Identifying microRNA-mRNA regulatory networks in colorectal cancer by a combination of expression profile and bioinformatics analysis

A multi-step approach combining microarray profile and bioinformatics analysis was adopted to identify the CRC specific miRNA-mRNA regulatory network. First, differentially expressed miRNAs and mRNAs were found out in CRC samples compared with normal epithelial tissues by miRNA and mRNA microarray respectively. Secondly the target mRNAs of dysregualted miRNA were identified by a combination of Pearson correlation coefficient between the expression level of miRNAs and mRNAs and online miRNA target predicting databases. Thirdly, the biological pathways which the miRNA-mRNA pairs involved in were identified by DAVID. Finally, some of the dysregualted miRNAs and mRNAs were validated by qRT-PCR RNA isolated from 8 colorectal cancer tissues and their corresponding adjacent normal tissues were analyzed.