The Influence of Human Astrocyte-Conditioned Media on Glioblastoma Multiforme Response to Temozolomide and Bay 11-7082

Abstract

Glioblastoma Multiforme (GBM) cells interact with a complex, heterogeneous tumor microenvironment (TME). This TME consists of astrocytes, endothelial cells, microglia, and pericytes, which together play a role in GBM progression and resistance. However, there are not enough in vitro three-dimensional (3D) models to study the effect of the TME on GBM resistance to chemotherapeutics. In this study, we created a GBM TME by culturing GBM cells with media that had been conditioned by human astrocytes (HA) in 3D microwells. In order to investigate the effect of the TME on GBM resistance to chemotherapeutic agents, cells were treated with Temozolomide (TMZ) in combination with nuclear factor- $\kappa \text{B}$ (NF- $\kappa \text{B}$ ) inhibitor “Bay 11-7082”. We examined the influence of HA conditioned media (CM) on the expression of various genes and the response to TMZ and Bay 11–7082 in our 3D cultures. Our data suggested that proteins and metabolic factors produced by HA in CM can significantly alter GBM response to chemotherapeutics. Our results indicated lower levels of apoptosis- and drug resistance-related genes were detected in LN229 and U87 cultures in their respective cell culture media compared to HA CM. Our results confirmed HA affect GBM response to therapy.

Keywords

• Glioblastoma
• 3D models
• tumor microenvironment
• co-culture