Lineage plasticity driven by GATA6 loss fuels colorectal cancer metastasis.

Colorectal cancer (CRC) liver metastases are the leading cause of CRC-related mortality, yet the genetic and epigenetic drivers underlying this process remain poorly understood. Here, we established a pro-metastatic CRC organoid library through serial orthotopic transplantation of liver metastasis-derived organoids. Integrative RNA sequencing (RNA-seq) and assay for transposase-accessible chromatin using sequencing (ATAC-seq) analyses identified a pro-metastatic signature characterized by multilineage plasticity, including fetal-like and basal-like/squamous transcriptional programs. Motif and transcription factor activity analyses identified GATA6 as a key regulator of these epigenetic alterations. GATA6 expression is downregulated in liver metastases, and its genetic ablation enhances liver metastasis with minimal effects on primary tumor growth. Mechanistically, GATA6 loss triggers pro-metastatic transcriptional programs, including fetal-like and basal-like/squamous states, accompanied by LGR5- cell generation. This reprogramming is mediated by the direct repression of HNF4A and increased H3K27ac and occurs independently of SOX17. Together, these findings identify GATA6 loss as a central regulator of multilineage plasticity that drives liver metastasis in CRC.