Abstract 2387: Characterization of orthotopic bioluminescent patient-derived xenograft model of glioma for drug discovery
Authors: Wang Jinxi , Chen Ling , Zhou Jun , Zhang Likun , Huang Jinyu , Zhu Xueluan , Bourre Ludovic , Wang Jingjing 
Published: April 2023

Abstract
Introduction: Gliomas account for majority of primary brain tumors and are composed of different grades, which present distinct molecular alterations, histological characteristics, and response to treatments. Patient-derived xenografts (PDXs) are the most “close-to-patient” models for oncology studies which largely maintain the histo- and molecular- pathology of the original tumors and are widely applied in preclinical evaluations. Subcutaneously inoculated glioma PDX models provide convenient evaluation of treatments’ efficacy but are difficult to mimic the in-situ microenvironment and diffuse invasive growth to peripheral tissue in the brain. Orthotopic implantation of bioluminescent labelled glioma models provides a more relevant preclinical model to evaluate and quantify treatment response.
Methods: A glioma PDX model was established by subcutaneously engrafting tumor directly from patient following surgery into immunodeficient mice. Once established and expanded through passaging, glioma cells were isolated from fresh PDX tumor and transduced with pLVX-IRES-ZsGreen1 lentiviral vector, which expressed both luciferase and GFP, rapidly. Cells were then subcutaneously inoculated into immunodeficient mice directly without in vitro culture and selection. Cell sorting of the following tumors based on GFP expression was performed to exclude the luciferase negative cells and enrich for stable luciferase signal in subsequent passages. The in vivo expansion and sorting of GFP+ tumor cells were repeated for two rounds. Cells from third passages of subcutaneous tumor were orthotopically inoculated in the brain of NOD.scid mice. The tumor progression in the brain was further confirmed by the IVIS® Spectrum In Vivo Imaging System. Response of orthotopically inoculated BN2289-Luc to temozolomide was also evaluated according to the bioluminescent signal in brain.
Results: We successfully established a luciferase-GFP dual-labeled glioma PDX model BN2289-Luc which was stably passaged in vivo. The successful transduction of luciferase-GFP cascade was detected by in vitro luciferase assay and fluorescence imaging. Stable tumor progression and bioluminescent signal growth of BN2289-Luc were validated orthotopically and subcutaneously in immunodeficient mice, and a histological study revealed the consistency between orthotopic and subcutaneous tumors. Efficacy studies showed that orthotopically inoculated BN2289-Luc responded to temozolomide (25mg/kg, p.o., Day1-5/wkx4wks).
Conclusion: An orthotropic glioma PDX model, BN2289-Luc displayed luciferase signal of in situ tumor progression and response to temozolomide treatment, providing an ideal approach for orthotopic investigation of gliomas and preclinical testing of new drugs.
Citation Format: Jinxi Wang, Ling Chen, Jun Zhou, Likun Zhang, Jinyu Huang, Xueluan Zhu, Ludovic Bourre, Jingjing Wang. Characterization of orthotopic bioluminescent patient-derived xenograft model of glioma for drug discovery [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 2387.