Figure 6. Anti-β₂M mAbs enhance anti-MM effects of BTZ in vivo.

Shown are tumor volumes (A, B) and M-protein levels (C, D) in ARP-1 or MM.1S tumor-bearing mice, respectively (n = 4), treated with mouse IgG1 or DMSO (control), BTZ, anti-β₂M mAbs (Ab), or the combination of BTZ and anti-β₂M mAbs (BTZ+Ab). ARP-1 or MM.1S cells were subcutaneously injected into SCID mice. At 3 to 4 weeks after MM cell injection, mice were intraperitoneally injected with BTZ (0.1 mg/kg) or subcutaneously around tumors with anti-β₂M mAbs (0.6 mg/kg), singly or in combination, every 3 days for 3 weeks. Tumor volumes were measured every 3 days after treatment. The level of circulating human kappa or lambda chain in mouse serum was measured by ELISA. (E) Representative images of in situ TUNEL assay and immunohistochemistry of Ki67 and cleaved caspase 3 (c-cas 3) showing MM tumor cell apoptosis and proliferation. **P < 0.01.