The effect of CHRDL2 overexpression on gene expression in CACO2 CRC cells

Chordin-like-2 (CHRDL2) is a secreted BMP antagonist, with overexpression and genomic variants associated with colorectal cancer (CRC) risk. BMP signalling in the normal intestinal epithelium operates in opposition to the WNT signalling pathway, which maintains stem-cells and self-renewal. Elevated WNT signalling leads to expansion of the stem cell compartment and hyperproliferation, defining characteristics of CRC. Here, we explored the impact of CHRDL2 overexpression on CRC cells to investigate whether CHRDL2's inhibition of BMP signalling intensified WNT signalling, and enhanced the cancer stem-cell phenotype. RNA-seq analysis revealed that CHRDL2 increased the expression of stem cell markers and well-established cancer-associated pathways. We suggest that CHRDL2 overexpression can augment the stem-cell potential of CRC and normal intestinal cells. To investigate the effect of CHRDL2 overexpression in CRC, Caco-2 cell lines were engineered to stably overexpress CHRDL2 cDNA upon addition of doxycyline. Doxycyline was administered in 3 levels of "low" "medium" and "high" to induce corresponding CHRDL2 gene expression. Cell were harvested for analysis at 3, 5, and 7 days post treatment. Differential expression was performed matching treatment type to a DMSO control at each time point.