Ethnic-specific genetic susceptibility loci for endometriosis in Taiwanese-Han population: a genome-wide association study.

Endometriosis is a common gynecological disorder affecting around 10% of reproductive-age women. Although many hypotheses were proposed, genetic alteration has been considered as one of the key factors promoting pathogenesis. Due to racial/ethnic disparities in the process of hormone regulation and nutrition metabolism, a genome-wide association study (GWAS) with 2794 cases and 27,940 controls was conducted in a Taiwanese-Han population. Our study identified five significant susceptibility loci for endometriosis, and three of them, WNT4 (on the 1p36.12), RMND1 (6q25.1), and CCDC170 (6q25.1), have been previously associated with endometriosis across different populations, including European and Japanese descent cohorts. Other two including C5orf66/C5orf66-AS2 (5q31.1) and STN1 (10q24.33) are newly identified ones. Functional network analysis of potent risk genes revealed the involvement of cancer susceptibility and neurodevelopmental disorders in endometriosis development. In addition, long non-coding RNAs (lncRNAs) C5orf66 and C5orf66-AS2 can interact with many RNA-binding proteins (RBPs) which can influence RNA metabolic process, mRNA stabilization, and mRNA splicing, leading to dysregulation in tumor-promoting gene expression. Those findings support clinical observations of differences in the presentation of endometriosis in Taiwanese-Han population with higher risks of developing deeply infiltrating/invasive lesions and the associated malignancies.

Genetic variations in UCA1, a lncRNA functioning as a miRNA sponge, determine endometriosis development and the potential associated infertility via regulating lipogenesis.

Endometriosis is a hormone-associated disease which has been considered as the precursor for certain types of ovarian cancer. In recent years, emerging evidence demonstrated potent roles of lncRNA in regulating cancer development. Since endometriosis shares several features with cancer, we investigated the possible involvement of cancer-related lncRNAs in endometriosis, including UCA1, GAS5 and PTENP1. By using massARRAY system, we investigated certain genetic variations in cancer-related lncRNAs that can change the thermo-stability, leading to up-regulation or down-regulation of those lncRNAs. Our data indicated three risk genetic haplotypes in UCA1 which can stabilize the RNA structure and increase the susceptibility of endometriosis. Of note, such alterations were found to be associated with long-term pain and infertility in patients. It has been known that UCA1 can function as a ceRNA to sponge and inhibit miRNAs, resulting in loss-of-control on downstream target genes. Gene network analyses revealed fatty acid metabolism and mitochondria beta-oxidation as the major pathways associated with altered UCA1 expression in endometriosis patients. Our study thus provides evidence to highlight functional/epigenetic roles of UCA1 in endometriosis development via regulating fatty acid metabolism in women.

A More Diverse Cervical Microbiome Associates with Better Clinical Outcomes in Patients with Endometriosis: A Pilot Study.

Infection-induced chronic inflammation is common in patients with endometriosis. Although microbial communities in the reproductive tracts of patients have been reported, little was known about their dynamic profiles during disease progression and complication development. Microbial communities in cervical mucus were collected by cervical swabs from 10 healthy women and 23 patients, and analyzed by 16S rRNA amplicon sequencing. The abundance, ecological relationships and functional networks of microbiota were characterized according to their prevalence, clinical stages, and clinical features including deeply infiltrating endometriosis (DIE), CA125, pain score and infertility. Cervical microbiome can be altered during endometriosis development and progression with a tendency of increased Firmicutes and decreased Actinobacteria and Bacteroidetes. Distinct from vaginal microbiome, upregulation of Lactobacillus, in combination with increased Streptococcus and decreased Dialister, was frequently associated with advanced endometriosis stages, DIE, higher CA125 levels, severe pain, and infertility. Significantly, reduced richness and diversity of cervical microbiome were detected in patients with more severe clinical symptoms. Clinical treatments against infertility can partially reverse the ecological balance of microbes through remodeling nutrition metabolism and transport and cell-cell/cell-matrix interaction. This study provides a new understanding on endometriosis development and a more diverse cervical microbiome may be beneficial for patients to have better clinical outcomes.

Genetic impacts on thermostability of onco-lncRNA HOTAIR during the development and progression of endometriosis.

HOTAIR is a well-known long non-coding RNA (lncRNA) involved in various cellular signaling, whereas its functional impacts on endometriosis development are still largely unknown. To this end, six potential functional single nucleotide polymorphisms (SNPs) in HOTAIR, with minor allele frequencies more than 10% in Han population and altered net energy of RNA structures larger than 0.5 kcal/mol, were selected for genotyping study. The study included 207 endometriosis patients and 200 healthy women. Genetic substitutions at rs1838169 and rs17720428 were frequently found in endometriosis patients, and rs1838169 showed statistical significance (p = 0.0174). The G-G (rs1838169-rs17720428) haplotype showed the most significant association with endometriosis (p < 0.0001) with enhanced HOTAIR stability, and patients who harbor such haplotype tended to show higher CA125. Data mining further revealed higher mRNA HOTAIR levels in the endometria of patients with severe endometriosis which consistently showed reduced HOXD10 and HOXA5 levels. HOTAIR knockdown with specific shRNAs down-regulated cell proliferation and migration with the induction of HOXD10 and HOXA5 expression in human ovarian clear cancer cells. Our study therefore provided evidence to indicate a prominent role of HOTAIR in promoting endometriosis, which could be used as a potential target for clinical applications.