Induction of ER stress in the colon cancer cell line LS174 with SubAB

To assess the effect of activation of the unfolded protein response (UPR) in colon cancer cell lines, we treated cells with the AB5 subtilase cytotoxin (SubAB). This proteolytically cleaves the 78-kDa glucose-regulated protein (GRP78; also known as HSPA5 or BiP) inside the endoplasmic reticulum. We find that the WNT signaling pathway is highly affected upon treatment with SubAB. 500,000 cells were plated in a 10 cm2 plate, and the following day, treated for 20 hrs with SubAB or the control (SubAA272B), and then harvested. Three independent biological replicates per treatment.