Effect of O6-Substituted Guanine Analogs on O6-methylguanine DNA-methyltransferase Expression and Glioblastoma Cells Viability
Why this work is in the frame
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Bibliographic record
Abstract
BACKGROUND: Glioblastoma multiforme (GBM) is often associated with a poor survival prognostic for patients. The main reason seems to be the acquired or inherent resistance to the chemotherapeutic agent used to treat the tumor, temozolomide (TMZ). To this day, the most recognized pathway of resistance is the DNA Direct Repair pathway by the means of the protein O6- methylguanine DNA-methyltransferase (MGMT). OBJECTIVES: To design and synthesize a series of MGMT inhibitors that can sensitize GBM cells to TMZ. METHODS: Twenty-five O6-alkyl, O6-aryl and O6-substituted-aryl guanine analogs including nine novel compounds were synthesized, characterized, analyzed by molecular docking and tested on the T98G GBM cells viability. RESULTS: Following molecular modeling with MGMT, the newly designed compounds 19, 22, and 24 emerged as the most promising MGMT ligands and displayed modest cytotoxicity. Guanine analog (19), bearing a p-nitrobenzyl moiety, reduced considerably the O6-methylguanine DNAmethyltransferase expression level. When combined with TMZ (1), which is used as first line treatment for brain tumors, compounds 19, 22, and 24 decreased T98G cells proliferation by 32%, 68% and 50%, respectively. TMZ (1) displayed negligible effect on the proliferation of these cells further supporting the notion that this cell model is resistant to this alkylating agent. CONCLUSION: Overall, these results notably highlight a group of MGMT inhibitors that warrants further exploration in the development of therapeutic options to circumvent TMZ resistance in brain tumors.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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 it