Effects of microRNA-29b on invasion and proliferation of human high peritoneal metastatic gastric cancer cells / 中华消化杂志

ABSTRACT

Objective To investigate the expression of microRNA-29b (miR-29b) in gastric cancer cell line GC9811 and high peritoneal metastatic gastric cancer cell line GC9811-P and its effect on invasion,proliferation and apoptosis.Methods The relative quantitative expression of miR-29b was detected by quantitative realtime polymerase chain reaction(qRT PCR).GC9811 cells were divided into three groups,miRNA down-regulated and transfected with lentiviruses LV-miR-29b inhibitor group,negative control group with negative transfection,and untransfected blank control group.GC9811-P cells were divided into three groups,miR-29b up regulated and transfected with lentiviruses LV miR 29b group,negative control with negative transfection group,and untransfected blank control group.The cell invasion ability was detected with Transwell assay,the cell proliferation ability was measured by methyl-thiazolyl tetrazolium (MTT) test,the colony forming ability was determined by plate colony formation assay,and the apoptosis was tested by flow cytometry.The expressions of miR 29b and secreted protein,acidic and rich in cystenie (SPARC) in gastric cell line GC9811-P,GC9811,MKN28M,MKN28NM and normal gastric cell line GES were determined by qRT-PCR,and the correlation was analyzed.Two independent samples t test or SNK-q test was performed for mean comparison between two groups,and one way analysis of variance was used for mean comparison among three groups.Results The relative quantitative expression of miR-29b inGC9811-P (0.21±-0.04) was significantly lower than that of GC9811 (1.00±0.03,t 28.140,P＜ 0.01).After GC9811 cells transfected with lentiviruses LV-miR-29b inhibitor,the expression of miR-29b (0.21±0.04) was significantly lower than that of control group (0.89±0.07) and blank control group (1.00±0.04,q 12.76,14.73,both P＜0.01).Compared with negative group,the transmembrane cell number and the clonality of miRNA up-regulated group raised(274.33± 9.03 vs 110.67 ± 13.69,t=9.981,P＜0.01;131.33±4.91 vs69.67±2.33,t 11.340,P＜0.01),and the results of MTT test also shows the proliferation was increased.After GC9811-P cells transfected with LV-miR-29b,the expression of miR 29b (4.08±0.20) was significantly higher than that of negative control group (1.15±0.05) and blank control group (1.00±0.10,q=21.73,22.81,both P＜0.01).Compared with negative group,the transmembrane cell number and the clonality of miRNA up regulated group reduced (51.33±5.55 vs 104.00±6.24,t 6.305,P＜0.01; 48.00±5.51 vs 113.33±5.17,t 11.340,P＜0.01),and the results of MTT test also shows the proliferation was weakened.Apoptosis assays demonstrated miR-29b promoted apoptosis; however,the difference was not statistically significant.The expression of miR-29b was negatively correlated with SPARC mRNA in gastric cancer cells (r=-0.97,P=0.03).Conclusions The low expression of miR-29b in high peritoneal metastatic gastric cancer cell inhibited the ability of invasion and proliferation.MiR-29b might be a new target of inhibiting peritoneal metastasis in gastric cancer.