CD137 and CD137 ligand constitutively coexpressed on human T and B leukemia cells signal proliferation and survival

• DOI: 10.1002/ijc.11574
• Publication Date: 2003-11-21T22:10:06Z
• Authors: Carla Palma; Monica Binaschi; Mario Bigioni; Carlo Alberto Maggi; Cristina Goso
• Keywords: CD137

Abstract CD137, a member of the tumor necrosis factor receptor family, provides expansion and survival signal to T cells. Its ligand, CD137L, in addition its ability costimulate cells, signals back into antigen presenting cells promoting their activation differentiation. Recently, CD137 has been proposed as therapeutic target improve sustain anticancer immune response. Several activated leukemia B lymphoma cell lines expressed or respectively, soluble CD137L found sera patients. However, functionality role these costimulatory molecules hematologic malignancies are until now unknown. Interestingly, we observed constitutive coexpression on both human lines. The expression unstimulated presents some differences compared PMA/ionomycin‐activated Surprisingly, spite low level, signaled inducing proliferation prolonging survival. In addition, CD137/CD137L system ligation opposed drug cytotoxic effects, reducing apoptotic DNA fragmentation stimulating doxorubicin‐escaped Although vivo is unknown, data suggest that might confer an advantage tumors survival, sustaining cellular growth contributing resistance. © 2003 Wiley‐Liss, Inc.