title: Chitooligosaccharides and N-acetyl-D-glucosamine stimulate peripheral             blood mononuclear cell-mediated antitumor immune responses.
abstract: The aim of the present study was to evaluate the anticancer effects of chitooligosaccharides (COS) and N-acetyl-D-glucosamine (NAG), as well as to investigate the possible mechanisms involved. MTT assay and flow cytometry were used to evaluate the effect of various concentrations of COS and NAG on the proliferation and differentiation of peripheral blood mononuclear cells (PBMCs). In addition, sarcoma 180 cells were transplanted into mice to establish a tumor model. COS and NAG were administered by gavage of various doses. The tumor inhibition rate, thymus and spleen indexes, natural killer (NK) cell activity, and interleukin-2 (IL-2) and interferon-γ (IFN-γ) serum levels were detected. Vascular endothelial growth factor (VEGF) expression levels, an important marker of angiogenesis, were also detected. As shown by immunohistochemistry, VEGF mRNA expression was decreased following treatment with COS and NAG, indicating that COS and NAG have an inhibitory effect on the expression of VEGF. The results from this study indicate that COS administered at a dose of 100 mg/kg and NAG at a dose of 300 mg/kg or 500 mg/kg can not only promote the differentiation of PBMCs and the secretion of IL-2 and IFN-γ, but can also inhibit the expression of VEGF mRNA in sarcoma 180 tumors. Our results show that the antitumor and immunoregulatory effects of COS and NAG are dose-dependent. Furthermore, the antitumor effect is achieved by the improvement of immunoregulation indirectly.
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong, PR China.
authors.forename: Wenhua
authors.initials: W
authors.lastname: Xu
authors.forename: Changqing
authors.initials: C
authors.lastname: Jiang
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Kong
authors.forename: Ye
authors.initials: Y
authors.lastname: Liang
authors.forename: Mi
authors.initials: M
authors.lastname: Rong
authors.forename: Wanshun
authors.initials: W
authors.lastname: Liu
mesh_terms: D000117:Acetylglucosamine / Q000276:immunology / Q000494:pharmacology*; D000818:Animals; D000970:Antineoplastic Agents / Q000276:immunology / Q000494:pharmacology*; D017209:Apoptosis; D002454:Cell Differentiation; D049109:Cell Proliferation / Q000187:drug effects; D004306:Dose-Response Relationship, Immunologic; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D007111:Immunity, Cellular; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000097:blood; D007376:Interleukin-2 / Q000097:blood; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D009844:Oligosaccharides / Q000494:pharmacology*; D009929:Organ Size; D012510:Sarcoma 180 / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D013154:Spleen / Q000276:immunology / Q000473:pathology; D013950:Thymus Gland / Q000276:immunology / Q000473:pathology; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D007376:Interleukin-2; D009844:Oligosaccharides; D042461:Vascular Endothelial Growth Factor A; D007371:Interferon-gamma; D000117:Acetylglucosamine