B-cell lymphoma 2 protein (BCL-2)

B-cell lymphoma 2 protein (BCL‑2) is the founding member of the Bcl‑2 family of regulator proteins that control programmed cell death (apoptosis). It is localized primarily at the outer mitochondrial membrane where it acts as a key inhibitor of apoptosis by sequestering pro-apoptotic members within its family. This regulation maintains cellular homeostasis by balancing survival and death signals. The anti-apoptotic activity arises from its ability to bind BH3 domains on pro-apoptotic proteins such as Bax or Bak, preventing them from permeabilizing the mitochondrial membrane—a critical step in caspase activation and apoptotic execution. Dysregulation or overexpression of BCL‑2 is implicated in various cancers—most notably follicular lymphoma—where it contributes to malignant cell survival. Targeting this pathway has led to development and approval of drugs like venetoclax that specifically inhibit its function, restoring apoptotic sensitivity in cancer cells. However, therapeutic targeting can be associated with risks such as tumor lysis syndrome due to rapid induction of apoptosis in susceptible tumors[1][3][4][5].

Other names

Bcl-2BCL2B-cell leukemia/lymphoma 2 protein

Inhibition of anti-apoptotic function to restore apoptosis in cancer cells (e.g., venetoclax binds to and inhibits BCL‑2, releasing pro-apoptotic proteins like Bax/Bak to induce cell death)[3]