Heterogeneity in clone dynamics within and adjacent to intestinal tumours identified by Dre-mediated lineage tracing

Somatic models of tissue pathology commonly use induction of genespecific mutations in mice mediated by spatiotemporal regulation of Cre recombinase. Subsequent investigation of the onset and development of disease can be limited by the inability to track changing cellular behaviours over time. Here, a lineage-tracing approach based on liganddependent activation of Dre recombinase that can be employed independently of Cre is described. The clonal biology of the intestinal epithelium following Cre-mediated stabilisation of beta -catenin reveals that, within tumours, many new clones rapidly become extinct. Surviving clones show accelerated population of tumour glands compared to normal intestinal crypts but in a non-uniform manner, indicating that intra-tumour glands follow heterogeneous dynamics. In tumouradjacent epithelia, clone sizes are smaller than in the background epithelia, as a whole. This suggests a zone of similar to seven crypt diameters within which clone expansion is inhibited by tumours and that may facilitate their growth.

Automated summary

This study introduces a lineage-tracing approach based on Dre recombinase activation, independent of Cre, to investigate clonal biology of the intestinal epithelium. The research reveals that many new clones within tumors rapidly become extinct, while surviving clones exhibit accelerated population growth compared to normal crypts, showing heterogeneous dynamics within intra-tumor glands.