Fig. 2: MSCs initially suppress prostate cancer growth in the bone microenvironment.
a, b Prostate cancer growth (PAIII) overtime in the presence (1:1 ratio) or absence of MSCs (n = 8/group). An MSC-alone group was also included as a control (n = 7). Representative images of bioluminescence for each group at day 11 time point are shown. Graphs illustrate collected RLUs over time for each group thru days 11 and 14. Error bars represent mean ± SEM. Linear regression was used to determine significance at day 11 (p = 0.0324). c Analysis of RLU values at day 11 and 14 in the PAIII vs. PAIII + MSC group. Error bars represent the mean ± SEM. d, e Ex vivo analyses from study endpoint of proliferative and apoptotic indices using phospho-histone H3 (p-H3; red arrows; c) and cleaved caspase 3 (CC3; red, arrows, d), respectively. Pan-cytokeratin (green) was used to identify prostate cancer cells. f Representative images (n ≥ 3 biologically independent samples) of smooth muscle actin staining (α-SMA; red) in tissues derived from the PAIII + MSC group. Pan-cytokeratin (pCK; green) was used to localize prostate cancer cells. Dashed box in merge represents area of magnification. g X-ray analysis of cancer-induced bone destruction. Representative X-ray from PAIII group is shown with dashed box defining area of magnification. Arrows indicate areas of cancer-induced bone destruction. The area of bone destruction was calculated as a percentage of total volume. h The number of osteoclasts (TRAcP positive; red, multinucleated; arrows) per μm of bone was calculated in non-sequential sections derived from the PAIII and PAIII + MSC groups. i Trabecular bone volume (BV) was measured via histomorphometry on non-sequential H&E multiple sections derived from each group and calculated as a percentage of total volume. Representative gross H&E images are illustrated from the PAIII and PAIII + MSC group. Representative micrographs (d, e, g, i) are derived from independent bones (≥ 3) from each study group. Statistical analyses were generated from one-way ANOVA with multiple comparisons at 95% CI. Asterisks denote statistical significance (*p ≤ 0.05, **p ≤ 0.01) while NS denotes not significant.
