title: Antitumor activity of Listeria monocytogenes on a guinea pig fibrosarcoma.
abstract: Listeria monocytogenes-mediated tumor inhibition was studied in strain 13 guinea pigs by using a methylcholanthrene-induced fibrosarcoma (MCA-1). Mixtures of Listeria and tumor cells in ratios of 1:100, 1:200, or 1:400 (Listeria:MCA-1 cells) led to significant suppression of tumor growth. Intralesional injection of tumors on day 6 posttransplantation led to the regression of a highly significant number of tumors. Animals receiving injections of Listeria, either in a mixture with tumor cells or intralesionally, displayed enhanced skin test reactivity to a tumor extract. Tumor regressors were resistant for at least 2 to 3 months after the initial transplant to rechallenge with MCA-1 cells. Thus, with this particular tumor-host system, Listeria was successfully employed as an antitumor agent with no visibly detrimental side effects to the host.
mesh_terms: D000818:Animals; D002455:Cell Division; D005260:Female; D005354:Fibrosarcoma / Q000276:immunology* / Q000473:pathology; D006168:Guinea Pigs; D006968:Hypersensitivity, Delayed; D007109:Immunity; D008089:Listeria monocytogenes / Q000276:immunology*; D008297:Male; D009374:Neoplasms, Experimental