Synthetic circular miR-21 RNA decoys enhance tumor suppressor expression and impair tumor growth in mice (RNA-Seq)
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ABSTRACT: Natural and synthetic circular RNAs effectively impair miRNA function. MiR-21-5p is a potent oncomiR presenting ~33% of all miRNAs across cancers, ~41% in lung adenocarcinoma (LUAD), and ~68% in LUAD-derived cells. We validate and identify five main tumor suppressors targeted by miR-21-5p by deletion of the MIR21 locus in LUAD cells. Synthetic, liposome-delivered circular miR-21-5p decoys enhance expression of these tumor suppressors and severely impair tumor cell vitality at low doses. Decoy efficacy is not increased by bulging of miR-21-5p targeting sites, but associated with substantial cellular decoy stability, indicated by a half-life of ~20h. The intraperitoneal application of nanoparticle-delivered miR-21-5p decoys significantly impairs tumor growth in mouse LUAD tumor models. Decoys are well tolerated and were enriched in lung tissue. However, despite low decoy abundance, tumor suppressor expression was only increased in subcutaneous tumors. These findings suggest nanoparticle-delivered circular miRNA decoys as potent therapeutics in cancer treatment.
Project description:Natural and synthetic circular RNAs effectively impair miRNA function. MiR-21-5p is a potent oncomiR presenting ~33% of all miRNAs across cancers, ~41% in lung adenocarcinoma (LUAD), and ~68% in LUAD-derived cells. We validate and identify five main tumor suppressors targeted by miR-21-5p by deletion of the MIR21 locus in LUAD cells. Synthetic, liposome-delivered circular miR-21-5p decoys enhance expression of these tumor suppressors and severely impair tumor cell vitality at low doses. Decoy efficacy is not increased by bulging of miR-21-5p targeting sites, but associated with substantial cellular decoy stability, indicated by a half-life of ~20h. The intraperitoneal application of nanoparticle-delivered miR-21-5p decoys significantly impairs tumor growth in mouse LUAD tumor models. Decoys are well tolerated and were enriched in lung tissue. However, despite low decoy abundance, tumor suppressor expression was only increased in subcutaneous tumors. These findings suggest nanoparticle-delivered circular miRNA decoys as potent therapeutics in cancer treatment.
Project description:Natural and synthetic circular RNAs effectively impair miRNA function. MiR-21-5p is a potent oncomiR presenting ~33% of all miRNAs across cancers, ~41% in lung adenocarcinoma (LUAD), and ~68% in LUAD-derived cells. We validate and identify five main tumor suppressors targeted by miR-21-5p by deletion of the MIR21 locus in LUAD cells. Synthetic, liposome-delivered circular miR-21-5p decoys enhance expression of these tumor suppressors and severely impair tumor cell vitality at low doses. Decoy efficacy is not increased by bulging of miR-21-5p targeting sites, but associated with substantial cellular decoy stability, indicated by a half-life of ~20h. The intraperitoneal application of nanoparticle-delivered miR-21-5p decoys significantly impairs tumor growth in mouse LUAD tumor models. Decoys are well tolerated and were enriched in lung tissue. However, despite low decoy abundance, tumor suppressor expression was only increased in subcutaneous tumors. These findings suggest nanoparticle-delivered circular miRNA decoys as potent therapeutics in cancer treatment.
Project description:We aimed to characterize decoy to the RNA-binding protein CUG-RNA binding protein 1 (CUGBP1 mechanism in A549 lung cancer cells. We identified several new canonical targets of CUGBP1 but those were not regulated by miR-574-5p via the decoy mechanism. This can be explained by the localization of CUGBP1 and miR-574-5p in the nucleus, where CUGBP1 regulates alternative splicing. Next, we analyzed the 3’UTRs of potential targets and found that the decoy-dependent regulation of mPGES-1 splicing is unique. Therefore, we postulate that in A549 cells mPGES-1 is the only protein regulated by the decoy mechanism of CUGBP1 and miR-574-5p which suggests that the decoy mechanism allows the specific regulation of the expression of distinct targets.
Project description:Next Generation Sequencing technique was performed to compare the miRNA expression pattern of tumor brain tissue sample of 6 Glioblastoma patients, and 6 patients with brain metastases (BM) originated from lung adenocarcinoma (LUAD). In order to analyse the difference on miRNA expresion level between GBM and LUAD-BM cases, we applied cluster analysis on the NGS dataset of 6 samples for each of the two goups with iDEP 1.1 software. Log2FC values were calculated to determine the exact level of up- and downregulation in case of the deregulated miRNAs, using the iDEP 1.1 web tool applying the DESeq2 algorithm. Evaluate the results of analysis 99 known miRNAs were detected with altered expression using a threshold of false discovery rate (FDR) <0.05 and fold-change> 2. Among them, 62 miRNAs were upregulated (log2FC > 2) and 37 miRNAs were downregulated (log2FC < -2) with biological revelance in tissue LUAD-BM samples compared with the GBM samples. To validate our results obtained by NGS, four upregulated miRNAs: hsa-miR-200c-5p, hsa-miR-141-5p, hsa-miR-200a-5p, hsa-miR-375-3p and two downregulated miRNAs: hsa-miR-410-3p, hsa-miR-9-5p were chosen for RT-qPCR analysis. As the result of that hsa-miR-200c-5p, hsa-miR-141-5p, hsa-miR-200a-5p, hsa-miR-375-3p was significantly upregulated, while hsa-miR-410-3p, hsa-miR-9-5p was significantly downregulated in LUAD-BM - GBM comparison.
Project description:Natural circular RNAs have been found to sequester microRNAs and suppress their function. We have used this principle as a molecular tool, and produced artificial circular RNA sponges in a cell-free system by in vitro transcription and ligation. Formerly, we were able to inhibit hepatitis C virus propagation by applying a circular RNA decoy strategy against microRNA-122, which is essential for the viral life cycle. In another proof-of-principle study, we used circular RNAs to sequester microRNA-21, an oncogenic and pro-proliferative microRNA. This strategy slowed tumor growth in a 3D cell culture model system, as well as in xenograft mice upon systemic delivery. In the wake of the global use of an in vitro transcribed RNA in Covid-19 vaccines, the question arose if therapeutic circular RNAs trigger cellular antiviral defense mechanisms when delivered systemically. In this study, we present data on the cellular innate immune response as a consequence of liposome-based transfection of the circular RNA sponges we previously used to inhibit microRNA function. We find that circular RNAs produced by the presented methodology do not trigger the antiviral response and do not activate innate immune signaling pathways.
Project description:Transcriptional profiling of MDA-MB-231 comparing the regulatory consequences of transfecting synthetic decoys carring sRSM1 motifs versus synthetic scrambled oligos Two decoy/scrambled sets, each with two biological replicates