The Role of Histone Acetylation and Death Receptor 5 (DR5) Expression in the Treatment of Chronic Lymphocytic Leukemia (CLL).
Bibliographic record
Abstract
Abstract Chronic lymphocytic leukemia (CLL) is a disease in which two-thirds of patients will require therapy, usually with the alkylating agent, chlorambucil (CLB) or the nucleoside analog, fludarabine (FLU). TRAIL is a death receptor ligand that has shown selective cytotoxicity towards a variety of malignancies. CLL cells, however, are relatively resistant to this agent. We have previously demonstrated that CLB- and Flu-induced apoptosis is partially mediated through activation of the TRAIL apoptotic pathway and this is related to the up-regulation of the TRAIL death receptors, DR4 and DR5 (Oncogene, 22:8356–8369, 2003). Combining CLB or Flu with TRAIL produced a synergistic apoptotic response in CLL cells. In contrast, the upregulation of DR5 and the synergistic apoptotic response was not observed in normal lymphocytes. We have subsequently demonstrated that the up-regulation of DR5 is mediated by transcription factors, nuclear factor κB (NFκB) and p53, and histone acetylation. Using chromatin immunoprecipitation assays, we have found that the p65 subunit of NFκB and p53 are bound to the DR5 gene in CLL cells following either CLB or Flu treatment. In addition, histone 3 is acetylated following CLB and Flu treatment corresponding to histone acetylase p300 binding to the DR5 gene. Histone deacetylase 1 (HDAC1) also binds to the DR5 gene following CLB or Flu treatment, but generally at later time points. Overall histone acetylation was also found to be increased in CLL cells, as compared to normal lymphocytes. Treatment with HDAC inhibitors, which are being evaluated in clinical trials, resulted in increased binding of p53 and NFκB, but not HDAC1, to the DR5 gene and increased DR5 mRNA levels in cells. Furthermore, enhanced apoptosis was also observed in CLL cells treated with combinations of SAHA (another HDAC inhibitor) and TRAIL. These findings suggest that histone acetylation is important in regulating DR5 expression and that HDAC inhibitors increase DR5 expression mediated by p53 and NFκB. This could provide a mechanism to sensitize CLL cells to TRAIL-induced apoptosis.
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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) | 0.001 | 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".