title: Effects of sequence and temperature of hyperthermia and peplomycin on human pharyngeal carcinoma KB cells in vitro.
abstract: To maximize the interactive effect, we examined the time sequence of high (above 43 degrees C) or low (below 43 degrees C)-hyperthermia and peplomycin (PEP)(0.5 microgram/ml). Simultaneous or post-hyperthermic PEP treatment at 44 degrees C resulted in a slight synergistic effect with thermoenhancement ratios (TER) of 1.30 or 1.34, respectively. However, at 42 degrees C, maximal interaction was obtained (TER = 10.19) when KB cells were simultaneously heated with PEP. Furthermore, pre-treatment at 44 degrees C for 25 min or 42 degrees C for 4 h enhanced PEP cytotoxicity more than that of post-treatment at 44 degrees C for 25 min or 42 degrees C for 4 h, respectively. However, chemoenhancement ratios (CER) of pre-treatment at 44 degrees C for 25 min and at 42 degrees C for 4 h were 19.1 and 3.5, respectively, although the isothermic dose decreased the cell count to 60% in both cases. These results indicated that simultaneous or post-hyperthermic PEP treatment with high-hyperthermia, and simultaneous PEP treatment with low-hyperthermia, are the most effective means of PEP thermochemotherapy with hyperthermia.
authors.affiliation: Department of Otolaryngology Fukui Medical School, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ohtsubo
authors.forename: H
authors.initials: H
authors.lastname: Saito
authors.forename: I
authors.initials: I
authors.lastname: Noda
authors.forename: C
authors.initials: C
authors.lastname: Sugimoto
authors.forename: T
authors.initials: T
authors.lastname: Saito
authors.forename: E
authors.initials: E
authors.lastname: Kano
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D006979:Hyperthermia, Induced / Q000009:adverse effects*; D007624:KB Cells / Q000187:drug effects*; D017663:Peplomycin / Q000494:pharmacology*; D013696:Temperature; D013997:Time Factors; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D017663:Peplomycin