Experimental Study Of The Effect Of Epidermal Growth Factor Receptor Signal Pathway On Biological Behavior Of Gliomas

Objective To investigate the effect of the epidermal growth factor receptor signal pathway on the proliferation and PCNA expression of glioma cell line GL15.Methods GL15 cell culture was established, GFAP and EGFR expression was analyzed by immunohistochemical method, after treated with EGF at different concentration, cell count was used to determine the proliferation of gliomas, PCNA expression was analyzed by flow cytometry (FCM) and immunohistochemical method. Results GFAP was expressed in GL15 cell, EGFR was highly expressed, EGF at dosage 0.1 ng/ml, 1ng/ml can significantly stimulate cell proliferation, EGF at dosage 10ng/ml, 100ng/ml can inhibit the cell proliferation significantly. Conclusion GL15 cell was a typical glioblastoma mutiforme cell line, the EGFR signal transduction pathway has a dual effect on gliomas to vary dose of EGF, low dose of EGF can stimulate the cell proliferation of gliomas, high dose of EGF can inhibit the proliferation of gliomas. Part Two The Molecular Mechanism of Epidermal Growth Factor Receptor Signal Transduction Pathway on Proliferation of GL15 cell.【Abstract】Objective To explore the effect of epidermal growth factor receptor signal transduction pathway on cell cycle and the cytoplasmic free calcium of GL15 cell. Methods GL15 cell was exposed to EGF at different concentration, cell cycle and apoptosis were analyzed by flow cytometry (FCM), laser scan confocal microscope (LSCM) was used to measure the cytoplasmic free calcium. Results After treated with 0.1ng/ml, 1ng/mlEGF, cells in phase G0/G1 decreased and cells in phase S increased compared to control group, an obviously apoptosis peak was appeared after treating with 10ng/ml and 100ng/ml EGF, the apoptosis ratio of high dose of EGF group was higher than control group. EGF can significantly induce a quick rise of intracellular free calcium, but the peak value of intracellular free calcium activated by high dose of EGF was higher than the low dose group. Conclusion. These data indicate low dose of EGF can induce the cell enter DNA synthesis stage from quiescent stage, but high dose of EGF can induce the cell apoptosis, which result in inhibition of proliferation of gliomas. The dual response may be due to the difference of intracellular free calcium.Part Three The Effect of LRIG1 on Proliferation and Cell Cycle Cytoplasmic Free Calcium of Glioma【Abstract】Objective To investigate the effects of LRIG1 on proliferation and EGFR signal transduction pathway of glioma. Methods The LRIG1-EGFP was thansfected into human glioma cell line GL15 with lipofectamine. The growth study, PCNA expression and cell cycle were observed by means of cell count and FCM assay, laser scan confocal microscope (LSCM) was used to measure the cytoplasmic free calcium. Results The growth of GL15 cell transfected with LRIG1 gene was markedly suppressed, cell cycle analysis by flow cytomtry show that the cells in G0/G1 phase was significantly increased while cells in S and G2/M phase was decreased, intracellular free calcium measured by LSCM show that the peak value of intracellular free calcium of activated by EGF was decreased compared to that of control GL15 cells. Conclusion LRIG1 protein can inhibit the effect of EGF on proliferation of human glioma by decreasing intracellular calcium, LRIG1 may be a new molecular target for malignant gliomas therapy.