title: The cell fate: senescence or quiescence.
abstract: Senescence and quiescence are frequently used as interchangeable terms in the literature unwittingly. Despite the fact that common molecules play role in decision of cell cycle arrest, senescent and quiescent cells have some distinctive phenotypes at both molecular and morphological levels. Thus, in this review we summarized the features of senescence and quiescence with respect to visual characteristics and prominent key molecules. A PubMed research was conducted for the key words; "senescence", "quiescence" and "cell cycle arrest". The results which are related to cell cycle control were selected. The selection criteria of the target articles used for this review included also key cell cycle molecules such as p53, pRB, p21, p16, mTOR, p27, etc. The results were not evaluated statistically. The mechanistic target of rapamycin (mTOR) has been claimed to be key molecule in switching on/off senescence/quiescence. Specifically, although maximal p53 activation blocks mTOR and causes quiescence, partial p53 activation sustains mTOR activity and causes senescence subsequently. In broader perspective, quiescence occurs due to lack of nutrition and growth factors whereas senescence takes place due to aging and serious DNA damages. Contrary to quiescence, senescence is a degenerative process ensuing a certain cell death. We highlighted several differences between senescence and quiescence and their key molecules in this review. Whereas quiescence (cell cycle arrest) is only one half of the senescence, the other half is growth stimulation which causes actual senescence phenotype.
authors: Department of Medical Biology, Faculty of Medicine, Mustafa Kemal University, Serinyol Campus, 31034, Antakya, Hatay, Turkey.
authors: Menderes Yusuf
authors: MY
authors: Terzi
authors: Department of Medical Biology, Faculty of Medicine, Mustafa Kemal University, Serinyol Campus, 31034, Antakya, Hatay, Turkey. muzeyyenizmirli@gmail.com.
authors: Muzeyyen
authors: M
authors: Izmirli
authors: Department of Medical Biology, Faculty of Medicine, Mustafa Kemal University, Serinyol Campus, 31034, Antakya, Hatay, Turkey.
authors: Bulent
authors: B
authors: Gogebakan
mesh_terms: D000818:Animals; D059447:Cell Cycle Checkpoints; D016922:Cellular Senescence; D005786:Gene Expression Regulation; D006801:Humans; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D016159:Tumor Suppressor Protein p53; D058570:TOR Serine-Threonine Kinases
keywords: Quiescence; Senescence; mTOR; p53