Journal Article

A novel method of screening combinations of angiostatics identifies bevacizumab and temsirolimus as synergistic inhibitors of glioma-induced angiogenesis

Wada, Jessica F., Coopwood, Carley, Kast-Woelbern, Heidi R., Botts, Ryan T., Kurz, Troy L., Fortin, Bridget M., Gillette, Charisa E., Siles, Erik N., Tremblay, Jacob R., Snowbarger, Jeffrey M., Rausch, Amy L., Booth, Caylor B., Elson, Daniel J., Alexander, MaryAnn, Silva, Jordan A., Johnson, Alec M., Goral, Dawn M., Thompson, Paul, Purington, Kaitlyn J., Rusing, Jack C., Bravo, Stephen A., Wheelock, Michael, Lowey, Connor A., Villegas, Gabriel, Hale, Allison L., Garcia, Eric, Dorrell, Michael I., Tadros, Roujih, Giles, Sarah, Everett, Haylie M.

2021

Overview

Tumor angiogenesis is critical for the growth and progression of cancer. As such, angiostasis is a treatment modality for cancer with potential utility for multiple types of cancer and fewer side effects. However, clinical success of angiostatic monotherapies has been moderate, at best, causing angiostatic treatments to lose their early luster. Previous studies demonstrated compensatory mechanisms that drive tumor vascularization despite the use of angiostatic monotherapies, as well as the potential for combination angiostatic therapies to overcome these compensatory mechanisms. We screened clinically approved angiostatics to identify specific combinations that confer potent inhibition of tumor-induced angiogenesis. We used a novel modification of the ex ovo chick chorioallantoic membrane (CAM) model that combined confocal and automated analyses to quantify tumor angiogenesis induced by glioblastoma tumor onplants. This model is advantageous due to its low cost and moderate throughput capabilities, while maintaining complex in vivo cellular interactions that are difficult to replicate in vitro . After screening multiple combinations, we determined that glioblastoma-induced angiogenesis was significantly reduced using a combination of bevacizumab (Avastin®) and temsirolimus (Torisel®) at doses below those where neither monotherapy demonstrated activity. These preliminary results were verified extensively, with this combination therapy effective even at concentrations further reduced 10-fold with a CI value of 2.42E-5, demonstrating high levels of synergy. Thus, combining bevacizumab and temsirolimus has great potential to increase the efficacy of angiostatic therapy and lower required dosing for improved clinical success and reduced side effects in glioblastoma patients.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Angiogenesis / Angiogenesis inhibitors / Apoptosis / Auroral kilometric radiation / Bevacizumab / Biology / Biology and Life Sciences / Brain cancer / Brain tumors / Cancer / Cancer therapies / Care and treatment / Cell death / Chemotherapy / Clinical trials / Computer programs / CTLA-4 protein / Cytotoxicity / Diagnosis / Direct reduction / Editing / Funding / Glioma / Gliomas / Immunotherapy / Inhibitor drugs / Lymphocytes / Lymphocytes T / Mathematical analysis / Medicine and Health Sciences / Metastasis / Methodology / Military base closures / Military bases / Monoclonal antibodies / Movement disorders / Patients / PD-1 protein / Proteins / Radiation / Software / Survival / Targeted cancer therapy / Temozolomide / Tumors