45 research outputs found
Ribavirin restores ESR1 gene expression and tamoxifen sensitivity in ESR1 negative breast cancer cell lines
Tumor growth is estrogen independent in approximately one-third of all breast cancers, which makes these patients unresponsive to hormonal treatment. This unresponsiveness to hormonal treatment may be explained through the absence of the estrogen receptor alpha (ESR1). The ESR1 gene re-expression through epigenetic modulators such as DNA methyltransferase inhibitors and/or histone deacetylase inhibitors restores tamoxifen sensitivity in ESR1 negative breast cancer cell lines and opens new treatment horizons in patients who were previously associated with a poor prognosis
Estrogen receptor-α polymorphism in a Taiwanese clinical breast cancer population: a case–control study
INTRODUCTION: Receptor-mediated estrogen activation participates in the development and progression of breast cancer. Estrogen receptor (ER)-α polymorphism has been found to be associated with breast cancer and clinical features of the disease in Caucasians. Epidemiologic studies have revealed that age–incidence patterns of breast cancer in Asians differ from those in Caucasians. Genomic data for ER-α in either population is therefore of value in the clinical setting for that ethnic group. METHODS: A case–control study was conducted to establish a database of ER-α polymorphisms in a Taiwanese population in order to compare Western and Taiwanese (Asian) distributions and to evaluate ER-α polymorphism as an indicator of clinical outcome. The ER-α gene was scanned in a Taiwanese clinical breast cancer group (189 patients) and in healthy individuals (177 healthy control individuals). PCR single-strand conformation polymorphism technology was employed and real-time PCR melting curve analysis was performed. RESULTS: Three sites of silent single nucleotide polymorphism (SNPs) were found, as reported previously in Western studies, but at significantly different frequencies. Among the three SNPs, the frequency of allele 1 (TCT → TCC) in codon 10 was significantly lower in breast cancer patients (32.0%) than in control individuals (40.4%; P = 0.018). We found that allele 1 (ACG → ACA) in codon 594 was less common in breast cancer patients with a family history of breast cancer (5.9%) than in those without such a history (19.6%; P = 0.049). Individually, both allele 1 in codon 325 (CCC → CCG) and allele 1 in codon 594 exhibited a reverse association with the occurrence of lymph node metastasis. Furthermore, incorporation of both SNP markers further increased predictive accuracy. CONCLUSIONS: Our data suggest that ER-α polymorphisms are correlated with various aspects of breast cancer in Taiwan. ER-α genotype, as determined during presurgical evaluation, might represent a surrogate marker for predicting breast cancer lymph node metastasis
DNA methylation analysis at distal and proximal promoter regions of the oestrogen receptor gene in breast cancers
Estrogen receptor alpha gene polymorphism and endometrial cancer risk – a case-control study
Background: Estrogen is an established endometrial carcinogen. One of the most important
mediators of estrogenic action is the estrogen receptor alpha. We have investigated whether
polymorphic variation in the estrogen receptor alpha gene (ESR1) is associated with endometrial
cancer risk.
Methods: In 702 cases with invasive endometrial cancer and 1563 controls, we genotyped five
markers in ESR1 and used logistic regression models to estimate odds ratios (OR) and 95 percent
confidence intervals (CI).
Results: We found an association between rs2234670, rs2234693, as well as rs9340799, markers
in strong linkage disequilibrium (LD), and endometrial cancer risk. The association with rs9340799
was the strongest, OR 0.75 (CI 0.60–0.93) for heterozygous and OR 0.53 (CI 0.37–0.77) for
homozygous rare compared to those homozygous for the most common allele. Haplotype models
did not fit better to the data than single marker models.
Conclusion: We found that intronic variation in ESR1 was associated with endometrial cancer
risk
Estrogen Receptor-Beta Gene Polymorphism in women with Breast Cancer at the Imam Khomeini Hospital Complex, Iran
ER-alpha and ER-beta genes have been proven to play a significant role in breast cancer. Epidemiologic studies have revealed that age-incidence patterns of breast cancer in Middle East differ from those in the Western countries. Two selected coding regions in the ER-β gene (exons 3 and 7) were scanned in Iranian women with breast cancer (150) and in healthy individuals (147). PCR single-strand conformation polymorphism was performed. A site of silent single nucleotide polymorphism was found only on exon 7. The SNP was found only in breast cancer patients (5.7%) (χ2 = 17.122, P = 0.01). Codon 392 (C1176G) of allele 1 was found to have direct association with the occurrence of lymph node metastasis. Our data suggest that ER-β polymorphism in exon 7 codon 392 (C1176G) is correlated with various aspects of breast cancer and lymph node metastasis in our group of patients
Tamoxifen may prevent both ER+ and ER- breast cancers and select for ER- carcinogenesis: an alternative hypothesis
INTRODUCTION: Breast Cancer Prevention Trial (BCPT) and Multiple Outcomes of Raloxifene (MORE) data have been interpreted to indicate that tamoxifen reduces the risk of ER+ but not ER- breast carcinogenesis. We explored whether these data also support an alternative hypothesis, that tamoxifen influences the natural history of both ER+ and ER- cancers, that it may be equally effective in abrogating or delaying ER- and ER+ carcinogenesis, and place selection pressure, in some cases, for the outgrowth of ER- cancers. METHODS: BCPT and MORE data were used to investigate whether: first, tamoxifen could reduce equally the emergence of ER- and ER+ tumors; and second, tamoxifen could select a fraction of emerging ER+ cancers and promote their transformation to ER- cancers. Assuming that some proportion, Z, of ER+ tumors becomes ER- after tamoxifen exposure and that the risk reduction for both ER- and ER+ tumors is equal, we solved for both the transformation rate and the risk reduction rate. RESULTS: If tamoxifen equally reduces the incidence of ER+ and ER- tumors by 60%, the BCPT results are achieved with a transformation of approximately Z = 20% of ER+ to ER- tumors. Validation with MORE data using an equal risk reduction of 60% associated with tamoxifen produces an almost identical transformation rate Z of 23%. CONCLUSION: Data support an alternative hypothesis that tamoxifen may promote ER- carcinogenesis from a precursor lesion that would otherwise have developed as ER+ without tamoxifen selection
Oestrogen receptor α gene haplotype and postmenopausal breast cancer risk: a case control study
INTRODUCTION: Oestrogen receptor α, which mediates the effect of oestrogen in target tissues, is genetically polymorphic. Because breast cancer development is dependent on oestrogenic influence, we have investigated whether polymorphisms in the oestrogen receptor α gene (ESR1) are associated with breast cancer risk. METHODS: We genotyped breast cancer cases and age-matched population controls for one microsatellite marker and four single-nucleotide polymorphisms (SNPs) in ESR1. The numbers of genotyped cases and controls for each marker were as follows: TA(n), 1514 cases and 1514 controls; c.454-397C → T, 1557 cases and 1512 controls; c.454-351A → G, 1556 cases and 1512 controls; c.729C → T, 1562 cases and 1513 controls; c.975C → G, 1562 cases and 1513 controls. Using logistic regression models, we calculated odds ratios (ORs) and 95% confidence intervals (CIs). Haplotype effects were estimated in an exploratory analysis, using expectation-maximisation algorithms for case-control study data. RESULTS: There were no compelling associations between single polymorphic loci and breast cancer risk. In haplotype analyses, a common haplotype of the c.454-351A → G or c.454-397C → T and c.975C → G SNPs appeared to be associated with an increased risk for ductal breast cancer: one copy of the c.454-351A → G and c.975C → G haplotype entailed an OR of 1.19 (95% CI 1.06–1.33) and two copies with an OR of 1.42 (95% CI 1.15–1.77), compared with no copies, under a model of multiplicative penetrance. The association with the c.454-397C → T and c.975C → G haplotypes was similar. Our data indicated that these haplotypes were more influential in women with a high body mass index. Adjustment for multiple comparisons rendered the associations statistically non-significant. CONCLUSION: We found suggestions of an association between common haplotypes in ESR1 and the risk for ductal breast cancer that is stronger in heavy women
Pembauran Budaya di Desa Rantau Sakti Kecamatan Tambusai Utara Kabupaten Rokan Hulu
This study is to research how the intercourse of culture that existed in the Rantau Sakti village Tambusai Utara District and Rokan Hulu Regent intertribal nasions of Java, Medan Java, Batak, Minang, and Melayu. Theres a launching factors and hindrance factors too in culture intercourse. The data tekhnic collection with the koesioner, interview, and documentation. And the analisys of data is descriptive where the data presented in the form of a diagrams, percentages, pictures, and explanations. The research results show that The lives of the multicultural that could lead to the occurrence of intercourse of culture through assimilation, acculturation, and amalgamation. The intercourse of culture through three aspects of it can run well theres happened in Rantau Sakti village on seven principles like language, system of knowledge , a social organization , celebration life and technologi, means of subsistence, religion, and art . There is also intercourse of culture with amalgamation culture that leads to assimilation and acculturation. Its launching factor are the attitude of tolerance and open, in common religion, and the same occasion in the economic field. While the hindrance factor are differences of religion and stereotype (ethnic prejudice). Those two factors each happened to the process of changing culture with assimilation, acculturation, and amalgamation That leads to a positive thing.Keyword: The Culture Intercourse, Inter-ethnic