Mitogen-activated protein kinase signaling pathway (MAPK signaling pathway) (MAPK pathway)

The Mitogen-activated protein kinase (MAPK) signaling pathway is a central intracellular transduction system that coordinates diverse cellular processes including growth, proliferation, differentiation, and survival [2, 11, 13]. This highly conserved cascade typically involves the sequential activation of three kinase tiers: a MAPK kinase kinase (MAP3K), a MAPK kinase (MAP2K), and a final MAPK, with the Ras-Raf-MEK-ERK branch being the primary mediator of mitogenic signals [7, 17]. Under pathological conditions, particularly in malignancies like melanoma and colorectal cancer, the pathway is often constitutively activated by oncogenic mutations in RAS or RAF, driving uncontrolled tumor expansion [3, 15, 16]. Pharmaceutical intervention, often referred to as "MAPK signaling pathway inhibition," utilizes targeted small molecules like vemurafenib or trametinib to block these hyperactive nodes and restore pathway regulation [1, 5]. While these therapies offer significant initial clinical responses, their utility is frequently limited by the emergence of acquired resistance via pathway reactivation or bypass mechanisms, as well as notable safety concerns like cutaneous toxicities and ocular events [2, 12, 16].

Other names

Ras-Raf-MEK-ERK signaling pathwayMAP kinase signaling pathwayExtracellular signal-regulated kinase (ERK) signaling pathwayMitogen-activated protein kinase cascade

Small-molecule inhibition of specific protein kinases (such as BRAF, MEK, or ERK) within the cascade to block downstream signal transmission and inhibit oncogenic cell growth [1, 5, 7].