MLN3897 overcomes the survival and proliferation advantage conferred by OCs in coculture. (A) We assessed cell survival of INA6 and MM primary cells alone and in the presence of OCs, with or without MLN3897. At 2 and 5 days, viable cells were counted by trypan blue staining. (B) INA6 cells were cocultured with mature OCs with or without MLN3897 (10 nM) and cell proliferation was assessed by thymidine uptake at 48 hours. Results are expressed as means (± SD) counts per minute (cpm). (C) At the same time point, IL-6 secretion was evaluated by ELISA. Results are expressed as mean (± SD).