Association of an estrogen receptor variant with increased height in women

Gene-Environment Interactions Relevant to Estrogen and Risk of Breast Cancer: Can Gene-Environment Interactions Be Detected Only among Candidate SNPs from Genome-Wide Association Studies?

In this study we aim to examine gene-environment interactions (GxEs) between genes involved with estrogen metabolism and environmental factors related to estrogen exposure. GxE analyses were conducted with 1970 Korean breast cancer cases and 2052 controls in the case-control study, the Seoul Breast Cancer Study (SEBCS). A total of 11,555 SNPs from the 137 candidate genes were included in the GxE analyses with eight established environmental factors. A replication test was conducted by using an independent population from the Breast Cancer Association Consortium (BCAC), with 62,485 Europeans and 9047 Asians. The GxE tests were performed by using two-step methods in GxEScan software. Two interactions were found in the SEBCS. The first interaction was shown between rs13035764 of NCOA1 and age at menarche in the GE|2df model (p-2df = 1.2 × 10-3). The age at menarche before 14 years old was associated with the high risk of breast cancer, and the risk was higher when subjects had homozygous minor allele G. The second GxE was shown between rs851998 near ESR1 and height in the GE|2df model (p-2df = 1.1 × 10-4). Height taller than 160 cm was associated with a high risk of breast cancer, and the risk increased when the minor allele was added. The findings were not replicated in the BCAC. These results would suggest specificity in Koreans for breast cancer risk.

Height at menarche is influenced by estrogen receptor alpha gene polymorphisms

BACKGROUND

It has been suggested that polymorphic variations in estrogen receptors (ERs) genes may have an impact on linear growth of girls during puberty.

AIM

The aim of the study was to investigate whether height at menarche is influenced by PvuII and XbaI polymorphisms of the ERalpha gene.

SUBJECTS AND METHODS

The study population consisted of 127 healthy girls, who were observed from premenarcheal period at six monthly intervals, until menarche occurred in all participants. Anthropometric measurements were taken at each visit and their values at menarche were calculated using centile curves drawn individually for each subject. PvuII and XbaI ERalpha gene polymorphisms were evaluated with RLFP-PCR.

RESULTS

The age at menarche was not related to ERalpha gene polymorphisms. Girls with pp genotype were at menarche on average 3.2 cm shorter than PP homozygotes and in addition xx homozygotes were shorter than subjects with XX and Xx genotypes: 3.0 cm and 3.9 cm respectively. Subjects with px haplotype were, at the onset of the first menstrual period, from 2.3 cm to 3.1 cm shorter than carriers of other haplotypes. The leg length-to-height ratio at menarche was lower in xx homozygotes than in Xx heterozygotes and lower in px haplotype in comparison to Px and pX haplotypes carriers. Corresponding associations were observed at the final visit.

CONCLUSIONS

Height at menarche is influenced by the ERalpha gene polymorphism.

Disproportionate body lengths correlate with idiopathic-type curvature in the curveback guppy

STUDY DESIGN

A comparative allometric study of body lengths in an animal model for human idiopathic-type scoliosis.

OBJECTIVE

To compare body length variation among adult curved and noncurved curveback female guppies.

SUMMARY OF BACKGROUND DATA

Tallness and/or abnormal anthropometric parameters have been correlated to idiopathic-type scoliosis (IS) in numerous studies. Heritable curvature in curveback has demonstrated morphologic and developmental similarities to human IS. Because control of body length in the guppy is heritable and variable, we investigated whether length might also be correlated to curvature in the curveback population.

METHODS

Component body lengths were measured from digital photographs for 321 (246 curved and 75 noncurved) females. Sources of experimental variation were omitted by only measuring 2-dimensional curves in mature females all from the same pedigree, and raised under controlled conditions of diet and environment. Body length was divided into 2 component parts (precaudal and caudal). Body lengths were tested statistically for correlation to curvature and curve magnitude.

RESULTS

Although absolute length does not correlate to curvature, this survey of length in the curveback model reveals 2 important similarities to anthropometric studies of IS: that there are disproportionate body lengths among females with curvature, and the suggestion of an underlying growth abnormality among curved individuals.

CONCLUSION

In order to better characterize the relationship between growth, length disproportion, and curvature in the guppy, further studies are warranted. However, this inquiry further supports the usefulness of curveback as a model for understanding the basic biology of idiopathic-type scoliosis and encourages study of growth-related factors.

Association of the estrogen receptor 1 (ESR1) gene with body height in adult males from two Swedish population cohorts

Human body height is a complex genetic trait with high heritability. We performed an association study of 17 candidate genes for height in the Uppsala Longitudinal Study of Adult Men (ULSAM) that consists of 1153 elderly men of age 70 born in the central region of Sweden. First we genotyped a panel of 137 single nucleotide polymorphism (SNPs) evenly distributed across the candidate genes in the ULSAM cohort. We identified 4 SNPs in the estrogen receptor gene (ESR1) on chromosome 6q25.1 with suggestive signals of association (p<0.05) with standing body height. This result was followed up by genotyping the same 25 SNPs in the ESR1 gene as in ULSAM in a second population cohort, the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort that consist of 507 males and 509 females of age 70 from the same geographical region as ULSAM. One SNP, rs2179922 located in intron 4 of ESR1 showed and association signal (p = 0.0056) in the male samples from the PIVUS cohort. Homozygote carriers of the G-allele of the SNP rs2179922 were on average 0.90 cm taller than individuals with the two other genotypes at this SNP in the ULSAM cohort and 2.3 cm taller in the PIVUS cohort. No association was observed for the females in the PIVUS cohort.

Variations in RANK gene are associated with adult height in Caucasians

Height is a complex trait significantly influenced by genetic factors, with heritability ranging from 48% to 98%. Previous studies have yielded a number of important genomic regions that may account for the variation of height in human populations. However, more 'height' genes still wait for identification. Recent studies have revealed that tumor necrosis factor receptor superfamily member 11a (RANK) is a vital factor for chondroclastic/osteoclastic differentiation and activity that influence the morphology of growth plates and linear bone growth. Despite its importance, little effort has been made to find out whether the RANK polymorphisms are associated with adult height variation in normal populations. Herein, we performed a family based association test (FBAT) in 1873 white subjects from 405 nuclear families. Among eighteen single nucleotide polymorphisms (SNPs) and seven blocks, SNP rs6567274 was detected to be significant even after multiple-testing correction. In corroboration with single-locus analysis, a major haplotype in block 5 bearing the variant "T" of rs6567274 was significantly associated with higher stature. Our findings firstly suggested the RANK polymorphisms might contribute to adult height variation. Further researches need to be launched to replicate the present results and further unravel the molecular mechanism underlying the significant associations discovered.

Estrogen receptor mutations in human disease

As early as the 1800s, the actions of estrogen have been implicated in the development and progression of breast cancer. The estrogen receptor (ER) was identified in the late 1950s and purified a few years later. However, it was not until the 1980s that the first ER was molecularly cloned, and in the mid 1990s, a second ER was cloned. These two related receptors are now called ERalpha and ERbeta, respectively. Since their discovery, much research has focused on identifying alterations within the coding sequence of these receptors in clinical samples. As a result, a large number of naturally occurring splice variants of both ERalpha and ERbeta have been identified in normal epithelium and diseased or cancerous tissues. In contrast, only a few point mutations have been identified in human patient samples from a variety of disease states, including breast cancer, endometrial cancer, and psychiatric diseases. To elucidate the mechanism of action for these variant isoforms or mutant receptors, experimental mutagenesis has been used to analyze the function of distinct amino acid residues in the ERs. This review will focus on ERalpha and ERbeta alterations in breast cancer.

Estrogen receptor alpha polymorphisms and renal cell carcinoma--a possible risk

Renal cell carcinoma is the most common form of kidney cancer. However, the genetic basis of renal cancer is not fully understood. Estrogens and their receptors (ERs) have been shown to play a role in various cancers and it is speculated that they can also affect the human kidney. One of the animal models utilized to study the effects of estrogens on renal cancer is the Syrian hamster. Exposing these hamsters to estrogens results in the development of kidney cancer and thus, the hormone-ER complex may be playing a role. The ER is expressed in reproductive as well as non-reproductive tissues and is implicated in the control of proliferation, differentiation, and development of many tissues. There are two types of ERs and they are the alpha and beta forms. Genetic polymorphisms of various factors have been shown to play a role in the alteration of their functions. The NH2-terminal region of the ERalpha protein influences its structure and function and thus, inherited variants of the ERalpha gene may alter tissue responsiveness to estrogens and possibly lead to renal carcinogenesis. Polymorphisms have been determined in the coding region of the human ERalpha gene and are located at the following codons: 10 T-->C, 85 G-->C, 87 G-->C, 243 C-->T, 325 C-->G, and 594 G-->A. There are also two polymorphisms that have been identified in intron 1 and give rise to a PvuII and XbaI restriction site. These polymorphisms of ERalpha have been shown to be associated with various cancers. Based on the evidence, it is hypothesized that polymorphisms of the ERalpha gene are associated with renal cell carcinoma.

Mechanisms of estrogen action

Our appreciation of the physiological functions of estrogens and the mechanisms through which estrogens bring about these functions has changed during the past decade. Just as transgenic mice were produced in which estrogen receptors had been inactivated and we thought that we were about to understand the role of estrogen receptors in physiology and pathology, it was found that there was not one but two distinct and functional estrogen receptors, now called ER alpha and ER beta. Transgenic mice in which each of the receptors or both the receptors are inactive have revealed a much broader role for estrogens in the body than was previously thought. This decade also saw the description of a male patient who had no functional ER alpha and whose continued bone growth clearly revealed an important function of estrogen in men. The importance of estrogen in both males and females was also demonstrated in the laboratory in transgenic mice in which the aromatase gene was inactivated. Finally, crystal structures of the estrogen receptors with agonists and antagonists have revealed much about how ligand binding influences receptor conformation and how this conformation influences interaction of the receptor with coactivators or corepressors and hence determines cellular response to ligands.

Estrogen receptor mutations

The purpose of this paper is to review potential novel functional pathways by which estradiol and estrogenic compounds elicit biological responses in mammals. We will limit our approach to those novel functions suggested by phenotypes associated with estrogen receptor-alpha (ER alpha) gene mutations and polymorphisms. The study of these pathways has been greatly aided by the availability of ER alpha-minus mice, which lack classic biological responses to estradiol. In addition, the availability of an ER alpha-minus human family, aromatase-minus human families, and in the near future an aromatase-minus mouse model will allow correlations of novel phenotypes with the lack of active ER alpha protein. The ER alpha-minus mice can potentially be used to characterize in depth novel clinical phenotypes that link the functions of estrogens with sexual maturation, cardiovascular disease, osteoporosis, diabetes, and cancer.

Interactive effect of estradiol and vitamin D receptor gene polymorphisms as a possible determinant of growth in male and female infants

An association between vitamin D receptor (VDR) gene polymorphism and body size has been observed in infants. We hypothesized that the estradiol receptor (ER) gene is another determinant of infant growth and that the effects of the VDR and ER genotypes may interact with each other. The ER genotype (PvuII and XbaI sites), VDR genotype (BsmI site), and body size during the first 2 yr of life were analyzed in 161 healthy Caucasian full-term babies homozygous for the BsmI polymorphism of the VDR gene (BB or bb). There was no significant association between ER polymorphism and 1) body weight in boys and girls, 2) body length in girls, or 3) body length in boys with a bb genotype. In contrast, ER polymorphism and body length were significantly associated in BB boys. Boys with the BBpp genotype were shorter at birth (P < 0.005) and at 10 months of age (P < 0.001) than boys with other genotypes. They were even shorter than girls with the same genotype. These results indicate some degree of interaction between the effects of the VDR and ER genes, leading to significant variations in body growth during infancy, especially in boys.

Nuclear receptors: structure, function and involvement in disease

Nuclear hormone receptors are acting as transcription factors in the cell nucleus. They regulate gene expression of hormonal regulated target genes. The role of hormone in the transcriptional process is to modulate and change the nuclear receptor functionality. Receptors contain a DNA binding domain that enables them to bind to hormone response elements of target genes. Nuclear hormone receptors bind to lipophilic hormones produced by the organisms' endocrine system, which links the secretion of hormones directly to regulation of gene expression of responsive tissues. In recent years increasing numbers of naturally occurring mutations of a variety of nuclear hormone receptor genes were identified in patients showing abnormalities in hormonal response. Here, we present an overview of nuclear receptors and their mutant forms which cause human syndromes or are associated with cancer progression. The major scope of this article is to give an overview on the structural-functional relationship and based on that, to understand the effects of naturally occurring receptor mutants on the molecular level. Thereby, functional aberrations of naturally occurring receptors for androgen, glucocorticoids, mineralocorticoid, estrogen, vitamin D3, retinoic acid, and thyroid hormone as well as the orphan receptor DAX1 are discussed.

Estrogen receptor variants and mutations

There is a large and increasing body of experimental and clinical data supporting the existence or variant estrogen receptor (ER) proteins in both normal and neoplastic estrogen target tissues including human breast. Therefore, future examination of ER signal transduction and/or measurement of ER protein must take into account variant ER expression. The functions of variant ER proteins, either physiological or pathological, remain unclear, although a role(s) for some ER variants in breast tumorigenesis and breast cancer progression would be consistent with the accumulated data. Possible tissue specific expression leads to the speculation that ER variants may have a role in tissue specific estrogen action. The following review focuses on the current knowledge available in the scientific literature with respect to the type and characteristics of estrogen receptor variants and mutations that have been identified to occur naturally in tissues and cell lines.

Oestrogen receptor variants and mutations in human breast cancer

Several oestrogen receptor variant and mutated mRNA species have been identified in human breast samples and cell lines. Over-expression and altered expression of some of these mRNAs have been correlated with breast tumourigenesis and progression. The following review focuses on the current knowledge available in the scientific literature with respect to the type and characteristics of oestrogen receptor variants and mutations that have been identified as occurring naturally in human breast tissues and cell lines.