[Oral administration of OK-432 is an effective immunotherapy against colon cancer--a study in a murine mesenteric lymphnode metastasis model].
A simple and highly reproducible mouse colonic cancer model with mesenteric lymph node (MLN) metastasis was established by injecting COLON-26 tumor cells into lymphatic nodules in the tip of vermiform appendix of BALB/C mice. In this model, antitumor effect of orally administered OK-432 was examined. OK-432 was given orally at three different periods: before injection of COLON-26 cells (Protocol-A), early after injection of COLON-26 cells (Protocol-B), and late after injection of COLON-26 cells (Protocol-C). As a result, MLN metastasis was significantly suppressed and survival rate was significantly improved in every protocol as compared to mice without OK-432 administration. Then, in vivo anti-tumor activities of MLN cells and splenic lymphocytes were evaluated by Winn assay. Tumor neutralizing activity against syngenic COLON-26 cells was induced in the MLN cells after OK-432 administration and the effector cells were found in CD4-positive T lymphocytes because MLN cells treated with anti-L3/T4 and anti-LFA plus complement lost their anti-tumor efficacy. In conclusion, oral administration of OK-432 appears to be an effective immunotherapy against colonic cancer especially in the prevention and the treatment for MLN metastasis.
First Department of Surgery, Tohoku University School of Medicine, Sendai, Japan.
Y
Y
Nukata
K
K
Shiiba
N
N
Ebine
S
S
Ishii
S
S
Matsuno
D000230:Adenocarcinoma / Q000139:chemically induced / Q000556:secondary / Q000628:therapy*; D000284:Administration, Oral; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000628:therapy*; D007167:Immunotherapy; D008207:Lymphatic Metastasis; D008297:Male; D008643:Mesentery / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009605:Nitrosomethylurethane; D010844:Picibanil / Q000008:administration & dosage*
D000970:Antineoplastic Agents; D010844:Picibanil; D009605:Nitrosomethylurethane