ALK mutation dynamics and clonal evolution in a neuroblastoma model exhibiting two ALK mutations

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Neuroblastoma is a pediatric cancer often driven by anaplastic lymphoma kinase (ALK) gene alterations.
• Understanding ALK mutation dynamics is crucial for developing targeted therapies.

Purpose of the Study:

• To characterize ALK mutation evolution in neuroblastoma cell lines derived from primary tumors and bone marrow.
• To investigate the impact of ALK mutations on cellular behavior and drug response.

Main Methods:

• Establishment and characterization of two neuroblastoma cell lines (PT and BM).
• Genomic profiling, Whole Exome Sequencing, and Digital droplet PCR.
• In vitro proliferation assays, xenograft tumor formation in nude mice.
• In vitro drug treatment with alectinib and crizotinib, single-cell RNA sequencing.

Main Results:

• BM-derived cells showed higher proliferation and tumor formation, with all cells harboring the ALK F1174L mutation.
• PT-derived cells initially had low F1174L mutation frequency, which increased with passages, alongside the emergence of a second ALK L1196M mutation.
• Alectinib treatment enriched for the L1196M mutation and showed better efficacy than crizotinib in xenografts.
• Single-cell RNA-seq confirmed ALK activation by both mutations.

Conclusions:

• Neuroblastoma cell lines exhibit distinct ALK mutation profiles and clonal evolution.
• Drug treatment can lead to the enrichment of specific ALK mutations, impacting therapeutic outcomes.
• This model provides insights into ALK-driven neuroblastoma heterogeneity and resistance mechanisms.