Identification of ALK as a major familial neuroblastoma predisposition gene

Abstract

SUMMARY Survival rates for the childhood cancer neuroblastoma have not substantively improved despite dramatic escalation in chemotherapy intensity. Like most human cancers, this embryonal malignancy can be inherited, but the genetic etiology of familial and sporadically occurring neuroblastoma was largely unknown. Here we show that germline mutations in the anaplastic lymphoma kinase gene (ALK) explain the majority of hereditary neuroblastomas, and that activating mutations can also be somatically acquired. We first identified a significant linkage signal at the short arm of chromosome 2 (maximum nonparametric LOD=4.23 at rs1344063) using a whole-genome scan in neuroblastoma pedigrees. Resequencing of regional candidate genes identified three separate missense mutations in the tyrosine kinase domain of ALK (G1128A, R1192P and R1275Q) that segregated with the disease in eight separate families. Examination of 491 sporadically occurring human neuroblastoma samples showed that the ALK locus was gained in 22.8%, and highly amplified in an additional 3.3%, and that these aberrations were highly associated with death from disease (P=0.0003). Resequencing of 194 high-risk neuroblastoma samples showed somatically acquired mutations within the tyrosine kinase domain in 12.4%. Nine of the ten mutations map to critical regions of the kinase domain and were predicted to be oncogenic drivers with high probability. Mutations resulted in constitutive phosphorylation consistent with activation, and targeted knockdown of ALK mRNA resulted in profound growth inhibition of 4 of 4 cell lines harboring mutant or amplified ALK, as well as 2 of 6 wild type for ALK. Our results demonstrate that heritable mutations of ALK are the major cause of familial neuroblastoma, and that germline or acquired activation of this cell surface kinase is a tractable therapeutic target for this lethal pediatric malignancy.

Renal cell carcinoma with novel VCL–ALK fusion: new representative of ALK-associated tumor spectrum

“…23 ALK is also activated in B5 to 35% of neuroblastomas and neuroblastoma cell lines by a different mechanism involving point mutations and/or gene locus amplifications. 24,25 ALK belongs to the insulin receptor superfamily of receptor tyrosine kinases and is ontogenetically silenced in mature human tissues with the exception of certain areas of the brain; however, full-length ALK is expressed in some pediatric sarcomas. 26 A total of 16 ALK fusion oncogenes have been reported; all include an obligatory 3 0 portion encoding for the kinase domain.…”

GSK1838705A inhibits the insulin-like growth factor-1 receptor and anaplastic lymphoma kinase and shows antitumor activity in experimental models of human cancers

“…Fusion of ALK with NPM and EML4 has been observed in ALCL and NSCLC, respectively, and fusions with other genes have also been identified in patients with these and other malignancies (44). More recently, both germ-line and somatic mutations in ALK gene have been reported in neuroblastoma patients (45). IGF-IR and IR share a high degree of sequence homology with ALK kinase, and thus, it was not surprising that GSK1838705 also inhibits ALK kinase, although other small-molecule IGF-IR inhibitors have not reported activity against ALK.…”

Embryonal neural tumours and cell death

“…Besides expression in the normal developing neural system the ALK protein is expressed in neuroblastoma tumours and cell lines and some of these respond to ALK-specific small molecule inhibitors [89,90]. Recently, specific germline mutations targeting the ALK tyrosine kinase domain were described in families with hereditary neuroblastoma and subsequently somatic mutations and gene amplifications were detected in sporadic primary tumours predominantly of metastatic stage or locally advanced tumours [91][92][93][94][95]. Specific knockdown of ALK expression in sensitive neuroblastoma cell lines in vitro as well as treatment using small molecule inhibitors (TAE684 and PF2341066) could inhibit cell proliferation and expression of downstream targets, and induce apoptosis.…”