Expression of melanoma-associated antigen of thermotolerant human cells.
The expression of the melanoma-associated antigen p250 on thermotolerant cells and the effect of a second heat dose on the antigen expression have been measured by flow cytometry. The human melanoma cell line FME was heated at 43.5 degrees C for 120 min after a priming heat dose at 43.5 degrees C for 20, 40 or 60 min. Cells preheated at 43.5 degrees C for 40 and 60 min followed the same kinetics of development and decay of thermotolerance, with maximum thermotolerance 16 h after the priming heating, and the thermotolerance had decayed by 48 h. Cells preheated at 43.5 degrees C for 20 min showed maximum thermotolerance after 7 h and decay by 24 h. Heat reduced the expression of the melanoma-associated antigen in a dose-dependent manner. Thermotolerant cells were given a second heat dose (43.5 degrees C for 120 min) and the antigen expression measured immediately after heating. Fractionated hyperthermia using the lower predose (43.5 degrees C for 20 min) might have an additive effect on the reduction of antigen expression, while the highest predose (43.5 degrees C for 60 min) protected against reduction in antigen expression. The development and decay of resistance against heat-induced reduction in expression of melanoma-associated antigen followed a similar time course as thermotolerance in terms of cell survival. Maximum resistance was observed 12 h after the priming heat treatment, and the resistance had decayed by 48 h.
Davies
C D
CD
Department of Physics, Norwegian Institute of Technology, University of Trondheim, Norway.
Falch
B M
BM
D000951:Antigens, Neoplasm / Q000096:biosynthesis*; D002470:Cell Survival; D005434:Flow Cytometry; D006801:Humans; D008545:Melanoma / Q000276:immunology* / Q000503:physiopathology; D013696:Temperature; D014407:Tumor Cells, Cultured
D000951:Antigens, Neoplasm