Study Of LncRNA Expression Profiles And DNA Methylation Of HOXA9, HOXA10, HOXA11and HOXD10in Ovarian Endometriosis

Although the pathogenesis of endometriosis is still unclear, it is generally recognized that it is a multi-factorial disease, with genetic factors, epigenetic regulation in particular, playing an important part. For example, DNA methylation status changes are involved in the down-regulation of HOXA10and HOXA11in the eutopic endometrium, which take pivotal parts in the pathogenesis of endometriosis and related infertility. While HOXA9and HOXD10are found to have very similar expression pattern and functions, compared with HOXA10and HOXA11. And in our previous study, peripheral circulating microRNAs showed potential of acing as biomarkers of endometriosis.Long non-coding RNAs （lncRNAs）, as an important component of the transcriptome, have fundamental regulatory effects in human diseases, development and stem cells. In this study, by microarray technology, we explored the lncRNA expression in eutopic and ectopic endometrium from ovarian endometriosis and established an expression profile, on the basis of which, we predicted the functions of these lncRNAs. Besides, the methylation status of HOXA10, HOXA11, H0XA9and H0XD10was studied to explore whether aberrant mythelation may contribute to their dysregulation in ectpic endometrium.Part I:Genome-wide profiling of lncRNA expression in ectopic and eutopic endometrial tissues from ovarian endometriosis Objective:To compare the expression levels of lncRNAs in eutopc and ectopic endometrial tissues from ovarian endometriosis and establish their expression profiles.Method:Through high-throughput microarray gene chip technology, the expression level of lncRNAs and mRNAs was determined in the genome-wide range in4autologous-paired samples of ectopic and eutopic endometrial tissues from patients with ovarian endometriosis. Dysregulated mRNAs and lncRNAs were screened. And lncRNA exression profiles were established. Result:Compared to eutopic endometria, there are4,088mRNA and948lncRNA transcripts dysregulated in ovarian endometrial tissues. Conclusion:Compared to eutopic endometrial tissues, mRNAs and lncRNAs are systemically dysregulated in ovarian ectopic endometrial tissues. Part â…¡:Functional prediction and qRT-PCR validation of dysregulated lncRNAs discovered in Part â… Objectives:To explore the possible functions lncRNAs exert in endometriosis, as well as validate the results of Part â… .Methods:As a start, mRNAs that are co-expressed with dysregulated lncRNAs were found. Next, through bioinformatic analysis, on the basis of known mRNA functional annotations, possible functions of dysregulated lncRNAs were predicted. Then quantitative real-time polymerase chain reaction （qRT-PCR） was conducted in another21pairs of ectopic and eutopic endometrial tissues to validate the expression of10dysregulated lncRNAs found in part I. Result:The dysregulated lncRNAs were predicted to involve in many biological pathways, some of which are known important pathways in the pathogenesis of endometriosis. lncRNAs may regulate protein-coding genes through cis-and trans-regulatory mechanisms. By qRT-PCR validation, lncRNA FN0206, MGC24103, L0C375295, CHL1-AS2, XL0C₀12981, L0C375295and CHL1-AS2are found up-regulated;LIMS3-L0C440895, LOC389906, HOXA11-AS, KLKP1, L0C100505776and XL0C₀12981are found down-regulated. Conclusion:lncRNAs may involve in the pathogenesis of endometriosis through many biological pathways. The expression profiles of lncRNAs found in part I are reliable. Part â…¢:study of DNA methylation status of HOXA9、HOXA10、HOXA11and HOXD10in eutopic and ectopic endometrial tissues from ovarian endometriosisObjectives:To explore whether aberrant mythelation may contribute to the dysregulation of HOXA9, HOXA10, HOXA11and HOXD10in ectopic endometrium.Methods:Firstly,the expression of HOXA9, HOXA10, HOXA11and HOXD10mRNAs were determined by qRT-PCR in20pairs of samples. Next, the methylation status of their promoter regions were evaluated in another5pairs of samples by methylation mass-array technology.Results:The down-regulated expressions were validated by qRT-PCR for all the four HOX family genes. No significant methylation status changes were found among these genes, except for the hypomethylation of HOXA10in CpG island1.Conclusion:DNA methylation in the promoter region may not be the underlying reason for their down-regulation in ovarian endometriosis compared with eutopic endometrium.