High Sensitivity of an Ha-RAS Transgenic Model of Superficial Bladder Cancer to Metformin Is Associated with ∼240-Fold Higher Drug Concentration in Urine than Serum
Bibliographic record
Abstract
While pharmacoepidemiologic and laboratory studies have supported the hypothesis that the antidiabetic drug metformin may be useful in treating or preventing cancer, there is limited evidence to suggest which specific cancer sites may be particularly sensitive. Sensitivity likely is determined both by features of tumor pathophysiology and by pharmacokinetic factors. We used UPII-mutant Ha-ras transgenic mice that develop hyperplasia and low-grade, papillary urothelial cell carcinoma to determine whether metformin has activity in a model of superficial bladder cancer. Metformin significantly improved survival, reduced urinary tract obstruction, reduced bladder weight (a surrogate for tumor volume), and led to clear activation of AMP α kinase and inhibition of mTOR signaling in neoplastic tissue. We investigated the basis of the unusual sensitivity of this model to metformin, and observed that following oral dosing, urothelium is exposed to drug concentrations via the urine that are approximately 240-fold higher than those in the circulation. In addition, we observed that bladder cancer cell lines (RT4, UMUC-3, and J82) with homozygous deletion of either TSC1 or PTEN are more sensitive to metformin than those (TEU2, TCCSUP, and HT1376) with wild-type TSC1 and PTEN genes. Our findings provide a strong rationale for clinical trials of oral metformin in treatment of superficial bladder cancer.
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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 | 0.000 |
| 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".