OC expression of Bcl-2 and Bax. The analysis of Bcl-2 and Bax expression by OCs, developed in unfractionated as well as T-cell–depleted PBMC cultures derived from patients with MM with osteolysis, was performed by RT-PCR (A) and Western blotting (B). T-cell–depleted cultures were stimulated with exogenous M-CSF and RANKL. The intensity of the bands was quantified by densitometry. The graphs represent the mean optical density (OD) of Bcl-2/Bax ratio normalized to the OD of GAPDH or β-actin of a representative experiment for RT-PCR and Western blotting, respectively. Bcl-2 is highly expressed in the OCs obtained in the presence of T cells.