Successful immortalization of endometrial glandular cells with normal structural and functional characteristics.
The human endometrium is a dynamic tissue, the proliferative activity of which dramatically changes throughout the menstrual cycle, with exquisite regulation by sex-steroid hormones. Primary endometrial epithelial cells fall into senescence within 2 weeks when cultured on plastic dishes, and more complete understanding of endometrial biology has been delayed because of, in part, a lack of an in vitro culture model for endometrial epithelial cells. Our goal was to establish immortalized human endometrial glandular cells that retain the normal functions and characteristics of the primary cells. Because the Rb/p16 and p53 pathways are known to be critical elements of epithelial senescence in early passages, we used human papillomavirus E6/E7 to target these pathways. The combination of human papillomavirus-16 E6/E7 expression and telomerase activation by the introduction of human telomerase reverse transcriptase (hTERT) led to successful immortalization of the endometrial glandular cells. E6/E7 expression alone was sufficient to extend their life span more than 20 population doublings, but the telomerase activation was further required to enable the cells to pass through the subsequent replicative senescence at 40 population doublings. Isolated immortalized cells contained no chromosomal abnormalities or only nonclonal aberrations, retained responsiveness to sex-steroid hormones, exhibited glandular structure on three-dimensional culture, and lacked transformed phenotypes on soft agar or in nude mice. These findings support the notion that both Rb inactivation/p53 inactivation and telomerase activation are necessary to immortalize endometrial epithelial cells, but additional factors are required for endometrial carcinogenesis. Our established cell lines show great promise for investigation of hormone functions, endometrial biology, and endometrial carcinogenesis.
Kyo
Satoru
S
Department of Obstetrics and Gynecology, Kanazawa University, School of Medicine, Kanazawa, Japan.
Nakamura
Mitsuhiro
M
Kiyono
Tohru
T
Maida
Yoshiko
Y
Kanaya
Taro
T
Tanaka
Masaaki
M
Yatabe
Noriyuki
N
Inoue
Masaki
M
D000328:Adult; D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division / Q000502:physiology; D002461:Cell Line, Transformed; D002470:Cell Survival / Q000502:physiology; D004268:DNA-Binding Proteins; D004702:Endocrine Glands / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D004717:Endometrium / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology; D006801:Humans; D008875:Middle Aged; D009856:Oncogene Proteins, Viral / Q000378:metabolism / Q000502:physiology; D050725:Papillomavirus E7 Proteins; D010641:Phenotype; D012097:Repressor Proteins; D019098:Telomerase / Q000378:metabolism / Q000502:physiology; D013997:Time Factors
D004268:DNA-Binding Proteins; C068651:E6 protein, Human papillomavirus type 16; D012739:Gonadal Steroid Hormones; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012097:Repressor Proteins; C059731:oncogene protein E7, Human papillomavirus type 16; D019098:Telomerase