Description
PTEN imparts tumor suppression in mice by cell autonomous and non-autonomous mechanisms. Whether these two tumor suppressor mechanisms are mediated through similar or distinct signaling pathways is not known. Here we generated and analyzed knockin mice that express a series of human cancer-derived mutant alleles of PTEN that differentially alter the Akt axis in either stromal or tumor cell compartments of mammary glands. We find that cell non-autonomous tumor suppression by Pten in stromal fibroblasts strictly requires activation of P-Akt signaling, whereas cell autonomous tumor suppression in epithelial tumor cells is independent of overt canonical pathway activation. These findings expose distinct Akt-dependent and independent tumor suppressor functions of PTEN in stromal fibroblasts and tumor cells, respectively, that can be used to guide clinical care of breast cancer patients