Abstract B24: Targeting promoter regions of oncogenic drivers in pediatric AML cells using G-quadruplex Interacting Drugs (GQIDs)

Cancer is primarily a disease characterized by aberrant gene expression that is manifested by the overexpression of key genes that support tumor development and maintenance. In many instances, oncogenic drivers are frequently ‘undruggable’ because of structural challenges, the inability to effectively inhibit high concentrations of overexpressed proteins, and the development of drug resistance mutations. An alternative therapeutic approach is to directly inhibit gene transcription by targeting unique secondary DNA structures, called G-quadruplexes, that are associated with subsets of promoters. Our laboratory investigated the activity of a class of compounds termed G-quadruplex Interacting Drugs (GQIDs) that are able to shut down the expression of specific genes used by tumor cells for growth and survival. We tested the activity of two GQIDs GQC-05 and GSA-1103 on cell growth of a panel of eight pediatric and eight adult AML cell lines. Drug dose response analysis showed IC50 values ranging from approximately 10 nM to 1 µM for GQC-05 and from 40 nM to 2 µM for GSA-1103. The AML cell lines had different sensitivities to each GQID indicating a different mechanism of action for each compound. Three AML cell lines that were highly resistant to cytarabine were among the more sensitive to GQC-05. Four cell lines sensitive to GQC-05 had high expression of either c-myc and/or bcl-2, both of which are potential targets of these two GQIDs. Furthermore, treatment of cells with the GQC-05 decreased expression of c-myc and bcl-2. These studies will help define a novel approach of repressing key drivers of leukemia by targeting selective promoter structures. Validation of such an approach for AML will have important implications for testing this therapeutic approach to other childhood cancers in order to improve the length and quality of survival. Citation Format: Apurvi Patel, Justin J. Montoya, Megan Turnidge, Marya Sabir, Daniel H. Wai, David W. Lee, Vijay Gokhale, Eiman Aleem, Laurence J. Hurley, Robert J. Arceci, David O. Azorsa. Targeting promoter regions of oncogenic drivers in pediatric AML cells using G-quadruplex Interacting Drugs (GQIDs). [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B24.