CircRNAs –Potential Diagnostic Biomarkers and Therapeutic Targets for Receptive and Cancerous Endometrium

Circular RNAs (circRNAs) are small, non-coding RNAs in which the 5’ and 3’ ends are linked covalently by back-splicing of exons from a single pre-mRNA. More and more scientific evidence is gathered for their wide distribution in the animal world, playing the role of regulators for biological processes, being cell and tissue-specific. They can influence cellular physiology by various molecular mechanisms, finally modulating gene expression. CircRNAs are believed nowadays to be expressed in both receptive and cancerous endometrium. Due to their abundant expression in the endometrial tissue and their small size and stability, they have been considered potential diagnostic markers and treatment targets for endometrial-related diseases. The regulation of proliferation and differentiation is important for the formation of receptive endometrium and for endometrial cancer emergence and progression. It may be worth investigating whether there are universal circRNAs-miRNAs-mRNAs regulatory networks that can promote or suppress the proliferation and differentiation of endometrial cells by activating specific signaling pathways in both receptive and cancerous endometrium.