A high-MAPK, low-WNT cell state drives metastatic dissemination in colorectal cancer

Colorectal cancer (CRC), a leading cause of cancer-related mortality due to distant metastases, is largely driven by activating mutations in the WNT and mitogen-activated protein kinase (MAPK) pathways. Understanding the mechanism underlying the metastatic process is essential for developing effective treatments. Using serial in vivo orthotopic passaging, we developed an immunocompetent mouse model of metastatic CRC. Highly metastatic tumor cells exhibited chromosomal amplifications in MAPK pathway genes, resulting in increased MAPK pathway activity and suppression of WNT-associated transcriptional programs, including stem cell genes. Pharmacological inhibition of mutant KRAS^G12D led to a reduction in the MAPK-high-WNT-low transcriptional state and decreased both lung and liver metastases. Analysis of CRC patient data revealed that the metastatic gene signature associated with the MAPK-high-WNT-low state correlated with poorer survival outcomes. These findings underscore the plasticity of metastasis-initiating cells in CRC driven by the opposing roles of MAPK and WNT signaling, despite their synergy observed during colon tumorigenesis.