DICKKOPF-1 (DKK-1) Gene Associations in Human Cancers by Vitamin D and Sulforaphane
Author(s): Sharmin Hossain, Zhenhua Liu, Richard J
Dickkopf Wnt Signaling Pathway Inhibitor-1 gene (DKK-1) encodes a member of the Dickkopf family of proteins and is involved primarily in the embryonic development and bone formation in adults. Based on its known relationship to Wnt signaling pathway, we set out to determine how this gene is affected by dietary agents- vitamin D and sulforaphane (SFN). Cells were exposed for 24 hours to vitamin D3 [1,25(OH)2D3] (100nM) either alone or in combination with L-sulforaphane and TSA (20μM and 1μM respectively) at 70% confluency. We hypothesized that DKK-1 expression will be increased in both cancer cells using our select treatments. In proliferating Caco-2 cells, treatment with 1,25(OH)2D3 had nearly a 3-fold increase in DKK-1 (p<0.05) expression while in MCF-7 cells saw no effect of the treatments. Co-treating the cells with both compounds seemed to attenuate the D effect, implying competing needs along the signaling pathway and require further investigation.