CRISPR/Cas9-mediated claudin-2 knockout in HCT116 cells reveals its key role in colorectal cancer progression.

Colorectal cancer (CRC) progression involves complex mechanisms of invasion and metastasis. Claudin-2 (CLDN2), a tight junction protein, has emerged as a key regulator paracellular permeability and its dysregulation is implicated in chronic inflammatory diseases and cancer. The present study aimed to determine the mechanisms by which CLDN2 deletion affects genes associated with motility and invasion of colon cancer cells. CRISPR/Cas9 was used to knock out CLDN2 in HCT116 cells. Subsequently, gene expression was analyzed using reverse transcription-quantitative PCR and migratory capacity was assessed using wound healing assays. CLDN2 deletion led to the downregulation of genes associated with motility and metastasis, including zonula occludens-1-associated nucleic acid binding protein, N-Myc downstream-regulated gene 1, CLDN14, CLDN23, Bcl-2, p53 and Bcl-6, suggesting that CLDN2 supports pro-migratory gene networks. These findings demonstrated that CLDN2 regulates metastatic gene expression in CRC. Although further mechanistic studies are warranted, the present study provided notable genetic and phenotypic evidence of the role of CLDN2 in promoting cancer cell migration and invasion, offering a potential foundation for future studies into its signaling interactions and therapeutic potential.