# Paired mutation calling and spatial transcriptomics identify cellular neighbourhoods dictating the neoplastic outcome of colitis

## TL;DR

This study explores how the cellular environment influences the development of cancer in colitis by combining various techniques in a mouse model.

## Contribution

The study introduces a model linking tissue environment to tumor initiation through the selection of pro-oncogenic clones.

## Key findings

- Epithelial- and immune-enriched neighborhoods were identified in colitis-associated tumorigenesis.
- A reparative tissue environment promotes the selection and expansion of pro-oncogenic clones.
- Inflammation-resistant neighborhoods containing non-oncogenic clones are reduced in this process.

## Abstract

In the progression from Inflammatory Bowel Disease to associated cancer, the clonal mutational landscape shifts from selection of mutations in inflammatory genes to selection of cancer-driver mutations1–4. How prevalence and expansion of either type of mutated clones could be impacted by the cellular environment in which they arise, and how this affects the neoplastic outcome of colitis is unknown. Here, we combine in vivo lineage tracing, in-silico modelling, mutational profiling and spatial transcriptomics in a mouse model of colitis-associated tumorigenesis to capture clone fates associated with chronic inflammation. We identify epithelial- and immune-enriched neighbourhoods and propose a model in which establishment of a reparative tissue environment facilitates tumours initiation by promoting the selection and expansion of pro-oncogenic clones, reducing the span of inflammation-resistant neighbourhoods containing non-oncogenic clones.