Expression data from human primary keratinocytes

The genetic expression profile of a Wnt signal agonist, BIO, was evaluated in human primary keratinocytes. Accelerating scaling up of primary keratinocytes benefits skin autografts for severely burned patients. Wnt signal, a conserved pathway controlling cell cycle and morphogenesis of embryo, has been postulated to promote the cell proliferation and tumorigenesis in adult. Here, the effects of Wnt signal on the growth of interfollicular keratinocytes were investigated. We demonstrated that recombinant Wnt3a significantly promoted the primary keratinocyte growth at a low cell density. A well-characterized GSK-3beta inhibitor, BIO, activated the Wnt signals and also enhanced the colony formation of keratinocytes dose-dependently. Gene expression profile of the BIO-treated keratinocytes revealed the linkage of the BIO with the cell mitosis and indicated that epithelial cell adhesion molecule (EpCAM), a Wnt target gene, was upregulated. Comparing to the EpCAM- keratinocytes, the EpCAM+ cells showed higher proliferation rate and efficacy of the colony formation. Especially, inhibiting the EpCAM expression by shRNA attenuated the proliferation effect of BIO and the growth advantage of the EpCAM+ keratinocytes. These evidences emphasize the positive role of canonical Wnt and EpCAM on the regulation of cell growth and self-renewal for human keratinocytes.