Figure 1

Morphology of metastatic PC3 and Bone stromal (HS5) cells in monoculture and co-culture (PC3 + HS5) conditions. (A) Differential Interference Contrast (DIC) images of PC3 cells. (A’) F-actin staining of a 3D reconstruction of a PC3 spheroid mass. PC3 cells displayed radiating tubular structures (filled arrowheads). (A”) A central Z-slice of a 3D PC3 mass. (B) DIC images of HS5 cells. (B’) F-actin staining of a 3D reconstruction of a HS5 spheroid mass. (B”) A central Z-slice of a 3D HS5 mass displaying an absence of cells in the inner region (arrow). (C) DIC images of a co-cultured cells. (C’) Immunostaining of co-cultures revealed that HS5 (STRO-1) and (C”) PC3 cells (Cell Mask blue; arrows) formed cell-cell contacts. (D-D’) Immunostaining of co-cultures with HS5 (STRO-1) and DU145 cells (arrows) revealed an absence of cell-cell contacts. (E) Western blot and densitometric analysis of endogenous expression of α6 and β1 integrin subunits in monocultured HS5 cells and in co-cultures over 9 days. (F-F’) Immunostaining of endogenous β1 integrin expression on HS5 (STRO-1 positive; green fluorescence) and PC3 (cell mask blue positive; STRO-1 negative) cells in co-culture. (G) Quantification of the percentage of PC3 and HS5 cells expressing β1 integrin in co-culture. (H-H’) Immunostaining of endogenous α6 integrin expression on HS5 (STRO-1 positive; green fluorescence) and PC3 (cell mask blue positive; STRO-1 negative) cells in co-culture. i) Quantification of the percentage of PC3 and HS5 cells expressing α6 integrin in co-culture (**p < 0.01, ***p < 0.001). Error bars denote S.E.M. Scale bars = 40 μm.