Abstract 2663: CR42-24, a novel colchicine derivative, a therapeutic for bladder cancer

Abstract

Abstract Colchicine is an anti-mitotic drug that targets unpolymerized tubulin, and inhibits microtubule polymerization. It is primarily used to treat gout but has been investigated in numerous clinical trials to treat conditions such as leukemia (ALL), prostate cancer, Behcet's disease, etc.. However, due to its narrow therapeutic window colchicine has had limited clinical translation. A possible approach to reduce general is to produce a derivative with an increased cancer specificity and selectivity by a narrower molecular target selection. Previously, our lab has designed and synthesized a novel colchicine derivative (CR42-24) with a more favorable pharmacological profile compared to colchicine. This was accomplished by designing a structure with an increased affinity for βIII tubulin. βIII tubulin is a β-tubulin isotype that is incorporated into tubulin dimers that make up microtubules. βIII is an excellent target for novel therapies as it has low expression in healthy tissue, is overexpressed in metastatic cancers, and is a clinical marker of poor prognosis. Using cell line screening we demonstrate that CR42-24 is highly toxic to a variety of cancer types with IC50 values at low nanomolar concentrations. More specifically CR42-24 is shown to be highly effective against bladder cancer. Current chemotherapy for bladder cancer is a combination of gemcitabine and cisplatin (Gem/Cis). Although marginally successful, many patients develop resistance to Gem/Cis leaving them with limited options for a second line therapy, thus development of alternative therapies is highly desired. Using in vitro assays we demonstrate that CR42-24 kills aggressive bladder cancer cell types, and is more effective than gemcitabine and cisplatin. Additionally, CR42-24 doubles survival rates of mice with bladder cancer xenografts. We also show that CR42-24 is highly synergistic with other chemotherapies, thereby increasing its therapeutic potential. Through our studies we have shown that CR42-24 is effective in treating aggressive bladder cancer and thus may serve as an alternative or second line therapy. Citation Format: Clayton Bell, Kyle Potts, Desmond Pink, John Lewis, Jack Tuszynski. CR42-24, a novel colchicine derivative, a therapeutic for bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2663.