Selective induction of apoptosis in MM cells by edelfosine and perifosine and correlation with Fas/CD95 cell-surface expression. (A) MM cell lines were incubated for 24 and 48 hours with 10 μM edelfosine or perifosine, and apoptosis was then quantitated as the percentage of cells in the sub-G1 region in cell-cycle analysis by flow cytometry. (B) Cell-surface expression of Fas/CD95 in different MM cell lines was analyzed by flow cytometry. Percentage of Fas-positive cells and MFI values were estimated using the P3X63 myeloma supernatant and an isotype-matched FITC-conjugated nonrelevant IgG monoclonal antibody as negative controls. (C) Freshly isolated tumor MM cells and normal mononuclear cells (NCs) from patients with MM were incubated for the indicated times with 10 μM edelfosine or perifosine and analyzed for apoptosis as above. (D) Normal peripheral blood lymphocytes (PBLs), purified PBL-T cells, and purified PBL-B cells, as well as leukemic T-lymphoid Jurkat (JK) and B-lymphoid JY cells, were incubated for the indicated times with 10 μM edelfosine or perifosine and analyzed for apoptosis as described. Untreated control cells were run in parallel. Data shown are means ± SD of 4 independent determinations.
