title: MicroRNA-22 promotes cell survival upon UV radiation by repressing PTEN.
abstract: DNA damage response upon UV radiation involves a complex network of cellular events required for maintaining the homeostasis and restoring genomic stability of the cells. As a new class of players involved in DNA damage response, the regulation and function of microRNAs in response to UV remain poorly understood. Here we show that UV radiation induces a significant increase of miR-22 expression, which appears to be dependent on the activation of DNA damage responding kinase ATM (ataxia telangiectasia mutated). Increased miR-22 expression may result from enhanced miR-22 maturation in cells exposed to UV. We further found that tumor suppressor gene phosphatase and tensin homolog (PTEN) expression was inversely correlated with miR-22 induction and UV-induced PTEN repression was attenuated by overexpression of a miR-22 inhibitor. Moreover, increased miR-22 expression significantly inhibited the activation of caspase signaling cascade, leading to enhanced cell survival upon UV radiation. Collectively, these results indicate that miR-22 is an important player in the cellular stress response upon UV radiation, which may promote cell survival via the repression of PTEN expression.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
authors.forename: Guangyun
authors.initials: G
authors.lastname: Tan
authors.forename: Yuling
authors.initials: Y
authors.lastname: Shi
authors.forename: Zhao-Hui
authors.initials: ZH
authors.lastname: Wu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000528:radiation effects*; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000235:genetics; D002470:Cell Survival / Q000528:radiation effects; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000235:genetics; D015536:Down-Regulation; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D035683:MicroRNAs / Q000235:genetics / Q000502:physiology*; D051059:PTEN Phosphohydrolase / Q000096:biosynthesis* / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000235:genetics; D014466:Ultraviolet Rays; D015854:Up-Regulation
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C548375:MIRN22 microRNA, human; D035683:MicroRNAs; D025521:Tumor Suppressor Proteins; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C576325:Atm protein, mouse; D017346:Protein Serine-Threonine Kinases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human