[Patients with gastric cancer submitted to gastrectomy: an integrative review]

Effects of PLK1 on proliferation, invasion and metastasis of gastric cancer cells through epithelial-mesenchymal transition

Effects of polo-like kinase (PLK1) on proliferation, migration and invasion capacities of gastric cancer cells through epithelial-mesenchymal transition (EMT) were investigated. Small-interfering ribonucleic acid (siRNA) with targeted interference in PLK1 gene was designed and transfected into gastric cancer MGC-803 cells via Lipofectamine to inhibit the expression of PLK1 gene in MGC-803 cells. The proliferation of MGC-803 cells was detected via methyl thiazolyl tetrazolium (MTT) assay. The mRNA and protein expression of PLK1 and EMT-related marker (E-cadherin) was detected via real-time polymerase chain reaction and western blot analysis, respectively. The effects of interference in PLK1 gene on migration and invasion of MGC-803 cells were studied via wound healing assay and Transwell chamber assay, respectively. Results of MTT assay showed that compared with that in control group, the cell proliferation in PLK1 siRNA group was significantly inhibited (p<0.01). Compared with those in control group, the mRNA and protein expression of PLK1 in PLK1 siRNA group was significantly decreased (p<0.01), but the mRNA and protein expression of E-cadherin was obviously upregulated (p<0.01). Results of wound healing assay and invasion assay showed that the capacity of migration and invasion of MGC-803 cells in PLK1 siRNA group was significantly inhibited compared with those in control group (p<0.01). In conclusion, PLK1 enhances the proliferation, migration and invasion of gastric cancer MGC-803 cells through affecting EMT.

Resveratrol inhibits the growth of gastric cancer via the Wnt/β-catenin pathway

The inhibitory effect of resveratrol on the growth of gastric cancer cells through downregulation of the Wnt/β-catenin signaling pathway were studied. First we determined the effective concentration of resveratrol on the growth and proliferation of MGC-803 gastric cancer cells. Methylthiazolyl tetrazolium assay showed that resveratrol significantly inhibited the proliferation of MGC-803 cells in a dose-dependent manner. Resveratrol induced apoptotic morphological changes in MGC-803 cells. Reverse transcription-polymerase chain reaction and western blot analysis showed that resveratrol downregulated the expression of three important components of the Wnt signaling pathway, β-catenin, c-myc, and cyclin D1, at the mRNA and protein levels. Overall, resveratrol inhibits the growth of MGC-803 cells by inhibiting the Wnt signaling pathway. This study provides a new idea and direction for the antitumor mechanism of resveratrol.

氯化两面针碱对胃癌细胞株SGC7901凋亡的影响及初步机制

目的

探讨氯化两面针碱对胃癌细胞株SGC7901凋亡的影响, 并研究其可能的初步机制.

方法

MTT法检测不同浓度氯化两面针碱(0、5、10、20和40 μmol/L)对胃癌细胞株SGC7901存活率的影响; Hoechst染色观察SGC7901细胞的形态学; Annexin V-FITC/PI双染法检测SGC7901细胞的凋亡; JC-1单标法检测细胞内线粒体膜电位变化; 免疫印迹法检测caspase-3剪切体、caspase-9剪切体和PARP剪切体与其各自未激活体的蛋白表达变化.

结果

SGC7901的存活率随着氯化两面针碱浓度的增加而逐渐下降, 并与时间呈正相关; Hoechst染色与Annexin V-FITC/PI双染法结果分别显示氯化两面针碱干预后SGC7901细胞的凋亡特征更显著, 细胞凋亡率明显增多; 经过氯化两面针碱处理后, SGC7901细胞线粒体膜电位显著下降, caspase-3剪切体、caspase-9剪切体和PARP剪切体蛋白表达水平显著上升, 其未激活体蛋白表达明显下降.

结论

氯化两面针碱呈浓度依赖性抑制SGC7901细胞的存活率, 增加细胞凋亡率, 可能是通过激活内源性线粒体通路有关.