All ETDs from UAB

Advisory Committee Chair

Christopher D Willey

Advisory Committee Members

George Y Gillespie

Anita B Hjelmeland

Timothy M Wick

Document Type

Thesis

Date of Award

2015

Degree Name by School

Master of Science in Biomedical Engineering (MSBME) School of Engineering

Abstract

Glioblastoma multiforme (GBM), the most common form of primary malignant brain cancer in adults, is a devastating disease for which effective treatment has remained elusive for over 75 years. A likely reason for the minimal progress during this time is the lack of accurate preclinical models to represent the patient in vivo environment, causing a disconnect in drug therapy effectiveness between the laboratory and clinic. Our proposed solution to address this disconnect and the issues of traditional preclinical modeling is to use innovative HuBiogel-based MicroTumors as a three-dimensional (3D) drug screening model for GBM. Six subcutaneous patient-derived xenografts (PDXs) prepared as single cell suspension were embedded, grown, and assayed in natural amnion-derived HuBiogel. Kinomic analysis, indicative of kinase signaling, which is a key feature of signaling validation, of PDX MicroTumors was performed at Day 7 with an in vitro kinase assay microarray platform (PamStation12, PamGene International) in the UAB Kinome Core, and generated kinomic activity of each was compared to previously characterized in vivo orthotopic xenolines via statistical analyses to determine kinase signaling concordance. Additionally, small molecule kinase inhibitors, WP1066, Selumetinib, Crizotinib, and Cediranib, were selected for single and combination drug screening experiments. Day 7 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) response data were evaluated using the Chou-Talalay method of synergy testing via CalcuSyn. Kinomic activity for biological replicates of each PDX suggests that each xenoline has a relatively distinct kinomic profile and shows that the kinomic profiles of the MicroTumor xenolines predominantly cluster by tumor type. Also, initial paired t-tests between the MicroTumor model and orthotopic xenoline model indicate that the overall kinase signaling is not significantly changed in the microenvironment of HuBiogel and, kinomically, the MicroTumor is a promising reflective model. We have also identified two promising kinase inhibitors, Crizotinib and Cediranib, through in vitro single and combination drug screening and synergy testing. We demonstrate that the MicroTumor model has promising potential as a comparative, or even possibly replacement, model for orthotopic PDXs. With the drug screening information, in vivo testing will be performed in the murine model to determine if the MicroTumor model can predict drug response in orthotopic PDXs.

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