MicroRNAs miRNAs , a class of small noncoding RNAs that regulate gene expression, have fundamental roles in biological processes, including cell differentiation and proliferation. These small molecules mainly direct either target messenger RNA mRNA degradation or translational repression, thereby functioning as gene silencers. Epithelial cells of the uterine lumen and glands undergo cyclic changes under the influence of the sex steroid hormones estradiol beta and progesterone.

Because the expression of miRNAs in human endometrium has been established, it is important to understand whether miRNAs have a physiological role in modulating the expression of hormonally induced genes.

Talbi S, Hamilton AE, Vo KC, Tulac S, Overgaard MT, Dosiou C, et al. Molecular phenotyping of human endometrium distinguishes menstrual cycle phases and underlying biological processes in normo-ovulatory women.

Hematoxylin end eosin-stained sections from paraffin-embedded blocks were classified as: The hormonal phases of all normal endometrium specimens were established according to the criteria of Noyes et al. The endometrial adenocarcinomas were graded according the World Health Organization grading system: The patients had not received any preoperative therapy. Immunohistochemistry was performed according to a standard streptavidin-biotin peroxidase complex method Zymed, S.

Endogenous peroxidases were quenched by incubation in 0. The secondary biotinylated antibody was incubated as previously described The reaction was revealed by adding diaminobenzidine-tetrahydrochloride DAB chromogen mixture Zymed. After hematoxylin counterstaining, slides were permanently mounted and analyzed for the presence and distribution of the immunostaining. Staining was scored based on semiquantitative assessment of the distribution pattern of staining plasma membrane and cytoplasm and number of immunoreactive epithelial cells.

Samples were considered negative when they showed no immunoreactivity.