Identification And Characterization Of Long Non-coding RNAs In Ovarian Endometriosis By High-throughput Sequencing

Endometriosis, a common gynecologic disorder, affects 10%-15% women of reproductive age. Although the exact etiology and pathogenesis of endometriosis remain unknown, it is believed to be influenced by multiple genetic factors. Endometriosis is usually classified as superficial or peritoneal, ovarian or deep infiltrative endometriosis according to the location of lesions, and ovarian endometriosis is one of the most common type. Desregulated long non-coding RNAs (lncRNAs) can lead to the occurrence of various diseases. However, information regarding the number, sequences,characteristics and potential functions of IncRNAs in endometriosis is so far limited.High-throughput sequencing is now widely used in identifying lncRNAs. To our knowledge, this is the first report of expression profile of lncRNAs in ectopic, eutopic and normal endometrium by high-throughput sequencing. This collection of lncRNAs may prove useful to explore the pathogenesis and development of ovarian endometriosis.PART1 Study of lncRNA expression profiles in ovarian endometriosisObjective: To identify the lncRNAs differentially expressed in ovarian endometriosis and their potential clinical value.Methods: We collected five normal endometria and eight paired ectopic and eutopic endometria from patients with ovarian endometriosis. LncRNAs were analyzed by high-throughput sequencing. Bioinformatics prediction was used to investigate the potential function of these differentially expressed lncRNAs.Results: A total of 683 known lncRNAs and 443 novel lncRNAs were differentially expressed between ectopic and eutopic endometrium. 5 known lncRNAs and 56 novel lncRNAs were differentially expressed between ectopic and normal endometrium. 603 known lncRNAs and 408 novel lncRNAs were differentially expressed between ectopic and normal endometrium. Bioinfornatic analysis suggested a series of cellular and biological abnormalities in endometriosis.Conclusions: This is the first report of expression profile of IncRNAs in ectopic, eutopic and normal endometrium by high-throughput sequencing. Abnormal IncRNAs expression may play an important role in ovarian endometriosis.PART2 Expression of IncRNA GAPLINC, CTD-2207P18.1 and RP11-1100L3.8 in ovarian endometriosisObjective: To identify the IncRNA GAPLINC, CTD-2207P18.1 and RP11-1100L3.8 differentially expressed in ovarian endometriosis and explore their possible biological roles.Methods: We collected five normal endometria and 20 paired ectopic and eutopic endometria from patients with ovarian endometriosis. The relative levels of IncRNA GAPLINC, CTD-2207P18.1 and RP11-1100L3.8 expressed were detected using quantitative real time PCR. The expression of each IncRNA was represented as fold change using 2-△△Ct methods. Comparison between groups was done with Student’s t test.Bioinformatics prediction was used to investigate the potential function of these aberrantly expressed IncRNAs.Results: LncRNA GAPLINC and CTD-2207P18.1 were up-regulated in ectopic endometrium compared with normal endometrium tissues. LncRNA RP11-1100L3.8 was up-regulated in eutopic endometrium compared with normal endometrium tissues. These desregulated IncRNAs were involved in a series of GO terms and KEGG pathways.Conclusions: The results anaylized by qRT-PCR were consistent with those by high-throughput sequencing. LncRNA GAPLINC. CTD-2207P18.1 and RP11-1100L3.8 were differently expressed in ectopic,eutopic and normal endometrium tissues, and they may participate in the pathogenesis and development of ovarian endometriosis.