The Studies Of Celecoxib Affecting Its Expression Profiles Of MicroRNA Mechanisms On Human Colon Cancer Cell Line HT-29 In Vitro

Objective: To study the anti-tumor effects of celecoxib on colon cancer line HT-29 in vitro and its effect on the expression profiles of microRNAs(miRNAs).Methods: Human colon cancer cell line HT-29 was treated by celecoxib in various concentrations respectively alone.The inhibitory effect of cell growth was assayed by CCK-8 method, expression prifiles of miRNAs were detected by using microRNA microarray based on illumina microarray platform. Furthermore, some of the differentially expressed miRNAs were chosen to validate by the real-time RT-PCR. Using the bioinformatic techniques, target genes of deregulated miRNAs in colon cancer cells treated with celecoxib compared to solvent control cells were picked out .Then, target genes of these miRNAs were predicted by the following softwares miRNAs, RNAHybrid and Targetscan. Finally, the target genes of deregulation miRNAs were subjected to enrichment and pathway analysis.Results: The inhibitory effects of celecoxib on the proliferation of cell line HT-29 were found in a does-and-time dependent manner. The IC50 value was 237.73±1.65μmol/L. After 48h treated with celecoxib, 28 miRNAs, including statistically significant 20 up-regulated and 8 down-regulated miRNAs, were identified in colon cancer cells compared to solvent controls. Furthermore, 20 up-regulated miRNAs including HS₁88,HS₂03,HS₂2.1,HS₂43.1,HS₄3.1,hsa-let-7f-1*,hsa-let-7i* , hsa-miR-129-3p , hsa-miR-1303 , hsa-miR-141 , hsa-miR-142-5p , hsa-miR-301a ,hsa-miR-30c-1*,hsa-miR-33b,hsa-miR-570,hsa-miR-647,hsa-miR-886-3p,solexa-2526-361,solexa-499-2217,solexa-826-1288 and 8 down-regulated ones comprising of HS₅8,hsa-miR-1244,hsa-miR-1268,hsa-miR-26a-1*,hsa-miR-552,hsa-miR-622,solexa-3044-295,solexa-603-1846. Then the qutantitative RT-PCR analysis results showed that miR-142p was significantly upregulated and miR-26a-1* was downregulated compared with solvent controls, which in accordance to the microarray results. By bioinformatic prediction, several target genes were found specific to seperatly differentially expressed miRNAs. Then the target genes of deregulation miRNAs were subjected to high enrichment and GeneGo pathway analysis.We found WNT pathway is the most likely pathway which the target genes of mir-570 involved in, its target genes are the core of the molecular pathway.Conclusions: Our results indicated that celecoxib could inhibit the cell line HT-29 cell growth in vitro, partly attributting to its effect on the miRNAs expression. miRNAs might regulate post-transcriptly their target genes through certain pathways and then affect the HT-29 cell growth in vitro .