5' ALK Amplification in Neuroblastoma: A Case Report

Identification of ALK Mutation in Neuroblastoma on the Point of Molecular Heterogeneity

BACKGROUND AND AIM

In neuroblastoma, anaplastic lymphoma kinase mutations have recently received attention as molecular targets for the treatment of neuroblastoma, as 6% to 10% of patients with neuroblastoma have anaplastic lymphoma kinase mutations. There are little data from the cases in Turkey. We aimed to detect anaplastic lymphoma kinase mutations and molecular heterogeneity in neuroblastoma using next-generation sequencing. This study is the first one with this many cases in Turkey.

METHODS

Next-generation sequencing analysis was performed using an Illumina MiniSeq custom gene panel. Clinically important mutations were selected for the analysis. We also gathered clinical data of the patients from Turkish Pediatric Oncology Group cohorts to associate them with anaplastic lymphoma kinase mutations. This study is a retrospective cross-sectional study. We followed STROBE guideline (https://www.equator-network.org/reporting-guidelines/strobe/) on this study.

RESULTS

We analyzed anaplastic lymphoma kinase in 108 patients with neuroblastoma, with a mean age of 43.76 months. Pathogenic anaplastic lymphoma kinase mutations were detected in 13 patients (12.04%). We noted that anaplastic lymphoma kinase mutations were primarily observed in intermediate- and high-risk patients (P  =  .028). R1275Q and F1174-related mutations were predominant; I1171T, L1226F, S1189F, V1135A, and G1125S mutations were rare. Duplicate samples did not exhibit any heterogeneity.

CONCLUSIONS

We found that F1174 and R1275Q-related anaplastic lymphoma kinase mutations are the most common pathogenic mutations in neuroblastoma. Anaplastic lymphoma kinase mutation status did not show any heterogeneity, and the mutations were correlated with intermediate- or high-risk groups.

MYCN in Neuroblastoma: "Old Wine into New Wineskins"

MYCN Proto-Oncogene, BHLH Transcription Factor (MYCN) has been one of the most studied genes in neuroblastoma. It is known for its oncogenetic mechanisms, as well as its role in the prognosis of the disease and it is considered one of the prominent targets for neuroblastoma therapy. In the present work, we attempted to review the literature, on the relation between MYCN and neuroblastoma from all possible mechanistic sites. We have searched the literature for the role of MYCN in neuroblastoma based on the following topics: the references of MYCN in the literature, the gene's anatomy, along with its transcripts, the protein's anatomy, the epigenetic mechanisms regulating MYCN expression and function, as well as MYCN amplification. MYCN plays a significant role in neuroblastoma biology. Its functions and properties range from the forming of G-quadraplexes, to the interaction with miRNAs, as well as the regulation of gene methylation and histone acetylation and deacetylation. Although MYCN is one of the most primary genes studied in neuroblastoma, there is still a lot to be learned. Our knowledge on the exact mechanisms of MYCN amplification, etiology and potential interventions is still limited. The knowledge on the molecular mechanisms of MYCN in neuroblastoma, could have potential prognostic and therapeutic advantages.