Figure 5: Both basal and luminal cells can initiate prostate tumours by different division modes.

(a) Immunostaining of AP Pten-null prostates at different stages (4, 6, 9 weeks) with P-AKT and p63 antibodies indicates a single transformed luminal cell and clones of sole transformed luminal cells. Arrowhead points to a single transformed luminal cell. Dotted lines denote the transformed clone boundary that contains only transformed luminal cells. (b) Immunostaining of AP Pten-null prostates at different stages (4, 6, 9 weeks) with P-AKT and p63 antibodies indicates a transformed basal cell or mixed clones of transformed basal and luminal cells. Red and yellow arrowheads point to a single transformed basal cell and a single transformed luminal cell, respectively. Dotted lines denote the transformed clone boundary that consists of both transformed luminal cells and basal cells. (c) Division mode analysis of luminal cells by staining Pten-null tumour sections with p63 and Survivin indicates that the transformed luminal cells undergo symmetrical divisions to give rise to daughter cells that are both luminal cells. (d) Division mode analysis of luminal cells by staining Pten-null tumour sections with p63 and P-AKT, or P-H3 and P-AKT antibodies. Arrowheads point to two transformed daughter cells indicated by positive P-AKT staining. (e) Division mode analysis of basal cells in Pten-null tumour by staining p63, CK8 with Survivin indicates a dividing basal cell is undergoing asymmetrical division to give rise one basal cell (p63⁺) and one luminal cell (p63⁻/CK8⁺). (f) Cell polarity analysis of basal cells by staining p63 with aPKC, and p63 with Par3. (g) Detection of the dividing basal cells in Pten-null prostate by staining P-H3 and p63. Dashed lines denote the cell boundaries or positions of the basement membrane. Scale bars, 10 μm.