Expression pattern of Dkk-3, a secreted Wnt pathway inhibitor, in mouse intestinal tissue and three-dimensional cultured Caco-2 spheroids

We investigated the expression pattern of Dkk-3, a secreted Wnt pathway inhibitor, in mouse intestinal tissue and three-dimensional cultured Caco-2 spheroids. Dkk-3 was expressed at the bottom of crypts from the mouse small intestine. Human colon adenocarcinoma Caco-2 cells expressed Dkk-3 under a semi-confluent condition, but Dkk-3 expression was seen in only some of the Caco-2 cells when the cells were sparse. Caco-2 cells formed hollow spheroids in Matrigel, and the layer-forming cells in the hollow spheroids expressed Dkk-3. Our results demonstrated that Dkk-3 might affect intestinal cells when the fate of stem cells changes.