Molecular Analysis Of Clonality In Endometriosis Lesions

BACKGROUND:Endometriosis is a common gynecological disorder. It is defined by the presence of endometrial tissue outside the uterine cavity. The pathogenesis of endometriosis remains unclear. The current etiological theories can not folly explain clinical varieties of endometriosis. It is important to explore the pathogenesis of endometriosis and look for new methods of treatment. A series of recent research have suggested that dislocation of basal endometrial stem cell might result in endometriosis and it might be a stem cell related disorder.OBJECTIVE:The proliferation clonality of endometriosis lesions is detected with a method of molecular analysis. The stem cell hypothesis of EM will be tested.METHODS:The heterozygosity of HumAR gene of obtained endometriosis lesions were identified by a polymerase chain reaction (PCR) assay and STR analysis. The clonality of EM gland and stromal were detected after microdissection.RESULTS:55.1%of EM lesions were monoclonal. The monoclonal proportions of different EM lesions were different:OEM44.9%(31/69), PEM84.6%(11/13), DIE100%(6/6), Abdominal EM64.3%(10/14), Perineum EM40%(2/5). Compared with endometrial tissue and normal tissue, the monoclonal proportion was significantly increased in OEM/PEM/DIE/Abdominal EM (P<0.05), not significantly increased in Perineum EM (P<0.05). Polyclonal EM lesions were microdissected and every single gland was monoclonal, but different glands could be from different monoclonal origins.CONCLUSIONS:Most EM lesions are monoclonal. Certain types of EM (e.g.DIE) show the monoclonality significantly. Different EM lesions from the same patient can have different monoclonal origins. A single endometiosis gland is monoclonal. It revealed that endometiosis could derive from a single stem cell, but different glands/lesions could be from different stem cells. This research showed a certain relationship between endometriosis and stem cells. But more basic research and clinical evidence will be needed to support the stem cell hypothesis of EM.