Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0476089 (endometrial cancer)
 11,379 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to approach the molecular basis of the tissue-specific agonistic activity of antioestrogens, we have compared, at the mRNA level, the expression of various transcriptional cofactors (activators or repressors) of estrogen receptors in different breast (MCF7, ZR75-1, T47D, MDA-MB231) and endometrial (Ishikawa, RL-95-2 and HEC1A) human cancer cell lines. We showed that for SRC-1, CBP, TIF1alpha, RIP140, N-CoR, and SMRT, no significant differences in the expression levels were observed between breast and endometrial cells. For TIF1alpha mRNA, both isoforms were also detected at similar levels in all the cells tested. By contrast, over-expression of AIB1 mRNA was observed in MCF7 cells, but not in other breast or endometrial cells, irrespective of their ER-status. We then used protein-protein interaction assay (far-Western blot) to confirm the increased expression of at least one of the p160 proteins in MCF7 cells. Finally, we demonstrated that RIP140 mRNA is directly induced by estrogens in ER-positive MCF7 breast cancer cell lines but not in Ishikawa endometrial cells. Together these results indicate that some differences exist between breast and endometrial cancer cell lines at the level of estrogen receptor transcription cofactor expression.
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PMID:Estrogen receptor cofactors expression in breast and endometrial human cancer cells. 1061 26

Members of the p160 steroid receptor cofactor family, including AIB1 (Amplified in Breast Cancer 1) (also known as SRC-3/RAC3/ACTR/pCIP/TRAM-1), are of interest in endometrial carcinoma as they affect the function of estrogen (ER) and progesterone receptors (PR). Since it is feasible that alterations in the expression levels of coregulators can either augment ER activity or reduce the ability of PR to oppose ER action in endometrial cancers, our primary aim was to analyze expression of the AIB1 protein in endometrial carcinoma, carcinoma-associated complex atypical hyperplasia, and carcinoma-associated normal endometrium using immunohistochemistry and tissue microarrays. Expression of AIB1 was compared with other biomarkers and clinicopathologic parameters. We also tested AIB1 expression in non-carcinoma associated hyperplastic, normal secretory and proliferative endometrium to determine baseline AIB1 levels. In endometrial carcinoma, there is a higher expression of AIB1 compared to carcinoma-associated complex atypical hyperplasia (0.007) or carcinoma-associated normal endometrium (<0.001). AIB1 expression correlates with older age (P = 0.003), peri- or postmenopausal status (P = 0.002) and a higher grade of carcinomas (P = 0.04). There were no differences in the expression of additional steroid hormone receptor co-activators (SRC-1 and p300/CBP) and the co-repressor SMRT between histologic categories. AIB1 expression correlated with ER (r = 0.30, P = 0.006). The strongest correlation was between ER and PR-B isoform nuclear expression (r = 0.52, P < 0.0001). AIB1 levels were higher in non-carcinoma associated normal and hyperplastic endometrium compared to carcinoma-associated complex atypical hyperplasia and carcinoma-associated normal endometrium, and were the highest in normal secretory endometrium. In conclusion, high AIB1 expression in endometrial carcinoma is associated with parameters of poor prognosis. We propose that when AIB1 is overexpressed in endometrial carcinoma, ER action is augmented, leading to endometrial hyperplasia and progression to malignancy. Future studies correlating expression with response to hormonal therapy may be beneficial.
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PMID:Steroid receptor coactivator AIB1 in endometrial carcinoma, hyperplasia and normal endometrium: Correlation with clinicopathologic parameters and biomarkers. 1698 Sep 45

Tamoxifen and 17beta-estradiol are capable of up-regulating the expression of some genes and down-regulate the expression of others simultaneously in the same cell. In addition, tamoxifen shows distinct transcriptional activities in different target tissues. To elucidate whether these events are determined by differences in the recruitment of co-regulators by activated estrogen receptor-alpha (ER-alpha) at target promoters, we applied chromatin immunoprecipitation (ChIP) with promoter microarray hybridisation in breast cancer T47D cells and identified 904 ER-alpha targets genome-wide. On a selection of newly identified targets, we show that 17beta-estradiol and tamoxifen stimulated up- or down-regulation of transcription correlates with the selective recruitment of co-activators or co-repressors, respectively. This is shown for both breast (T47D) and endometrial carcinoma cells (ECC1). Moreover, differential co-regulator recruitment also explains that tamoxifen regulates a number of genes in opposite direction in breast and endometrial cancer cells. Over-expression of co-activator SRC-1 or co-repressor SMRT is sufficient to alter the transcriptional action of tamoxifen on a number of targets. Our findings support the notion that recruitment of co-regulator at target gene promoters and their expression levels determine the effect of ER-alpha on gene expression to a large extent.
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PMID:Identification of novel ER-alpha target genes in breast cancer cells: gene- and cell-selective co-regulator recruitment at target promoters determines the response to 17beta-estradiol and tamoxifen. 1969 61