Apoptosis pathway (in tumor cells)

The apoptosis pathway in tumor cells encompasses both the intrinsic (mitochondria-mediated) and extrinsic (death receptor-mediated) signaling cascades that promote programmed cell death—an essential process for eliminating damaged or malignant cells. These cascades are tightly regulated by protein families such as Bcl-2 (balance of pro- and anti-apoptotic proteins), death receptors (e.g., TNFR1, Fas, TRAIL receptors), and executioner caspases. Defects in apoptosis pathways allow tumor cells to evade cell death, leading to cancer progression and resistance to therapy. Many cancer drugs aim to reactivate apoptosis, either by mimicking death ligands, inhibiting anti-apoptotic proteins, or directly activating caspases. However, the broad targeting of cell death mechanisms may introduce toxicity and unexpected effects such as increased metastatic potential through mechanisms like nuclear expulsion in dying cancer cells. Because this query refers to a whole pathway rather than a single, canonical molecular target, structured database entries (e.g., for DrugBank or UniProt) typically require specification of individual molecular components such as "B-cell lymphoma 2 protein (Bcl-2)", "Caspase-8", or "Tumor necrosis factor receptor 1 (TNFR1)", etc.

Other names

Apoptotic pathwayprogrammed cell death pathwayextrinsic apoptosis pathwayintrinsic apoptosis pathway

Activation of caspases (initiates execution phase of apoptosis); Inhibition of anti-apoptotic Bcl-2 family proteins (restores pro-apoptotic signaling); Agonism of death receptors (stimulates extrinsic pathway); Restoration/activation of wild-type p53 in mutant p53-driven cancers.