In Vitro and In Vivo Biodistribution of ZRS1, a Stabilized Type I N-Acetoxymethyl Carbamate-Containing Combi-Molecule
Bibliographic record
Abstract
Combi-molecules are agents designed to block receptors on their own and to further degrade to bioactive agents. Here we studied the fate of a novel combi-molecule of triazene class termed "ZRS1" in biological medium using multilayer aggregates and mouse tumour models. ZRS1 is a second generation derivative of RB107, a prodrug designed to release an EGFR inhibitor FD105 plus a methyl diazonium species. RB107 contains an acetoxymethyl function that is hydrolyzed too rapidly to generate BJ2000, a monoalkyltriazene that further degrades to FD105 and DNA alkylating methyldiazonium species. Recently, in order to prevent rapid hydrolysis of the acetoxymethylene function in the absence of cells and to delay the release of BJ2000, we designed ZRS1 that contains a more stable acetoxymethyl carbamate function. The results showed that ZRS1 was more stable than RB107 in cell culture medium supplemented with serum, with a rather long half life (>2 h). However, in an experiment where it was allowed to degrade in multilayer aggregates of ovarian cancer cells OV90, it rapidly released BJ2000 and its corresponding metabolite FD105, both in the medium and the multilayer aggregates. Interestingly, the intact ZRS1 could be detected in the multilayer aggregates with a T(max) around 10 min. Studies in vivo, in human DU145 prostate cancer xenograft model, revealed that ZRS1 blocked tumour growth and released FD105 and its acetylated metabolite FD105Ac, the latter being the major metabolite. Likewise, time course analysis in 4T1 mouse syngeneic breast cancer model showed a rapid release of FD105 and FD105Ac in the plasma and in the tumours. In summary, ZRS1 appeared as a good prodrug of the stable EGFR inhibitory metabolites FD105 and FD105Ac. Its ability to generate high concentrations of FD105Ac, a more potent EGFR inhibitor as is its major metabolite, is significant over previous methylating combi-molecules. Furthermore, this study showed that multilayer OV90 aggregates could be developed as an effective model to predict the stability and degradation of ZRS1 in vivo.
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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".