Selective lethal effect of supranormal temperatures on human neoplastic cells.

The effects of supranormal temperatures upon normal human cells (derived from normal adult and embryonal tissues) and neoplastic human cells (derived from biopsies of malignant tumors) have been quantitatively studied in tissue culture. Melanoma cells have been compared with melanocytes derived from fetal uveas. Colon carcinoma cells have been compared with embryonal intestinal epithelial cells. Malignant neuroepithelial cells derived from a teratocarcinoma of the ovary have been compared with neuroepithelial cells derived from fetal brain. Fibrosarcoma cells have been compared with normal adult fibroblasts. All cells defined as neoplastic have produced malignant tumors when injected into nude thymus-deficient mice at doses of 1 X 10(7) cells or less. Exposure to temperatures of 42.5-43.0 degrees for 4 to 8 hr has been shown to have significantly greater lethal effect on the tumor cells than on the nonneoplastic cells.