Identification of aberrantly expressed miRNAs in rectal cancer / 中南大学学报(医学版)

ABSTRACT

OBJECTIVE@#To identify aberrantly expressed miRNAs in rectal cancer.@*METHODS@#We used the miRCURY™ Array® LNA microRNA chip (v.14.0) to evaluate miRNA expression levels between rectal cancer tissues and adjacent non-tumor tissues; an average change more than 2-fold (and P value less than 0.05) was set as a cutoff level. All 6 paired rectal cancers were classified pathology stage C or D.@*RESULTS@#Eighty-eight miRNAs were up-regulated and 46 miRNAs have been reported in colorectal cancer; 40 miRNAs were down-regulated in rectal cancers and 15 miRNAs have been reported in colorectal cancer. To compare the relative miRNA expression levels as measured by RT-qPCR and chip analysis, we analyzed expression levels of these miRNAs in the cancer tissues. The results showed that miRNA expression (increased or decreased) in the paired benign and tumor tissue was consistent between the two methods in all cases. Expression levels of 6 up-regulated miRNAs (by chip analysis compared to RT-qPCR) varied in a range from -11.9% to 39.1% . Expression levels of 5 down-regulated miRNAs varied in a range from 1.4% to 29.4%. The Pearson correlation of relative miRNAs expression levels was analyzed by cDNA array versus RT-qPCR, and found to be 0.96 (P<0.01).@*CONCLUSION@#miRNA profile in rectal cancer showed unique characteristics, and identified a series of new, aberrantly expressed miRNAs.