Abstract B39: NQO1 as a therapeutic target for atypical teratoid/ rhabdoid tumor

Abstract

Abstract Atypical Teratoid/ Rhabdoid Tumor (ATRT) is an aggressive cancer that accounts for up to 20% of infant brain tumors. Even with intense chemotherapy and radiation, approximately 75% of children die from their disease at a median of 10 months after diagnosis. We found that the pathognomonic genetic lesion of ATRTs and related malignant rhabdoid tumors (MRTs), loss of the SWI/SNF chromatin remodeling complex member INI1/hSNF5/SMARCB1, is associated with high expression of NAD(P)H:quinone oxidoreductase 1 (NQO1), a two-electron oxidoreductase. Thus, we hypothesized that ATRTs will be vulnerable to drugs such as ß-lapachone (ß-lap, ARQ761 in clinical form) that selectively kill NQO1-expressing cells via mu-calpain mediated cell necrosis. A panel of ATRT cell lines exhibited overall high NQO1 expression and sensitivity to ß-lap (IC50 1.6-4 uM). A two-hour pulse with ß-lap caused a burst of ROS-mediated DNA damage and PARP1 hyperactivation, resulting in NAD+ and ATP depletion. Lack of NQO1 expression or inhibition of NQO1 with dicoumarol abrogated sensitivity to ß-lap. Low expression of NQO1 in normal brain and other pediatric tissues suggests a wide therapeutic window for ß-lap, and a survival advantage was observed after treatment in a heterotopic mouse xenograft model with several mice achieving apparent cures. Furthermore, the mechanism of ß-lap results in synergy with standard of care agents such as ionizing radiation, increasing its potential for clinical applications. Citation Format: Julia C. Meade, Zachary R. Moore, Sarai H. Stuart, Agnieszka Cholka, Richard L. Boriack, Jingying Xu, Anat Erdreich-Epstein, Dinesh Rakheja, David A. Boothman, James F. Amatruda, Theodore W. Laetsch. NQO1 as a therapeutic target for atypical teratoid/ rhabdoid tumor. [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 B39.