中文摘要：

目的研究异戊二烯化酶二牛龙牛儿基转移酶I（GGTase-I）在舌鳞状细胞癌增殖中的作用。方法登录Genebank确定人GGTase-I基因序列，设计3条小干扰RNA（siRNA），并将siRNA转染至舌癌细胞Cal-27（GGTase-I siRNA组）。设立空白对照组（只加入转染试剂，不加入siRNA）和阴性对照组（NC-siRNA）。采用实时定量聚合酶链反应和蛋白质免疫检测转染后各组细胞GGTase-I、RhoA的mRNA和蛋白表达；蛋白质免疫检测转染48h后CyclinDI、p21的表达变化；细胞增殖活性检测试剂盒和流式细胞术检测细胞的增殖活性和细胞周期变化。结果与阴性对照组和空白对照组相比，GGTase—I siRNA组细胞的GGTase—I的mRNA和蛋白表达下降（P〈0．05），RhoA的mRNA和蛋白表达无明显改变（P〉0．05）；Cyclin D1的表达下降，p21表达升高，细胞的增殖活性下降，细胞周期发生改变（P〈0．05）。结论GGTase-I siRNA能抑制舌鳞状细胞癌细胞中GGTase-I的表达，抑制细胞增殖，提示GGTase-I在舌鳞状细胞癌增殖中可能发挥重要作用。

英文摘要：

Objective This study aims to investigate the effect of geranylgeranyltransferase I （GGTase- I ） on the proliferation and growth of tongue squamous cancer cells. Methods Three small interfering RNAs （siRNAs） were designed on the basis of the GGTase- I sequence in GeneBank. These siRNAs were then transfected imo tongue squamous cancer cells Cal-27. The mRNA and protein expression of GGTase- I and RhoA were examined by real-time quantitative polymerase chain reaction and Western blotting, respectively. The expression of Cyclin D 1 and p21 were examined by Western blotting. The proliferation and growth ability were analyzed by cell counting kit-8 assay and flow cytometry. Results The mRNA and protein expression of GGTase- I in Cal-27 was reduced significantly after the GGTase- I siRNAs were transfected （P〈0.05）. No significant difference in RhoA mRNA and protein expression was detected （P〉0.05）. Cyclin D1 expression decreased, whereas p21 expression increased significantly. The cell cycle was altered, and the growth-proliferative activity was inhibited （P〈0.05）. Conclusion GGTase- I siRNA can inhibit the expression of GGTase- I and the proliferative activity of tongue squamous cancer cells. GGTase-I may be a potential target for gene therapy in tongue squamous cell cancer.