Estrogen Receptor-α Phosphorylated at Ser118 Is Present at the Promoters of Estrogen-Regulated Genes and Is Not Altered Due to HER-2 Overexpression
Bibliographic record
Abstract
Detection of estrogen receptor (ER)-alpha phosphorylated at Ser(118) (P-Ser(118)-ER-alpha) may be an indicator of an intact ligand-dependent ER-alpha in breast tumors in vivo and may predict responsiveness to endocrine therapy. The current study addresses whether P-Ser(118)-ER-alpha is functionally involved in ER target gene transcription and if this is modulated by HER-2 overexpression. Using chromatin immunoprecipitation analysis, P-Ser(118)-ER-alpha was found associated with the promoters of several estrogen-regulated genes in MCF-7 breast cancer cells 30 minutes following estrogen treatment. Coactivators AIB1 and p300 were coimmunoprecipitated with P-Ser(118)-ER-alpha following estrogen treatment. The overexpression of HER-2 protein in MCF-7 cells did not affect estrogen induction of phosphorylation of Ser(118) or its presence at the promoters of several estrogen-regulated genes. U0126, an inhibitor of mitogen-activated protein kinase (MAPK) pathway, had no effect on P-Ser(118)-ER-alpha. The lack of effect of HER-2 overexpression on P-Ser(118)-ER-alpha expression in cell models is supported by similar levels of expression of P-Ser(118)-ER-alpha in ER(+)/HER-2-overexpressing and ER(+)/HER-2(-) breast tumors in vivo. Using inhibitors of cyclin-dependent kinase 7 (Cdk7), [(5,6-dichloro-1-beta-d-ribofuranosylbenzimidazole and 2-(R)-1-ethyl-2-hydroxyethylamino)-6-benzylamino-9-isopropylpurine], and IkappaB kinase-alpha (IKK-alpha; BAY-11-7082), we show that IKK-alpha, but not Cdk7, is at least in part involved in estrogen-mediated phosphorylation at Ser(118) in MCF-7 cells. Our data provide direct evidence for a functional role of P-Ser(118)-ER-alpha in estrogen-regulated signaling and do not support the hypothesis that resistance of breast tumors to tamoxifen therapy involves ligand independent activation of ER-alpha due to constitutive phosphorylation of Ser(118) by constitutive activation of MAPK pathway.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".