PTP1B基因对人胃癌细胞株的增殖和迁移能力的影响

Effect of PTP1B gene on the proliferation and migration of human gastric cancer cell lines

背景与目的:胃癌是我国常见的消化道恶性肿瘤,术后易复发和转移。前期研究发现,蛋白酪氨酸磷酸酶1B(protein tyrosine phosphatase 1B,PTP1B)基因与胃癌肿瘤大小、淋巴结转移及TNM分期有关。本研究通过RNA干扰技术和基因克隆技术分别沉默和上调胃癌细胞中PTP1B基因的表达,观察PTP1B基因对胃癌细胞增殖和迁移能力的影响。方法:将靶向沉默PTP1B基因的短发夹RNA(short hairpin RNA,shRNA)序列和克隆人的PTP1B cDNA基因序列分别转染MKN28和MKN45细胞,采用实时定量PCR(quantitative realtime PCR,qRT-PCR)、蛋白[质]印迹法(Western blot)分别检测转染后细胞中PTP1B基因和蛋白的表达水平,使用细胞计数试剂盒(cell counting kit-8,CCK-8)、Transwell迁移试验和划痕试验分别观察PTP1B基因对细胞增殖和迁移能力的影响。结果:转染shRNA后,MKN28细胞中PTP1B mRNA和蛋白表达量与空白对照组、阴性对照组相比抑制显著(P<0.05)。CCK-8增殖活性实验显示,shRNA沉默PTP1B基因表达后能显著抑制胃癌MKN28细胞在48、72和96 h的增殖活性(P<0.05)。Transwell迁移试验和划痕实验显示,PTP1B表达下调后胃癌MKN28细胞的迁移能力受到显著抑制(P<0.05)。而提高PTP1B在MKN45细胞中表达后,细胞的增殖和迁移能力则显著提高(P<0.05)。结论:PTP1B基因是胃癌细胞增殖和迁移的重要调控因子。

Background and purpose：Gastric cancer is the most common malignant tumor of digestive tract, and the possibility of postoperative recurrence and metastasis is higher. Our previous studies showed that protein tyrosine phosphatase1B （PTP1B） gene is closely correlated with tumor size, lymph node metastasis and TNM stage of gastric cancer. The purpose of the present study was to explore the effect ofPTP1B gene on cell proliferation and migration of gastric cancer cell lines.Methods：Short hairpin RNA （shRNA） sequence targetingPTP1B gene and PTP1B cDNA were transfected into MKN28 and MKN45 cells, respectively. The expression of PTP1B mRNA and its protein in MKN28 and MKN45 cells were detected by quantitative real-time PCR （qRT-PCR） and Western blot, respectively. The effect of PTP1B on cell proliferation and migration was respectively assessed by cell counting kit-8 （CCK-8） assay, Transwell migration assay and wound healing assay.Results：Compared with blank and negative controls, the expressions of PTP1B mRNA and protein in MKN28 cells were successfully suppressed after the cells were transfected with shRNA （P〈0.05）. As CCK-8 test showed, the proliferation of MKN28 cells was successfully restrained at 48, 72 and 96 h after transfected with shRNA compared with blank control and negative control （P〈0.05）. Transwell and wound healing test were performed after PTP1B expression was interfered by shRNA. The result demonstrated that migration of MKN28 cells was signiifcantly inhibited （P〈0.05）. On the contrary, the expressions of PTP1B mRNA and protein in MKN45 cells were obviously enhanced after the cells were transfected with PTP1B cDNA. And the proliferation and migration of cells were significantly increased.Conclusion：PTP1B gene is an important enchancer for the proliferation and migration of gastric cancer.