Fig. 3

SMAD1 is required for MM cell growth and its over-expression confers drug resistance upon MM cells. a SMAD1 expression was determined by western blot analysis in MM1.R and OPM2 vel/R. (b left) Representative results showing SMAD1 knockdown induces cell cycle arrest in MM1.R and OPM2 vel/R. MM1.R and OPM2 vel/R were transfected with si-SMAD1 30 nM or siRNA control for 48 h, then the cells were subjected to cell cycle analysis. (b right) Quantitative results of the cell cycle phase of results. c The 8226 R5, MM1.R and OPM2 vel/R cell lines were transfected with synthetic si-SMAD1 50 nM or siRNA control and treated with different concentrations of BTZ for 48 h and cell viability was measured using MTT assay. d 8226 R5 was treated with indicated different concentration of DM for 24 h and SMAD1 phosphorylation was assessed by western blot. e 8226R5, MM1.R and OPM2 vel/R cells were treated with indicated concentrations of DM and anti-myeloma drug alone, or combination for 48 h and cell viability was assessed by MTT assay. f Combination of drugs (DM, BTZ) synergistically induces cytotoxic effects on primary mononuclear cells MM patients’ samples. Primary mononuclear cells derived from 5 MM patients were treated with indicated concentration of BTZ and DM for 48 h, and then cell viability was evaluated by MTT assays. Results are presented as means±SD. from at least three separate experiments. *: p < 0.05; **: p < 0.01; ***: p < 0.001. g CD138 + cells derived from 2 MM patients were treated with indicated concentration of BTZ, and DM for 48 h, and then cell viabiility was evaluated by MTT assays. Results are presented as means±SD. from at least three separate experiments. *: p < 0.05; **: p < 0.01; ***: p < 0.001. h 8226R5, MM1.R and OPM2 vel/R were transfected with si-SMAD1 50 nM or siRNA control. Protein lysate was subjected to western blot with indicated antibodies