title: The role of syncytins in human reproduction and reproductive organ cancers.
abstract: Human life begins with sperm and oocyte fusion. After fertilization, various fusion events occur during human embryogenesis and morphogenesis. For example, the fusion of trophoblastic cells constitutes a key process for normal placental development. Fusion in the placenta is facilitated by syncytin 1 and syncytin 2. These syncytins arose from retroviral sequences that entered the primate genome 25 million and more than 40 million years ago respectively. About 8% of the human genome consists of similar human endogenous retroviral (HERVs) sequences. Many are inactive because of mutations or deletions. However, the role of the few that remain transcriptionally active has not been fully elucidated. Syncytin proteins maintain cell-cell fusogenic activity based on ENV: gene-mediated viral cell entry. In this review, we summarize how syncytins and their receptors are involved in fusion events during human reproduction. The significance of syncytins in tumorigenesis is also discussed.
authors.affiliation: Department of Histology and EmbryologyAkdeniz University School of Medicine, Antalya, Turkey.
authors.forename: Bikem
authors.initials: B
authors.lastname: Soygur
authors.affiliation: Department of Histology and EmbryologyAkdeniz University School of Medicine, Antalya, Turkey leylasati@yahoo.com.
authors.forename: Leyla
authors.initials: L
authors.lastname: Sati
mesh_terms: D000818:Animals; D005260:Female; D015686:Gene Products, env / Q000378:metabolism*; D006801:Humans; D009369:Neoplasms / Q000378:metabolism / Q000473:pathology*; D010929:Placentation; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000378:metabolism*; D012098:Reproduction / Q000502:physiology*; D012190:Retroviridae
chemical_list: D015686:Gene Products, env; D011257:Pregnancy Proteins; C405335:syncytin