PO-314 ALK inhibitor, ceritinib, abrogates activation of the novel ALK-I1171T mutation in neuroblastoma

Abstract

IntroductionMutations in the kinase domain of Anaplastic Lymphoma Kinase (ALK) are undoubtedly implicated in the pathogenesis of the childhood cancer, neuroblastoma. However, clinical response of ALK positive neuroblastoma patients to the first generation ALK inhibitor has been rather disappointing.Here we report the appearance of a novel ALK mutation in neuroblastoma together with other chromosomal aberrations that mediate neuroblastoma initiation and progression.Material and methodsGenomic tumour DNA from biopsy samples were extracted and exome sequencing was performed through paired-end sequencing on Illumina plateforms.The novel ALK-I1171T mutant was biochemically analysed by western blot and neurite-outgrowth assay in PC12 cells, and foci formation assay in NIH3T3 cells.Results and discussionsAnalyses of genomic tumour DNA from biopsy samples initially showed an 11q deletion, 17q gain with a mutation of the ALK gene at protein position 1171, which mediate an amino acid change from isoleucine to threonine. We show that mutation of I1171 to threonine generates a potent gain-of-function mutant, as observed in two independent systems. Firstly, in PC12 cell lines expressing ALK-I1171T display ligand independent activation of ALK, neurite outgrowth and further downstream signalling activation. Secondly, ALK-I1171T meditate foci formation in a NIH3T3 transformation analysis. Finally, pharmacological inhibition of ALK-I1171T employing ceritinib, an FDA approved ALK inhibitor show 14-fold better ability to abrogate ALK-I1171T compared with crizotinib.ConclusionThis study suggests that ceritinib presents a viable therapeutic option for ALK-positive neuroblastoma.