415 Intraoperative Molecular Imaging of Gliomas using Indocyanine-Conjugated Choline Kinase Alpha Inhibitor

Abstract

OBJECTIVES/GOALS: Distinguishing tumor tissue from normal brain parenchyma remains a major challenge during the resection of gliomas, leading to the persistence of tumor cells. This study aims to assess the choline kinase alpha-targeting fluorophore JAS239 as a novel fluorescent agent to intraoperatively visualize gliomas in an orthotopic murine model. METHODS/STUDY POPULATION: The human glioblastoma-derived U87 MG-Luc2 cell line will be intracranially implanted in nude mice and tumor growth will be assessed using bioluminescence imaging. After 14 days, the mice will be treated with either antiangiogenic therapy (10 mg/kg bevacizumab, twice/week) or saline (control). Tumor growth will be monitored until 21-28 days after initial implantation, at which point JAS239 (4.0 mg/kg, 90 min before sacrifice) and Evans Blue (4 ml/kg, 60 min before sacrifice) will be administered. The mice will be sacrificed, and their brains will be harvested and sectioned for near-infrared imaging. The brain sections will be processed for histopathologic analysis, allowing for the correlation of observed fluorescence with the distribution of tumor and comparison of signal-to-background ratios. RESULTS/ANTICIPATED RESULTS: JAS239 is an indocyanine-based choline mimetic (excitation 745 nm, emission 775 nm) that has been shown to cross the blood-tumor barrier (BTB) in rodent glioblastoma studies. PET imaging with choline-based radiotracers like 18F-choline has also been shown to delineate both contrast-enhancing tumor (CET) and non-contrast-enhancing tumor (NCET) regions, supporting the hypothesis that JAS239 will be able to visualize heterogeneous glioma tissue in our mouse model. Evans Blue is a passive dye in the visible light spectrum (excitation 620 nm, emission 680 nm) expected to only fluoresce in CET regions due to the disruption of the BTB. JAS239 is expected to fluoresce in both CET and NCET regions, which will be assessed by the fluorescence in mice treated with bevacizumab (expected to renormalize the BTB and model NCETs). DISCUSSION/SIGNIFICANCE: JAS239 may allow for real-time visualization of heterogeneous glioma tissue, which is important because there are no current intraoperative imaging agents for NCETs. Future research and clinical translation of this class of agents may allow surgeons to maximize the safe resection of gliomas, improving progression-free and overall survival rates.