Multigenerational cell tracking of DNA replication and heritable DNA damage

Area of Science:

• Cellular biology
• Genomics
• Cancer research

Background:

• Cell heterogeneity is fundamental to life, influencing development, tumor evolution, and drug responses.
• Understanding the origins and propagation of cell-to-cell variation is crucial but challenging.
• Retrospective analyses of cancer genomics struggle to resolve the emergence and inheritance of cellular heterogeneity.

Purpose of the Study:

• To elucidate how oncogenic perturbations induce sister cell asymmetry and phenotypic heterogeneity.
• To develop a framework for dissecting phenotypic plasticity at the single-cell level.
• To investigate cellular processes relevant to early cancer development.

Main Methods:

• Multigenerational single-cell tracking using endogenously labeled proteins.
• Dual CRISPR-based genome editing for simultaneous tracking of DNA replication and heritable DNA lesions.
• Time-resolved lineage analysis combined with iterative staining for cell cycle and DNA damage markers, and single-cell transcriptomics.

Main Results:

• Detailed tracking of cell lineage trees up to four generations in asynchronously growing cells.
• Revealed replication and repair dynamics, damage inheritance, and the emergence of sister cell heterogeneity across multiple generations.
• Delineated how oncogenic events trigger distinct routes to polyploidization, affecting genome integrity.

Conclusions:

• The study provides a novel framework for dissecting phenotypic plasticity and cell heterogeneity.
• Identified mechanisms by which oncogenic perturbations drive cell asymmetry and diverse cellular outcomes.
• Offers insights into early cellular events during cancer development.