Effect of corynebacterium liquefaciens on a C3Hf mouse squamous cell carcinoma.
The antitumor effect of anaerobic Corynebacterium liquefaciens was compared with that of specific immunization. Experimental tumors were fourth or fifth generation isotransplants of a NR-Sl squamous cell carcinoma that arose spontaneously in a C3Hf/He female mouse. Specific immunization failed to exhibit an antitumor effect, whereas a single administration of the bacterium markedly inhibited the growth of the tumor. This growth inhibition was most effective when C. liquefaciens was administered 2 to 4 days before transplantation of tumor cells, but marked inhibition was also observed when this agent was administered after transplantation. The inhibitory effect was independent of dose within a range of 0.1 to 2.0 mg/mouse; a single dose of less than 0.05 mg/mouse did not exhibit antitumor effect. Multiple administrations of large doses, if given with short treatment intervals, were no more effective than one small dose. Multiple doses given at 14-day intervals resulted in marked growth retardation. The dose of cells that produced 50% tumor takes in C. liquefaciens-treated animals was not significantly different from that in nontreated animals, indicating that this bacterium exhibited no lethal effect on the tumor cells studied.
D000818:Animals; D000951:Antigens, Neoplasm / Q000008:administration & dosage; D002294:Carcinoma, Squamous Cell / Q000276:immunology / Q000628:therapy*; D003352:Corynebacterium / Q000276:immunology*; D004306:Dose-Response Relationship, Immunologic; D007167:Immunotherapy; D051379:Mice; D008809:Mice, Inbred C3H; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000276:immunology / Q000628:therapy; D014185:Transplantation, Isogeneic
D000951:Antigens, Neoplasm