Abstract A25: COTI-2, a novel small molecule that is effective against multiple human cancer cell lines in vitro and in vivo
Authors: Salim Kowthar Y. , Vareki Saman Maleki , Danter Wayne R. , Koropatnick James 
Published: January 2017

Introduction: Identification of novel anti-cancer compounds with high efficacy and low toxicity is critical in drug development. High-throughput screening and other such strategies are generally resource-intensive. Therefore, in silico computer-aided drug design has gained rapid acceptance and popularity. We employed our proprietary computational platform (CHEMSAS®), which uses a unique combination of traditional and modern pharmacology principles, statistical modeling, medicinal chemistry, and machine-learning technologies to discover and optimize novel compounds that could target various cancers. COTI-2 is a novel, small molecule, candidate anti-cancer drug identified using CHEMSAS. This study describes the in vitro and in vivo evaluation of COTI-2.

Methods: A series of cell proliferation and cell viability assays including alamarBlue®, cell counting, CellTiter-Blue®, and flow cytometry were used to measure the effect of COTI-2 on tumor cell proliferation and apoptosis in a wide range of human cancer cell lines. COTI-2 was also tested in vivo against several human xenograft models. Two independent kinase assays were used to examine whether COTI-2 is a kinase inhibitor. The capacity of COTI-2 to inhibit Hsp90 was determined using an Hsp90 ATPase activity assay. A series of knockdown studies of the PI3K/AKTmTOR pathway were used to evaluate the effect of COTI-2 on this pathway. Finally, the effect of COTI-2 on mutant p53 was evaluated using p53 conformational studies.

Results: Our data demonstrate that COTI-2 is effective against a diverse group of human cancer cell lines regardless of their tissue of origin or genetic makeup. Most treated cancer cell lines were sensitive to COTI-2 at nanomolar concentrations. When compared to traditional chemotherapy or targeted-therapy agents, COTI-2 showed superior activity against tumor cells, in vitro and in vivo. Despite its potent anti-tumor efficacy, COTI-2 was safe and well-tolerated in mouse hosts of human tumor xenografts in vivo. Our preliminary mechanism of action results indicate that COTI-2 is not a traditional kinase or an Hsp90 inhibitor but that AKT and p53 are likely targets of COTI-2.

Conclusion: COTI-2 is a novel, anti-cancer agent that was designed by our proprietary computational platform CHEMSAS. It is effective against a wide variety of human cancer cell lines in vitro and in vivo, regardless of their tissue of origin or genetic make-up. COTI-2 induces apoptosis in tumor cells in vitro, is well-tolerated in vivo, and does not cause toxicity in treated animals. COTI-2 is not a traditional kinase or Hsp90 inhibitor. Finally, COTI-2 appears to target mutant p53 and the PI3K/AKT/mTOR pathway.

Citation Format: Kowthar Y. Salim, Saman Maleki Vareki, Wayne R. Danter, James Koropatnick. COTI-2, a novel small molecule that is effective against multiple human cancer cell lines in vitro and in vivo. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Targeting the Vulnerabilities of Cancer; May 16-19, 2016; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(1_Suppl):Abstract nr A25.