Figure 3.

Immunophenotype of prostatospheres. Immunofluorescent images of confocal cross sections from mouse wt prostate spheres stained for prostate lineage epithelial markers CK8, CK5, and CK14 (left panel) and stem cell markers: p63, SOX2, CD49f, and SCA-1 (right panel). Prostatospheres displayed a heterogenous population of cells displaying intermediate cytokeratin profiles, where major population of cells co-expressed CK8 (luminal prostate cell marker) and either CK5 or CK14 (basal prostate cell marker). Furthermore, positive expression of the neuroendocrine marker β3 tubulin was detected in a minor population of cells within the prostatospheres. On the other hand, co-expression of p63 [basal prostate cell marker and believed to be a marker of the stem cells of developing prostate epithelium (46)] and SOX2 [essential embryonic stem cell gene involved in prostate tumorigenesis (47)] was also detected, besides expression of the stem cell marker CD49f and SCA-1, which have been shown to identify putative prostate stem-like cells (48, 49). The nuclei were stained with anti-fade reagent Fluorogel II with DAPI. Scale bars = 100 μm. Representative confocal microscopy images were acquired using the 63x oil objective and images were processed using the Zeiss ZEN 2012 image-analysis software. Microscopic analysis was performed using Zeiss LSM 710 laser scanning confocal microscope (Zeiss). DAPI, 40,6-diamidino-2-phenylindole.