Overexpression ofmiR33b inhibits tumor growth and prolongs survival in human plasmacytoma xenograft models. 5 × 106 or 2 × 106/100 μL of GFP-miR33b–transfected MM.1S cells or vector-transfected MM.1S cells were subcutaneously or intravenously injected into NOD.CB17-Prkdcscid/J mice (5 mice/group). Tumor volume was calculated using the following formula: V = 0.5a Xb2, where “a” and “b” are the long and short diameter of the tumor, respectively. Survival was evaluated from the first day of tumor injection until death. Representative photos of mice with tumor burden were taken with Imager Analyzer. (A) Representative image of mice with subcutaneous tumors. Left panel shows a mouse injected with vector-transfected MM.1S cells; the right panel shows a mouse injected with miR33b-transfected MM.1S cells. (B) Overexpression of miR33b inhibits tumor growth in a subcutaneous model. (C) Overexpression of miR33b prolongs survival in a subcutaneous model. (D) Mice tumors from the experiment described in panel A were analyzed for PIM-1 protein expression. (E) Representative image from mice receiving MM.1S miR33b-overexpressing cells in a disseminated MM model. Photo shows tumor homing in the backbone and skull region. (F) Overexpression of miR33b prolongs survival of mice in disseminated model. The log-rank test was used to evaluate the significance of survival of mice.
