In Vitro and In Vivo Biodistribution of ZRS1, a Stabilized Type I N-Acetoxymethyl Carbamate-Containing Combi-Molecule

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.

Advances in the development of hybrid anticancer drugs

“…The combi-molecule strategy aims to the vectorization of anticancer drugs to target specific tissues is also a promising method to design highly effective, non-toxic and useful hybrids. Compound 97 is a hybrid connecting also aromatic nitrogen mustards (40)(41)(42) and tyrosine that was designed to mimic the estradiol nucleus [55]. Compound 97 exhibits antiproliferative activity in the M range on prostate, breast, ovarian and uterine cancer cell lines and was slightly more active than chlorambucil (41).…”

Detection of Carbofuran-Protein Adducts in Serum of Occupationally Exposed Pesticide Factory Workers in Pakistan

“…Carbofuran is a very toxic carbamate compound and among the most readily absorbed insecticides as compared to several well-known pesticides including carbaryl, chlorpyrifos, dichlorodiphenyltrichloroethane (DDT), malathion, and parathion. Upon rapid absorption through the skin, lungs, GI tract, and mucous membranes, carbofuran is distributed to all organs and is rapidly eliminated. ,, Over the years, carbofuran poisoning has been extensively studied by many researchers in humans, insects, mice, and plants. − In humans, carbofuran metabolism is mediated by the cytochrome P450 (CYP3A4) enzyme, which is one of the most abundant drug-metabolizing CYP isoforms in the human liver that metabolizes endogenous compounds. The main pathway of oxidative metabolism of carbofuran in animals, insects, and plants appears to consist of hydroxylation of a benzylic carbon to yield a major ring oxidation metabolite, 3-hydroxycarbofuran, and two minor metabolites (Scheme ).…”