title: A cationic amphiphilic peptide ABP-CM4 exhibits selective cytotoxicity against leukemia cells.
abstract: Some cationic antibacterial peptides exhibit a broad spectrum of cytotoxic activity against cancer cells, which could provide a new class of anticancer drugs. In the present study, the anticancer activity of ABP-CM4, an antibacterial peptide from Bombyx mori, against leukemic cell lines THP-1, K562 and U937 was evaluated, and the cytotoxicity compared with the effects on non-cancerous mammalian cells, including peripheral blood mononuclear cells (PBMCs), HEK-293 and erythrocytes. ABP-CM4 reduced the number of viable cells of the leukemic cell lines after exposure for 24h. The reduction was concentration dependent, and the IC50 values ranged from 14 to 18 microM. Conversely, ABP-CM4, even at 120 microM, exhibited no cytotoxicity toward HEK-293 or PBMCs, indicating that there was no significant effect on these two types of non-cancer cells. ABP-CM4 at a concentration of 200 microM had no hemolytic activity on mammalian erythrocytes. Together, these results suggested a selective cytotoxicity in leukemia cells. Flow cytometry demonstrated that the binding activity of ABP-CM4 to leukemia cells was much higher than that to HEK-293 or PBMCs, and there was almost no binding to erythrocytes. FITC-labeled ABP-CM4 molecules were examined under a confocal microscope and found to be concentrated at the surface of leukemia cells and changes of the cell membrane were determined by a cell permeability assay, which led us to the conclusion that ABP-CM4 could act at the cell membrane for its anticancer activity on leukemia cells. Collectively, our results indicated that ABP-CM4 has the potential for development as a novel antileukemic agent.
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, Life Sciences College, Nanjing Normal University, Nanjing 210046, Jiangsu, PR China. yuqingchen515@yahoo.com
authors.forename: Yu Qing
authors.initials: YQ
authors.lastname: Chen
authors.forename: Cui
authors.initials: C
authors.lastname: Min
authors.forename: Ming
authors.initials: M
authors.lastname: Sang
authors.forename: Yang Yang
authors.initials: YY
authors.lastname: Han
authors.forename: Xiao
authors.initials: X
authors.lastname: Ma
authors.forename: Xiao Qing
authors.initials: XQ
authors.lastname: Xue
authors.forename: Shuang Quan
authors.initials: SQ
authors.lastname: Zhang
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000627:therapeutic use*; D002460:Cell Line; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D019476:Insect Proteins / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000627:therapeutic use*; D007938:Leukemia / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D008958:Models, Molecular; D008970:Molecular Weight; D017433:Protein Structure, Secondary; D013501:Surface-Active Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000627:therapeutic use*
chemical_list: D023181:Antimicrobial Cationic Peptides; D000970:Antineoplastic Agents; C534224:CM4 peptide, Bombyx mori; D019476:Insect Proteins; D013501:Surface-Active Agents