Hyperthermia Effects on the Growth of a Laryngeal Squamous Cell Carcinoma Cell Line Treated with Recombinant Human Interferons α and γ

Abstract

Clinical therapy with either interferon alpha or interferon gamma is associated with a febrile response. However, the effects of hyperthermia on the response to these interferons have not been elucidated fully. In this study, a cell line derived from a laryngeal squamous cell carcinoma (JHU-011-SCC-L-P) was grown in the presence of recombinant human interferon alpha (rHuIFN alpha) or recombinant human interferon gamma (rHuIFN gamma) and incubated at either 37 degrees or 39 degrees C, and cell growth rates were measured. Cells incubated with rHuIFN alpha demonstrated no difference in growth rates from control cells. Cells treated with rHuIFN gamma showed significant inhibition of growth at both temperatures, and the ratio of decreased growth at 39 degrees C was significantly greater than for the rHuIFN alpha and control groups. This hyperthermic effect did not depend on the continued exposure to rHuIFN gamma, and the effect appeared to depend on the duration of hyperthermia instead of the time sequence of hyperthermic exposure. Moreover, initial treatment at 39 degrees C for 24 hours was ineffective in producing the hyperthermic response produced with continuous hyperthermic exposure. These findings would indicate that the effect of rHuIFN gamma on this laryngeal squamous cell carcinoma cell line is enhanced significantly at 39 degrees C compared with 37 degrees C. There appears to be no similar hyperthermia-augmented antiproliferative effect of rHuIFN alpha-treated cells.