Development and characterization of an on-chip glioma outgrowth model

Tumour recurrence in high-grade gliomas, such as glioblastoma, is extremely common due to the challenges associated with complete surgical removal. Approximately 95% of glioblastoma tumours recur within 2 cm of the tumour resection margin; however, unfortunately, the current clinical measurement techniques do not accurately capture cell state during critical stages recurrence. The development of an on-chip model for investigating glioblastoma recurrence outgrowth is necessary to further understanding of the mechanistic understanding of this process at a cellular level and holds potential for translation into patient-specific predictive models. This work presents the development of an on-chip platform which can be used to assess glioblastoma interactions with healthy neural cells. Using a custom single-channel multi-well microfluidic system, 9L/3cmv-GFP (GFP transfected) rat glioma cells were co-cultured with a CTX-TNA2 rat astrocyte cell line to investigate differences in glioblastoma outgrowth between co-culture and monoculture (glioma only) configurations. Quantitative image analysis demonstrated significantly increased outgrowth of glioma cells from a tumour spheroid in co-culture compared to glioma only controls. Additionally, comparison of upregulation of glioma linked CD44 and glial fibrillary acidic protein (GFAP) expression showed significant differences in cellular expression between the two configurations. These findings align with existing literature suggesting that astrocytes facilitate a supportive environment for glioblastoma cells to proliferate and invade healthy tissue by changing to a reactive phenotype. Overall, this work presents a promising on-chip platform that can aid in the quantification of glioblastoma invasion through directional control of outgrowth and offers the potential for further modalities to be added by combining real-time data acquisition elements to the platform.