B-cell lymphoma 2 family (indirect modulation)

The B-cell lymphoma 2 (BCL-2) family of proteins consists of critical regulators of the intrinsic apoptotic pathway, categorized into pro-survival (e.g., BCL-2, MCL-1, BCL-XL) and pro-apoptotic (e.g., BAX, BAK, BIM) members (Source: UniProt). Indirect modulation refers to therapeutic strategies that influence these proteins' activity or abundance without direct binding, often by targeting upstream signaling or transcriptional machinery (Source: Nature Reviews Cancer). For instance, inhibiting CDK9 or BET proteins can rapidly deplete the levels of MCL-1, a protein with a short half-life that often confers resistance to direct BCL-2 inhibitors like venetoclax (Source: PubMed). This approach is particularly relevant in oncology, where cancer cells frequently overexpress anti-apoptotic BCL-2 members to evade programmed cell death (Source: NIH). By shifting the balance toward apoptosis through indirect means, these therapies can sensitize resistant tumors to chemotherapy or direct BH3 mimetics (Source: Journal of Clinical Oncology). However, because these upstream targets often have pleiotropic effects, indirect modulation can lead to broader systemic toxicities compared to highly selective direct inhibitors (Source: StatPearls).

Other names

Indirect BCL-2 family inhibitionTranscriptional inhibition of BCL-2 proteinsMCL-1 indirect targetingBCL-2 family regulatory network modulation

Indirect modulation of the BCL-2 family involves the inhibition of upstream regulators such as cyclin-dependent kinases (CDKs), BET proteins, or the proteasome to reduce the levels of anti-apoptotic proteins like MCL-1 and BCL-2, thereby lowering the threshold for apoptosis.