title: PSGL-1/selectin and ICAM-1/CD18 interactions are involved in macrophage-induced drug resistance in myeloma.
abstract: Chemoresistance is the major obstacle in multiple myeloma (MM) management. We previously showed that macrophages protect myeloma cells, on a cell contact basis, from melphalan or dexamethasone-induced apoptosis in vitro. In this study, we found that macrophage-mediated myeloma drug resistance was also seen with purified macrophages from myeloma patients' bone marrow (BM) in vitro and was confirmed in vivo using the human myeloma-SCID (severe combined immunodeficient) mouse model. By profiling differentially regulated and paired plasma membrane protein genes, we showed that PSGL-1 (P-selectin glycoprotein ligand-1)/selectins and ICAM-1/CD18 played an important role in macrophage-mediated myeloma cell drug resistance, as blocking antibodies against these molecules or genetic knockdown of PSGL-1 or ICAM-1 in myeloma cells repressed macrophages' ability to protect myeloma cells. Interaction of macrophages and myeloma cells via these molecules activated Src and Erk1/2 kinases and c-myc pathways and suppressed caspase activation induced by chemotherapy drugs. Thus, our study sheds new light on the mechanism of drug resistance in MM and provides novel targets for improving the efficacy of chemotherapy in patients.
authors.affiliation: Department of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Zheng
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.forename: J
authors.initials: J
authors.lastname: Qian
authors.forename: P
authors.initials: P
authors.lastname: Qiu
authors.forename: S
authors.initials: S
authors.lastname: Hanabuchi
authors.forename: Y
authors.initials: Y
authors.lastname: Lu
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: Z
authors.initials: Z
authors.lastname: Liu
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: He
authors.forename: P
authors.initials: P
authors.lastname: Lin
authors.forename: D
authors.initials: D
authors.lastname: Weber
authors.forename: R E
authors.initials: RE
authors.lastname: Davis
authors.forename: L
authors.initials: L
authors.lastname: Kwak
authors.forename: Z
authors.initials: Z
authors.lastname: Cai
authors.forename: Q
authors.initials: Q
authors.lastname: Yi
mesh_terms: D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D001853:Bone Marrow / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D018821:CD18 Antigens / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007124:Immunoenzyme Techniques; D047468:Immunoprecipitation; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D008558:Melphalan / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D016513:Mice, SCID; D009101:Multiple Myeloma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D019007:P-Selectin / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D059016:Tumor Microenvironment
chemical_list: D018906:Antineoplastic Agents, Alkylating; D018821:CD18 Antigens; D008562:Membrane Glycoproteins; D019007:P-Selectin; C084882:P-selectin ligand protein; D012333:RNA, Messenger; D018799:Intercellular Adhesion Molecule-1; D008558:Melphalan