TWIST1 mediated transcriptional activation of SPON2 drives colorectal cancer peritoneal metastasis through stromal cell signaling network.

Colorectal cancer (CRC) peritoneal metastasis (PM) accounts for 25-35% of stage IV cases. CRC PM carries a median overall survival of 16 months with systemic chemotherapy and an almost 0% 5-year survival rate. The molecular mechanisms driving CRC PM remain poorly defined. CRC heterogeneity is classified into four Consensus Molecular Subtypes (CMS1-4), with CRC PM predominantly exhibiting the CMS4 signature-characterized by increased stromal/mesenchymal enrichment and cellular plasticity-features linked to frequent disease progression and therapeutic resistance. Here, we investigated the molecular mechanisms driving CRC PM and CMS4 signature. TWIST1 was identified to be significantly upregulated in CRC PM. We established TWIST1-SPON2 as a novel transcriptional axis contributing to CRC PM tumorigenesis, through mediating tumor-stroma interactions. We identified SPP1, secreted by the tumor stroma, as an upstream regulator of the TWIST1-SPON2 cascade via AKT activation in tumor cells in vitro and in vivo. This defined SPP1-TWIST1-SPON2 signaling circuit is pivotal in shaping the tumor microenvironment and promoting CRC PM progression. The findings establish the SPP1-TWIST1-SPON2 axis as potential biomarkers and therapeutic targets in CRC PM.