Label-free proteomics uncovers SMC1A expression is Down-regulated in AUB-E.

BACKGROUND While heavy menstrual bleeding (HMB) is a prevalent symptom among women with abnormal uterine bleeding caused by endometrial disorder (AUB-E) seeking gynecologic care, the primary endometrial disorder remains poorly understood. METHODS Five human endometrial samples from women with AUB-E and the age-matched healthy women were selected, respectively. Proteins from the samples were analyzed by a linear ion trap (LTQ)-Orbitrap Elite mass spectrometer based label-free proteomic approach. The purpose protein was validated by western blot and immunohistochemistry staining. RESULTS A total of 2353 protein groups were quantified under highly stringent criteria with a false discovery rate of < 1% for protein groups, and 291 differentially expressed proteins were significantly changed between the two groups. The results showed that the down-regulation of structural maintenance of chromosomes protein 1A (SMC1A) in AUB-E patients. Next, this change in the glandular epithelial cells was validated by immunohistochemistry. CONCLUSION The results indicated a novel mechanism for the cause of AUB-E, as down-expression SMC1A potentially regulated the cell cycle progression in endometrial glandular epithelium further led to bleeding.