Figure 6. Representative histologic sections from XRK3F2 treated animals with new bone formation (B-F) and a vehicle treated animal without new bone formation (A).

All sections shown are from animals that received MM cell inoculation. A. Sections from 5TGM1-inoculated mice that did not receive XRK3F2 demonstrate a significant plasma cell infiltrate in the marrow space, as expected, and normal cortical morphology with no evidence of new bone formation (x50, scale bar = 500µ). B. Sections from mice treated with XRK3F2 stained with H&E show abundant new bone formation along the periosteal surface of the tibia (bracket) inoculated with 5TGM1 cells (×50, scale bar = 100µ). C. anti-GFP immunohistochemistry confirmed that plasma cell (5TGM1-tk-gfp) infiltration (long arrow) in the marrow space was in close proximity to areas of new bone formation (short arrow) (×16, scale bar indicates 500µ). D. Higher magnification demonstrates new bone (short arrows) and active osteoblasts (long arrows) (×200, scale bar = 100µ). E. TRAP stained section from a representative section with new bone formation shows the presence of red-staining osteoclasts (arrows) along the new bone surface (×100, scale bar = 100µ). F. Polarizing microscopy demonstrates a disorganized (woven) arrangement of the newly laid bone, indicating that this bone was laid rapidly. (×100, scale bar = 100 microns. Collagen fibrils are green.)