title: The host defence peptide LL-37/hCAP-18 is a growth factor for lung cancer cells.
abstract: Cancer development can be viewed as dysregulated repair. Antimicrobial peptides (AMPs) are effector molecules of the innate immune system with direct antimicrobial activity. Beside this host defence function several AMPs play a role in the regulation of inflammation and tissue repair. The aim of the present study was to investigate whether the human cathelicidin AMP LL-37/hCAP-18 is involved in the biology of lung cancer. Human cancer cell lines were found to express the human cathelicidin LL-37/hCAP-18 mRNA and peptide at different levels. Immunohistochemistry of human lung cancers showed that the peptide is expressed mostly in adenocarcinoma and squamous cell carcinoma. Application of exogenous LL-37 at low concentrations of 5ng/ml to cancer cell lines increased proliferation and growth of anchorage-independent colonies. At the molecular level, LL-37 induced phosphorylation of the epidermal growth factor receptor (EGFR) and activation of downstream MAP kinase signalling pathways. Lung cancer cell lines that stably overexpress the peptide by means of a doxycycline-regulated promoter system also showed a faster growth. When these cell lines were injected subcutaneously into nude mice, cathelicidin overexpression resulted in increased tumourigenicity and the formation of significantly larger tumours. In conclusion, cathelicidin is expressed in human lung cancers. The peptide activates tumour cells resulting in increased cell growth in vitro and in an animal model. The host defence peptide cathelicidin LL-37/hCAP-18 acts as growth factor for human lung cancer.
authors.affiliation: Department of Internal Medicine, Philipps-University, 35043 Marburg, Germany.
authors.forename: Judith
authors.initials: J
authors.lastname: von Haussen
authors.forename: Rembert
authors.initials: R
authors.lastname: Koczulla
authors.forename: Renat
authors.initials: R
authors.lastname: Shaykhiev
authors.forename: Christian
authors.initials: C
authors.lastname: Herr
authors.forename: Olaf
authors.initials: O
authors.lastname: Pinkenburg
authors.forename: Dietlind
authors.initials: D
authors.lastname: Reimer
authors.forename: Rainer
authors.initials: R
authors.lastname: Wiewrodt
authors.forename: Stefan
authors.initials: S
authors.lastname: Biesterfeld
authors.forename: Achim
authors.initials: A
authors.lastname: Aigner
authors.forename: Frank
authors.initials: F
authors.lastname: Czubayko
authors.forename: Robert
authors.initials: R
authors.lastname: Bals
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D045744:Cell Line, Tumor; D066246:ErbB Receptors / Q000502:physiology; D005260:Female; D006133:Growth Substances / Q000502:physiology*; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D012333:RNA, Messenger / Q000032:analysis; D015398:Signal Transduction; D054804:Cathelicidins
chemical_list: D023181:Antimicrobial Cationic Peptides; D006133:Growth Substances; D012333:RNA, Messenger; D066246:ErbB Receptors; D054804:Cathelicidins