HMCLs up-regulate OPGL expression in coculture.

Semiquantitative RT-PCR analysis of OPGL and β-actin mRNA in the following coculture systems: XG-6 with preOBs (A) or with BMSCs (B), XG-1 with preOBs (C), pre–B-cell line NALM-6 with BMSCs (D), and primary myeloma cells isolated from 2 patients with BMSCs or preOBs (E). Graphics represent the mean optical density (OD) of OPGL normalized to the OD of β-actin ( = OD ratio) of representative experiments. (F) Immunoblot analysis of OPGL in the following cellular lysates: COS-7 transfected with OPGL-pCEP4 = cont+ (lane 1), COS-7 transfected with empty pCEP4 = cont− (lane 2), preOBs (lane 3), preOBs and XG-6 after 36 hours of coculture (lane 4), and XG-6 (lane 5).