FK866 abrogates the survival advantage conferred by the bone marrow microenvironment. (A) Expression levels (linear scale) for Nampt transcripts were evaluated using oligonucleotide microarray data for MM1S, MM1R, and INA6 cells cultured in vitro in the presence or absence of HS-5 bone marrow stromal cells (GSE 20 540). (B) MM-1S cells were treated with FK866 (1-10nM) in the presence or absence of rhIL-6 (10 ng/mL) or rhIGF-1 (100 ng/mL) for 72 hours, and DNA synthesis was determined by (3H)-thymidine uptake. The results presented are a mean ± SD of triplicate samples (*/**/***; P < .0001). (C) MM-1S cells were treated with FK866 (1-10nM) in the presence or absence of BMSCs for 72 hours, followed by measurements of proliferation using (3H)–thymidine incorporation assay. Data presented are means ± SD of triplicate samples (*P = .0019; **P = .0010;***P = .0034).
