Figure 2

Inhibitors of HSP90 and HSF1 co-operate differently with antimyeloma drugs. (A) LP1 MM cells were treated with 10 μM KNK-437 or 100 nM 17-AAG or/and 10 nM bortezomib. Whole cell extracts were analyzed as before by Western blots with the indicated Abs. Anti-GAPDH Ab controlled gel loading. ▲ marked an unspecific band. (B) L363, LP1, and 8,226 cells were cultured on HS-5 cells 24 h before being treated as previously, stained with anti-APO2.7-PE recognizing specifically apoptotic cells followed by flow cytometry analysis (Gallios, Beckman Coulter). Means and SD of three independent experiments are presented in histograms. *p < 0.05, **p < 0.01, ns, not significant with Student’s t test. (C) Primary cells from patient #3 were treated with vehicle or bortezomib (5 or 10 nM) or KNK-437 (10 or 50 μM) for 24 h and then analyzed for CD138 labeling (FL2) as described [10]. Cell death was determined by the percentage of CD138+ cells that have lost CD138 expression. The percentage of living cells (CD138+) for each culture condition is indicated on the graph. At least 2 × 10⁴ events were gated for each culture condition with the FACsCalibur cytometer; data were analyzed with the CellQuest software.