RESUMEN
OBJECTIVE: We studied the possibility that addition of Tyrphostin AG 1478 which is selective epidermal growth factor inhibitor, would enhance the effect of radiation on human cervical cancer cell lines, HeLa and CaSki. METHODS: Tyrphostin was added to the cells which were irradiated. The ratio of dead cells was estimated by trypan blue dye examination, and survived cell fractions were estimated by clonogenic assays. The presence and degree of apoptosis were examined by DNA electrophoresis and nuclear dye using propium iodide. RESULTS: The growth was completely inhibited in both cell lines, but the addition of tyrphostin resulted in different effects on the radiation induced cell death and apoptosis in each cell line. However, the percentage of dead cells and apoptotic cells was decreased in HeLa cell line compared with CaSki cell line. The ultimate survived cell fractions determined by clonogenic assays were decreased in both cell lines and the size of colony was also decreased. CONCLUSION: These data suggest that the addition of Tyrphostin is able to increase the radiotherapeutic effects on human cervical cancer cells, and this synergistic effect may result from effective blocking of radiation-induced accelerated repopulation of cancer cells by tyrphostin.