In this first association study about breast cancer risk and polymorphisms in the ERbeta gene we have screened 219 Finnish sporadic breast cancer cases and 248 ethnically matched male controls.
Our results are consistent with the hypothesis of a joint effect of estrogen receptor beta sequence variants and endogenous estrogen exposure on breast cancer risk.
Two selected coding regions in the ER-beta gene (exons 3 and 7) were scanned in Iranian women with breast cancer (150) and in healthy individuals (147).
We hypothesized that heritable methylation potential might be a risk factor for breast cancer and evaluated possible association with breast cancer for single nucleotide polymorphisms (SNPs) either involving CpG sequences in extended 5'-regulatory regions of candidate genes (ESR1, ESR2, PGR, and SHBG) or CpG and missense coding SNPs in genes involved in methylation (MBD1, MECP2, DNMT1, MGMT, MTHFR, MTR, MTRR, MTHFD1, MTHFD2, BHMT, DCTD, and SLC19A1).
DNA was isolated and genotyped for six ESR1 and two ESR2 single-nucleotide polymorphisms (SNPs) from tumor specimens from 3691 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1-98 trial to receive tamoxifen and/or letrozole for 5 years.
PvuII and XbaI polymorphisms of the estrogen receptor-alpha gene (ERalpha) and RsaI and AluI polymorphisms of the estrogen receptor-beta gene (ERbeta) have been associated with breast cancer.
ESR1 rs3798577 and ESR2rs1256049 were associated with breast cancer in ER-positive cases, and ESR1 rs2234693, and rs3798577 were associated with breast cancer in Her-2-negative cases, while the association of ESR2rs1256049 with breast cancer was seen in Her-2 positive cases.
The ESR2rs4986938 and rs1256049 polymorphisms were described to present association with breast cancer, rheumatoid arthritis, and bone mineral density, however the association with IS has not been evaluated.
We investigated three common ESR2 polymorphisms, rs1256049 (G1082A), rs4986938 (G1730A) and rs928554 (Cx+56 A-->G) for association to breast cancer risk.
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.
The relevance of ERβ variants in breast cancer outcomes and response to therapy is difficult to assess because of conflicting reports in the literature, likely due to variable methods used to assess ERβ in patient tumors.
Genotype frequencies of five SNPs (rs3020449, rs3020450, rs2987983, rs1271572 and rs1887994) in the promoter region of the ERβ gene in 873 women with breast cancer, 645 women with fibroadenoma and 700 healthy women were determined using an allele-specific tetra-primer polymerase chain reaction (PCR).
In conclusion, an association for breast cancer risk between short (SS) alleles for the repeat variants of the ESR2 and AR genes was found in women of Greek descent.
However, when combined with MSI/LOH in AR, ERβ and CYP19 genes, we were able to detect significant associations with the GSTP1 wild-type genotype in PR (progesterone receptor) negative breast cancers or the CYP17 wild-type genotype in ER (estrogen receptor) and PR-negative breast tumors.
Banked DNA from tamoxifen-treated individuals with breast cancer from the Marshfield Clinic Personalized Medicine Research Project, a population-based DNA repository, was tested for association between incidence of tamoxifen-associated thromboembolic events (TTE) and single nucleotide polymorphisms encoding the estrogen receptors 1,2 (ESR1, ESR2) or drug metabolism enzymes cytochrome P450 2D6 (CYP2D6) and aromatase (CYP19).
Our findings suggest that polymorphisms in the estrogen receptor beta gene may modify the association between isoflavone intake and breast cancer risk.