Figure 5
From: Osteogenic BMPs promote tumor growth of human osteosarcomas that harbor differentiation defects
Osteogenic BMPs fail to induce in vivo osteogenic differentiation of OS cells, but effectively promote OS tumor growth. (a) Osteogenic BMPs induce bone formation in normal MSCs but not in OS cells. AdBMP2, AdBMP9, or AdGFP-infected C3H10T1/2 (panels i and ii) and MG63 cells (panels iii and iv) were injected subcutaneously. Animals were killed at 6 weeks after injection, and the retrieved masses were subjected to H&E histologic evaluation. Note that GFP-treated cells did not form any detectable masses at the end point of the experiment. Ac, adipocytes; BM, bone matrix; Ch, chondrocytes. Magnification, × 200. (b) BMP9 promotes tumor growth formed by MG63 cells. Subconfluent MG63-Luc cells were infected with AdBMP9 or AdGFP. At 16 h after infection, cells were collected and injected into athymic mice intratibially (five animals per assay condition), as described in ‘Materials and Methods’. Animals were subjected to Xenogen imaging at the indicated time points. Sizes of tumors (in photons/sec/cm2/steradian) were calculated by using Xenogen's Living Image software (i). Xenogen optical images of the athymic mice intratibially injected with GFP or BMP9-transduced MG63-Luc cells at weeks 2 and 8 are shown (ii and iii). *P<0.05 when compared with GFP group at corresponding time points. (c) BMP2 and BMP9 also promote tumor growth formed by human OS line 143B. Athymic mice were intratibially injected with AdBMP2, AdBMP9, or AdGFP-infected 143B-Luc cells. Bioluminescence images taken at 4 weeks after injection are shown (i). Animals were killed after 6 weeks, and the gross images of xenograft tumors formed by intratibially injected with AdGFP- (ii) or AdBMP9- (iii) transduced 143B-Luc OS cells are shown.
