表皮生长因子受体信号通路在人鼻腔上皮RPMI-2650细胞中的作用

摘要

目的 通过对表皮生长因子受体(epidermal growth factor receptor,EGFR)信号通路不同部位的干预,观察体外培养的人鼻腔上皮细胞RPMI-2650中EGFR和黏蛋白5AC(mucin 5AC,MUC5AC)的变化.方法 对人鼻腔上皮细胞RPMI-2650进行体外培养,记录生长曲线,并行扫描电镜观察细胞超微结构.当细胞大部分融合时,将细胞分为四组,A组:在原Eagle最小必需培养基(Eagle's minimum essential media,EMEM)培液中继续培养;B组:加入人重组表皮生长因子(epidermalgrowth factor,EGF)25 ng/ml;C组:加入AG1478(EGFR选择性抑制剂)10 μmol/L,30 min后加人人重组EGF 25 ng/ml;D组:加入PD98059(p44/42MAPK选择性抑制剂)30μmol/L,30 min后加入人重组EGF 25 ng/ml.以上四组细胞均继续培养24 h后,分别进行细胞免疫和Western blotting实验,观察EGFR和MUC5AC蛋白在各组细胞中的表达.结果 细胞在培养第3天开始融合,第5～7天大量融合.扫描电镜可见细胞呈圆形或椭圆形,表面覆有大量微绒毛,当细胞融合时可变为梭形或多角形生长.EGFR蛋白在B组细胞中强表达,A组和D组细胞中有较强表达,而在C组中仅有弱表达,A、B、D组与C组平均吸光度值(A值)相比差异均具有统计学意义(P值均<0.01).而MUC5AC蛋白在B组细胞中有强表达,A组细胞中有较强表达,在C组和D组中仅为弱表达,B组与C、D组间相比吸光度值差异均具有统计学意义(P值均<0.01),而C组与D组之间差异无统计学意义(P>0.05).结论 从细胞和蛋白水平上发现,EGFR信号通路在RPMI-2650细胞中发挥作用.对该通路不同部位进行干预,细胞中EGFR和MUC5AC蛋白随之发生相应改变.证实了EGFR信号通路在鼻腔上皮细胞RPMI-2650中对MUC的分泌具有调节作用.%Objective To explore the roles of epidermal growth factor receptor (EGFR) signaling pathway on cultured human nasal epithelial cells RPMI-2650. Methods RPMI-2650 cells were cultured in vitro, the growth curve was measured and the ultrastructure was observed using scanning electron microscope. When the cells were significantly confluent, they were divided into 4 groups, group A: maintained in Eagle's minimum essential media (EMEM) medium without adding any stimulators; group B: added with epidermal growth factor (EGF) 25ng/ml; group C: added with AG1478 (EGFR selective inhibitor) 10 μmol/L followed by EGF 25 ng/ml 30 minutes later; group D: added with PD98069 (p44/ 42MAPK selective inhibitor) 30 μmol/L followed by EGF 25 ng/ml 30 minutes later. After incubated for 24 hours, the expression of EGFR and MUCSAC proteins in the cells of these 4 groups was studied using cytoimmunity and Western blotting. Results RPMI-2650 cells were significantly confluent after incubated for 5 to 7 days. The shape of cells was round or oval, and a large number of microvilli covered to their surface but without cilia under scanning electron microscope. The EGFR protein was expressed in the cells of group A and D, abundantly in group B, while weakly in group C. The values of comparative absorbance had significant difference between group A, B, D and group C, respectively (P < 0.01). For the MUCSAC protein, its expression was strong in the cells of group A, abundant in group B, and weak in group C and D. Significant difference of the values of comparative absorbance was analyzed between group B and group C、D, respectively (P <0.01), while no difference between group C and group D (P >0.05). Conclusions The production of MUCSAC in human nasal epithelial cells RPMI-2650 is regulated via the expression and activation of epidermal growth factor receptor signaling pathway.