Meso-scale spatial analysis of papilloma formation and clonal expansion in cancerized skin.

Meso-scale spatial analysis reveals that tissue signaling and heterogeneity constrain the tumorigenic potential of Hras mutations in skin, with only 6 out of 473 papillomas harboring the mutation.

• Why it matters: Understanding how tissue context influences clonal selection is crucial because many somatic mutations occur in normal tissues but rarely lead to cancer, highlighting the importance of local environment in tumor development.
• What they did: The study applied spatially resolved genotyping and transcriptomics, including WES, bulk, and single-cell RNA-seq, across multiple centimeters of mouse skin to analyze clonal and signaling dynamics.
• The result: Findings show that tissue signaling programs like necroptosis and TGFB topology reshape the selective landscape, limiting driver mutation effects and explaining variability in clone expansion and tumor progression.