The Acute Phase Protein Hepcidin Is Cytotoxic to Human and Mouse Myeloma Cells

Abstract

Background/Aim: Hepcidin is a cationic acute phase reactant synthesized by the liver. It has bactericidal properties and is a major regulator of iron homeostasis. Cationic antimicrobial peptides represent an innate antimicrobial defense system. We hypothesized that, like other cationic antimicrobial peptides, hepcidin is cytotoxic to cancer cells. Materials and Methods: The cytotoxicity of human hepcidin against myeloma cells was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and DNA fragmentation assays. Plasma membrane damage was quantified by propidium iodide (PI) staining. Cell membrane changes were visualized by scanning electron microscopy. Results: Hepcidin impaired myeloma cell survival and induced DNA fragmentation. PI staining and scanning electron microscopy revealed hepcidin-induced disruption of the plasma membrane. Conclusion: Human hepcidin is an anti-cancer peptide that induces myeloma cell lysis, and therefore may play a role in innate anticancer immunity. To our knowledge, this is the first biological function ascribed to human hepcidin that is not related to its antimicrobial and iron-regulatory properties.