MicroRNA signatures of iPSCs and endoderm-derived tissues
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ABSTRACT: MicroRNAs (miRNAs), small non-coding RNAs that fine-tune gene expression, play multiple roles in the cell, including cell fate specification. We have analyzed the differential expression of miRNAs during fibroblast reprogramming into induced pluripotent stem cells (iPSCs) and endoderm induction in iPSCs upon treatment with high concentrations of Activin-A in reduced serum. During reprogramming, adult mouse fibroblasts are converted into cells that resemble embryonic stem cells (ESCs) according to standard molecular and functional assays for pluripotency. The reprogrammed iPSCs assume an ESC-like miRNA signature, marked by the strong induction of pluripotency clusters miR-290-295 and miR-302/367 and conversely the downregulation of the let-7 family. On the other hand, endoderm induction in iPSCs results in the upregulation of 13 miRNAs. Given that the liver and the pancreas are common derivatives of the endoderm, the comparison of the expression levels of these 13 upregulated miRNAs with those in hepatocytes and pancreatic islets suggests a trend of miRNA upregulation in the endoderm tending towards an islet phenotype rather than that of a hepatocyte. These observations provide insights into how differentiation may be guided more efficiently towards the endoderm and further into the liver or pancreas. Moreover, we also report novel miRNAs enriched for each of the cell types analyzed. Stemloop RT-qPCR gene expression profiling. REPROGRAMMING: Differentially expressed miRNAs were determined between iPSCs (n=5 clones) and parent tail-tip fibroblasts (n=5) using mESCs R1 (n=3) and D3 (n=3). DIFFERENTIATION: Differentially expressed miRNAs were also analyzed in two iPSC clones upon treatment with Activin-A (n=2 each), and between primary mouse hepatocytes (n=3) and pancreatic islets (n=3).
Project description:Epithelial-mesenchymal transition (EMT) has recently been recognized as a key element of cell invasion, migration, metastasis, and drug resistance in several types of cancer, including non-small cell lung cancer (NSCLC). Our aim was to clarify microRNA (miRNA) -related mechanisms underlying EMT followed by acquired resistance to epidermal growth factor receptor tyrosine-kinase inhibitor (EGFR-TKI) in NSCLC. MiRNA expression profiles were examined before and after transforming growth factor-beta1 (TGF-M-NM-21) exposure in four human adenocarcinoma cell lines with or without EMT. Correlation between expressions of EMT-related miRNAs and resistance to EGFR-TKI gefitinib was evaluated. MiRNA array and quantitative RT-PCR revealed that TGF-M-NM-21 significantly induced overexpression of miR-134, miR-487b, and miR-655, which belong to the same cluster located on chromosome 14q32, in lung adenocarcinoma cells with EMT. MAGI2 (membrane-associated guanylate kinase, WW and PDZ domain-containing protein 2), a predicted target of these miRNAs and a scaffold protein required for PTEN (phosphatase and tensin homolog), was diminished in A549 cells with EMT after the TGF-M-NM-21 stimulation. Overexpression of miR-134 and miR-487b promoted the EMT phenomenon and affected the drug resistance to gefitinib, whereas knockdown of these miRNAs inhibited the EMT process and reversed TGF-M-NM-21-induced resistance to gefitinib. Our study demonstrated that the miR-134/487b/655 cluster contributed to the TGF-M-NM-21-induced EMT phenomenon and affected the resistance to gefitinib by directly targeting MAGI2, whose suppression subsequently caused loss of PTEN stability in lung cancer cells. The miR-134/miR-487b/miR-655 cluster may be new therapeutic targets in advanced lung adenocarcinoma patients, depending on the EMT phenomenon. miRNA expression profiles before and after TGF-M-NM-21 exposure were assessed in the four lung adenocarcinoma cell lines, A549, LC2/ad, PC3, and, PC9 by TaqMan miRNA arrays. Relative ratios of miRNAs in cells after TGF-M-NM-21 exposure were calculated when compared with the cells before TGF-M-NM-21 exposure.
Project description:miRNA expression profiling was performed on MM.1S MM cells cultured 8 hours in control media or 50nM RGB-286638, with or without BMSCs. The emerging role of miRNAs in the pathogenesis of multiple myeloma (MM) led us to hypothesize that the miRNA network might be among the inducible transcriptional alterations consequent to MM-bone marrow stromal cell (BMSC) interactions. Our data suggests that BMSC induced MM transcription led to aberrant miRNA expression. We therefore hypothesized that agents interfering with RNAPII transcription might inhibit aberrant miRNA expression in MM. To test this hypothesis we used RGB-286638, a novel protein kinase inhibitor, which works primarily via RNAPII inhibition followed by transcriptional arrest in MM cells. miRNA profiling of RGB-286638-exposed MM cells resulted in RNAPII arrest associated with reduced miRNA levels. RGB-286638 abrogated BMSCs-induced miRNAs, which correlated with growth arrest in MM cells. Analysis of RGB-286638-induced differentially-expressed miRNAs in MM cells, in the presence or absence of BMSCs, revealed RNAPII regulation of expression of BMSC-inducible miRNAs with established oncogenic functions in MM Our findings demonstrate the role of RNAPII in regulating miRNA network, suggesting a new rationale for using agents interfering with RNAPII transcription in the treatment of MM. TaqMan Low-Density Array (TLDA) using human miRNA version 2.0A and version 3.0B cards (Applied Biosystems) were applied to examine the global change of miRNA expression levels in MM.1S cells when co-cultured with BMSCs, with or without RGB-286638 treatment. A total of 756 mature miRNA updated in the Sanger miRBase v.15.0 were quantified according to the manufacturer's instructions as previously described. miRNAs with Ct values higher than 37 were excluded from the analysis. Normalization was carried out with the mean of RNU44 and RNU48. Relative quantification of miRNA expression was calculated with the 2M-bM-^HM-^RM-NM-^TM-NM-^TCt Ct method using the ddCt program (Shannon McCormack Advanced Molecular Diagnostics Laboratory Research Services). The data was presented as log10 of the relative quantity of each miRNA.
Project description:Global miRNA expression profiling of human malignancies is gaining popularity in both basic and clinically driven research. But to date, the majority of such analyses have used microarrays and quantitative real-time PCR. With the introduction of digital count technologies, such as next-generation sequencing (NGS) and the NanoString nCounter System, we have at our disposal, many more options. To make effective use of these different platforms, the strengths and pitfalls of several miRNA profiling technologies were assessed, including a microarray platform, NGS technologies and the NanoString nCounter System. These results were compared to gold-standard quantitative real-time PCR. Comparison of non-small cell lung cancer cell lines grown in vitro (n = 5) and in vivo (n = 5) as xenograft models.
Project description:Peripheral blood from 62 men with castration resistant prostate cancer was collected between 8/2006 and 6/2008. A panel of 168 inflammation-related and prostate cancer related genes was assessed with quantitative PCR to assess biomarkers predictive of survival. qPCR profiling of whole blood from patients with castration-resistant prostate cancer.
Project description:MicroRNAs (miRNAs) play a pivotal role in the regulation of hematopoiesis and development of leukemia. Great interest emerged in modulating miRNA expression for therapeutic purposes. In order to identify miRNAs, which specifically suppress leukemic growth of AML with t(8;21), inv(16) or MLL-rearrangement by inducing differentiation, we conducted a miRNA expression profiling in a cohort of 90 cytogenetically characterized, de novo pediatric AML cases. Four miRNAs, specifically downregulated in MLL-rearranged, t(8;21) or inv(16) AMLs, were characterized by their tumor suppressive properties in cell lines representing those respective cytogenetic groups. Among those, forced expression of miR-9 reduced leukemic growth and induced monocytic differentiation of t(8;21) AML cell lines in vitro and in vivo. The tumor suppressive functions of miR-9 were specifically restricted to AML cell lines and primary leukemic blasts with t(8;21). On the other hand, these functions were not evident in AML blasts from patients with MLL-rearrangements. We showed that miR-9 exerts its effects through the cooperation with let-7 to repress the oncogenic LIN28B/HMGA2 axis. Thus, miR-9 is a tumor suppressor-miR which acts in a stringent cell context-dependent manner. In order to identify miRNAs, which specifically suppress leukemic growth of AML with t(8;21) (n=21), inv(16) (n=17) or MLL-rearrangement (n=35) by inducing differentiation, we conducted a miRNA expression profiling in a cohort of 90 cytogenetically characterized, de novo pediatric AML cases, which also included 12 t(15;17) and 5 t(7;12) samples.
Project description:microRNA expression signatures can differentiate normal and breast cancer tissues and can define specific clinico-pathological phenotypes in breast tumors. In order to further evaluate the microRNA expression profile in breast cancer, we analyzed the expression of 667 microRNAs in 29 tumors and 21 adjacent normal tissues using TaqMan Low-density arrays. 130 miRNAs showed significant differential expression (adjusted P value=0.05, Fold Change=2) in breast tumors compared to the normal adjacent tissue. Importantly, the role of 43 of these microRNAs has not been previously reported in breast cancer, including several evolutionary conserved microRNA*, showing similar expression rates to that of their corresponding leading strand. The procedure begins with the retro-transcription of 70ng of total RNA with stem-loop primers to obtain a cDNA template. A pre-amplification step was included in order to increase the concentration of the original material and to detect microRNAs that are expressed at low levels. The pre-amplified product was loaded into the TaqManM-BM-. Low Density Arrays and amplification signal detection was carried out using the 7900 FAST real time thermal cycler (ABI). A total of 29 tumor and 21 normal samples (two pools: one containing five samples, other containing 12 samples, plus 4 independent normal samples) were analyzed. 23 tumors and the two normal pools were processed by triplicate, representing 82% of the total samples.
Project description:MicroRNA (miRNA) expression profiling identified miR-638 as one of the most significantly overexpressed miRNAs in metastatic lesions compared with primary melanomas. miR-638 enhanced the tumourigenic properties of melanoma cells in vitro and lung colonization in vivo. mRNA expression profiling of miR-638 and antagomir-transduced cells identified new candidate genes as miR-638 targets, the majority of which is involved in p53-mediated apoptosis regulation. miR-638 depletion stimulated expression of p53 and its downstream target genes and induced apoptosis and autophagy in melanoma cells. miR-638 promoter analysis revealed transcription factor associated protein 2-M-NM-1 (TFAP2A) as a direct negative regulator of miR-638. Further analyses provided strong evidence for a double negative regulatory feedback loop between miR-638 and TFAP2A. Taken together, miR-638 may support melanoma progression by suppressing p53-mediated apoptosis pathways and by targeting the transcriptional repressor TFAP2A. TaqManM-BM-. low-density arrays (TLDA; human microRNA Cards A v2.1 & B v2.0, Applied Biosystems, Darmstadt, Germany) were used for measuring the expression of 667 human miRNAs in primary melanomas (PM, n=8), lymph node metastases (LNM, n=9) or distant cutaneous metastases (DCM, n=10).
Project description:TaqMan low density array (TLDA) was carried out to screen of the profiles of circulating miRNAs in pooled plasma samples from healthy controls and pre-operative osteosarcoma patients. The expression changes of circulating miRNAs in osteosarcoma patients were identified. To select candidate plasma miRNAs for osteosarcoma detection and monitoring, we employed TLDA technique to screen expression levels of 739 miRNAs in pooled plasma samples from healthy controls and pre-operative osteosarcoma patients (each pooled from 10 individuals).
Project description:MicroRNAs (miRNAs), small non-coding RNAs that fine-tune gene expression, play multiple roles in the cell, including cell fate specification. We have analyzed the differential expression of miRNAs during fibroblast reprogramming into induced pluripotent stem cells (iPSCs) and endoderm induction in iPSCs upon treatment with high concentrations of Activin-A in reduced serum. During reprogramming, adult mouse fibroblasts are converted into cells that resemble embryonic stem cells (ESCs) according to standard molecular and functional assays for pluripotency. The reprogrammed iPSCs assume an ESC-like miRNA signature, marked by the strong induction of pluripotency clusters miR-290-295 and miR-302/367 and conversely the downregulation of the let-7 family. On the other hand, endoderm induction in iPSCs results in the upregulation of 13 miRNAs. Given that the liver and the pancreas are common derivatives of the endoderm, the comparison of the expression levels of these 13 upregulated miRNAs with those in hepatocytes and pancreatic islets suggests a trend of miRNA upregulation in the endoderm tending towards an islet phenotype rather than that of a hepatocyte. These observations provide insights into how differentiation may be guided more efficiently towards the endoderm and further into the liver or pancreas. Moreover, we also report novel miRNAs enriched for each of the cell types analyzed.
Project description:MicroRNAs (miRNAs) are important in the regulation of many biological processes including muscle development. However, little is known regarding miRNA regulation of muscle regeneration. In mature murine tibialis anterior muscle following injury, 298 miRNAs were significantly changed during the time course of muscle regeneration including 86 that were altered greater than 10-fold as compared to uninjured muscle. Temporal miRNA expression patterns were identified and included inflammation-related miRNAs (miR-223 and -147) that increased immediately after injury; this pattern contrasted to that of mature muscle-specific miRNAs (miR-1, -133a and -499) that were abruptly decreased following injury and then up-regulated in later regenerative events. Another cluster of miRNAs were transiently increased in the early days of muscle regeneration. This included miR-351, a miRNA that was also transiently expressed during myogenic progenitor cell (MPC) differentiation in vitro. Based on computational predictions, further studies demonstrated that E2f3 was a target of miR-351 in myoblasts. Moreover, knockdown of miR-351 expression inhibited MPC proliferation and promoted apoptosis during MPC differentiation, whereas miR-351 overexpression protected MPC from apoptosis during differentiation. Collectively, these observations suggest that miR-351 is involved in both the maintenance of MPC proliferation and the transition of MPC into differentiated myotubes. Thus, a novel, time-dependent sequence of molecular events during skeletal muscle regeneration has been identified, i.e., miR-351 inhibits E2f3 expression, a key regulator of cell cycle progression and proliferation, and promotes MPC proliferation and protects early differentiating MPC from apoptosis, important events in the hostile tissue environment after acute muscle injury. Skeletal muscles are damaged and repaired repeatedly throughout life. Muscle regeneration maintains locomotor function during aging and delays the appearance of clinical symptoms in neuromuscular diseases, such as Duchenne muscular dystrophy. The capacity for skeletal muscle growth and regeneration is conferred by satellite cells located between the basal lamina and the sarcolemma of mature myofibers. Upon injury, satellite cells reenter the cell cycle, proliferate, and then exit the cell cycle either to renew the quiescent satellite cell pool or to differentiate into mature myofibers. Despite recent advances, genes involved in these processes are still largely unknown. Understanding the molecular mechanisms that regulate satellite cell activities could promote development of novel countermeasures to enhance muscle regeneration that is compromised by diseases or aging. Using a muscle injury mouse model, we profiled miRNA expression during muscle regeneration.