aFGF对肺腺癌AGZY-83A细胞株TPK、PKC活性及Ca^(2+)浓度的影响

Effect of aFGF on the Activity of TPK,PKC and [Ca 2+ ] i in AGZY 83A Cell

目的：观察ａＦＧＦ与细胞膜上特异受体结合后引起的细胞内信号转导途径，探讨ａＦＧＦ导致细胞增殖的机理。方法：以不同浓度的ａＦＧＦ处理ＡＧＺＹ－８３Ａ细胞，利用［γ－３２Ｐ］ＡＴＰ掺入外源性底物的方法测定受体的酪氨酸蛋白激酶活性（ＴＰＫ）及蛋白激酶Ｃ（ＰＫＣ）活性；用Ｆｕｒａ－２／ＡＭ为荧光指示剂测定［Ｃａ２＋］ｉ。结果：随着ａＦＧＦ浓度增加，ＴＰＫ及ＰＫＣ活性随之升高。当ａＦＧＦ浓度为１．１２μｇ／ｍｌ时ａＦＧＦ处理组的ＴＰＫ是对照组的４倍；膜ＰＫＣ活性也是对照组的４倍，胞浆ＰＫＣ活性是对照组的１．７５倍。［Ｃａ２＋］ｉ是对照组的３倍。结论：该细胞株中ａＦＧＦ受体具有ＴＰＫ活性。ＴＰＫ激活后进一步促进蛋白质和酶磷酸化，而使ＰＫＣ活性及［Ｃａ２＋］ｉ升高，即ＰＫＣ和Ｃａ２＋是ＴＰＫ的下游信号分子，进一步促进ｃ－ｆｏｓ、ｊｕｎ基因表达增加。

Objective:In order to observe the molecular mechanism of aFGF in tumorigenesis, this paper was to study the signal transduction pathway of aFGF after aFGF bound to the specific receptor. Methods:We treated AGZY 83A cells with aFGF at different concentrations. The activity of TPK and PKC was determined by the incorporation of [γ 32 P] ATP into exogenous substrate. [Ca 2+ ] i was measured with Fura 2/AM as fluorescent indicator. Results:The activity of TPK and PKC increased in a dose dependent manner. When the concentration of aFGF was at 11.2 μg/ml, the activity of TPK and membrane PKC was four times that of the control. Cytosolic PKC activity was 1.75 times the activity of control group. [Ca 2+ ] i was elevated significantly as compared with the control group (334.83±50.21∶96.50±20.51 nmol/L). Conclusions:We assumed that aFGF receptor possesed TPK activity. These tyrosine specific protein phosphorylation might initiate a cascade of biochemical events, which ultimately promoted c fos c jun gene expression and cell proliferation. PKC and Ca 2+ were located downstream of TPK in AGZY 83A cells.