Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04155 (pS2)
 1,234 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A novel in vivo model of tamoxifen-stimulated endometrial cancer was developed and the role of HER-2/neu investigated by using trastuzumab. Tamoxifen-stimulated tumors (ECC-1TAM) were growth stimulated by 17beta-estradiol (E2), tamoxifen, or raloxifene. Trastuzumab inhibited growth of E2-stimulated ECC-1E2 tumors by 50% and tamoxifen-stimulated ECC-1TAM tumors by 100%. ECC-1 tumors expressed functional estrogen receptor alpha (ER alpha) as measured by induction of pS2 and c-myc mRNAs. E2 induced pS2 and c-myc mRNAs up to 40-fold in ECC-1E2 and ECC-1TAM. Tamoxifen induced pS2 and c-myc mRNAs up to 5-fold in ECC-1E2 tumors and up to 10-fold in ECC-TAM tumors. Trastuzumab blocked E2-induced pS2 mRNA (P < 0.01) in ECC-1E2 by 50% and tamoxifen-induced c-myc mRNA (P < 0.1) in ECC-1TAM tumors by 70%. Trastuzumab decreased phosphorylated and total HER-2/neu protein in ECC-1E2 and ECC-1TAM tumors. However, only phospho-ERK-1/2 and not phospho-Akt protein was decreased by trastuzumab in tamoxifen-treated ECC-1TAM tumors. The insulin-like growth factor (IGF-I) signaling pathway also activates extracellular signal-related kinase (ERK)-1/2 and could block the efficacy of trastuzumab in ECC-1E2 tumors. The results showed that IGF-I, IGF-IR mRNAs, and phospho-insulin receptor substrate-1 (IRS-1) protein were decreased in ECC-1TAM compared with ECC-1E2 tumors. The results show that trastuzumab is an effective therapy for both E2-stimulated and tamoxifen-stimulated endometrial cancer. The data suggest estrogenic activities of E2 and tamoxifen at ER alpha-regulated pS2 and c-myc genes are in part mediated by HER-2/neu. However, trastuzumab is a better growth inhibitor of ECC-1TAM tumors where there is diminished IGF-I signaling allowing for complete blockade of the downstream phospho-ERK-1/2 signal.
Cancer Res 2005 Sep 15
PMID:Trastuzumab therapy for tamoxifen-stimulated endometrial cancer. 1616 31

The trefoil factor (TFF) family includes three members : TFF1 also called pS2, TFF2 or spasmolytic peptide (SP) and TFF3 or intestinal trefoil factor (ITF). TFFs are associated with mucin-secreting epithelial cells and play a crucial role in mucosal defense and healing. In case of mucosa aggression (due to bacteria, virus or medication), inflammatory diseases and ulcerous pathology, they are involved in epithelium restitution and regeneration. In comparison with the other TFFs, pS2/TFF1 has particular functions. Notably, it acts like a suppressor gene for gastric tumors. Evidence of pS2/TFF1 overexpression has been found in a range of carcinomas (breast, bowel, prostate, pancreas, thyroid, lung...). In breast cancer, pS2/TFF1 overexpression contributes to a favorable prognosis. Moreover, it is a predictive factor of hormonotherapy response.
Bull Cancer 2005 Sep
PMID:[Trefoil factor 1 (pS2/TFF1), a peptide with numerous functions]. 1620 67

Induction of transcription requires an ordered recruitment of coregulators and specific combinations of histone modifications at the promoter. Occurrence of histone H4 arginine (Arg) 3 methylation by protein arginine methyltransferase 1 (PRMT1) represents an early promoter event in ER (estrogen receptor)-regulated gene activation. However, its in vivo significance in ER signaling and the prerequisites for PRMT1 recruitment to promoters have not been established yet. We show here that endogenous PRMT1 is a crucial and non-redundant coactivator of ER-mediated pS2 gene induction in MCF7 cells. By investigating promoter requirements for PRMT1 recruitment we find that the patient SE translocation (SET) protein, which was reported to protect histone tails from acetylation, associates with the uninduced pS2 gene promoter and dissociates early upon estrogen treatment. Knockdown of SET or trichostatin A (TSA) treatment causes premature acetylation of H4 and abrogation of H4 Arg3 methylation at the pS2 gene promoter resulting in diminished transcriptional induction. Thus, SET prevents promoter acetylation and is a prerequisite for the initial acetylation-sensitive steps of pS2 gene activation, namely PRMT1 function. Similar to pS2 we identify lactoferrin as a PRMT1-dependent and TSA-sensitive ER target gene. In contrast, we find that the C3 gene, another ER target, is activated in a PRMT1-independent manner and that SET is involved in C3 gene repression. These findings establish the existence of PRMT1-dependent and -independent ER target genes and show that proteins guarding promoter hypoacetylation, like SET, execute a key function in the coactivation process by PRMT1.
J Biol Chem 2006 Sep 15
PMID:SET-mediated promoter hypoacetylation is a prerequisite for coactivation of the estrogen-responsive pS2 gene by PRMT1. 1686 Dec 34

The aryl hydrocarbon receptor (AhR) binds with high affinity to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related halogenated aromatics, but also binds with lower affinity to structurally diverse exogenous and endogenous chemicals. One study reported that 3-methylcholanthrene (3MC) activated the estrogen receptor (ER) through the AhR, which acts as co-regulatory protein, whereas a recent report showed that 3MC directly bound and activated ERalpha. This study also shows that the AhR agonists benzo[a]pyrene, 3,3',4,4'-tetrachlorobiphenyl, chrysin, 6-methyl-1,3,8-trichlorodibenzofuran, and 3,3'-diindolylmethane also induce ERalpha-dependent transactivation. Moreover, in chromatin immunoprecipitation assays, these compounds induce binding of AhR and ERalpha to the CYP1A1 and pS2 gene promoters, which is consistent with their activities as both selective AhR modulators (SAhRMs) and selective ER modulators (SERMs).
Biol Chem 2006 Sep
PMID:Aryl hydrocarbon receptor agonists directly activate estrogen receptor alpha in MCF-7 breast cancer cells. 1697 88

Multiple factors influence estrogen receptor alpha (ERalpha) transcriptional activity. Current models suggest that the silencing mediator of retinoic acid and thyroid hormone receptor (SMRT) corepressor functions within a histone deactylase-containing protein complex that binds to antiestrogen-bound ERalpha and contributes to negative regulation of gene expression. In this report, we demonstrate that SMRT is required for full agonist-dependent ERalpha activation. Chromatin immunoprecipitation assays demonstrate that SMRT, like ERalpha and the SRC-3 coactivator, is recruited to an estrogen-responsive promoter in estrogen-treated MCF-7 cells. Depletion of SMRT, but not histone deacetylases 1 or 3, negatively impacts estradiol-stimulated ERalpha transcriptional activity, while exogenous expression of SMRT's receptor interaction domains blocks ERalpha activity, indicating a functional interaction between this corepressor and agonist-bound ERalpha. Stimulation of estradiol-induced ERalpha activity by SMRT overexpression occurred in HeLa and MCF-7 cells, but not HepG2 cells, indicating that these positive effects are cell type specific. Similarly, the ability of SMRT depletion to promote the agonist activity of tamoxifen was observed for HeLa but not MCF-7 cells. Furthermore, impairment of agonist-stimulated activity by SMRT depletion is specific to ERalpha and not observed for receptors for vitamin D, androgen, or thyroid hormone. Nuclear receptor corepressor (N-CoR) depletion increased the transcriptional activity of all four tested receptors. SMRT is required for full expression of the ERalpha target genes cyclin D1, BCL-2, and progesterone receptor but not pS2, and its depletion significantly attenuated estrogen-dependent proliferation of MCF-7 cells. Taken together, these data indicate that SMRT, in conjunction with gene-specific and cell-dependent factors, is required for positively regulating agonist-dependent ERalpha transcriptional activity.
Mol Cell Biol 2007 Sep
PMID:The silencing mediator of retinoic acid and thyroid hormone receptor (SMRT) corepressor is required for full estrogen receptor alpha transcriptional activity. 1759 92

Deoxybenzoins are plant compounds with similar structure to isoflavones. In this study, we evaluated the ability of two synthesized deoxybenzoins (compound 1 and compound 2) (a) to influence the activity of the estrogen receptor subtypes ERalpha and ERbeta in HeLa cells co-transfected with an estrogen response element-driven luciferase reporter gene and ERalpha- or ERbeta-expression vectors, (b) to modulate the IGFBP-3 and pS2 protein in MCF-7 breast cancer cells, (c) to induce mineralization of KS483 osteoblasts and (d) to affect the cell viability of endometrial (Ishikawa) and breast (MCF-7, MDA-MB-231) cancer cells. Docking and binding energy calculations were performed using the mixed Monte Carlo/Low Mode search method (Macromodel 6.5). Compound 1 displayed significant estrogenic activity via ERbeta but no activity via ERalpha. Compound 2 was an estrogen-agonist via ERalpha and antagonist via ERbeta. Both compounds increased, like the pure antiestrogen ICI182780, the IGFBP-3 levels. Compound 2 induced, like 17beta-estradiol, significant mineralization in osteoblasts. The cell viability of Ishikawa cells was unchanged in the presence of either compound. Compound 1 increased MCF-7 cell viability consistently with an increase in pS2 levels, whereas compound 2 inhibited the cell viability. Molecular modeling confirmed the agonistic or antagonistic behaviour of compound 2 via ER subtypes. Compound 2, being an agonist in osteoblasts, an antagonist in breast cancer cells, with no estrogenic effects in endometrial cancer cells, makes it a potential selective estrogen receptor modulator and a choice for hormone replacement therapy.
Steroids 2007 Sep
PMID:Deoxybenzoins are novel potent selective estrogen receptor modulators. 1765 12

Tamoxifen resistance (TAMr) in breast cancer is a serious clinical dilemma, with no satisfactory explanation. We hypothesised that changes in the expression of steroid hormone receptors (ERalpha, ERbeta), their downstream target genes (PR, pS2) and their associated co-regulators (AIB-1, SRC-1, SRA, NCoR-1, SMRT and REA) could be related to the acquisition of TAMr. To test this hypothesis, we developed in vitro TAMr cell line models by continuous exposure of MCF-7 cells to 4-hydroxytamoxifen (4-HT) over 12 (MCF-7MMU1) and 21 (MCF-7MMU2) months, respectively and examined the expression of the above by Western blotting and immunohistochemistry. In addition, we further examined the changes in global gene expression in TAMr cells in comparison with TAM-sensitive cells by microarray analysis. We report here that acquisition of TAMr is associated with changes in the expression of PR, pS2 and several co-activators, but not ERs. In addition, genes associated with cell cycle, cell adhesion and extracellular matrix, were up-regulated while those associated with apoptosis or growth factors/hormones were down-regulated. Based on our results, it appears that increased co-activator expression, in concert with alterations in genes associated with controlling cell proliferation and survival contribute to TAMr in breast cancer.
Int J Oncol 2007 Sep
PMID:Changes in expression of steroid receptors, their downstream target genes and their associated co-regulators during the sequential acquisition of tamoxifen resistance in vitro. 1767 82

Breast cancers expressing estrogen receptor-alpha (ERalpha) are associated with a favorable biology and are more likely to respond to hormonal therapy. In addition to ERalpha, other pathways of estrogen response have been identified including ERbeta and GPR30, a membrane receptor for estrogen, and the key mechanisms regulating expression of ERs and hormone response remain controversial. Herein, we show that TFAP2C is the key regulator of hormone responsiveness in breast carcinoma cells through the control of multiple pathways of estrogen signaling. TFAP2C regulates the expression of ERalpha directly by binding to the ERalpha promoter and indirectly via regulation of FoxM1. In so doing, TFAP2C controls the expression of ERalpha target genes, including pS2, MYB, and RERG. Furthermore, TFAP2C controlled the expression of GPR30. In distinct contrast, TFAP2A, a related factor expressed in breast cancer, was not involved in estrogen-mediated pathways but regulated expression of genes controlling cell cycle arrest and apoptosis including p21(CIP1) and IGFBP-3. Knockdown of TFAP2C abrogated the mitogenic response to estrogen exposure and decreased hormone-responsive tumor growth of breast cancer xenografts. We conclude that TFAP2C is a central control gene of hormone response and is a novel therapeutic target in the design of new drug treatments for breast cancer.
Cancer Res 2007 Sep 15
PMID:TFAP2C controls hormone response in breast cancer cells through multiple pathways of estrogen signaling. 1787 80

The ethanol extract of the fruits of Vitex rotundifolia (VRE) and its four major compounds (casticin, luteolin, rotundifuran and agnuside) were tested for their estrogen-like activity by using the modified cell proliferation assay (E-SCREEN assessment system), as well as the estrogen receptor (ER(alpha)), estrogen receptor-regulated progesterone receptor and pS2 mRNA expression in MCF-7 cells. The results showed that only agnuside and rotundifuran could stimulate the proliferation of MCF-7 cells. These actions were dose dependent (range from 100 nM to 10 microM) and could be significantly inhibited by the specific estrogen receptor antagonist ICI 182,780. The estrogen receptor ER(alpha) and the estrogen receptor-regulated progesterone receptor and pS2 mRNA levels were increased by treatment with rotundifuran and agnuside within 24 h, and the effects could be reversed by ICI 182,780. The standardization of the extract and constituents were carried out by means of a high-performance liquid chromatography-fingerprint. It was concluded that VRE and its compounds showed estrogen-like activity and that the estrogenic effects of rotundifuran and agnuside were mediated by the estrogen inducible gene, which may be useful in regulating the hormone levels to treat related diseases. However, further studies are required to assess the physiological significance of VRE in animals and man.
J Pharm Pharmacol 2007 Sep
PMID:Evaluation of the estrogenic activity of the constituents in the fruits of Vitex rotundifolia L. for the potential treatment of premenstrual syndrome. 1788 2

Activin is a member of the transforming growth factor beta superfamily that regulates mammary cell function during development, lactation, and in cancer. Activin slows the growth of breast cancer cells by inducing G(0)/G(1) cell cycle arrest. Estrogen is a steroid hormone that stimulates the proliferation of mammary epithelial cells in development and oncogenesis. The crosstalk between estrogen and activin that regulates activin ligand expression, activin and estrogen signal transduction, and cell cycle arrest was investigated in this study. Estrogen antagonized activin-dependent production of plasminogen activator inhibitor 1 (PAI-1) mRNA, while activin repressed estrogen-dependent transcription of trefoil factor 1. The repression of estrogen signaling by activin was recapitulated using a simple estrogen response element-luciferase construct and was enhanced in the presence of overexpressed estrogen receptor alpha (ERalpha). In contrast, estrogen-mediated repression of activin signaling could not be recapitulated on a simple CAGA Smad-binding element but did inhibit the short PAI-1 promoter, p3TP-luciferase, especially when ERalpha was overexpressed. Repression of both estrogen- and activin-regulated transcription was found to be ligand induced and Smad3 dependent. In addition to transcriptional repression, estrogen also reduced the amount of activin B mRNA and protein produced by MCF7 breast cancer cells. These studies demonstrate the importance of activin and estrogen crosstalk during mammary cell growth and cancer initiation.
Endocr Relat Cancer 2007 Sep
PMID:Activin and estrogen crosstalk regulates transcription in human breast cancer cells. 1791 98


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