Abstract 1246: Single-cell profiles of multiplexed in vivo models facilitate the characterization of phenotypic plasticity and invasion in glioblastoma

Abstract

Abstract The lethality of glioblastoma and the failure of surgical treatment are in part attributable to the invasive properties of this cancer; however, our understanding of the cell-biological process is limited due to the complex representation of invasion phenotype in glioblastoma models. Here, to overcome this limitation, we developed an in vivo approach with human glioblastoma spheroid lines multiplexed for mouse intracranial xenografts. We validated this with 20 patient-derived models and identified, by 3’end single-cell RNA-sequencing (scRNA-seq) coupled with deconvolution analysis, in vivo models capable of infiltrating along the periphery of either neurons or blood vessels. We previously found that the diverse malignant cells in glioblastoma specimens exist in a limited set of four cellular states: neural progenitor-like (NPC-like), oligodendrocyte progenitor-like (OPC-like), astrocyte-like (AC-like), and mesenchymal-like (MES-like), with potential for state plasticity under the influence of tumor microenvironment. To determine whether or not the cell state heterogeneity is implicated in glioblastoma invasion, we profiled and characterized programs, states, and clonality of invading glioblastoma cells by comparing cells from the contralateral invasive edge to their counterparts residing at the original bulk tumor. This analysis showed evidence of a bi-directional state transitioning model for cells undergoing distinct environmental spaces. Exploration of cell state distribution at the primary tumors revealed that presence of an OPC-like state was significantly associated with invasion phenotype regardless of the infiltration routes. Our results suggest that cellular plasticity may be a prerequisite for the topographically diffusive nature of glioblastoma, urging further assessment by perturbing critical regulators of the cellular state programs. In conclusion, this work describes multiplexed in vivo models as an enabling platform for the rapid interrogation of patient-derived xenografts, coupling the molecularly measurable states with functional identity driving malignant phenotypes such as cancer invasion. Citation Format: Toshiro Hara, Rony Chanoch-Myers, Alissa Greenwald, Lillian Bussema, Jinan Behnan, Rossella Galli, Hiroaki Wakimoto, Itay Tirosh, Mario Suvà. Single-cell profiles of multiplexed in vivo models facilitate the characterization of phenotypic plasticity and invasion in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1246.