title: Reactivation of codogenic endogenous retroviral (ERV) envelope genes in human endometrial carcinoma and prestages: Emergence of new molecular targets.
abstract: Endometrial carcinoma (EnCa) is the most common invasive gynaecologic carcinoma. Over 85% of EnCa are classified as endometrioid, expressing steroid hormone receptors and mostly involving pathological prestages. Human endogenous retroviruses (ERV) are chromosomally integrated genes, account for about 8% of the human genome and are implicated in the etiology of carcinomas. The majority of ERV envelope (env) coding genes are either not present or not consistently represented between common gene expression microarrays. The aim of this study was to analyse the absolute gene expression of all known 21 ERV env genes including 19 codogenic and two env genes with premature stop codons in EnCa, endometrium as well as in hyperplasia and polyps. For EnCa seven env genes had high expression with >200 mol/ng cDNA (e.g. envH1-3, Syncytin-1, envT), two middle >50 mol/ng cDNA (envFc2, erv-3) and 12 low less than 50 mol/ng cDNA (e.g. Syncytin-2, envV2). Regarding tumor parameters, Syncytin-1 and Syncytin-2 were significantly over-expressed in advanced stage pT2 compared to pT1b. In less differentiated EnCa Syncytin-1, erv-3, envT and envFc2 were significantly over-expressed. Syncytin-1, Syncytin-2 and erv-3 were specific to glandular epithelial cells of polyps, hyperplasia and EnCa using immunohistochemistry. An analysis of 10 patient-matched EnCa with endometrium revealed that the ERV-W 5' long terminal repeat regulating Syncytin-1 was hypomethylated, including the ERE and CRE overlapping MeCP2 sites. Functional analyses showed that 10 env genes were regulated by methylation in EnCa using the RL95-2 cell line. In conclusion, over-expressed env genes could serve as indicators for pathological pre-stages and EnCa.
authors.affiliation: University-Clinic Erlangen, Department of Gynecology and Obstetrics, Laboratory for Molecular Medicine, Erlangen, Germany.
authors.forename: Pamela L
authors.initials: PL
authors.lastname: Strissel
authors.forename: Matthias
authors.initials: M
authors.lastname: Ruebner
authors.forename: Falk
authors.initials: F
authors.lastname: Thiel
authors.forename: David
authors.initials: D
authors.lastname: Wachter
authors.forename: Arif B
authors.initials: AB
authors.lastname: Ekici
authors.forename: Friedericke
authors.initials: F
authors.lastname: Wolf
authors.forename: Franziska
authors.initials: F
authors.lastname: Thieme
authors.forename: Klemens
authors.initials: K
authors.lastname: Ruprecht
authors.forename: Matthias W
authors.initials: MW
authors.lastname: Beckmann
authors.forename: Reiner
authors.initials: R
authors.lastname: Strick
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D002454:Cell Differentiation; D019175:DNA Methylation; D020077:Endogenous Retroviruses / Q000235:genetics*; D016889:Endometrial Neoplasms / Q000235:genetics* / Q000473:pathology; D004717:Endometrium / Q000378:metabolism* / Q000473:pathology; D005260:Female; D015686:Gene Products, env / Q000235:genetics; D006801:Humans; D007124:Immunoenzyme Techniques; D008156:Luciferases / Q000378:metabolism; D009367:Neoplasm Staging; D011230:Precancerous Conditions / Q000235:genetics* / Q000473:pathology; D011257:Pregnancy Proteins / Q000235:genetics; D011379:Prognosis; D011401:Promoter Regions, Genetic / Q000235:genetics; D014759:Viral Envelope Proteins / Q000235:genetics*
chemical_list: D015686:Gene Products, env; D011257:Pregnancy Proteins; D014759:Viral Envelope Proteins; C405335:syncytin; D008156:Luciferases