In vitro synergy of reovirus with BTZ in oncolysis of RPMI 8226, KMS11, and OPM2 human myeloma cell lines. (A) Viability of human myeloma cells following single or dual treatment. RPMI 8226, KMS11, and OPM2 cells were treated with constant ratios of ED₅₀ values generated for reovirus (2.31, 13.25, and 63.05 MOI, respectively) and BTZ (2.8, 4.76, and 0.87 nM, respectively). Cell viability was assessed at 48 hours via the WST assay. N = 4 independent experiments. *P < .05, Conover’s test. (B) Viral progeny production in RPMI8226, KMS11, and OPM2 following treatment with LV alone or LV in combination with BTZ. Myeloma cells in 24-well plates were infected with ED₅₀ values of LV or a combination of ED₅₀ values of LV and BTZ (as in panel A). Samples were collected at 12-hour time points up to 72 hours; virus yields were determined by plaque titration on L929 cells and represented as log plaque-forming unit per milliliter. The linear rates of viral progeny production in the 2 groups were similar within the 3 cell lines, but the rate in the RPMI8226 cell line was nearly triple that of OPM2. N = 3, 3 independent experiments. DV accomplished through ultraviolet-inactivation.²⁵