Direct tumor cytolysis by natural killer cell activation pathways

The term "Direct tumor cytolysis by natural killer cell activation pathways" does not refer to a single molecular target but rather describes the collective mechanisms by which natural killer (NK) cells recognize and destroy tumor cells through their array of activating and inhibitory surface receptors. These processes involve multiple molecules—such as NKG2D, CD16, NCRs—and complex intracellular signaling cascades that integrate signals from both activating and inhibitory inputs. When the balance shifts toward activation—often due to loss of MHC class I molecules on stressed/tumor cells combined with upregulation of stress ligands—NK cells form an immunological synapse with their targets. This leads to polarization and exocytosis of lytic granules containing perforin and granzymes that induce apoptosis in the target. Additionally, engagement with death receptors via ligands like FasL or TRAIL can trigger programmed cell death in tumors[1][2][3]. The "pathway" is thus an ensemble process central to innate immune surveillance against cancer but is not itself a discrete druggable protein/receptor, making it unsuitable for structured annotation as an individual therapeutic target. “With an array of activating and inhibitory receptors, natural killer (NK) cells can specifically eradicate infected and transformed [tumor] cells... Target cell killing is achieved through directed release of lytic granules.”[1] “The activating and inhibitory receptor signaling regulates the natural killer (NK) cells activation... signal from activating receptors shifts balance toward NK cell activation leading to secretion of cytokines & killing tumor cells directly through cytotoxicity.”[2] In summary: this entry refers broadly to cellular processes/pathways—not one canonical molecule/receptor—and should be flagged as incorrect for use as a structured therapeutic target entry.

Other names

Natural killer cell activation pathwayNK cell-mediated cytotoxicityNK cell effector function pathways

Mechanisms involve modulation of activating/inhibitory signals on NK cells, not direct action on a discrete molecular target.