Figure 7.

STAT5 signaling prevents luminal differentiation of the prostate epithelium. (A). Schematic representation of luminal differentiation placing LSC^med cells in-between basal and luminal cells. (B). The relative content in the three epithelial cell populations (basal/stem, LSC^med, luminal) in the various prostate lobes of 6-month old Pb-PRL mice or in WT mice (any lobe), as determined in Figure 3 is symbolized by the size of each population name. Below, the level of STAT5 activation in each lobe as determined in Figure 1 is also schematically represented by the black stair-bar. Based on these measurements, the highest the level of STAT5 activation, the lowest the level of epithelium differentiation was observed (see text for discussion).