Single-cell genotyping demonstrates complex clonal diversity in acute myeloid leukemia

Area of Science:

• Hematology
• Cancer Biology
• Genetics

Background:

• Clonal evolution drives cancer progression, metastasis, and relapse.
• Next-generation sequencing (NGS) is commonly used to track mutant alleles and determine clonality.
• Current NGS methods rely on assumptions about mutation patterns and heterozygosity, which may not hold true for all cancer types, including acute myeloid leukemia (AML).

Purpose of the Study:

• To assess the appropriateness of current models of clonal diversity in AML.
• To develop protocols for direct single-cell genotyping in AML.
• To investigate the patterns of common mutations (FLT3, NPM1) in AML at the single-cell level.

Main Methods:

• Development of protocols for direct single-cell genotyping of AML samples.
• Analysis of mutations in FLT3 and NPM1 genes within individual AML cells.
• Characterization of clonal populations and their evolutionary trajectories.

Main Results:

• Single-cell analysis revealed that FLT3 and NPM1 mutations occur in both homozygous and heterozygous states.
• At least nine distinct clonal populations were identified in all analyzed AML samples.
• Evidence of convergent evolution and differential evolutionary trajectories for cells with distinct mutations was observed.

Conclusions:

• Current computational models based on bulk sequencing may underestimate tumor heterogeneity in AML.
• The observed clonal diversity and evolutionary patterns suggest a more complex landscape than previously understood.
• These findings have significant implications for developing targeted therapies to effectively manage AML and prevent relapse.