Published in Cancer Detection and Prevention 1997; 21(5):476-.

Preventive Effects of Polysaccharides Extracted From Human Tubercie Bacilli (Supecific Substance of Maruyama) on Colonic Carcinogenesis in Rats

K Iida, VMDa, K Fujita, MDa, H Hirai, MDa H Goto, MDa, S Miyazakia, Y Arai, MDa, H Iwaki, MDa, M Otake, MDa, S Sassab, M Maemura, MDb, T Nakayama, MDb, H Kudo, MDb, and S Sakamoto, MDb

aResearch Institute of Vaccine Therapy for Tumors and Infectious Diseases, Nippon Medical School, Tokyo, Japan; bMedical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan

Address all correspondence and reprint requests to: Keishirou Fujita, MD, Research Institute of Vaccine Therapy for Tumors and Infectious Diseases, Nippon Medical School, 1-1-5. Sendagi, Bunkyo-ku, Tokyo 113, Japan.

ABSTRACT: Polysaccharides extracted from human tubercle bacilli (supecific substance of Maruyama [SSM]) have been clinically applied with satisfactory results. Thymidylate synthetase (TS) and thymidine kinase (TK) are key enzymes in de novo and salvage pathways for pyrimidine nucleotide synthesis. Well- and moderately well differentiated adenocarcinomas induced with 1,2-dimethylhydrazine (DMH) are widely distributed throughout the colorectal tract with high TK activity, and the poorly differentiated type is mainly restricted in the proximal colon and the cecum with high TS activity in rats. Subcutaneously injecting the rats with SSM reduced TS activity in colonic nontumorous regions, but in the tumorous regions it reduced TK activity compared with that of the DMH-treated rats without SSM treatment. SSM is suggested to reduce the colorectal carcinogenesis induced with DMH by inhibiting DNA synthesis in a de novo pathway, and to suppress the development of the tumors by decreasing DNA synthesis in the salvage pathway in rats.

KEY WORDS: rat colonic carcinogenesis, supecific substance of Maruyama, thymidine kinase, thymidylate synthetase.