MicroRNA Expression Profiling And Target Genes Study In Congenital Microtia

BackgroundMicrotia is a complicated congenital anomaly with a genetic and environmental predisposition, and the molecular events underlying this disease are not fully understood. MicroRNAs (miRNAs) are a class of20-22nucleotide non-coding RNAs that function to control post-transcriptional gene expression. The aim of this study was to find alterations in miRNA expression levels between microtic cartilages and normal controls and investigate its functions in later studies.MethodsWe selected9microtia cartilages and3normal controls for GeneChip(?)miRNA2.0Arrays analysis.The altered miRNA were analyzed by poly (A) RT-PCR from58microtia samples and16normal controls. We predicted the target genes of miRNAs by miRGen databases and using RT-PCT analysis of target genes.ResultsUsing GeneChip(?)miRNA2.0Arrays, there are11miRNAs with significantly altered expression in the microtic group compared to the normal controls, which included6up-regulated miRNAs and5down-regulated miRNAs. These miRNAs were further examined using poly (A) RT-PCR analysis, hsa-miR-451and hsa-miR-486-5p were significantly up-regulated and hsa-miR-200c was significantly down-regulated in the microtic group compared to the normal controls (p<0.05). Several complementary target messenger RNAs (mRNAs) had been predicted. OSR1, the target gene of miR-451and miR-200c, was up-regulated (p<0.01) and TRPS1, the target gene of miR-200c, was significantly down-regulated in the microtic group compared to the normal controls (p<0.0001).ConclusionsThe reduction in hsa-miR-200c expression and the accretion of hsa-miR-451and hsa-miR-486-5p expression in microtic samples may be the causes of the abnormal development of the external ear. OSR1and TRPS1, as the complementary target mRNAs, may play important roles during the development of the external ear.Further studies are still needed to identify the miRNA target genes and to determine their function in the pathogenesis of microtia.