Anaplastic lymphoma kinase fusion protein (ALK)

Anaplastic lymphoma kinase (ALK) fusion proteins are oncogenic drivers resulting from chromosomal translocations that join the 3' end of the ALK gene with various 5' partner genes, such as NPM1 or EML4 [3, 5]. These rearrangements lead to the constitutive activation of the ALK tyrosine kinase domain, which is normally expressed primarily during embryonic nervous system development [1, 7]. The resulting chimeric proteins trigger multiple downstream signaling cascades, including the PI3K/AKT, RAS/MAPK, and JAK/STAT pathways, which promote aberrant cell growth, survival, and migration [3, 10]. ALK fusions are primary therapeutic targets in several malignancies, most notably non-small cell lung cancer (NSCLC) and anaplastic large cell lymphoma (ALCL) [5, 9]. Treatment typically involves small-molecule tyrosine kinase inhibitors (TKIs) that block the ATP-binding site of the kinase domain to inhibit autophosphorylation [4, 10]. Despite high initial response rates, clinical management is often complicated by the emergence of secondary resistance mutations within the kinase domain and the activation of bypass signaling mechanisms [9, 10].

Other names

NPM-ALKEML4-ALKAnaplastic lymphoma receptor tyrosine kinase fusionCD246 fusion proteinX-ALK fusion oncoproteinTFG-ALKKIF5B-ALK

Tyrosine kinase inhibition via ATP-competitive binding to the ALK catalytic domain, preventing autophosphorylation and downstream oncogenic signaling.