Primary MM cells can be luciferase gene marked, which allows real-time analysis of pMM cell growth. (A) Mononuclear cells of patient 3 were gene marked with luciferase and green fluorescent protein (GFP). Transduction efficiency was analyzed using anti–CD138-PE, TO-PRO-3-iodide, and green fluorescent protein 48 hours after transduction. (B-F) Humanized mice were created by implanting mice with 4 MSC-loaded BCP constructs (sites 2-5) and 2 controls, 1 loaded with MSCs and exposed to 30 Gy of x-rays before implantation (site 1) and the other without MSCs (site 6). Humanized and control mice (ie, mice without ossicles) were inoculated with luciferase-marked pMM cells of patient 3 at 4 sites directly into the ossicle (sites 1-3 and 6) or subcutaneously, respectively, and followed by BLI. (B) BLI images from humanized and control mice 4 days after injection. (C) Tumor growth was determined by average photon emission intensity measured for a region of interest in time. The results are expressed as relative growth with the intensity at day 4 set to 100. The lines represent the mean signal of 2 mice ± SD. (D) BLI images of a representative mouse at day 4 (left panel) and day 104 (right panel) after injection with transduced pMM cells, indicating migration of pMM cells to noninjected sites 4 and 5. (E) Immunohistochemical analysis of ossicles for luciferase with the scaffold material (s) covered with bone (b) and infiltrated by pMM cells. (F) A pMM-carrying humanized mouse was subjected to total body irradiation (6 Gy x-rays) and analyzed by BLI 2 weeks before and after irradiation.