上调Periostin基因表达对人胃癌细胞增殖的影响

背景：有文献报道，在内源性periostin低表达的人肿瘤细胞株中，过表达periostin基因可抑制细胞的非贴壁依赖性生长，提示该基因具有肿瘤抑制功能。但亦有较多研究发现periostin在一些肿瘤细胞中呈高表达，并可促进其生长、侵袭和转移。目的：探讨上调periostin基因表达对人胃癌细胞增殖的影响。方法：构建、鉴定pcDNA3.1-periostin重组质粒并稳定转染人胃癌细胞株SGC7901和MGC-803，同时设置空载体稳定转染组和不予转染的对照组。蛋白质印迹法检测各组细胞periostin蛋白表达，MTT实验检测细胞活力。结果：pcDNA3.1-periostin重组质粒构建成功。periostin稳定转染组SGC7901和MGC-803细胞periostin蛋白相对表达量明显增高，分别约为相应空载体稳定转染组的2.5倍和4倍（P〈0.05）；MTT实验显示两组细胞在5 d培养过程中的细胞活力均与相应对照组相似，两组间差异亦无统计学意义。结论：稳定转染pcDNA3.1-periostin重组质粒能使人胃癌细胞过表达periostin基因，但periostin基因过表达对人胃癌细胞，至少是本研究检测的两株胃癌细胞的增殖能力无明显影响。

Effect of Enforced Expression of Periostin Gene on Proliferation of Human Gastric Cancer Cells

Background： In human cancer cell lines with reduced endogenous periostin expression, up-regulation of periostin gene could inhibit anchorage-independent growth of cancer cells, which indicated a tumor suppressor effect of periostin. However, there are also evidences demonstrated that periostin was overexpressed in some malignancies, and promoted the growth, invasion and metastasis of cancer cells. Aims： To investigate the effect of enforced expression of periostin gene on proliferation of human gastric cancer cells. Methods： pcDNA3.1-periostin recombinant plasmid was constructed and identified by sequencing analysis. Then the recombinant plasmid was transfected into human gastric cancer cell lines SGC7901 and MGC-803 to establish stable transfection cell lines. Cells transfected with empty pcDNA3.1 plasmid and non-transfected cells were served as controls. Protein expression of periostin was measured by Western blotting and the cell viability was assessed by MTT assay. Results： pcDNA3.1-periostin recombinant plasmid was successfully constructed. SGC7901 and MGC-803 cells transfected stably with the recombinant plasmid had a significantly higher expression level of periostin protein than those transfected with empty pcDNA3.1 plasmid by approximately 2.5 times and 4 times, respectively （P〈0.05）. Results of MTT assay revealed that cell viabilities were comparable among cells transfected with recombinant plasmid, empty pcDNA3.1 plasmid and non-transfected cells in a 5-day culture process. Conclusions： Stable transfection of pcDNA3.1-periostin recombinant plasmid results in overexpression of periostin gene in human gastric cancer cells. However, enforced periostin gene expression has no influence on proliferation capacity of human gastric cancer cells, at least in the two cell lines tested in this study.