title: The FA/BRCA pathway is involved in melphalan-induced DNA interstrand cross-link repair and accounts for melphalan resistance in multiple myeloma cells.
abstract: Melphalan, a DNA cross-linker, is one of the most widely used and effective drugs in the treatment of multiple myeloma (MM). In this report, we demonstrate that enhanced interstrand cross-link (ICL) repair via the Fanconi anemia (FA)/BRCA pathway contributes to acquired drug resistance in melphalan-resistant myeloma cell lines, and disruption of this pathway reverses drug resistance. Using the alkaline comet assay (single-cell gel electrophoresis), we observed that melphalan-resistant cells have reduced ICL formation and enhanced ICL repair compared with melphalan-sensitive cells. Cell-cycle studies demonstrated that enhanced ICL repair released cells from melphalan-induced cell-cycle delay. Using siRNA to knock down FANCF in 8226/LR5 and U266/LR6 drug-resistant cells demonstrated a direct relationship between ICL repair capacity and drug sensitivity. Overexpression of FANCF in 8226/S and U266/S drug-sensitive cells partially reproduced the drug-resistant phenotype. These data show that enhanced DNA repair via the Fanconi anemia/BRCA pathway is involved in acquired melphalan resistance. Our findings provide for a new target to enhance response to DNA cross-linking agents in cancer treatment.
authors.affiliation: Department of Interdisciplinary Oncology and Experimental Therapeutics Program, Biostatistics Core Facility, H. Lee Moffitt Cancer Center & Research Institute at University of South Florida, 12902 Magnolia Dr, Tampa, FL 33612, USA.
authors.forename: Qing
authors.initials: Q
authors.lastname: Chen
authors.forename: Pieter C
authors.initials: PC
authors.lastname: Van der Sluis
authors.forename: David
authors.initials: D
authors.lastname: Boulware
authors.forename: Lori A
authors.initials: LA
authors.lastname: Hazlehurst
authors.forename: William S
authors.initials: WS
authors.lastname: Dalton
mesh_terms: D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000235:genetics; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D004260:DNA Repair / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000235:genetics; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D052219:Fanconi Anemia Complementation Group F Protein; D051856:Fanconi Anemia Complementation Group Proteins; D015870:Gene Expression / Q000187:drug effects; D020868:Gene Silencing; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D006801:Humans; D008558:Melphalan / Q000494:pharmacology*; D009101:Multiple Myeloma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics
chemical_list: D018906:Antineoplastic Agents, Alkylating; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C499901:FANCF protein, human; D052219:Fanconi Anemia Complementation Group F Protein; D051856:Fanconi Anemia Complementation Group Proteins; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D008558:Melphalan