Effect of hyperthermia on the antitumor actions of interferons.
Hyperthermia treatment has been shown to enhance the in vitro antiproliferative effects of IFN-alpha, IFN-beta, and IFN-gamma, with IFN-gamma being more strongly enhanced than IFN-alpha. The comparative effects of hyperthermia on the in vivo antitumor activities of IFN-alpha and IFN-gamma were evaluated in the murine system using both subcutaneous and intraperitoneal B16 melanoma tumor model systems. Heat-induced whole body hyperthermia, resulting in a 2 degree C rise in body temperature, was administered by incubating the mice for 8 hours in a dry incubator at 37.1 degrees C. Whole body hyperthermia was found to enhance the antitumor activity of IFN-alpha by approximately 1.0 fold and 1.2 fold for the subcutaneous and intraperitoneal tumor models, respectively. This represented an additive effect of hyperthermia and IFN-alpha. Hyperthermia was found to enhance the antitumor activity of IFN-gamma by approximately 2.9 fold and 2.2 fold for the subcutaneous and intraperitoneal tumor models, respectively. This represented a synergistic effect of hyperthermia and IFN-gamma. The results of this in vivo study confirm and extend the in vitro observation that hyperthermia more strongly enhances the antitumor action of IFN-gamma than IFN-alpha. These results may have clinical importance because they suggest that hyperthermia may be used in combination with IFN-gamma to provide a synergistically enhanced antitumor action.
Anjum
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Department of Microbiology, University of Texas Medical Branch, Galveston.
Fleischmann
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D000818:Animals; D003131:Combined Modality Therapy; D005260:Female; D006979:Hyperthermia, Induced; D007372:Interferons / Q000627:therapeutic use*; D008546:Melanoma, Experimental / Q000473:pathology / Q000628:therapy*; D051379:Mice; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation
D007372:Interferons