Project description:The control of cell cycle progression mostly relays on the concerted activity of cyclins, CDKs and CDKs inhibitor. Recent data demonstrated that microRNAs, by regulating the expression of these proteins, contribute to the control of cell cycle progression. Here we provide evidences that the CDK inhibitor p27Kip1 directly regulates microRNAs stability thereby influencing cell cycle exit following contact inhibition. By the use of wild type and p27 knock-out cells we uncovered several microRNAs whose expression is linked to the cell cycle exit in a p27-dependent manner. By studying one of this microRNA, miR-223, we provide evidence that p27 is an RNA binding protein able to bind miR-223 to stabilize its expression. High miR-223 levels participate in the control of cell proliferation. Overall, we identify a previously completely unknown and conserved function of p27Kip1 that contributes to the proper regulation of cell cycle progression impinging on microRNA expression.
Project description:The control of cell cycle progression mostly relays on the concerted activity of cyclins, CDKs and CDKs inhibitor. Recent data demonstrated that microRNAs, by regulating the expression of these proteins, contribute to the control of cell cycle progression. Here we provide evidences that the CDK inhibitor p27Kip1 directly regulates microRNAs stability thereby influencing cell cycle exit following contact inhibition. By the use of wild type and p27 knock-out cells we uncovered several microRNAs whose expression is linked to the cell cycle exit in a p27-dependent manner. By studying one of this microRNA, miR-223, we provide evidence that p27 is an RNA binding protein able to bind miR-223 to stabilize its expression. High miR-223 levels participate in the control of cell proliferation.
Project description:We used a multi-omics approach combining transcriptomics, proteomics and metabolomics to study the impact of over-expression and inhibition of the microRNA miR-223, a pleiotropic regulator of metabolic-related disease, in the RAW monocyte-macrophage cell line. We analyzed the levels of proteins, mRNAs, and metabolites in order to identify genes involved in miR-223 regulation, to determine candidate disease biomarkers and potential therapeutic targets. We observed that both up- and down-regulation of miR-223 induced profound changes in the mRNA, protein and metabolite profiles in RAW cells. Microarray-based transcriptomics evidenced a change in 120 genes that were linked predominantly to histone acetylation, bone remodeling and RNA regulation. In addition, 30 out the 120 genes encoded long noncoding RNAs. The nanoLC-MS/MS revealed that 52 proteins were significantly altered when comparing scramble, pre- and anti-miR-223 treatments. Sixteen out of the mRNAs coding these proteins genes are predicted to have binding sites for miR-223. CARM-1, Ube2g2, Cactin and Ndufaf4 were confirmed to be miR-223 targets by western blotting. Analyses using Gene Ontology annotations evidenced association with cell death, splicing and stability of mRNAs, bone remodeling and cell metabolism. miR-223 alteration changed the expression of CARM-1, Ube2g2, Cactin and Ndufaf4 during osteoclastogenesis and macrophage, indicating that these genes are potential biomarkers of these processes. The most important discriminant metabolites found in the metabolomics study were found to be hydrophilic amino acids, carboxylic acids linked to metabolism and pyrimidine nucleotides, indicating that changes in miR-223 expression alter the metabolic profile of cells, and may affect their apoptotic and proliferative state.
