Research on the typical miRNA and target genes in squamous cell carcinoma and adenocarcinoma of esophagus cancer with DNA microarray.

To identify the typically expressed miRNAs in squamous cell carcinoma (SCC) and adenocarcinoma (ADC) of esophagus cancer and their target genes, and explore the related functions and pathways, providing potential biomarkers for esophageal carcinoma diagnosis and treatment. Gene expression profile GSE13937 was downloaded from Gene Expression Omnibus database which includes 152 samples, paired non-cancerous and cancerous, 44 SCC cases and 32 ADC cases; the differentially expressed miRNAs were identified with limma packages in R language after the data were normalized. Selected differentially expressed miRNAs were further analyzed using bioinformatics methods. Firstly, verified targets of miRNAs in two miRNA databases: miRecods and miRTarBase were integrated to select the targets genes of differentially expressed miRNAs. Next, String software was used to construct the target genes interaction network. Finally, function and pathway enrichment analysis of genes in the interaction network was carried out with Gestalt software. Up-regulated hsa-miR-21 and down-regulated hsa-miR-203 were identified by comparing normal and cancer tissue samples, and the targets genes regulated by these two miRNAs were most significantly related to cell cycle function and pathway, especially in the phase of G1/S. The two differentially expressed miRNA: hsa-miR-21 and hsa-miR-203 provide evidence for early diagnosis and treatment of esophageal carcinoma. The functions and pathways of target genes shows that deep understanding of cell cycle G1/S will help to illustrate the relationship between cell cycle regulation and pathogenesis of esophageal cancer.