Abstract 3015: Precise investigation of cancer stem cells in mouse glioblastoma

In this study, we employ mouse models to investigate features and roles of cancer stem cells (CSCs) in glioblastoma (GBM). A nestin-TK-GFP transgene is firstly used to label CSCs in a fully penetrant mouse model of GBM (M7: hGFAP-Cre; Nf1fl/+; p53fl/fl; Ptenfl/+). Food-mediated ganciclovir (GCV) delivery kills proliferative transgene positive cells and significantly prolongs the lives of the transgene bearing mice. Isolation and transplantation of the tumor cells indicates the GFP+ cells are more tumorigenic than the GFP- cells. We then generate and characterize a novel transgene (CGD: nestin-CreERT2-H2BeGFP-hDTR) that labels all the neural stem/progenitor cells in the subventricular zone (SVZ). This transgene efficiently promotes brain tumors by eliminating tumor suppressor genes (CGD-M4: CGD; Nf1fl/+; p53fl/+; Ptenfl/+) in the corresponding cells. The CGD-GFP+ tumor cells are quiescent in vivo, yet form more spheres in vitro than the GFP- cells. The GFP+ cells are competent to develop tumors in a serial transplantation assay and constantly maintain a quiescent subpopulation pool in the newly formed tumors. Diphtheria toxin treatment ablates the CGD-GFP+ tumor cells and greatly reduces the tumor bulk. Temozolomide, the conventional chemotherapy for human GBM patients, benefits only mice transplanted with GFP- but not CGD-GFP+ tumor cells. Our study demonstrates the essential role of CSCs in GBM initiation, recurrence, and drug resistance. Further analysis of the CGD-GFP+ cells might delineate novel treatments for this deadly disease. Citation Format: Xuanhua P. Xie, Dan R. Laks, Daochun Sun, Asaf Poran, Ashley M. Laughney, German Belenguer, Joan Massague, Xiuping Zhou, Isabel Farinas, Olivier Elemento, Luis F. Parada. Precise investigation of cancer stem cells in mouse glioblastoma [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 3015.