Cross-species single-cell and spatial transcriptomic mapping reveals EFNA1-EPHA4-mediated stem-like epithelial-macrophage crosstalk driving colorectal cancer progression.

Colorectal cancer (CRC) typically follows the "normal-adenoma-carcinoma" (NAC) progression, with approximately 70-90% of cases driven by an adenomatous polyposis coli (APC) mutation-dependent pathway. The Apc-mutant (Min) mouse, valuable for dissecting gene function and mechanisms in CRC, provides an important basis for cross-species analyses with human data. Here, we performed a cross-species analysis of single-cell and spatial transcriptomic data across multiple stages of colorectal tissues in both humans and Min mice, constructing a spatiotemporal atlas. Our study identified key microenvironmental regulatory networks involved in CRC progression and highlighted the central role of epithelial-macrophage interactions within the tumor microenvironment. We further validated the suitability of the Min mouse as a model for the intrinsic Consensus Molecular Subtypes 2(iCMS2) microsatellite-stable (MSS) subtype of CRC. Focusing on the crosstalk between tumor-associated macrophages (TAMs) and epithelial cells, we identified the EFNA1-EPHA4 axis as a critical regulator promoting the immunosuppressive polarization of TAMs and enhancing tumor cell stemness. In addition, inhibition of EFNA1 was found to slow tumor growth. This study not only provides a systematic framework for mapping CRC correspondence between humans and mice, but also uncovers key molecular mechanisms underlying CRC progression and proposes promising therapeutic targets.