Treatment with 2ME2 leads to growth arrest and apoptosis in myeloma cell lines with low endogenous SOD2 that can be reversed by enforced expression of SOD2. (A) An MTT assay was preformed to determine proliferation of cell lines either untreated (▪) or treated (⊡) with 30 μM 2ME2 for 72 hours. The assay was performed in triplicate, and standard error is shown. *P < .005. This is a representative experiment from 2 experiments performed. (B) The amount of apoptosis in the cell lines following treatment with 2ME2 was determined by flow cytometry. The fold increase in apoptotic cells (treated cells vs untreated cells) is shown. (C) Percentage of apoptosis in cell lines with altered SOD2 expression following treatement with 2ME2 was determined by flow cytometric measurement of Annexin V⁺/PI⁺ cells. The percentage change in apoptotic cells relative to control cells treated with 2ME2 is shown.