FIGURE 4 from Identification and Characterization of a Small Molecule Bcl-2 Functional Converter

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posted on 2024-03-04, 22:24 authored by Prasad R. Kopparapu, Martin C. Pearce, Christiane V. Löhr, Cathy Duong, Hyo Sang Jang, Shanthakumar Tyavanagimatt, Edmond F. O'Donnell, Harikrishna Nakshatri, Siva K. Kolluri

Interaction of BFC1108 with Bcl-2. A, Limited proteolysis of Bcl-2 loop domain in the presence of BFC1108. Purified GST-tagged Bcl-2 loop domain and GST only control were incubated with 50 µmol/L BFC1108. The proteolysis pattern of loop domain was determined at the indicated times upon coincubation with trypsin. B, BFC1108 stabilizes and increases melting temperature (Tm) of Bcl-2 full-length protein. Thermal unfolding of Bcl-2 full-length protein in the presence of BFC1108 was monitored by SYPRO Orange fluorescence. Z-tag and no protein control samples were included to confirm BFC1108 specific interaction with Bcl-2. Two-way ANOVA with Sidak multiple comparisons post hoc test, **, P < 0.01; ****, P < 0.0001. C, BFC1108 stabilizes and increases Bcl-2 loop domain melting temperature (Tm). Thermal unfolding of Bcl-2 loop domain in the presence of BFC1108 monitored by SYPRO Orange fluorescence. One-way ANOVA with Dunnett multiple comparisons post hoc test, ****, P < 0.0001. D, MDA-MB-231/Bcl-2, H460 cells were exposed to BFC1108 at 10 µmol/L concentration for 48 hours in a medium containing 10% serum. Change in conformation of Bcl-2 was determined by using Bcl-2 BH3 antibody followed by flow cytometric analysis.

Funding

HHS | NIH | National Cancer Institute (NCI)

DOD | USA | MEDCOM | Congressionally Directed Medical Research Programs (CDMRP)

U.S. Department of Agriculture (USDA)

History

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DOI - Is supplement to Identification and Characterization of a Small Molecule Bcl-2 Functional Converter

ARTICLE ABSTRACT

Cancer cells exploit the expression of anti-apoptotic protein Bcl-2 to evade apoptosis and develop resistance to therapeutics. High levels of Bcl-2 leads to sequestration of pro-apoptotic proteins causing the apoptotic machinery to halt. In this study, we report discovery of a small molecule, BFC1108 (5-chloro-N-(2-ethoxyphenyl)-2-[(4-methoxybenzyol)amino]benzamide), which targets Bcl-2 and converts it into a pro-apoptotic protein. The apoptotic effect of BFC1108 is not inhibited, but rather potentiated, by Bcl-2 overexpression. BFC1108 induces a conformational change in Bcl-2, resulting in the exposure of its BH3 domain both in vitro and in vivo. BFC1108 suppresses the growth of triple-negative breast cancer xenografts with high Bcl-2 expression and inhibits breast cancer lung metastasis. This study demonstrates a novel approach to targeting Bcl-2 using BFC1108, a small molecule Bcl-2 functional converter that effectively induces apoptosis in Bcl-2–expressing cancers. We report the identification of a small molecule that exposes the Bcl-2 killer conformation and induces death in Bcl-2–expressing cancer cells. Selective targeting of Bcl-2 and elimination of cancer cells expressing Bcl-2 opens up new therapeutic avenues.