Antitumor activity of the DNA fraction from Mycobacterium bovis BCG. II. Effects on various syngeneic mouse tumors
Shimada, S.; Yano, O.; Inoue, H.; Kuramoto, E.; Fukuda, T.; Yamamoto, H.; Kataoka, T.; Tokunaga, T.
Journal of the National Cancer Institute 74(3): 681-688
1985
ISSN/ISBN: 0027-8874 PMID: 3856070 Document Number: 253285
MY-1, a fraction extracted from BCG and composed of 70.0% DNA and 28.0% RNA, was examined for its antitumor activity against 9 different syngeneic mouse tumors. Tumor regression was induced in almost all of the mice bearing any of 5 kinds of solid tumors by repeated intralesional injections of 100 .mu.g MY-1. When cells of some tumors were inoculated intradermally together with MY-1, tumor growth was suppressed, lung metastases were inhibited, the survival times of mice bearing 1 of 3 leukemic tumors were prolonged. Repeated s.c. injections with MY-1 in sites remote from tumor cell inoculation or repeated i.v. injections were more or less effective against 3 kinds of solid tumors. Mice inoculated with Lewis lung carcinoma cells in a hind footpad and whose legs were amputated 9 days later were given i.v. or s.c. injections of MY-1 every other day (8 times in total), resulting in substantial prolongation of survival. No direct cytotoxicity of MY-1 for these tumors could be shown in 3 kinds of experiments, which indicates that the antitumor mechanism of MY-1 is host mediated. MY-1 was equally effective in mice with or without presensitization with BCG; BCG was much more effective in BCG-sensitized mice. Apparently, a delayed-type hypersensitivity reaction elicited by BCG protein is not required for the antitumor activity of MY-1.