EGF对一膜表面稳定表达EGFR细胞系生物学特性的影响

Effect of epidermal growth factor(EGF) on the biological characteristics of a cell line expressing EGF receptor on its membrane

目的探讨表皮生长因子(ep iderm al growth factor,EGF)对一膜表面稳定表达表皮生长因子受体(EGF receptor,EGFR)细胞系CHO-EGFR-GFP1生物学特性的影响。方法采用台盼蓝染色计数活细胞数观察不同浓度EGF刺激48 h后细胞增殖情况;PI染色一步法流式细胞仪检测不同浓度EGF刺激48 h和100 ng/mL EGF刺激不同时间细胞周期改变以及细胞凋亡,Ho-echst 33258染色观察细胞凋亡;流式细胞术测定GFP(green fluorescent prote in,绿色荧光蛋白)平均荧光强度判定EGFR表达水平的变化。结果低浓度的EGF可促进CHO-EGFR-GFP1细胞增殖,而高浓度EGF刺激则引起CHO-EGFR-GFP1细胞失去黏附、细胞周期阻滞、促进细胞凋亡以及抑制细胞增殖;高浓度EGF以一种剂量依赖性方式同时上调EGFR的表达和引起细胞凋亡。结论不同浓度EGF对CHO-EGFR-GFP1细胞生长特性影响不同,高浓度EGF刺激引起肿瘤细胞失去黏附可能是导致肿瘤细胞容易脱落、发生转移的机制之一。

Objective To study the effect of EGF on the biological characters of a cell line （ CHO-EGFR-GFP1 ） expressing EGFR on its membrane. Methods Trypan blue exclusion assays were used to test cell viability and proliferation after EGF treatment at different concentrations. Cell cycle and apoptosis were determined with flow cytometry after the cells were treated with EGF at different concentrations for 48h or 100 ng/mL EGF for different interval and stained with piopidium iodide. The apoptosis was also analyzed with Hoechst 33258 staining. EGFR expression levels were detected with flow cytometry by evaluating the mean fluorescence intensity （MFI） of GFP （green fluorescent protein）. Results EGF at low concentrations promoted proliferation, while EGF at high concentrations induced loss of adhesion, cell cycle arrest, apoptosis, and inhibition of proliferation. The effects of EGF on cell proliferation correlated well with the expression levels of EGFR. EGF at high concentrations induced both EGFR expression and apoptosis in a dose - dependent manner. Conclusion EGF treatments at different concentrations have different effects on the biological characteristics of CHO-EGFR- GFP1. The loss of adhesion caused by EGF treatment at high concentrations might be one of mechanisms promoting the metastasis of tumor cells.