Cancer cell death strategies by targeting Bcl-2's BH4 domain.
BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021;
1868:118983. [PMID:
33549704 DOI:
10.1016/j.bbamcr.2021.118983]
[Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/15/2022]
Abstract
The Bcl-2-family proteins have long been known for their role as key regulators of apoptosis. Overexpression of various members of the family is associated with oncogenesis. Its founding member, anti-apoptotic Bcl-2 regulates cell death at different levels, whereby Bcl-2 emerged as a major drug target to eradicate cancers through cell death. This resulted in the development of venetoclax, a Bcl-2 antagonist that acts as a BH3 mimetic. Venetoclax already entered the clinic to treat relapse chronic lymphocytic leukemia patients. Here, we discuss the role of Bcl-2 as a decision-maker in cell death with focus on the recent advances in anti-cancer therapeutics that target the BH4 domain of Bcl-2, thereby interfering with non-canonical functions of Bcl-2 in Ca2+-signaling modulation. In particular, we critically discuss previously developed tools, including the peptide BIRD-2 (Bcl-2/IP3R-disrupter-2) and the small molecule BDA-366. In addition, we present a preliminary analysis of two recently identified molecules that emerged from a molecular modeling approach to target Bcl-2's BH4 domain, which however failed to induce cell death in two Bcl-2-dependent diffuse large B-cell lymphoma cell models. Overall, antagonizing the non-canonical functions of Bcl-2 by interfering with its BH4-domain biology holds promise to elicit cell death in cancer, though improved tools and on-target antagonizing small molecules remain necessary and ought to be designed.
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