翻译控制肿瘤蛋白在鳞状细胞癌和细胞株A431及SCL-1中的表达

Expression of translationally controlled tumor protein in squamous cell carcinoma tissue and cell lines A431 and SCL-1

目的探讨翻译控制肿瘤蛋白（TCTP）在人皮肤鳞状细胞癌（scc）组织及其细胞株A431及SCL-1中的表达，观察其对SCC细胞凋亡及增殖的影响。方法免疫组化法观察TcTP蛋白在SCC组织中的表达。Western印迹法检测TCTP蛋白在SCC细胞株A431及SCL-1中的表达情况。继而构建针对编码TCTP的基因TPT1的siRNA序列，通过脂质体转染法转入A431细胞中，RT-PCR法检测TPT1的表达，Western印迹法检测TcTP蛋白的表达，流式细胞仪检测细胞凋亡率，MTT法检测A431细胞增殖情况。结果免疫组化结果显示，在SCC中存在着TCTP的高表达，且其表达水平与癌组织的分级有着正相关关系（P〈0．05）。Western印迹结果证实，在A431细胞及SCL-1细胞株中都存在着TCTP的表达，以A431细胞表达为最高。荧光检测siRNA转染效率可达到90％-95％。RT-PCR及Western-Blot结果显示合成的siRNA可以有效下调A431细胞中TPT1及TCTP的表达（P〈0．05）。结论合成的siRNA可以有效下调A431细胞中TP及TCTP的表达，这种下调可引起A431细胞凋亡率的上升和细胞增殖的抑制。

Objective To detect the expression of translationally controlled tumor protein （TCTP） in squamous cell carcinoma （SCC） tissue and cell lines A431 and SCL-1, and to evaluate the effect of TCTP on apoptosis in and proliferation of SCC cells. Methods An immunohistochemical method was used to measure the expression of TCTP in tissue specimens from 65 patients with SCC. Western blot was performed to detect the expression of TCTP in A431 and SCL-1 cells. Three small interference RNAs （siRNAs） targeting the TPT1 gene were designed, synthesized, and transfected into A431 cells. Then, reverse transcription （RT）-PCR and Western blot were conducted to measure the expression of TPT1 mRNA and TCTP, respectively, methyl thiazolyl tetrazolium （MTT） assay and flow cytometry were carried out to detect cell proliferation and apoptosis, respectively. Results TCTP was overexpressed in SCC tissue specimens, and the expression level was positively correlated with the histologic grading of SCC （P 〈 0.05）. Western blot showed that TCTP was expressed in both A431 and SCL-1 cells, and the expression was relatively high in A431 cells. The transfection efficiency of siRNAs varied from 90% to 95%. A decrease in the expression of TPT1 mRNA and TCTP was induced by the siRNAs in A375 cells （all P 〈 0.05）. Conclusion The downregulation of TCTP expression may increase the apoptosis in and suppress the proliferation of A431 ceils.