Analysis Of The Different Long Non-coding RNA Expression Profiles Between Aldosterone-producing Adenoma And Normal Adrenal Tissue

BackgroundPrimary aldosteronism (PA) is the most common endocrine-related cause of hypertension. In the majority of cases, it is the result of an adrenal aldosterone producing adenoma (APA), which accounts for60percent of all the PA patients. However, the molecular mechanisms underlying aldosterone hypersecretion and nodulation of the adrenal cortex are still largely unknown. Long non-coding RNAs (lncRNAs) are defined as RNAs greater than200nucleotides in length, which can transcribe but do not encode for proteins. They have been recently identified as an important class of pervasive transcription products involved in a variety of biological functions and are aberrantly expressed in various diseases.ObjectiveThis study was aimed to compare the long non-coding RNA expression profiles between APA and normal adrenal tissue (NAT). Then, make preliminary bio informatics analysis of the differentially expressed long-non coding RNAs in order to lay a foundation for further research on their regulatory mechanism in APA.MethodTotal RNA was extracted from six APA and six normal adrenal tissues. RNAs were checked its quality and integrity. Then the RNA was reversed transcribed into double strand cDNA. After the cDNA was transcribed into biotinylated cRNA target, purified and fragmented it according to the manufacturer’s instructions. Utilize lncRNAs hybridization-based microarrays technology to determine the differential expression profiles between APA and NAT. Screen out the significantly differential expression lncRNAs after pretreatment and homogenization of raw data. Bioinformatic analysis of differentially expressed lncRNAs and genes (lncRNA classification and subgroup analysis, gene ontology and pathway analysis) was performed for further research. Then, randomly chose four differentially expressed lncRNA and confirmed the changes by real time-PCR on an expanded set of samples (APA, n=10; NA, n=9).ResultsThe number of lncRNAs that expressed at a certain level could be detected is16160. The lncRNA microarray reveals differentially expressed lncRNAs between APA and normal adrenal tissues. In the APA group,1181lncRNAs were up regulated and628were down regulated (fold change≥1.5, P<=0.05). The real-time PCR showed that the expression of two of the four lncRNAs was obviously different, while the expression differences of the other two were not significant.ConclusionsOur study is the first one to determine genome-wide lncRNAs expression patterns in APA by microarray. The results displayed that clusters of lncRNAs were aberrantly expressed in APA compared with normal adrenal samples. The result of real-time PCR showed that the differences of the lncRNAs detected by the array should be confirmed on an expanded set of clinical samples before further research. Our results suggest that further investigation of lncRNA expression in APA may further elucidate the molecular pathogenesis of this disorder.