p27kip1基因转移对食管癌细胞生存素表达和端粒酶活性的影响

背景：p27kip1是新近发现的一种抑癌基因，早期研究表明p27kip1基因转移能显著抑制食管癌细胞和人食管癌裸鼠移植瘤的生长，表明该基因疗法可能是食管癌治疗的新途径，但其抑癌机制尚未完全阐明。目的：研究p27kip1基因转移对食管癌细胞生存素（survivin）表达和端粒酶活性的影响。从而阐明p27kip1的抑癌机制，为p27kip1基因治疗食管癌提供理论依据。方法：将携带p27kip1基因的重组腺病毒（Ad—p27kip1）和LacZ重组腺病毒（Ad—LacZ）分别转染食管癌细胞系Eca9706，观察细胞形态变化。以免疫细胞化学染色和蛋白质印迹法检测p27kip1和生存素的表达．以端粒重复序列扩增程序（TRAP）聚合酶链反应（PCR）-酶联免疫吸附测定（ELISA）检测端粒酶活性。结果：经Ad—p27kip1转染后，Eta9706细胞变圆，呈葡萄串样聚集以致脱落。细胞p27kip1表达明显增强，生存素表达降低，端粒酶活性显著受抑制。结论：p27kip1基因抑制食管癌细胞生长的作用机制可能与下调生存素表达和抑制端粒酶活性有关。

Effect of p27kip1 Gene Transfer on Survivin Expression and Telomerase Activity of Esophageal Carcinoma Cells

Background: p27kip1 is a newly identified anti-oncogene. Early investigation has demonstrated that p27kip1 gene transfer has significant inhibitory effect on growth of esophageal carcinoma cells and transplantable human esophageal carcinoma in nude mice. These results indicate that this gene transfer may be a novel strategy for esophageal carcinoma therapy. But the mechanism of its anticarcinogenic effect is not yet clearly known. Aims: To investigate the effect of p27kip1 gene transfer on survivin expression and telomerase activity of esophageal carcinoma cells, so as to clarify the anticancer mechanism of p27kip1 and to provide the theoretical basis for p27kip1 gene therapy. Methods: Recombinant adenoviral vectors carrying p27kip1 gene (Ad-p27kip1) and LacZ (Ad-LacZ) were transfected to esophageal carcinoma cell line Eca9706, respectively. The morphologic changes of Eca9706 cells were examined under microscope. Expressions of p27kip1 and survivin were detected by immunocytochemical technique and Western blotting. Activity of telomerase was determined by telomere repeat amplification protocol (TRAP) polymerase chain reaction (PCR)-enzyme-linked immunosorbent assay (ELISA). Results: After transfected with Ad-p27kip1, the Eca9706 cells became rounded, as bunch of grape-like aggregates in appearance and exfoliated; expression of p27kip1 markedly increased and expression of survivin decreased. In addition, telomerase activity was significantly inhibited. Conclusions: Down-regulation of survivin expression and inhibition of telomerase activity may be related to the inhibitory effect of p27kip1 gene on esophageal carcinoma cells.