Objective

3D organoid cultures more accurately reflect the complex in vivo microenvironment than 2D monolayers. However performing high-throughput histology testing of 3D models is challenging due to difficulties associated with staining and imaging throughout the tissues caused by lack of antibody penetration and fluorescence light scatter and quenching. To address this issue we have developed a spheroid tissue microarray (microTMA) platform where organoid cultures can be sectioned, stained , imaged and quantified in 96 well format.

We applied this approach for testing drugs against glioblastoma in a hybrid glioblastoma model (gBMPS). The model consists of human iPSC-derived neurons, glial cells and astrocytes grown in a spheroid also containing patient derived glioblastoma tumour cells.

We used this platform to assess the growth of glioblastoma tumours inside the spheroids and the response of gBMPS tumours and normal neuronal cells to sustained treatments with anti-cancer drugs temozolomide (TMZ) and adriamycin (ADR) at the level of apoptosis and cell proliferation.

Untreated gBMPS tumours increased in size over a 4 week culture period however there was no increase in the number of normal neuronal cells over this period consistent with their postmitotic state. TMZ (100uM) and ADR (0.3 uM) treatments caused ~30% (P~0.07) and ~80% (P<0.001) decreases in the size of the tumors, respectively, but little or no effect on the number of normal neuronal cells in the model. The anti-tumor effects of TMZ and ADR were mediated in part by selective induction of apoptosis in the glioblastoma cells.

These results indicate this platform has the potential to provide a novel approach for screening new anti-glioblastoma agents and evaluating different treatment options for a given patient.