1. ¹Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
2. ²Unidad de Investigación, Hospital Universitario de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain

Correspondence: Dr F Mollinedo, Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, E-37007, Spain. E-mail: fmollin@usal.es

Received 8 December 2008; Revised 17 April 2009; Accepted 19 May 2009; Published online 29 June 2009.

Abstract

We have found that resveratrol (trans-3,4',5-trihydroxystilbene) induced apoptosis in multiple myeloma (MM) and T-cell leukemia cells through coclustering of Fas/CD95 death receptor and lipid rafts, whereas normal lymphocytes were spared. Tumor necrosis factor-related apoptosis-inducing ligand receptors, Fas-associated death domain-containing protein (FADD), procaspase-8, procaspase-10, c-Jun amino-terminal kinase and Bid were also recruited into lipid rafts on resveratrol incubation with MM and T-cell leukemia cells. Raft disruption inhibited resveratrol-induced apoptosis. Bcl-X_L overexpression prevented resveratrol-induced disruption of mitochondrial transmembrane potential (_m) and apoptosis. A FADD dominant-negative mutant, that blocked Fas/CD95 downstream signaling, precluded resveratrol-induced _m loss and apoptosis, indicating a sequence of Fas/CD95 signalingmitochondrion in the apoptotic response triggered by resveratrol. Cells deficient in Fas/CD95 did not undergo resveratrol-induced apoptosis. Pretreatment of MM cells with interferon- upregulated Fas/CD95 and caspase-8, and potentiated resveratrol-induced apoptosis. Our data indicate that recruitment of Fas/CD95 death receptor and downstream signaling molecules into lipid rafts, followed by _m disruption, underlies the apoptotic action of resveratrol in MM and T-cell leukemic cells. Combination of resveratrol with perifosine or bortezomib potentiated the apoptotic response induced by each single drug. These results also highlight the role of recruitment of Fas/CD95 signaling in lipid rafts in antimyeloma and antileukemia chemotherapy.