Relapsed neuroblastomas show frequent RAS-MAPK pathway mutations

Area of Science:

• Oncology
• Genetics
• Molecular Biology

Background:

• Neuroblastoma frequently relapses after chemotherapy, developing therapy resistance.
• The underlying molecular mechanisms driving this aggressive relapse phenotype remain largely unknown.

Purpose of the Study:

• To investigate the molecular basis of therapy-resistant neuroblastoma relapse.
• To identify potential therapeutic targets and biomarkers in relapsed neuroblastoma.

Main Methods:

• Whole-genome sequencing of 23 paired diagnostic and relapse neuroblastoma tumors.
• Analysis of clonal evolution and somatic mutations in relapse samples.
• Functional validation of RAS-MAPK pathway mutations in neuroblastoma cell lines and in vivo models.

Main Results:

• Relapse tumors exhibited significant clonal evolution from diagnostic samples, with a median of 29 unique somatic mutations.
• Activating RAS-MAPK pathway mutations were identified in 78% (18/23) of relapse neuroblastomas.
• These RAS-MAPK pathway mutations were also found in 61% (11/18) of neuroblastoma cell lines and predicted sensitivity to MEK inhibition.

Conclusions:

• RAS-MAPK pathway mutations are a common feature of relapsed neuroblastoma, indicating their role in therapeutic resistance.
• These mutations serve as potential biomarkers for novel therapeutic strategies targeting refractory neuroblastoma.
• Genetic characterization of relapse neuroblastomas is crucial for guiding future treatment approaches.