MicroRNA-497 Inhibits The Expression Of Inflammation-Related Genes In Colon Cancer Cells

Objective:To analyse the gene expression profile of the colon cancer cells overexpressing mi R-497 and screen genes that were differentially expressed between the colon cancer cells overexpressing mi R-497 and the control group; explore the influence of mi R-497 overexpression on inflammation-related genes. Methods: 1. Establishment of colon cancer cell model of mi R-497 high expression miR-497 overexpression vector was constructed and used to package lentivirus. Colon cancer cells were transfected using the lentivirus of mi R-497. GFP positive cells were separated and purified after lentivirus transfection using flow cytometry(FCM).The growth inhibitive effect of mi R-497 on cell proliferation was evaluated by growth curves of the colon cancer cells overexpressing mi R-497 and the controls with cell counting method. 2. Identification of differential expression genes using gene expression microarray and RT-q PCR validationHuman(V2)Gene Expression Microarray was used to screen differential expression genes between the colon cancer cells overexpressing mi R-497 and the control group. The candidates were subjected to the GO and KEGG pathway enrichment analysis(Molecule Annotation System 3.0) and the target genes of mi R-497 were predicted by a bioinformatics website-Targetscan. The differential expression of representative genes relative to inflammation were confirmed by RT-q PCR. Results:1. Colon cancer cell model of mi R-497 high expression was established. GFP positive cells were more than 90 percent and the expression level of mi R-497 was 77 times higher than the control group(P-value < 0.05). Proliferation ability of the cells was markedly inhibited(P-value < 0.05) compared to the control groups.2. Of all the differential expression genes, 1053 genes had a 3-Fold Change including 471 up-regulated genes and 582 down-regulated genes. Most of the down-regulated genes were involved in the biological process such as transcriptional regulation, signal transduction and immune response. KEGG pathway analysis revealed that the down-regulated genes were mainly enriched in inflammation-related signaling pathways, such as the MAPK,cytokine receptor interactions and Jak-STAT pathways, in colon cancer cells overexpressing mi R-497. Among the down-regulated genes, 125 genes were predicted as the target genes of mi R-497. The decrease in 10 inflammation-related genes among the 15 representative genes was validated by RT-q PCR in the colon cancer cells overexpressing mi R-497 while the expression levels of IL29, TNFSF15, IL11, JAK3 and IL2Rβ were increased in the colon cancer tissues with a low expression of mi R-497. Conclusion:The colon cancer cell model of mi R-497 high expression was successfully established. mi R-497 inhibits the expression of inflammation-related genes in colon cancer cells.