete information regarding mammographic density, genotypes, and covariates. With multivariate linear regression, we examined the relation between percentage mammographic breast density (outcome) and each SNP (primary predictor), adjusting for age, race/ethnicity, parity, cigarette smoking, and body mass index (BMI).

Results

After multivariate adjustment, the CYP1B1 rs162555 CC genotype was associated with a 9.4% higher mammographic density than the TC/TT genotype (P = 0.04). The CYP19A1 rs936306 TT genotype was associated with 6.2% lower mammographic density than the TC/CC genotype (P = 0.02). The positive association between CYP1A1 rs2606345 and mammographic density was significantly stronger among participants with BMI greater than 30 kg/m² than among those with BMI less than 25 kg/m² (P_interaction = 0.05). Among white participants, the ESR1 rs2234693 CC genotype was associated with a 7.0% higher mammographic density than the CT/TT genotype (P = 0.01).

Conclusions

SNPs in certain genes encoding sex steroid metabolism enzymes and ESRs were associated with mammographic density. Because the encoded enzymes and ESR1 are expressed in breast tissue, these SNPs may influence breast cancer risk by altering mammographic density.

Role of genetic polymorphisms and ovarian cancer susceptibility

The value of identifying women with an inherited predisposition to epithelial ovarian cancer has become readily apparent with the identification of the BRCA1, and BRCA2 genes. Women who inherit a deleterious mutation in either of these genes have a very high lifetime risk of ovarian cancer (10-60%) and to some extent, increased risks of fallopian tube and peritoneal cancer. These highly lethal cancers are almost completely prevented by prophylactic salpingoophorectomy. BRCA1/2 mutation testing has become the accepted standard of care in families with a strong history of breast and/or ovarian cancer. This approach has the potential to reduce ovarian cancer mortality by about 10%. Although the ability to perform genetic testing for BRCA1 and 2 represents a significant clinical advance, the frequency of mutations in these high penetrance ovarian cancer susceptibility genes is low in most populations. There is evidence to suggest that ovarian cancer susceptibility might be affected by common low penetrance genetic polymorphisms like it was shown for several common disorders like diabetes or breast cancer. Although such polymorphisms would increase risk to a lesser degree, they could contribute to the development of a greater proportion of ovarian cancers by virtue of their higher frequencies in the population. It has been shown that the most powerful approach to studying low penetrance genes is an association study rather than a linkage study design. This review describes the efforts that have been made in this field by individual case-control studies and through multi-center collaborations as part of international consortia such as the Ovarian Cancer Association Consortium (OCAC).

Genetic variation in CYP19A1 and risk of breast cancer and fibrocystic breast conditions among women in Shanghai, China

CYP19A1 encodes for aromatase, which irreversibly converts androgens to estrogens; variation in this gene may affect individual susceptibility to breast cancer and other sex hormone-dependent outcomes. In a case-control study nested within a breast self-examination trial conducted in China, we examined whether CYP19A1 polymorphisms (rs1870049, rs1004982, rs28566535, rs936306, rs11636639, rs767199, rs4775936, rs11575899, rs10046, and rs4646) were associated with risk of breast cancer and fibrocystic breast conditions. Cases were diagnosed with breast cancer (n = 614) or fibrocystic breast conditions (n = 465) during 1989 to 2000. Controls were free of breast disease during the same period (n = 879). Presence of proliferative changes within the extratumoral tissue of women with breast cancer and the lesions of women with fibrocystic conditions only was assessed. None of the polymorphisms were associated with overall risk of breast cancer or fibrocystic breast conditions. Differences in breast cancer risk, however, were observed by proliferation status. The risk of breast cancer with (but not without) proliferative fibrocystic conditions was increased among women homozygous for the minor allele of rs1004982 (C), rs28566535 (C), rs936306 (T), and rs4775936 (C) relative to those homozygous for the major allele [age-adjusted odds ratios (95% confidence intervals), 2.19 (1.24-3.85), 2.20 (1.27-3.82), 1.94 (1.13-3.30), and 1.95 (1.07-3.58), respectively]. Also, haplotypes inferred using all polymorphisms were not associated with overall risk of either outcome, although some block-specific haplotypes were associated with an increased risk of breast cancer with concurrent proliferative fibrocystic conditions. Our findings suggest that CYP19A1 variation may enhance breast cancer development in some women, but further confirmation is warranted.

Association of mitochondrial DNA displacement loop (CA)n dinucleotide repeat polymorphism with breast cancer risk and survival among Chinese women

Mitochondrial genome alternations may be involved in carcinogenesis. The noncoding region of the mitochondrial DNA (mtDNA) displacement loop (D-loop) has emerged as a mutational hotspot. Using data from a population-based case-control study conducted among Chinese women in Shanghai, we evaluated associations of breast cancer risk and survival with the mtDNA D-loop (CA)(n) dinucleotide repeat polymorphism. Included in the study were 1,058 cases and 1,129 age frequency-matched community controls that participated in the Shanghai Breast Cancer Study between 1996 and 1998. Breast cancer patients were followed to determine intervals of overall survival and disease-free survival. Overall, there was no association between the mtDNA D-loop (CA)(n) repeat polymorphism and breast cancer risk. Patients with multiple alleles of the mtDNA D-loop (CA)(n) polymorphism (heteroplasmy) had significantly poorer disease-free survival than those with one allele of the mtDNA D-loop (CA)(n) polymorphism (hazard ratio 1.62; 95% confidence interval, 1.16-2.26). These results suggest that the mtDNA D-loop (CA)(n) repeat polymorphism may be associated with breast cancer survival. Additional studies with a larger sample size are warranted.

Association of genetic polymorphisms in CYP19A1 and blood levels of sex hormones among postmenopausal Chinese women

OBJECTIVE

Circulating estrogen levels have been related to the risk of several female cancers. Blood levels of estrogen are controlled by estrogen synthesis enzymes. Genetic variation of estrogen genes thus may influence circulating estrogen levels. We investigated the associations of genetic polymorphisms in CYP19A1, a critical gene involved in estrogen synthesis, with plasma levels of sex hormones among postmenopausal Chinese women.

METHODS

Included in this study were 345 postmenopausal community controls from a population-based case-control study conducted in Shanghai. Fasting blood samples from those women were measured for blood estradiol, estrone, estrone sulfate, and testosterone. A total of 19 genetic polymorphisms in CYP19A1 were genotyped using ABI7900 or PCR-restriction fragment length polymorphism methods. Differences in plasma levels of hormones by genotype were examined using variance analysis.

RESULT

The geometric means of plasma levels of estradiol, estrone, estrone sulfate, and testosterone were 10.1, 16.8, 969.0, and 202.9 pg/ml, respectively, for this study population. We found that plasma levels of estrone were associated with rs28566535 (P=0.0180), rs730154 (P=0.0141), and rs936306 (P=0.0274) in block 2. In the same block, the haplotype CGCTA was related to level of estrone (P=0.0064). Single nucleotide polymorphism rs1902584 in block 1 was associated with estradiol only in overweight postmenopausal women. No clear association with sex hormones was noted for the other genetic polymorphisms evaluated in the study.

CONCLUSION

Single nucleotide polymorphisms in blocks 1 and 2 of the CYP19A1 gene are related to plasma levels of estrogen among postmenopausal Chinese women and may therefore play an important role in the etiology of hormone-related cancers.

The CYP19 TTTA repeat polymorphism is related to the prognosis of premenopausal stage I-II and operable stage III breast cancers

PURPOSE

Given the critical role of the CYP19 gene, encoding aromatase, in estrogen synthesis and the association of the estrogen level with its TTTA repeat polymorphism, the potential influence of this polymorphism on breast cancer survival, and hence management, deserves further study.

METHODS

Genotyping for the CYP19 TTTA repeat polymorphism was performed on 482 stage I-II and operable stage III Taiwanese breast cancer patients. Patients with more than seven TTTA repeats in either allele of CYP19 were defined as having the long allele. We correlated clinical variables and CYP19 genotypic polymorphism with outcome.

RESULTS

In hormone receptor (HR)-positive breast cancers, premenopausal patients with the long allele of the CYP19 polymorphism had a significantly higher overall survival (OS) rate (8-year, 89% versus 68%; p= .003) than those without it. This difference was further demonstrated by a multivariate analysis (OS hazard ratio, 1.53; p= .041). In postmenopausal women or patients with HR-negative breast cancer, there was no significant difference in OS between patients with or without the long allele. In premenopausal women with HR-positive cancers, adequate intensity adjuvant chemotherapy did not achieve a greater OS rate than suboptimal chemotherapy in patients with the long allele, but it resulted in a significantly higher OS rate (p= .011) than suboptimal chemotherapy in women without the long allele.

CONCLUSIONS

The CYP19 TTTA repeat polymorphism is associated with survival in premenopausal women, but not in postmenopausal women, with HR-positive breast cancers. Premenopausal women with the long allele have a greater survival rate and may not gain benefit from adjuvant chemotherapy.

A rapid outcomes ascertainment system improves the quality of prognostic and pharmacogenetic outcomes from observational studies

PURPOSE

Case-control and observational studies are popular choices for evaluating molecular prognostic/pharmacogenetic outcomes, but data quality is rarely tested. Using clinical trial and epidemiologic methods, we assessed the quality of prognostic and outcomes data obtainable from a large case-control study of lung cancer.

METHODS

We developed an explicit algorithm (set of standard operating procedures forming a rapid outcomes ascertainment system) that encompassed multiple tests of quality assurance, and quality of data for a range of prognostic and outcomes variables, in several cancers, across several centers and two countries were assessed. Based on these assessments, the algorithm was revised and physicians' clinical practice changed. We reevaluated the quality of outcomes after these revisions.

RESULTS

Development of an algorithm with internal quality controls showed specific patterns of data collection errors, which were fixable. Although the major discrepancy rate in retrospective data collection was low (0.6%) when compared with external validated sources, complete data were found in <50% of patients for treatment response rate, toxicity, and documentation of patient palliative symptoms. Prospective data collection and changes to clinical practice led to significantly improved data quality. Complete data on response rate increased from 45% to 76% (P = 0.01, Fisher's exact test), for toxicity data, from 26% to 56% (P = 0.02), and for palliative symptoms, from 25% to 70% (P < 0.05), in one large lung cancer case-control study.

CONCLUSIONS

Observational studies can be a useful source for studying molecular prognostic and pharmacogenetic outcomes. A rapid outcomes ascertainment system with strict ongoing quality control measures is an excellent means of monitoring key variables.

Single nucleotide polymorphisms of the aromatase gene (CYP19A1), HER2/neu status, and prognosis in breast cancer patients

PURPOSE

Estrogen exposure is involved in both breast cancer susceptibility and the prognosis in patients with breast cancer. Aromatase is involved in the production of estrogens, and altered expression of it might be associated with the prognosis. The aim of this study was to examine the effect of single nucleotide polymorphisms (SNPs) in the aromatase gene, CYP19A1, on the prognosis, and in relation to tumor and patient characteristics in a cohort of breast cancer patients.

PATIENTS AND METHODS

The cohort analyzed in this study consisted of 1,257 patients with invasive primary breast cancer. Polymorphisms rs10046, rs4646 and rs700519 were genotyped within this group.

RESULTS

The variant genotypes of rs10046 and rs4646 were associated with a lower percentage of HER2-positive tumors. There was no association of rs700519 and rs4646 with disease-free survival (DFS) or overall survival (OS). The variant genotype of rs10046 was significantly associated with a better 5-year DFS (hazards ratio 0.51; 95% CI, 0.32 to 0.81; P=0.004) adjusted for age, nodal status, tumor size grading, and hormone receptor status. This effect appeared to be determined in the subgroup of premenopausal patients.

CONCLUSION

SNPs rs10046 and rs4646 may influence the HER2 status of breast cancer tumors, and rs10046 genotypes are associated with an altered DFS. Genotypes of aromatase polymorphisms may influence the prognosis for breast cancer patients not only by affecting the extent of estrogen exposure but also through an alteration in tumor characteristics.