Augmentation of Cytolytic Activity in Murine Natural Killer Cells and Inhibition of Tumor Growth by the Ethanol Fraction of Oyster Extract

A reduced number and/or reduced activity of natural killer (NK) cells, which are important for defense against a variety of cancers and viral infections, occur under various stress conditions and in patients with various diseases. In this article, we report that the 30% to 50% ethanol precipitate of...

Full description

Saved in:
Bibliographic Details
Published in:Integrative cancer therapies 2018-03, Vol.17 (1), p.31-40
Main Authors: Sakaguchi, Kaito, Zhong, Ming, Kawai, Saeko, Shimizu, Yoshio, Gohda, Eiichi
Format: Article
Language:English
Subjects:
Animals
Cell activation
Cell proliferation
Cytolytic activity
Cytotoxicity, Immunologic - immunology
Endopeptidase K
Ethanol
Female
Killer Cells, Natural - immunology
Melanoma
Melanoma, Experimental - immunology
Melanoma, Experimental - therapy
Mice
Mice, Inbred C57BL
Molecular weight
Natural killer cells
Oligonucleotides
Ostreidae
Polymers
Proteinase
Spleen
Spleen - cytology
Tissue Extracts - immunology
Tissue Extracts - pharmacology
Tumor cells
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A reduced number and/or reduced activity of natural killer (NK) cells, which are important for defense against a variety of cancers and viral infections, occur under various stress conditions and in patients with various diseases. In this article, we report that the 30% to 50% ethanol precipitate of oyster extract (EPOE50) dose-dependently enhanced the activity of mouse spleen NK cells in vitro and in vivo. The activity of EPOE50 was eluted with a molecular weight of about 2000 by gel filtration and was inactivated by periodate but not by proteinase K. The activity of highly purified NK cells was also augmented by EPOE50 but not by oligodeoxyribonucleotide 1585, which mimics bacterial DNA. Administration of EPOE50 to mice stimulated splenic NK cell activity without a change in splenic NK cell populations. Although the proliferation of B16 tumor cells in vitro was slightly stimulated by EPOE50, the growth of B16 melanoma in vivo was dose-dependently suppressed by administration of EPOE50. Taken together, our results indicate that EPOE50 augmented NK cell activity and that its administration to mice inhibited tumor growth presumably through the activation of NK cells and also suggest that the active substance is a sugar-containing oligomer or polymer and is not of bacterial origin.
ISSN:1534-7354
1552-695X
DOI:10.1177/1534735416681640