AUTHOR=Mert Ufuk , Özgür Emre , Tiryakioglu Duygu , Dalay Nejat , Gezer Ugur TITLE=Induction of p53-inducible microRNA miR-34 by gamma radiation and bleomycin are different JOURNAL=Frontiers in Genetics VOLUME=3 YEAR=2012 URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2012.00220 DOI=10.3389/fgene.2012.00220 ISSN=1664-8021 ABSTRACT=

microRNAs (miRNAs) are small molecules in their mature form and master regulators of gene expression. Recent work has shown that miRNAs are involved in the p53 network. Of the various miRNAs, miR-34 is regulated by the p53 protein. miR-34 can be induced by ionizing radiation (IR) in vitro and in vivo. However, there is no data in the literature for induction of miR-34 by a chemical agent inducing DNA damage. Here we studied the expression of miR-34 in HeLa and MCF-7 cells exposed to genotoxic stress-induced by bleomycin (BLM) or γ-radiation. We first analyzed p53 accumulation upon DNA damage induction. The basal level of p53 in MCF-7 cells was higher (approx. 6-fold) than in HeLa cells, and its accumulation was similar for both DNA-damaging agents in both cell lines. We have shown that miR-34 is significantly induced by γ-radiation in HeLa cells, but not in MCF-7 cells. BLM did not significantly affect miR-34 expression in both cell types. In conclusion, our findings reveal that miR-34 induction by genotoxic stress may be cell-type specific.