Objective

We assessed the growth and  anti-tumour response of glioblastoma tumours within a 3D spheroid model in the absence and presence of temozolomide (TZ), an established treatment  for glioblastoma.

Human brain microphysiological system spheroids (BMPS) seeded with green fluorescent protein (GFP) tagged glioblastoma tumour cells (gBMPS) were grown over a seven week period, and at 7 weeks (7w) differentiation were treated with vehicle control and increasing concentrations (0.1, 0.5, 10 and 100µM) of TZ for a period of 48 hours. Control and TZ treated gBMPS were immunofluorescence (IF) stained using a novel spheroid tissue microarray (TMA) technology. Sections were IF stained with anti-GFP and anti-cleaved Caspase-3  antibodies and imaged using a Zeiss 710 confocal microscope.

Quantitative image  analysis of the GFP IF stained TMA  showed a time-dependent  increase in the size of the glioblastoma tumours over a 4w period as reflected by an increase in the total area and number of  GFP positive cells. There was a dose-dependent increase in cleaved caspase 3 staining in the TZ treated gBMPS compared to control. These results indicate that it is possible to mimic glioblastoma growth within a BMPS model and that short term TZ treatment initiates apoptosis of the glioblastoma tumour and also non tumour neuronal cells.

Further work to test new TZ treatment approaches that model current clinical regimens involving repeat  drug administration is ongoing.