title: Biological mechanism and clinical effect of protein-bound polysaccharide K (KRESTIN(®)): review of development and future perspectives.
abstract: The mechanism of action of protein-bound polysaccharide K (PSK; KRESTIN(®)) involves the following actions: (1) recovery from immunosuppression induced by humoral factors such as transforming growth factor (TGF)-β or as a result of surgery and chemotherapy; (2) activation of antitumor immune responses including maturation of dendritic cells, correction of Th1/Th2 imbalance, and promotion of interleukin-15 production by monocytes; and (3) enhancement of the antitumor effect of chemotherapy by induction of apoptosis and inhibition of metastasis through direct actions on tumor cells. The clinical effectiveness of PSK has been demonstrated for various cancers. In patients with gastric or colorectal cancer, combined use of PSK with postoperative adjuvant chemotherapy prolongs survival, and this effect has been confirmed in multiple meta-analyses. For small-cell lung carcinoma, PSK in conjunction with chemotherapy prolongs the remission period. In addition, PSK has been shown to be effective against various other cancers, reduce the adverse effects of chemotherapy, and improve quality of life. Future studies should examine the effects of PSK under different host immune conditions and tumor properties, elucidate the mechanism of action exhibited in each situation, and identify biomarkers.
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. maehara@surg2.med.kyushu-u.ac.jp
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Maehara
authors.forename: Shunichi
authors.initials: S
authors.lastname: Tsujitani
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Saeki
authors.forename: Eiji
authors.initials: E
authors.lastname: Oki
authors.forename: Keiji
authors.initials: K
authors.lastname: Yoshinaga
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Emi
authors.forename: Masaru
authors.initials: M
authors.lastname: Morita
authors.forename: Shunji
authors.initials: S
authors.lastname: Kohnoe
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kakeji
authors.forename: Tokujiro
authors.initials: T
authors.lastname: Yano
authors.forename: Hideo
authors.initials: H
authors.lastname: Baba
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D017024:Chemotherapy, Adjuvant; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D009369:Neoplasms / Q000188:drug therapy* / Q000276:immunology*; D011509:Proteoglycans / Q000494:pharmacology*
chemical_list: D000276:Adjuvants, Immunologic; D016207:Cytokines; D011509:Proteoglycans; C010770:polysaccharide-K