EGF Receptor Tyrosine Kinase Inhibitor Tyrphostin AG1487 Induce Human Tongue Cancer Cells Tca8113 Cell Cycle at G1 Phase and Apoptosis

Objective. This study was to investigate the effects of tyrphostin AG1487 on expression of activated ERK1I2, distribution of cell cycle and apoptosis in Tca8113 cells. Materials and Methods. Tca8113 cells were ex- posed to different concentrations of phosphotyrosine kinase inhibitor tyrphostin AG1487, and then immunocytoche- mistry , Western blot, flow cytometry, and electron transmission microscopy were employed to investigate the ef- fects of AG1487 on expression of activated ERK1/2, distribution of cell cycle and apoptosis of Tca8113 cells. Re- sults. The results of immunocytochemistry showed intensity of activated ERK1/2 reactivity in treated cells was marked decreased. These results were corresponded with the expression of activated ERK1/2 in Western blot: ex- pressions of activated ERK1I2 gradually reduced along with the increasing of concentration of tyrphostin AG1487. Cell cycle kinetic analysis demonstrated that AG1487 induced a delay in cell cycle progression and arrested at G1 phase. Furthermore, AG1487 could induce a marked apoptosis of Tca8113 cells. All these effects were in a dose- dependent pattern. Conclusion. EGF receptor tyrosine kinase inhibitor tyrphostin AG1487 can inhibit the expres- sion of activated ERK1/2, induce cell cycle arrest at G1 phase and apoptosis. (Life Science Journal. 2005;2(1): 77 - 84) (ISSN: 1097 - 8135) .