Project description: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:In order to identify the targets of miR-193a-5p in osteosarcoma U2OS cell line, we used a lentivirus-mediated expression system to overexpressing miR-193a precusor, miR-193a-5p target sequence and non-target sequence, respectively, in osteosarcoma cell line U2OS. A tandem mass tag (TMT)-based quantitative proteomic strategy was employed to identify the global profile of miR-193a-5p-regulated proteins. order to identify the targets of miR-193a-5p, we used a lentivirus-mediated expression system to overexpressing miR-193a precusor, miR-193a-5p target sequence and non-target sequence, respectively, in osteosarcoma cell line U2OS. A tandem mass tag (TMT)-based quantitative proteomic strategy was employed to identify the global profile of miR-193a-5p-regulated proteins.
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: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:SPINK1 overexpression defines the second largest subtype of prostate cancer (PCa), however molecular mechanisms underlying its upregulation remains poorly understood. Here, we identified the role of miR-338-5p and miR-421 in post-transcriptional regulation of SPINK1. We established that miR-338-5p/miR-421 mediates several cellular responses against SPINK1-positive cancer by targeting oncogenic long non-coding RNA (lncRNA) MALAT1, inducing cell-cycle arrest, inhibiting epithelial-to-mesenchymal transition (EMT), cancer-stemness and drug resistance. Moreover, ectopic expression of miR-338-5p/miR-421 abrogates SPINK1-mediated oncogenesis, tumor growth and distant metastases in murine model. Importantly, RNA-sequencing expression analysis revealed an inverse correlation between miRNAs and SPINK1 or MALAT1 in PCa patients’ specimens. Further, we demonstrate Polycomb group protein EZH2-mediated epigenetic silencing of miR-338-5p/miR-421 in SPINK1-positive subtype. Thus, restoring miR-338-5p/miR-421 expression using epigenetic drugs or synthetic mimics could abrogate SPINK1-mediated oncogenesis by targeting multiple oncogenic pathways and eliciting anti-cancer pleiotropic effects. Taken together, the present study unravels the molecular mechanism underlying SPINK1 overexpression and suggests miR-338-5p and miR-421 replacement therapy for the treatment of SPINK1-positive malignancies.
Project description:Patients with advanced colorectal cancer (CRC) are commonly treated with systemic combination therapy but suffer eventually from drug resistance. MicroRNAs (miRNAs) are suggested to play a role in treatment resistance of CRC. We studied whether restoring downregulated miR-195-5p and 497-5p sensitize CRC cells to currently used chemotherapeutics 5-fluorouracil, oxaliplatin and irinotecan. Sensitivity to 5-FU, oxaliplatin and irinotecan before and after transfection with miR-195-5p and miR-497-5p mimics was analyzed in CRC cell lines HCT116, RKO, DLD-1 and SW480. Mass spectrometry based proteomic analysis of transfected and wild-type cells was used to identify targets involved in sensitivity to chemotherapy. Proteomic analysis revealed 181 proteins with significantly altered expression after transfection with miR-195-5p mimic in HCT116 and RKO, including 118 downregulated and 63 upregulated proteins. After transfection with miR-497-5p mimic, 130 proteins were significantly downregulated and 102 were upregulated in HCT116 and RKO (P<0.05 and FC<-3 or FC>3). CHUK and LUZP1 were coinciding downregulated proteins in sensitized CRC cells after transfection with either mimic. Resistance mechanisms of these two proteins may be related to nuclear factor kappa-B signaling and G1 cell cycle arrest, respectively. Restoring miR-195-5p and miR-497-5p expression enhanced sensitivity to chemotherapy, mainly oxaliplatin, in CRC cells and could be a promising treatment strategy for patients with mCRC. Proteomics revealed potential targets of these miRNAs involved in sensitivity to chemotherapy.
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:microRNA-7-5p (miR-7-5p) is an established tumor suppressor in multiple cancer types and inhibits growth and invasion by suppressing expression and activity of the epidermal growth factor receptor (EGFR) signaling pathway. While melanoma is not typically driven by EGFR signaling, expression of miR-7-5p is reduced in metastatic tumors compared to primary melanoma. Here, we investigated the biological and clinical significance of miR-7-5p in melanoma. Our results showed that augmenting miR-7-5p expression in vitro markedly reduced tumor cell viability, colony formation and induced cell cycle arrest. Furthermore, ectopic expression of miR-7-5p reduced migration and invasion of melanoma cells in vitro and reduced melanoma lung colonizationmetastasis in vivo. To investigate the mechanism underlying this effect, we used cDNA microarray analysis to identify a subset of putative miR-7-5p target genes associated with melanoma and metastasis. Of these, we confirmed nuclear factor kappa B (NF-κB) subunit RelA, as a novel direct target of miR-7-5p in melanoma cells, such that miR-7-5p suppresses NF-κB activity to decrease expression of canonical NF-κB target genes, including IL-1a, IL-6 and IL-8. Importantly, the effects of miR-7-5p on melanoma cell growth, cell cycle, migration and invasion were recapitulated by RelA knockdown. Finally, analysis of gene array datasets from multiple melanoma patient cohorts revealed an association between elevated RelA expression and poor survival, further emphasizing the clinical significance of RelA and its downstream signaling effectors.. Taken together, our data suggest that miR-7-5p replacement therapy might have clinical utility in melanoma to inhibit the metastatic process, in part through its inactivation of RelA/NF-kB signaling. Total RNA was extracted from WM266-4 cells transfected with miR-NC or miR-7-5p precursor molecules (30 nM) for 24 h, using Qiazol reagent (Qiagen).