CAL-101 enhances cytotoxicity of bortezomib. (A) LB and INA-6 MM cells were cultured with medium (■) and with CAL101 1.25μM (), 2.5μM (), or 5μM (□) in the presence or absence of bortezomib (0-5nM). Cytotoxicity was assessed by MTT assay; data are mean ± SD of quadruplicate cultures. (B) INA-6 cells were treated with CAL-101 (5μM) and/or bortezomib (5nM) for 6 hours. Phosphorylation of AKT was determined by Western blotting of cell lysates using phospho-AKT (ser473) Ab. Actin served as a loading control.