Protein-bound polysaccharide K partially prevents apoptosis of circulating T cells induced by anti-cancer drug S-1 in patients with gastric cancer

Oncology. 2008;74(3-4):143-9. doi: 10.1159/000151361. Epub 2008 Aug 18.


Background and methods: It has been shown that T-cell dysfunction, including apoptosis of peripheral blood T cells, commonly occurs in patients receiving chemotherapy. In order to evaluate whether concomitant administration of the oral biological response modifier protein-bound polysaccharide K (PSK) could induce anti-apoptotic effects in patients treated with the anti-cancer drug, S-1, peripheral blood T cells were analyzed for induction of apoptosis, caspase-3 activities and expression of proapoptotic protein Bax and anti-apoptotic protein Bcl-2 in patients with curatively resected stage III gastric cancer, who were randomly assigned to postoperative adjuvant therapy with S-1 alone (n = 10) or S-1 combined with PSK (n = 10).

Results: T-cell apoptosis 5 weeks after adjuvant therapy was significantly higher in the S-1 group (24.1 +/- 5.0%) than in the S-1 + PSK group (19.1 +/- 3.9%). S-1 induced T-cell apoptosis and concomitantly elevated caspase-3 activities and Bax expression in peripheral blood T cells. In addition, PSK partially prevented the T-cell apoptosis induced by S-1.

Conclusion: PSK could partially prevent the T-cell apoptosis induced by S-1.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Antibiotics, Antineoplastic / therapeutic use*
  • Antimetabolites, Antineoplastic / therapeutic use*
  • Apoptosis / drug effects*
  • Caspases / metabolism
  • Chemotherapy, Adjuvant
  • Drug Combinations
  • Drug Therapy, Combination
  • Female
  • Flow Cytometry
  • Humans
  • Male
  • Oxonic Acid / therapeutic use*
  • Proteoglycans / therapeutic use*
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Stomach Neoplasms / blood
  • Stomach Neoplasms / drug therapy*
  • Stomach Neoplasms / pathology
  • T-Lymphocytes / drug effects*
  • T-Lymphocytes / metabolism
  • Tegafur / therapeutic use*
  • bcl-2-Associated X Protein / metabolism


  • Antibiotics, Antineoplastic
  • Antimetabolites, Antineoplastic
  • Drug Combinations
  • Proteoglycans
  • Proto-Oncogene Proteins c-bcl-2
  • bcl-2-Associated X Protein
  • S 1 (combination)
  • Tegafur
  • polysaccharide-K
  • Oxonic Acid
  • Caspases