A latent pro-survival function for the mir-290-295 cluster in mouse embryonic stem cells

• Published in: PLoS genetics Vol. 7; no. 5; p. e1002054
• Main Authors: Zheng, Grace X Y, Ravi, Arvind, Calabrese, J Mauro, Medeiros, Lea A, Kirak, Oktay, Dennis, Lucas M, Jaenisch, Rudolf, Burge, Christopher B, Sharp, Phillip A
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01-05-2011; Public Library of Science (PLoS)
• Subjects: Animals; Antibiotics, Antineoplastic - pharmacology; Apoptosis; Apoptosis - genetics; Apoptosis Regulatory Proteins - genetics; Apoptosis Regulatory Proteins - metabolism; Base Sequence; Biology; Cancer; Caspase 2 - genetics; Caspase 2 - metabolism; Cell Survival - drug effects; Cell Survival - genetics; Cell Survival - radiation effects; Cells, Cultured; Chemotherapy; Deoxyribonucleic acid; DNA; DNA damage; DNA Damage - drug effects; DNA Damage - radiation effects; DNA methylation; Doxorubicin - pharmacology; Embryonic stem cells; Embryonic Stem Cells - drug effects; Embryonic Stem Cells - metabolism; Embryonic Stem Cells - radiation effects; Experiments; Gamma Rays; Gene Deletion; Gene expression; Gene Expression Profiling; Gene Expression Regulation; Genetic aspects; Mice; Mice, Knockout; MicroRNA; MicroRNAs - genetics; MicroRNAs - metabolism; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Phase transitions; Physiological aspects; Proteins; Signal Transduction; Stem cells; United States
• ISSN: 1553-7404; 1553-7390; 1553-7404
• DOI: 10.1371/journal.pgen.1002054

MicroRNAs (miRNAs) post-transcriptionally regulate the expression of thousands of distinct mRNAs. While some regulatory interactions help to maintain basal cellular functions, others are likely relevant in more specific settings, such as response to stress. Here we describe such a role for the mir-290-295 cluster, the dominant miRNA cluster in mouse embryonic stem cells (mESCs). Examination of a target list generated from bioinformatic prediction, as well as expression data following miRNA loss, revealed strong enrichment for apoptotic regulators, two of which we validated directly: Caspase 2, the most highly conserved mammalian caspase, and Ei24, a p53 transcriptional target. Consistent with these predictions, mESCs lacking miRNAs were more likely to initiate apoptosis following genotoxic exposure to gamma irradiation or doxorubicin. Knockdown of either candidate partially rescued this pro-apoptotic phenotype, as did transfection of members of the mir-290-295 cluster. These findings were recapitulated in a specific mir-290-295 deletion line, confirming that they reflect miRNA functions at physiological levels. In contrast to the basal regulatory roles previously identified, the pro-survival phenotype shown here may be most relevant to stressful gestations, where pro-oxidant metabolic states induce DNA damage. Similarly, this cluster may mediate chemotherapeutic resistance in a neoplastic context, making it a useful clinical target.