Abstract P2-06-03: Specific Transcriptional Response of Four Blockers of Estrogen Receptors on Estrogen-Modulated Genes in ZR-75-1 Breast Cancer Xenografts
Bibliographic record
Abstract
Abstract Introduction: Acolbifene (ACOL) is a novel compound completely free of estrogen-like activity in both the human and rat mammary gland and uterus. In previous studies, it was observed that ACOL could have a cytotoxic or tumoricidal rather only tumorostatic activity, with a lack of development of tumor resistance. The objective of the present study was to obtain information on the molecular basis of the tumoricidal properties of acolbifene, as well as on the identity of the genes potentially implicated in the resistance to tamoxifen (TAM). The specificity of action of ACOL was compared to the pure antiestrogen fulvestrant (FUL) as well as to tamoxifen (TAM) and raloxifene (RAL). Methods: The gene expression profile of the ZR-75-1 breast cancer xenografts was studied following treatment with ACOL, RAL, TAM and FUL. Ovariectomized female nude mice (10/group) bearing human ZR-75-1 breast cancer xenografts were supplemented with estrone (E1) (subcutaneous silastic implants) and were injected daily with the vehicle alone or 50 μg of ACOL, RAL, TAM or FUL for 6 months. Mice were killed 24h after the last injection and ZR-75-1 tumors were collected and processed for RNA extraction and microarray analyses (Affymetrix GeneChip U133 Plus 2.0). Results: Long-term exposure of ZR-75-1 xenografts to E1 causes a massive modulation of E1-responsive genes. When the antiestrogens were administered simultaneously with E1, some compound-specific prevention of the effect of E1 was observed. Globally, the efficacy of the compounds was ACOL>FUL or RAL>TAM. ACOL significantly prevented the effect of E1 on 195 responsive genes. Among these, the most enriched gene ontological group in Molecular Function was Receptor Activity, including ER, insulin, retinoid and thrombospondin receptor activity. One of the transcriptional repressors of the estrogen signaling pathway, the NKX31, was down-regulated by E1 and completely blocked by ACOL (fold-change −1.64 and 2.54, respectively). The most enriched biological processes were associated with mammary gland development, positive regulation of glucose metabolic processes and blood vessel morphogenesis. Between the genes implicated in cell death/apoptosis of breast cancer cells, the changes of expression of 57, 51, 48 and 31 genes were significantly neutralized by ACOL, RAL, FUL and TAM, respectively. Sixteen genes implicated in tumor resistance to TAM were significantly blocked by ACOL, including DEGS1, a gene implicated in the inhibition of EGF receptor biosynthesis. The other 15 genes in the group were up-regulated by E1, changes which were significantly blocked by ACOL. Conclusion: The present data offer a possible explanation for the potent tumoricidal action of acolbifene in human breast cancer xenografts, thus offering a new paradigm in the hormonal therapy of breast cancer. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-06-03.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 source (direct Gemma or distilled Codex), 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".