This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schultz, R. M. Articles by Chirigos, M. A. Search for Related Content PubMed PubMed Citation Articles by Schultz, R. M. Articles by Chirigos, M. A.

Macrophage Involvement in the Protective Effect of Pyran Copolymer against the Madison Lung Carcinoma (M109)

Viral Biology Branch, National Cancer Institute, NIH, Bethesda, Maryland 20014

Pyran copolymer (NSC 46015) therapy markedly enhanced host resistance to a murine lung carcinoma (M109) implanted s.c. Multiple dose schedules were not significantly better than single doses at increasing lifespan. Although tumor necrosis was much more extensive in the lesions of pyran-treated mice, pyran copolymer was not directly toxic to M109 cells in vitro. A comparative histopathological study revealed an intense histiocytic reaction in the connective tissue surrounding the primary tumor in mice receiving pyran as compared to 0.9% NaCl solutiontreated controls. Macrophages were often associated with necrobiotic tumor cells. Morphologically activated macrophages were recovered from pyran-treated animals which potently inhibited DNA synthesis of M109 tumor cells in vitro. This response peaked 6 days after drug treatment and was to a large extent specific for neoplastic cells. Our results from both in vivo and in vitro studies support the concept that pyran enhances host resistance to neoplasia by mobilization and activation of the reticuloendothelial elements of the host's defense.

¹ Visiting scientist from the Immunopathology Department, University of Cologne, West Germany.

Received 8/17/76. Accepted 10/25/76.

This article has been cited by other articles:

				T. Sawa, Y. Okumura, J. Sunamoro, J. L. Ding, and R. M. Ottenbrite Enhanced Growth of Cultured Fibroblasts by a Synthetic Polyanionic Polymer Journal of Bioactive and Compatible Polymers, January 1, 1996; 11(1): 17 - 27. [Abstract]

				L. Seymour Review : Synthetic Polymers with Intrinsic Anticancer Activity Journal of Bioactive and Compatible Polymers, January 1, 1991; 6(2): 178 - 216. [PDF]

				R. Schultz, J. Papamatheakis, and M. Chirigos Interferon: an inducer of macrophage activation by polyanions Science, August 12, 1977; 197(4304): 674 - 676. [Abstract] [PDF]