title: Keyhole limpet hemocyanin augmented the killing activity, cytokine production and proliferation of NK cells, and inhibited the proliferation of Meth A sarcoma cells in vitro.
abstract: OBJECTIVE
  Keyhole limpet hemocyanin (KLH) is a popular tumor vaccine carrier protein and an immunostimulant. The present study aimed to investigate the immunoregulatory activity of KLH on cytotoxicity, cytokines production, and proliferation of natural killer (NK) cells. Moreover, antiproliferative activity of KLH on Meth A sarcoma cells was studied.
  
  
  METHODS
  Cytotoxicity was determined with killing ability of NK cells against yeast artificial chromosome (YAC)-1 cells. Interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) productions by NK cells were measured by enzyme-linked immunosorbent assay (ELISA). Proliferations of NK and Meth A cells were determined by [(3)H]thymidine incorporated proliferation and 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) methods, respectively.
  
  
  RESULTS
  KLH at 6.25, 12.5, and 25 μg/well augmented cytotoxicity of NK cells against YAC-1 cells by 2.5, three, and five-times, respectively. KLH at 25 μg/well enhanced IFN-γ and TNF-α productions by 17- and 23-folds, respectively. The proliferation of NK cells was three times stimulated by KLH. The proliferation of Meth A cells was markedly inhibited by all the doses; the highest (4-folds higher) inhibition was observed at a dose of KLH (25 μg/well).
  
  
  CONCLUSIONS
  The study demonstrated the anticancer activity of KLH acting through the induction of NK cells and inhibition of cancer cells. KLH, therefore, may be a good candidate for an anticancer agent alone or in combination with other chemotherapeutic agents.
authors.affiliation: Department of Immunochemistry, Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka, Kita-ku, Okayama, Japan ; Clinical Investigation Centre, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Md Moklesur Rahman
authors.initials: MM
authors.lastname: Sarker
authors.affiliation: Department of Immunochemistry, Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka, Kita-ku, Okayama, Japan.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhong
mesh_terms: D000818:Animals; D016923:Cell Death / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D006433:Hemocyanins / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D012513:Sarcoma, Experimental / Q000473:pathology*
chemical_list: D016207:Cytokines; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin
keywords: Anticancer activity; Keyhole limpet hemocyanin; Meth A sarcoma cells; Natural Killer cells; YAC-1 cells; cytokines; cytotoxicity