*Review* **The Role of Long Non-Coding RNAs in Endometriosis**

**Quanah J. Hudson † , Katharina Proestling † , Alexandra Perricos, Lorenz Kuessel , Heinrich Husslein , René Wenzl and Iveta Yotova \***

> Department of Obstetrics and Gynecology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria; quanah.hudson@univie.ac.at (Q.J.H.); katharina.proestling@meduniwien.ac.at (K.P.); alexandra.perricos@meduniwien.ac.at (A.P.); lorenz.kuessel@meduniwien.ac.at (L.K.); heinrich.husslein@meduniwien.ac.at (H.H.); rene.wenzl@meduniwien.ac.at (R.W.)

**\*** Correspondence: iveta.yotova@meduniwien.ac.at

† These authors contributed equally to this work.

**Abstract:** Endometriosis is a chronic gynecological disorder affecting the quality of life and fertility of many women around the world. Heterogeneous and non-specific symptoms may lead to a delay in diagnosis, with treatment options limited to surgery and hormonal therapy. Hence, there is a need to better understand the pathogenesis of the disease to improve diagnosis and treatment. Long non-coding RNAs (lncRNAs) have been increasingly shown to be involved in gene regulation but remain relatively under investigated in endometriosis. Mutational and transcriptomic studies have implicated lncRNAs in the pathogenesis of endometriosis. Single-nucleotide polymorphisms (SNPs) in lncRNAs or their regulatory regions have been associated with endometriosis. Genome-wide transcriptomic studies have identified lncRNAs that show deregulated expression in endometriosis, some of which have been subjected to further experiments, which support a role in endometriosis. Mechanistic studies indicate that lncRNAs may regulate genes involved in endometriosis by acting as a molecular sponge for miRNAs, by directly targeting regulatory elements via interactions with chromatin or transcription factors or by affecting signaling pathways. Future studies should concentrate on determining the role of uncharacterized lncRNAs revealed by endometriosis transcriptome studies and the relevance of lncRNAs implicated in the disease by in vitro and animal model studies.

**Keywords:** endometriosis; long non-coding RNAs; lncRNAs; sponging; ceRNA; chromatin; chronic pain
