Temperature-induced alterations in protein composition of newt papilloma cells

Protein patterns of Japanese newt papilloma in vivo at low (4 degrees C), normal (10 degrees C, control) and elevated (30 degrees C) temperature were investigated by two-dimensional gel electrophoresis. There were nine protein spots in normal skin (skin specific spots: SSS) which did not exist in papillomas. At 10 degrees C, the papillomas possessed three specific protein spots (papilloma specific spots: PSS) which did not appear in normal skin. At the reduced environmental temperature, eight of the nine missing proteins in papillomas had reappeared by 12 weeks exposure. Differential responses in reappearance of SSS in papillomas varied with environmental temperature. The PSS generally were unchanged by environmental temperature modulation, although one specific protein disappeared at 12 weeks at 4 degrees C. Reappearance of normal SSS in papillomas occurred early in treatment and reflected only minor variations in high versus low temperature exposures. These data suggest that temperature-induced tumor regression may be associated with changes in protein composition.