[Antitumor effect of PSK (1). Interferon-inducing activity and intratumoral administration].
After oral administration of 20 mg/kg of PSK, a significant level of interferon (IFN) activity was detected in the sera of BCG (1 mg/mouse)-sensitized mice. A low titer of IFN was also detected in the sera of all of 4 cancer patients after 3 g/day oral administration of PSK for 7 consecutive days. Intratumoral administration of PSK (5 mg/mouse) strongly inhibited the growth of Meth-A solid tumors in male BALB/c mice and led to complete regression of tumors and resistance to reinoculated tumors in the host animals. Subsequently, the antimetastatic effect of PSK was examined in a "double grafted tumor system" in which mice first received simultaneous intradermal inoculations of Meth-A in the right (10(6) cells) and left (2 X 10(5) cells) flanks and were then injected with PSK in the right tumor on day 3. PSK significantly inhibited the growth of the left, non-treated tumor. When mice received an inoculation of Meth-A (2 X 10(5) cells) in the left flank and PSK was injected subcutaneously in the right flank on day 3 (single tumor system), the growth of the tumor was not inhibited. These findings suggest that intratumoral PSK immunotherapy in one region has an effect on tumor growth in another region.
D000368:Aged; D000818:Animals; D005260:Female; D005354:Fibrosarcoma / Q000276:immunology / Q000473:pathology / Q000628:therapy; D006801:Humans; D007369:Interferon Inducers; D007372:Interferons / Q000276:immunology*; D008114:Liver Neoplasms, Experimental / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D011509:Proteoglycans / Q000008:administration & dosage / Q000627:therapeutic use*; D013274:Stomach Neoplasms / Q000276:immunology / Q000473:pathology / Q000628:therapy*
D007369:Interferon Inducers; D011509:Proteoglycans; C010770:polysaccharide-K; D007372:Interferons