Epidermal growth factor modifies cell cycle control in A431 human squamous carcinoma cells damaged by ionizing radiation
Laderoute, K.R.; Ausserer, W.A.; Knapp, A.M.; Grant, T.D.; Sutherland, R.M.
Cancer Research 54(6): 1407-1411
1994
ISSN/ISBN: 0008-5472 PMID: 8137238 Document Number: 426796
Epidermal growth factor (EGF) has been shown to radiosensitize A431 and other human squamous carcinoma cells with high numbers of surface EGF receptors. In this study of the mechanistic basis of EGF-induced radiosensitization, both EGF and ionizing radiation caused G-1 phase arrests in cycling A431 cells, but only radiation caused a G-2-M arrest. However, EGF enhanced the magnitude of this G-2-M arrest, suggesting an interaction of signaling pathways involved in cellular responses to EGF and radiation damage. EGF and radiation also uniquely perturbed cyclin A and B-1, mRNA levels during the time of maximum radiation-induced G-2-M arrest The effects of EGF on G-2-M events probably originated in cells in G-1. It is possible that aberrant EGF signal transduction in human squamous carcinoma cells may be exploited as a novel strategy for radiotherapy.