Longitudinal evaluation of five nasopharyngeal carcinoma animal models on the microPET/MR platform

Abstract

We longitudinally evaluated the tumour growth and metabolic activity of two well-established nasopharyngeal carcinoma (NPC) animal models (C666-1, C17) and three novel models (Xeno76, Xeno23 and NPC43) using a microPET/MR system. With a better understanding of the interplay between tumour growth and metabolic characteristics of these NPC models, we aim to provide insights for the selection of appropriate NPC cell line/xenograft models to assist novel drug discovery and evaluation. MethodsMice were imaged by [ 18 F]FDG microPET/MR twice a week for consecutive 3-7 weeks. [ 18 F]FDG uptake was quanti ed by standardized uptake value (SUV) and presented as SUVmean tumour-to-liver ratio (SUVRmean). Longitudinal tumour growth patterns and metabolic patterns were recorded. SUVRmean and histological characteristics were compared across the ve NPC models. Cisplatin was administrated to one selected optimal tumour model, C17 to evaluate our imaging platform. ResultsWe found variable tumour growth and metabolic patterns across different NPC tumour types. C17 has an optimal growth rate and higher tumour metabolic activity compared with C666-1. C666-1 has a fast growth rate but is low in SUVRmean at endpoint due to necrosis as con rmed by H&E. NPC43 and Xeno76 have relatively slow growth rates and are low in SUVRmean, due to severe necrosis. Xeno23 has the slowest growth rate, and a relative high SUVRmean. Cisplatin showed the expected therapeutic effect in the C17 model in marked reduction of tumour size and metabolism. ConclusionOur study establishes an imaging platform that characterizes the growth and metabolic patterns of different NPC models, and the platform is well able to demonstrate drug treatment outcome supporting its use in novel drug discovery and evaluation for NPC.