Hyperthermic enhancement of rhodamine 123 cytotoxicity in B16 mouse melanoma cells in vitro

David N. Krag, Alain P Theon, Lydia Gan

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


The effect of elevated temperature on cytotoxicity of rhodamine 123 (R123) was tested in vitro on B16 mouse melanoma cells. Simultaneous 1-h exposure to R123 and hyperthermia (43°C for 1 h) resulted in marked enhancement of R123 cytotoxicity. Thermal enhancement of R123 cytotoxicity occurred at temperatures as low as 38°C. Heat treatment (43°C for 1 h) given immediately before or after R123 exposure (37°C for 1 h) yielded no significant increase in cytotoxicity over that expected for strict additivitv. The effects of heat on two mechanisms reported to be associated with R123 cytotoxicity were evaluated: (a) target inactivation by R123; and (b) R123 intracellular accumulation. Hyperthermia caused an increased rate of target inactivation by R123 and also caused an increased net intracellular accumulation of R123. This indicates that at least two mechanisms are responsible for the synergistic cytotoxicity of R123 and hyperthermia.

Original languageEnglish (US)
Pages (from-to)2385-2389
Number of pages5
JournalCancer Research
Issue number8
StatePublished - Apr 15 1990

ASJC Scopus subject areas

  • Cancer Research
  • Oncology


Dive into the research topics of 'Hyperthermic enhancement of rhodamine 123 cytotoxicity in B16 mouse melanoma cells in vitro'. Together they form a unique fingerprint.

Cite this