Publications and Research

Document Type

Article

Publication Date

8-1-2020

Abstract

Apoptotic resistance remains a hallmark of glioblastoma (GBM), the most common primary brain tumor in adults, and a better understanding of this process may result in more efficient treatments. By utilizing chromatin immunoprecipitation with next-generation sequencing (CHIP-seq), we discovered that GBMs harbor a super enhancer around the Mcl-1 locus, a gene that has been known to confer cell death resistance in GBM.We utilized THZ1, a known super-enhancer blocker, and BH3-mimetics, including ABT263, WEHI-539, and ABT199. Combined treatment with BH3-mimetics and THZ1 led to synergistic growth reduction in GBM models. Reduction in cellular viability was accompanied by significant cell death induction with features of apoptosis, including disruption of mitochondrial membrane potential followed by activation of caspases. Mechanistically, THZ1 elicited a profound disruption of the Mcl-1 enhancer region, leading to a sustained suppression of Mcl-1 transcript and protein levels, respectively. Mechanism experiments suggest involvement of Mcl-1 in the cell death elicited by the combination treatment. Finally, the combination treatment of ABT263 and THZ1 resulted in enhanced growth reduction of tumors without induction of detectable toxicity in two patient-derived xenograft models of GBM in vivo. Taken together, these findings suggest that combined epigenetic targeting of Mcl-1 along with Bcl-2/Bcl-xL is potentially therapeutically feasible.

Comments

This work was originally published in cancers, available at https://doi.org/10.3390/cancers12082137.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.