B-cell lymphoma 2 family proteins (BCL-2 family) (BCL-2 family)

The B-cell lymphoma 2 (BCL-2) family of proteins consists of critical regulators of the intrinsic apoptotic pathway, categorized into anti-apoptotic (e.g., BCL-2, BCL-XL, MCL-1) and pro-apoptotic (e.g., BAX, BAK, BIM) members [1]. These proteins interact at the mitochondrial outer membrane to control its permeability; anti-apoptotic members sequester pro-apoptotic proteins to prevent the release of cytochrome c and subsequent cell death [2]. In many malignancies, particularly hematologic cancers, anti-apoptotic BCL-2 proteins are overexpressed, allowing cancer cells to evade programmed cell death and resist chemotherapy [3]. Therapeutic intervention focuses on BH3 mimetics, such as venetoclax, which competitively bind to anti-apoptotic proteins, thereby liberating pro-apoptotic factors to initiate apoptosis [4]. While highly effective in certain leukemias and lymphomas, targeting this family requires careful management of toxicities like tumor lysis syndrome and cytopenias [5]. The balance between these family members serves as a rheostat for cell survival, making them central targets in oncology [3]. Sources: [1] UniProt (BCL2 family); [2] Nature Reviews Molecular Cell Biology (Youle & Strasser, 2008); [3] Nature Reviews Molecular Cell Biology (Czabotar et al., 2014); [4] Nature Medicine (Souers et al., 2013); [5] FDA Venclexta Prescribing Information.

Other names

BCL2 familyBcl-2 family apoptosis regulatorsApoptosis regulators of the BCL-2 familyBH domain-containing proteins

BH3 mimetics that competitively bind to the hydrophobic groove of anti-apoptotic BCL-2 family proteins, thereby displacing pro-apoptotic BH3-only proteins to trigger mitochondrial outer membrane permeabilization (MOMP), cytochrome c release, and subsequent caspase activation leading to apoptosis [1][2].