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

Sadaf E Pustchi,Charlotte Mae K Waits,Lindsey Mcgill,Metin Akay,Naze Gul Avci,Yasemin M Akay

doi:10.1109/access.2022.3146887

Sadaf E Pustchi, Charlotte Mae K Waits + Show 4 more

Open Access

https://doi.org/10.1109/access.2022.3146887

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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- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\kappa \text{B}$ </tex-math></inline-formula> (NF- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\kappa \text{B}$ </tex-math></inline-formula> ) 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.

Highlights

Glioblastoma Multiforme (GBM) has the highest mortality among adult primary brain tumors [1]
CONDITIONED MEDIA (CM) IN CULTURE IMPACTS TREATMENT RESPONSE We have used 3D microwells for GBM studies to understand the effect of the tumor microenvironment (TME) on GBM growth [22, 23], as well as to investigate the interaction of 3D GBM spheroids with endothelial cells [30]
We examined the influence of human astrocytes (HA) conditioned media (CM) on the expression of factors to study 3D GBM response to TMZ and Bay 11-7082 (Fig. 1a-d)

Summary

Introduction

Glioblastoma Multiforme (GBM) has the highest mortality among adult primary brain tumors [1]. GBM patients have an ∼30% survival rate over one year, and only ∼3–5% of patients survive beyond 5 years [2, 3]. Patients undergo maximal safe surgical resection followed by radiotherapy (RT) and concomitant oral chemotherapy using the DNA-alkylating agent Temozolomide (TMZ) [4, 5]. Recent treatment methods have increased the survival rate, the overall clinical outcome remains unsatisfactory, in part due to rising GBM resistance to TMZ [2]. The main factor believed to influence this chemoresistance is the O 6 -methylguanine-DNA methyltransferase (MGMT) gene [6]. The molecular mechanism of chemoresistance to TMZ is more complex than a simple dependence on one gene. MGMT expression can be suppressed by the nuclear factor-κB (NF-κB) inhibitor Bay 11-7082. Combined treatment of GBM with Bay 11-

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