Figure 5

Blocking BMP signaling in hair progenitor cells disrupts expression of key molecules that are essential for normal morphogenesis of hair follicles. (A) shows typical GFP/P-cad double staining of a neoplasia from an Nse-Noggin mouse. Note that P-cad is over expressed in GFP positive cells. (A'& A") show the split channel of GFP and P-cad, respectively. (B&C) show typical GFP/E-cad double staining of a tail neoplasia (B) and a section of WT tail tissue (C). Note that E-cad is normally expressed in basal epithelia and inner root sheath of tail. This normal expression is dramatically reduced not only in tumor cells but also in the basal epithelia adjacent to tumor. (D) shows typical GFP/CD44 double staining of a neoplasia. Note the clear inverse relationship of GFP and CD44 expression, i.e., secondary hair follicles that have strong GFP expression always have low CD44 expression. (D'&D") show the split channels of CD44 and GFP, respectively. (E&F) show typical Ki67 staining of a tail neoplasia (E) and a section of WT tail tissue (F). Note that, normally, a subpopulation of basal epithelia has strong expression of Ki67, but very few hair follicle cells are Ki67 positive. Ki67 positive cells are dramatically increased in the tumor. In contrast, Ki67 expression is reduced in the basal epithelia that adjacent to tumor. Bar = 40 μm.