title: Targeting poly (ADP-ribose) polymerase partially contributes to bufalin-induced cell death in multiple myeloma cells.
abstract: Despite recent pharmaceutical advancements in therapeutic drugs, multiple myeloma (MM) remains an incurable disease. Recently, ploy(ADP-ribose) polymerase 1 (PARP1) has been shown as a potentially promising target for MM therapy. A previous report suggested bufalin, a component of traditional Chinese medicine ("Chan Su"), might target PARP1. However, this hypothesis has not been verified. We here showed that bufalin could inhibit PARP1 activity in vitro and reduce DNA-damage-induced poly(ADP-ribosyl)ation in MM cells. Molecular docking analysis revealed that the active site of bufalin interaction is within the catalytic domain of PAPR1. Thus, PARP1 is a putative target of bufalin. Furthermore, we showed, for the first time that the proliferation of MM cell lines (NCI-H929, U266, RPMI8226 and MM.1S) and primary CD138(+) MM cells could be inhibited by bufalin, mainly via apoptosis and G2-M phase cell cycle arrest. MM cell apoptosis was confirmed by apoptotic cell morphology, Annexin-V positive cells, and the caspase3 activation. We further evaluated the role of PARP1 in bufalin-induced apoptosis, discovering that PARP1 overexpression partially suppressed bufalin-induced cell death. Moreover, bufalin can act as chemosensitizer to enhance the cell growth-inhibitory effects of topotecan, camptothecin, etoposide and vorinostat in MM cells. Collectively, our data suggest that bufalin is a novel PARP1 inhibitor and a potentially promising therapeutic agent against MM alone or in combination with other drugs.
authors.affiliation: Department of Hematology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: He
authors.initials: H
authors.lastname: Huang
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Shao-Yong
authors.initials: SY
authors.lastname: Lu
authors.forename: Yu-Bao
authors.initials: YB
authors.lastname: Chen
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Yan
authors.forename: Ying-Li
authors.initials: YL
authors.lastname: Wu
mesh_terms: D002018:Bufanolides / Q000494:pharmacology*; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D058990:Molecular Targeted Therapy; D009101:Multiple Myeloma / Q000201:enzymology* / Q000473:pathology*; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism
chemical_list: D002018:Bufanolides; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases; C022777:bufalin