甲胎蛋白新功能:调节HeLa细胞生长的信号转导机制

目的:观察甲胎蛋白(alpha-fetoprotein,AFP)调节HeLa细胞生长的细胞内信号转导机制。方法:用从人脐带血中提取的AFP作用于体外培养的HeLa细胞,通过MTT计数、3H-TdR参入法、流式细胞仪等研究细胞增殖;放射免疫结合法检测在AFP作用下,HeLa细胞第二信使物质环磷酸腺苷(cAMP)和蛋白激酶A(PKA)活性的改变;用共聚焦显微镜观测细胞内Ca2+浓度的变化;用Westernblotting分析法分析P21ras表达。结果:①表明AFP(浓度大于10mg/L)对HeLa细胞增殖有明显的促进作用。②在AFP(20mg/L)作用下,PKA活性升高达122.6%,而Ca2+浓度升高达125.71%;P21ras蛋白表达在作用24h时增高112.6%。③抗甲胎蛋白单克隆抗体能有效地阻断AFP对HeLa细胞信号转导的影响。结论:①AFP能促HeLa细胞生长;②AFP可能通过cAMP-PKA和Ca2+途径调节HeLa细胞生长。

THE NEW FUNCTION OF ALPHA -FETOPROTEIN: THE REGULATED-MECHANISM ON PROMOTING THE GROWTH OF HeLa CELLS

Objective:A lot of investigations had showed that alpha-fetoprotein(AFP)could regulate the proliferation of tumor or neoplastic cells.In order to study the mechanism of this func tion.Methods :AFP extracted from human cord blood serum was used to act on Hela cell in vit ro,the MTT assay,the 3 H-incorporation assay,Utilized radioactive immunosorbent assay to detect pro tein kinase A activity and confocal microscopy scanning intracellular calcium.,and the expression of P21 ras protein were analyzed by Western blot.Results:①It showed that AFP(10mg /L)had great effects on the enhancement of the proliferation of Hela cell;②AFP (20mg /L)could significantly in crease the concentration of Ca 2+ (125.7%)and protein kinase A activity(122.6%);It also showed that the expression of P21 ras protein of Hela cells were enhanced after treated with AFP(20mg /L)for24hours.Compared with control,The expression of the protein was increased up to112.6%.③The monoclone antibody of AFP can block these functions of AFP.Conclusion:①AFP can enhanced the grouth of hela cells;②The growth-regulatory effect of AFP on the cells were mediated by AFP rceceptor and through the transmembrane cAMP-PKA or /and Ca 2+ signal transduction pathway.