ABSTRACT
Colorectal cancer (CRC) is the second deadly and the third most common malignancy worldwide. It has been projected that annual new cases of CRC will increase by 63% in 2040, constituting an even greater health challenge for decades to come. This study has linked DEC1 (differentiated embryonic chondrocyte expressed gene 1) to the pathogenesis of CRC. Based on the analysis of patient samples and database data, DEC1 is expressed much higher in CRC than the adjacent normal tissues. CRC patients with higher DEC1 expression have a shorter survival time. The carcinogenesis protocol with azoxymethane/dextran sulfate induces a higher number of tumors with larger sizes in DEC1+/+ than DEC1-/- mice. Overexpression of DEC1 increases the expression of proliferation- and antiapoptosis-related genes, but decreases the level of proapoptotic genes. Mechanistically, this study has shown that DEC1 is functionally looped to the IL-6/STAT3 signaling pathway (interleukin-6/signal transducer and activator of transcription 3). IL-6 induces DEC1, and DEC1 enhances the phosphorylation of STAT3, resulting in increased pSTAT3/STAT3 ratio. DEC1 and STAT3 are present in reciprocal immunocomplexes, pointing to physical interactions (presumably with pSTAT3). These findings establish that DEC1 is a CRC enhancer. The enhancement is achieved largely through the IL-6/STAT3 pathway. The potential of the physical interaction between DEC1 and STAT3 will likely serve as a foundation to develop intervention strategies for CRC prevention and therapy.