title: Death receptor 4 is preferentially recruited to lipid rafts in chronic lymphocytic leukemia cells contributing to tumor necrosis related apoptosis inducing ligand-induced synergistic apoptotic responses.
abstract: Tumor necrosis related apoptosis inducing ligand receptor 1 (TRAIL-R1, death receptor 4 [DR4]) and TRAIL-R2 (DR5) have been proposed as targets for cancer therapy, but which death receptor to target for chemotherapy in chronic lymphocytic leukemia (CLL) is uncertain. Herein, we discovered that Burkitt lymphoma B cell line, BJAB, CLL-like cell line, I-83, and pre-acute lymphocytic leukemia B cell line, NALM-6, underwent apoptosis following TRAIL, whereas a CLL-like cell line, JMV-3, and primary CLL cells failed to undergo apoptosis. In TRAIL resistant CLL cells, only activation of DR4 provided an increase in fludarabine induced apoptosis. This was mediated in part by the localization of DR4 but not DR5 in lipid rafts following TRAIL and fludarabine treatment. This preference for DR4 activation leading to increased fludarabine induced apoptosis was also observed following SAHA, PS-341, and chlorambucil treatment in primary CLL cells. Thus, CLL cells selectively activate DR4 partially mediated through its localization to lipid rafts leading to apoptosis when combined with chemotherapeutic drugs.
authors.affiliation: Manitoba Institute of Cell Biology, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: Wenyan
authors.initials: W
authors.lastname: Xiao
authors.forename: Ganchimeg
authors.initials: G
authors.lastname: Ishdorj
authors.forename: Jinmei
authors.initials: J
authors.lastname: Sun
authors.forename: James B
authors.initials: JB
authors.lastname: Johnston
authors.forename: Spencer B
authors.initials: SB
authors.lastname: Gibson
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology; D061067:Antibodies, Monoclonal, Humanized; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D015973:Gene Expression Regulation, Leukemic; D055785:Gene Knockdown Techniques; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics / Q000378:metabolism*; D021962:Membrane Microdomains / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D034741:RNA, Small Interfering; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D053221:TNF-Related Apoptosis-Inducing Ligand; C510234:lexatumumab; C507357:mapatumumab