ABSTRACT: MiR-1287-5p has inhibitory effects on breast cancer growth mediated by interaction with phosphoinositide 3-kinase CB (miR-1287-5p overexpression study)
Project description:Background: Non-coding RNAs and especially microRNAs have been discovered as master regulators of cancer initiation and progression. The aim of our study was to discover and characterize the function of yet uncharacterized microRNAs in human breast carcinogenesis. Methods: In an unbiased approach, we made use of a commonly used model system for breast cancer (BC) stem cells (“mammospheres”) to identify whole miRNome alterations with a special focus on previously uncharacterized miRNAs in BC. We further characterized the influence of microRNA-1287-5p, a yet uncharacterized microRNA in BC, in patient samples (n=1262) and on several hallmarks of cancer in vitro and in vivo with a special focus on triple negative BC. The molecular mode of action was further characterized using whole transcriptome analysis, in silico prediction tools, miRNA-interaction luciferase assays and pheno-copy assays. Results: We identified miR-1287-5p among many others as differentially expressed in mammospheres. Clinical validation indicated that miR-1287-5p is significantly downregulated in human BC and associated with poor prognosis. This clinical finding can be explained by miR-1287-5p mediated growth inhibitory effects, G1 cell cycle arrest, decreased anchorage-independent growth and tumor growth in vivo. Finally, we identified PIK3CB as a direct molecular interactor of miR-1287-5p and a pheno-copy factor for miR-1287-5p. Finally, targeting PI3K-signaling pathway with chemical inhibitors together with miR-1287-5p mimics increased the pharmacological growth inhibitory potential. Conclusion: In conclusion, our data identified for the first time an involvement of miR-1287-5p in human BC and suggest a potential for therapeutic interventions in hardly to treat triple negative BC.
Project description:Background: Non-coding RNAs and especially microRNAs have been discovered as master regulators of cancer initiation and progression. The aim of our study was to discover and characterize the function of yet uncharacterized microRNAs in human breast carcinogenesis. Methods: In an unbiased approach, we made use of a commonly used model system for breast cancer (BC) stem cells (“mammospheres”) to identify whole miRNome alterations with a special focus on previously uncharacterized miRNAs in BC. We further characterized the influence of microRNA-1287-5p, a yet uncharacterized microRNA in BC, in patient samples (n=1262) and on several hallmarks of cancer in vitro and in vivo with a special focus on triple negative BC. The molecular mode of action was further characterized using whole transcriptome analysis, in silico prediction tools, miRNA-interaction luciferase assays and pheno-copy assays. Results: We identified miR-1287-5p among many others as differentially expressed in mammospheres. Clinical validation indicated that miR-1287-5p is significantly downregulated in human BC and associated with poor prognosis. This clinical finding can be explained by miR-1287-5p mediated growth inhibitory effects, G1 cell cycle arrest, decreased anchorage-independent growth and tumor growth in vivo. Finally, we identified PIK3CB as a direct molecular interactor of miR-1287-5p and a pheno-copy factor for miR-1287-5p. Finally, targeting PI3K-signaling pathway with chemical inhibitors together with miR-1287-5p mimics increased the pharmacological growth inhibitory potential. Conclusion: In conclusion, our data identified for the first time an involvement of miR-1287-5p in human BC and suggest a potential for therapeutic interventions in hardly to treat triple negative BC.
Project description:MiRNAs have been shown to alter both protein expression and secretion in different cellular contexts. By combining in vitro, in vivo and in silico techniques, we demonstrated that overexpression of pre-miR-1307 reduced the ability of breast cancer cells to induce endothelial cell sprouting and angiogenesis. However, the molecular mechanism behind this and the effect of the individual mature miRNAs derived from pre-miR-1307 on protein secretion and is largely unknown. Here, we overexpressed miR-1307-3p|0, -3p|1 and 5p|0 in MDA-MB-231 breast cancer cells and assessed the impact of miRNA overexpression on protein secretion by Mass Spectrometry. Unsupervised hierarchical clustering revealed a distinct phenotype induced by overexpression of miR-1307-5p|0 compared to the controls and to the 5’isomiRs derived from the 3p-arm. Together, our results suggest different impacts of miR-1307-3p and miR-1307-5p on protein secretion which is in line with our in vitro observation that miR-1307-5p, but not the isomiRs derived from the 3p-arm reduce endothelial cell sprouting in vitro. Hence these data support the hypothesis that miR-1307-5p is at least partly responsible for impaired vasculature in tumors overexpressing pre-miR-1307.
Project description:Oxidative stress is an important environmental exposure associated with psychiatric disorders, but the underlying molecular mechanisms remain elusive. We recently observed enrichment of neurodevelopmental processes and diseases among a large number of differentially expressed genes during or after exposure to oxidative stress in an in vitro model of neuronal differentiation. To further explore the regulatory mechanisms that might account for a coordinated response to this exposure, we investigated changes in the expression of small non-coding miRNA in this system and estimated their interaction with differentially expressed mRNA. These molecules are thought to play a crucial role in brain development and its response to stress. Here we observed more than a hundred differentially expressed miRNAs, including 72 previously reported to be dysregulated in psychiatric disorders. The 7 most influential miRNAs associated with pre-treatment exposure were miR-138-5p, miR-96-5p, miR-34c-5p, miR-1287-5p, miR-497-5p, miR-195-5p, and miR-16-5p. These were sup-ported by at least 10 negatively correlated mRNA connections, and formed hubs in interaction network with 134 genes enriched with neurobiological function. Whereas in the co-treatment con-dition, miRNA-mRNA interaction pairs were enriched not only in neuronal processes, but also in cardiovascular and immunity-related disease ontologies. Interestingly, 12 differentially expressed miRNAs originated from the same genomic location, DLK1-DIO3, which encodes a schizophre-nia-associated miRNA signature. Collectively, these findings suggest that early exposure to oxida-tive stress, before and during prenatal neuronal differentiation, might increase the risk of mental illnesses in adulthood by disturbing the expression of miRNAs that regulate neurodevelopmental-ly significant genes and networks.
Project description:Stem cell therapy requires massive scale homogeneous stem cells under strictly qualification control. However, Prolonged ex vivo expansion impairs the biological functions and results in senescence of mesenchymal stem cells (MSCs). We investigated the function of CTDSPL in premature senescence process of MSCs and clarified that miR-18a-5p played a prominent role in preventing senescence of long-term cultured MSCs and promoting the self-renew ability of MSCs. Inhibition of miR-18a-5p promoted the expression of CTDSPL and induced premature senescence of MSCs. Continuous overexpression of miR-18a-5p improved self-renewal of MSCs by reduced ROS level, increased expression of Oct4 and Nanog, promoted growth rate and differentiation capability. We reported for the first time the dynamic interaction of miR-18a-5p and CTDSPL is crucial for stem cell senescence.
Project description:From a previous microarray study we developed a small chondrogenesis model. We performed qPCR and measured how knockdown of miR-199a-5p or miR-199b-5p could modulate chondrogenesis. Several experiments were used to determine the parameters of this model. We utilised parameter scan and manual sliding to refine the model. Within are two models - an initial model which only comprises of genes which we have data for, and an enhanced model which expands of the initial model to make more predictions - e.g. how miR-140-5p is indirectly regulated by miR-199a-5p and miR-199b-5p.
Project description:For deep understading of miR-1285-5p in breast cancer, we have employed whole genome microarray expression profilings as a discovery platform to identify target genes of miR-1285-5p. Using human breast cancer cell lines (MCF7, MDA-MB-231, HCC1937 and HCC1954), 31 down-down regulated genes were identified by overexpression of miR-1285-5p reagardless of tumor biology. Functional interaction of miR-1285-5p with two genes (TMEM194A and SLC30A9) from this gene sets was evaluated by r-rt-PCR, Western blot and luciferase transporter assay.
Project description:One of the cellular processes influenced by microRNAs is senescence, a state of indefinite growth arrest triggered by sublethal cell damage. Here, through bioinformatic analysis and experimental validation, we identified miR-340-5p as a novel miRNA that foments cellular senescence. miR340-5p was highly abundant in diverse senescence models, and miR-340-5p overexpression in proliferating cells rendered them senescent. Among the target mRNAs, miR-340-5p prominently reduced the levels of LBR mRNA, encoding Lamin B Receptor (LBR). Loss of LBR by ectopic overexpression of miR-340-5p derepressed heterochromatin in lamina-associated domains (LADs), promoting the expression of DNA repetitive elements characteristic of senescence. Importantly, overexpressing miR-340-5p enhanced cellular sensitivity to senolytic compounds, while antagonization of miR-340-5p reduced senescent-cell markers and engendered resistance to senolytic-induced cell death. We propose that miR-340-5p can be exploited for clearing senescent cells to restore tissue homeostasis and mitigate damage by senescent cells in aging human pathologies.