[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.
Nukata
Y
Y
First Department of Surgery, Tohoku University School of Medicine, Sendai, Japan.
Shiiba
K
K
Ebine
N
N
Ishii
S
S
Matsuno
S
S
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