Loss of Postn leads to increased AR levels and activity. (A) H&E staining of primary tumors derived from wildtype (A) and Postn-null mic (B). Postn-deficient tumors displayed an apocrine-like morphology with granular eosinophilic cytoplasm and prominent nucleoli. (C-F) Immunohistochemical analysis of independent tumors from Postn-null mice shows an increase in AR levels and nuclear localization (G). At least 1000 nuclei from 3 independent tumors were assessed for AR nuclear translocation. The average and S.E.M. is shown. *
P <0.05. (H) Western blot analysis of Postn-null tumors reveals that Notch downregulation results in AR upregulation. Note one tumor sample where low AR levels can be correlated to high levels of Notch.