Reduced levels of methyltransferase DNMT2 sensitize human fibroblasts to oxidative stress and DNA damage that is accompanied by changes in proliferation-related miRNA expression

• Published in: Redox biology 2018-04, Vol.14, p.20-34
• Main Authors: Lewinska, Anna, Adamczyk-Grochala, Jagoda, Kwasniewicz, Ewa, Deregowska, Anna, Semik, Ewelina, Zabek, Tomasz, Wnuk, Maciej
• Format: Article
• Language: English
• Subjects: Apoptosis - drug effects; Cell Cycle Checkpoints - drug effects; Cell Line, Tumor; Cell Proliferation - drug effects; Cellular Senescence - drug effects; DNA (Cytosine-5-)-Methyltransferases - antagonists & inhibitors; DNA (Cytosine-5-)-Methyltransferases - genetics; DNA (Cytosine-5-)-Methyltransferases - metabolism; DNA Damage - drug effects; DNA Methylation - drug effects; DNMT2; Fibroblasts; Fibroblasts - cytology; Fibroblasts - metabolism; Genotoxicity; Humans; Hydrogen Peroxide - toxicity; MicroRNAs - metabolism; miRNAs; Oxidative stress; Oxidative Stress - drug effects; Proliferation; Reactive Oxygen Species - metabolism; Research Paper; RNA Interference; RNA, Small Interfering - metabolism; Transcriptome - drug effects
• ISSN: 2213-2317; 2213-2317
• DOI: 10.1016/j.redox.2017.08.012

Methyltransferase DNMT2 is suggested to be involved in the regulation of numerous processes, however its biological significance and underlying molecular mechanisms remain elusive. In the present study, we have used WI-38 and BJ human fibroblasts as an in vitro model system to investigate the effects of siRNA-based DNMT2 silencing. DNMT2-depleted cells were found to be sensitive to oxidative stress conditions as judged by increased production of reactive oxygen species and susceptible to DNA damage that resulted in the inhibition of cell proliferation. DNMT2 silencing promoted upregulation of proliferation-related and tumor suppressor miRNAs, namely miR-28-3p, miR-34a-3p, miR-30b-5p, miR-29b-3p, miR-200c-3p, miR-28-5p, miR-379-5p, miR-382-5p, miR-194-5p, miR-193b-3p and miR-409-3p. Moreover, DNMT2 silencing induced cellular senescence and DNMT2 levels were elevated in replicatively senescent cells. Taken together, we found that DNMT2 may take part in the regulation of cell proliferation and longevity in human fibroblasts and speculate that the manipulation of DNMT2 levels that limits cell proliferation may be potentially useful anticancer strategy. •DNMT2 silencing promotes oxidative stress and DNA damage in human fibroblasts.•DNMT2 silencing results in upregulation of proliferation-related miRNAs.•DNMT2 silencing inhibits cell proliferation and induces cellular senescence.•DNMT2 levels are elevated during replicative senescence.•DNMT2 is a novel regulator of cell proliferation and longevity in human fibroblasts.