cAMP依赖的蛋白激酶PKAR_(Iα)亚基在胃癌细胞中的表达及8-溴-环核苷酸对其表达及细胞增殖的影响

Expression of PKA R_(Iα) in gastric cancer cells and effects of 8-Bromo-cAMP on its expression and cells proliferation

目的 观察经位点选择性 8-溴 -环核苷酸 (8- Br- c AMP)诱导前后 ,两株胃癌细胞 SGC790 1 和 MGC80 3 PKA RIα亚基m RNA的表达状况及癌细胞增殖动力学的变化。 方法 应用分子杂交技术测定 8- Br- c AMP诱导前后两株胃癌细胞 PKARIα亚基不同的表达状态 ;用 MTT法和流式细胞仪 FCM观察 8- Br- c AMP诱导前后 ,细胞增殖动力学的变化。 结果 两株胃癌细胞均有 PKA RIα亚基的高表达状态 ,而且经 8- Br- c AMP诱导后 ,PKA RIα的表达水平明显减弱 ;此外 ,8- Br- c AMP对两株胃癌细胞系 SGC790 1 和 MGC80 3 细胞有明显的抗增殖作用 ,其 IC50 值分别为 40μmol/ L和 15μmol/ L ;流式细胞仪分析结果显示 ,经 8- Br- c AMP诱导后 ,在正常的细胞倍体峰前出现一群凋亡的细胞峰型 ,可能和诱导后肿瘤细胞发生凋亡有关。 结论 胃癌细胞株存在 PKA RIα亚基的过表达状态 ,通过 8- Br- c AMP作用 ,可抑制 RIα亚基的过表达并可抑制癌细胞的恶性增殖。

Objective In order to observe the effects of site selective 8 Bromo cAMP on the expression of cAMP dependent protein kinases PKA R Iα mRNA and the proliferation of gastric cancer cell lines. Methods The expression of PKA R Iα mRNA in both gastric cancer cell lines was performed by molecular hybridization. MTT method and Flowcytometry were used to test the proliferating dynamics of cancer cells. Results 1. There are overexpression of R Iα subunit both in SGC 7901 and in MGC 803 cell lines. However, when the cells were treated with 8 Br cAMP, the expression of R Iα was markedly downregulated, which is associated with growth arrest and the onset of differentiation. 2.8 Br cAMP can inhibit the growth of gastric cancer cell lines, their IC 50 value being at 40 μmol/L in SGC 7901 and 15 μmol/L in MGC 803 cell lines respectively; 3.The result of Flowcytometry was shown that an abnormal peak before G1 phase was exerted with 8 Br cAMP inducing. It was related to apoptosis of cancer cells. Conclusion 8 Br cAMP can downregulate the expression of PKA R Iα mRNA. It also inhibits the growth and induces the apoptosis in gastric cancer cell lines.