Therapeutic effects of DKK1-DNA vaccines against established myeloma. Balb/c mice (5 per group) were inoculated subcutaneously with MOPC-21 tumor cells, and when the tumors reached 25 mm2, received different treatments at a 3-day interval. Tumor burdens were measured twice every week. Mice were euthanized when subcutaneous tumors reached 225 mm2 or when mice became moribund. Shown are tumor burdens (A,C,E) and survival (B,D,F) of mice receiving 3 injections of PBS, CpG, DKK1-DNA vaccine (DKK1), or DKK1 DNA vaccine plus CpG (DKK1-CpG; A-B); or DKK1-DNA vaccine plus CpG (DKK1-CpG), rat IgG, B7H1 mAb, CpG plus B7H1 mAb (CpG+B7H1), or DKK1-DNA vaccine plus CpG (DKK1-CpG) in combination with B7H1 mAb (DKK1-CpG+B7H1; C-D); or DKK1-DNA vaccine plus CpG (DKK1-CpG), rat IgG, OX40 mAb, CpG plus OX40 mAb (CpG+OX40), or DKK1-DNA vaccine plus CpG (DKK1-CpG) in combination with OX40 mAb (DKK1-CpG+OX40; E-F). Representative results of 1 of 2 independent experiments are shown. *P < .05; **P < .01, compared with PBS controls.
