Study on the proliferation of human gastric cancer cell AGS by activation of EGFR in H2O2.

OBJECTIVE: This study is to investigate the effect of low concentration hydrogen peroxide (H2O2) on the proliferation of gastric cancer AGS cell line in vitro and the mechanism. MATERIALS AND METHODS: AGS cells were treated with different low concentrations of H2O2 (1, 0.1, 0.01, and 0.001 mu m) for 48 hours. The effect of H2O2 concentration gradient on the activity of AGS cell activities was detected by methyl thiazolyl tetrazolium (MTT) method. The expression of the epidermal growth factor receptor (EGFR) and its downstream signaling pathway extracellular signal-regulated kinase (ERK) protein in H2O2 was detected by Western blot method; moreover, the effect of H2O2 on intracellular reactive oxygen species (ROS) in AGS cells was observed under the fluorescence microscope and quantitative analysis by flow cytometry. The effect of H2O2 on the level of c-myc mRNA in AGS cells was also detected by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: MTT detection results showed that 1 mu m and 0.1 ae m H2O2 at 48h can effectively promote the proliferation of AGS cells (p< 0.05). The Western blot results showed that after 48 hours of low concentration of H2O2 treatment of AGS cells, the EGFR protein levels and ERK protein phosphorylation levels increased significantly (p< 0.05). Fluorescence microscopy and flow cytometry showed that the low concentration of H2O2 increased the intracellular reactive oxygen species (ROS). RT-PCR results showed the levels of c-myc mRNA in AGS cells treated with a low concentration of H2O2 were significantly increased (p< 0.05) and EGFR blocking agent AG1478 can resist the above effects. CONCLUSIONS: Low concentration of H2O2 can significantly promote the proliferation of AGS cells by activating EGFR/ERK signaling pathway.