Multi-Cell Type Glioblastoma Tumor Spheroids for Evaluating Sub-Population-Specific Drug Response.

Mahesh Devarasetty,Aleksander Skardal,Hemamylammal Sivakumar,Roy E Strowd,David E Kram

doi:10.3389/fbioe.2020.538663

Abstract

Glioblastoma (GBM) is a lethal, incurable form of cancer in the brain. Even with maximally aggressive surgery and chemoradiotherapy, median patient survival is 14.5 months. These tumors infiltrate normal brain tissue, are surgically incurable, and universally recur. GBMs are characterized by genetic, epigenetic, and microenvironmental heterogeneity, and they evolve spontaneously over time and as a result of treatment. However, tracking such heterogeneity in real time in response to drug treatments has been impossible. Here we describe the development of an in vitro GBM tumor organoid model that is comprised of five distinct cellular subpopulations (4 GBM cell lines that represent GBM subpopulations and 1 astrocyte line), each fluorescently labeled with a different color. These multi-cell type GBM organoids are then embedded in a brain-like hyaluronic acid hydrogel for subsequent studies involving drug treatments and tracking of changes in relative numbers of each fluorescently unique subpopulation. This approach allows for the visual assessment of drug influence on individual subpopulations within GBM, and in future work can be expanded to supporting studies using patient tumor biospecimen-derived cells for personalized diagnostics.

Highlights

Glioblastoma (GBM) is one of the most dangerous tumors across cancer types, and amongst brain tumors, the most lethal type of tumor which is currently incurable
Gold standard treatment includes maximally aggressive surgery to remove the bulk of the tumor and chemoradiotherapy to address remaining tumor cells
To begin to design a system to track GBM subtypes in 3D organoid cultures in response to chemotherapeutic treatments, we sought to employ a collection of GBM cell lines that, in terms of genomic variance, could serve as 4 distinct subpopulations GBM

Summary

INTRODUCTION

Glioblastoma (GBM) is one of the most dangerous tumors across cancer types, and amongst brain tumors, the most lethal type of tumor which is currently incurable. We describe the development and testing of a proof-of-concept GBM tumor spheroid model comprised of multiple fluorescently labeled cell lines which we use to visually track the relative contributions of each subpopulation too the overall spheroid as a result of the individual drug responses of each cell type. We demonstrate this tracking methodology using multiple GBM cell lines, but aim to deploy this approach in future work to track individual GBM subtypes within a patient-derived tumor organoid in response to therapy, thereby addressing the complexity of GBM heterogeneity

MATERIALS AND METHODS

RESULTS AND DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT