Colon cancer cells DLD1 cells incubated with kynurenine, TCDD, or CH223191 for 1 hour

The ligand-activated transcription factor Aryl Hydrocarbon Receptor (AHR) regulates cellular detoxification, proliferation, and immune evasion in a range of cell types and tissues, including cancer cells. In this study, we used RNA-seq to identify the signature of AHR target genes regulated by the pollutant 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and the endogenous ligand kynurenine (Kyn), a tryptophan-derived metabolite. This approach identified a signature of six genes (CYP1A1, ALDH1A3, ABCG2, ADGFR1, and SCIN) as commonly activated by endogenous or exogenous ligands of AHR in multiple colon cancer cell lines. Among these, the actin-severing protein Scinderin (SCIN) was necessary for cell proliferation; SCIN downregulation limited cell proliferation and its expression increased it. SCIN expression is elevated in a subset of colon cancer patient samples, which also contain elevated β-catenin levels. Remarkably, SCIN expression promotes nuclear translocation of β-catenin and activates the WNT pathway. Our study identified a new mechanism for adhesion-mediated signaling in which SCIN, likely via its ability to alter the actin cytoskeleton, facilitates the nuclear translocation of β-catenin. Cultured cells exposed to 10uM of each chemical