title: Evidence of the monoclonal composition of human endometrial epithelial glands and mosaic pattern of clonal distribution in luminal epithelium.
abstract: The endometrium is a highly regenerative tissue that plays a crucial role in implantation. We examined the clonal constitution of glandular cells as well as the luminal epithelium of this unique tissue. Using collagenase-based digestion techniques with microscopic manipulation, we isolated individual human endometrial glands and examined their clonality using a polymerase chain reaction-based assay for nonrandom X chromosome inactivation with an X-linked androgen receptor gene. Most of the glands analyzed were composed of monoclonal populations of epithelial cells and one of the glands exhibited a loss of heterogeneity in the androgen receptor gene. In addition, adjacent glands within a 1-mm(2) area shared clonality, suggesting that clonality of the luminal epithelium is regionally defined. The clonality of endometrium was further confirmed in a study of female mice that harbor the green fluorescent protein gene on either the maternal or paternal X chromosome. Fluorescent microscopy of uterine sections revealed that individual endometrial glands consisted completely of either fluorescent or nonfluorescent cells and that the surface epithelium exhibited a clear boundary between these cell types. These findings suggest that single or multiple stem cells with uniform clonality exist on the bottom of each endometrial gland and genetic alterations occurring in such cells may play a critical role in endometrial carcinogenesis. The possible association between area-specific X inactivation of the endometrial surface and the endometrial receptivity of embryo implantation remains to be clarified.
authors.affiliation: Department of Obstetrics and Gynecology, Kanazawa University, School of Medicine, Ishikawa, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Tanaka
authors.forename: Satoru
authors.initials: S
authors.lastname: Kyo
authors.forename: Taro
authors.initials: T
authors.lastname: Kanaya
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Yatabe
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Nakamura
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Maida
authors.forename: Masaru
authors.initials: M
authors.lastname: Okabe
authors.forename: Masaki
authors.initials: M
authors.lastname: Inoue
mesh_terms: D000818:Animals; D004303:Dosage Compensation, Genetic; D004717:Endometrium / Q000166:cytology*; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005088:Exocrine Glands / Q000166:cytology* / Q000378:metabolism; D005260:Female; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D009030:Mosaicism; D011944:Receptors, Androgen / Q000235:genetics; D013234:Stem Cells / Q000502:physiology
chemical_list: D008164:Luminescent Proteins; D011944:Receptors, Androgen; D049452:Green Fluorescent Proteins