Tight junction-high and CDH17-positive cell population is the source of colorectal cancer liver metastases

Colorectal cancer (CRC) frequently develops aggressive metastatic disease, yet the cellular features that enable dissemination remain poorly defined. IKKα, a kinase traditionally linked to stress and inflammatory signaling, is increasingly recognized for broader functions in cancer. Here, we show that loss of IKKα unexpectedly promotes metastasis in CRC. Using patient-derived organoids, we find that genetic or pharmacological inhibition of IKKα stabilizes tight-junction components, leading to the emergence of compact epithelial clusters with a heightened ability to spread and colonize the liver. Single-cell transcriptomics reveals expansion of a CDH17⁺/CLDN2⁺ epithelial subpopulation that dominates metastatic lesions, a finding validated by tissue staining. Remarkably, disrupting CLDN2 completely eliminates the metastatic advantage caused by IKKα loss. These results identify a metastasis-competent epithelial state driven by tight-junction remodeling and uncover a vulnerable node that may be exploited therapeutically in aggressive colorectal cancer. The IKKα kinase was previously reported to promote metastasis. Here, the authors reveal that loss of IKKα function promotes colorectal cancer liver metastasis by expanding a CDH17⁺/CLDN2⁺ epithelial subpopulation characterized by tight junction stabilization and collective migration.