title: Polysaccharide-K augments docetaxel-induced tumor suppression and antitumor             immune response in an immunocompetent murine model of human prostate cancer.
abstract: Advanced castration-resistant prostate cancer has high mortality rates and             limited treatment options. Novel therapies are needed to better contend with this             disease. Polysaccharide-K® (PSK), an extract of the mushroom Trametes versicolor,             has immunomodulatory and tumor suppressive activities. PSK is used in Asia as             a cancer immunotherapy. However, its benefit in combination with taxanes for prostate             cancer is unknown. We examined whether PSK would enhance docetaxel-induced apoptosis             and augment anti-tumor immune responses in orthotopic tumors using transgenic             adenocarcinoma of the mouse prostate (TRAMP)-C2-bearing mice. Combining PSK with             docetaxel induced significantly higher tumor suppression than either treatment             alone (p<0.05), including a reduction in tumor proliferation and enhanced apoptosis.             Combined PSK and docetaxel treatment led to a lower decrease in number of white             blood cells than docetaxel alone, an effect accompanied by increased numbers of             tumor-infiltrating CD4+ and CD8+ T cells. PSK with or without docetaxel significantly             enhanced mRNA expression of IFN-γ compared to control, but did not significantly             alter T-regulatory FoxP3 mRNA expression in tumors. PSK also augmented docetaxel-induced             splenic natural killer cell cytolytic activity against YAC-1 target cells (p=0.045).             This study is the first to show that PSK enhances docetaxel-induced prostate cancer             tumor suppression, apoptosis and antitumor responses.
authors.affiliation: Bastyr University Research Institute, 14500 Juanita Dr NE, Kenmore, WA 98028, USA. cindyw@bastyr.edu
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Wenner
authors.forename: Mark R
authors.initials: MR
authors.lastname: Martzen
authors.forename: Hailing
authors.initials: H
authors.lastname: Lu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Verneris
authors.forename: Hongbo
authors.initials: H
authors.lastname: Wang
authors.forename: Joel W
authors.initials: JW
authors.lastname: Slaton
mesh_terms: D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D000077143:Docetaxel; D004357:Drug Synergism; D006801:Humans; D007121:Immunocompetence; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D011509:Proteoglycans / Q000494:pharmacology*; D043823:Taxoids / Q000494:pharmacology*; D023041:Xenograft Model Antitumor Assays
chemical_list: D011509:Proteoglycans; D043823:Taxoids; D000077143:Docetaxel; C010770:polysaccharide-K