Synthetic lethality between Rb, p53 and miR-17~92 in retinal progenitors suppresses retinoblastoma formation
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Pieter mestdagh
PROVIDER: E-GEOD-39107 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Although Dicer1 functions as a haploinsufficient tumour suppressor its complete loss of function is selected against during tumourigenesis. Here we show that homozygous loss of Dicer1 prevents retinoblastoma formation in mice by synthetic lethality with combined inactivation of the p53 and Rb tumor suppressor pathways. We show that Dicer1 deficiency is tolerated in Rb-deficient retinal progenitor cells harbouring an intact p53 pathway, but not in absence of p53. The synthetic lethal interaction is mediated by the oncogenic miR-17∼92 cluster since its deletion phenocopies Dicer1 loss in this context. Accordingly, miR-17∼92- inactivation suppresses retinoblastoma formation in mice and co-silencing of miR17/20a and p53 cooperatively decrease the viability of pre-formed human retinoblastoma cells. These data provide important insights into what underlies selective pressure against loss of Dicer1 during tumorigenesis and indicate that targeting Dicer or miR-17-20a family members should be explored as a potential selective therapeutic approach for retinoblastoma prevention and/or treatment. 36 human samples
2012-07-05 | E-GEOD-39105 | biostudies-arrayexpress
Project description:Although Dicer1 functions as a haploinsufficient tumour suppressor its complete loss of function is selected against during tumourigenesis. Here we show that homozygous loss of Dicer1 prevents retinoblastoma formation in mice by synthetic lethality with combined inactivation of the p53 and Rb tumor suppressor pathways. We show that Dicer1 deficiency is tolerated in Rb-deficient retinal progenitor cells harbouring an intact p53 pathway, but not in absence of p53. The synthetic lethal interaction is mediated by the oncogenic miR-17?92 cluster since its deletion phenocopies Dicer1 loss in this context. Accordingly, miR-17?92- inactivation suppresses retinoblastoma formation in mice and co-silencing of miR17/20a and p53 cooperatively decrease the viability of pre-formed human retinoblastoma cells. These data provide important insights into what underlies selective pressure against loss of Dicer1 during tumorigenesis and indicate that targeting Dicer or miR-17-20a family members should be explored as a potential selective therapeutic approach for retinoblastoma prevention and/or treatment. 23 murine samples
2012-07-05 | E-GEOD-39106 | biostudies-arrayexpress
Project description:Bone marrow (BM) niches provide an optimal substrate for multiple myeloma (MM) cell lodgement and growth. Nevertheless, little is known about the putative mechanisms by which the BM microenvironment can lead to initiation or progression of oncogenesis in this disease. We have demonstrated that BM mesenchymal stromal cell-derived exosomes transfer their miRNA and protein content to clonal plasma cells, thus acting as synaptic vesicles responsible for molding the microenvironment surrounding multiple myeloma (MM) cells, leading to MM growth, dissemination and, therefore, disease progression. We used microarray to detail the changes in microRNA expression in MM-BM mesenchymal stromal cell (MSC)-derived exosomes, compared to normal- and monoclonal gammopathy of undetermined significance- BM-MSC-derived exosomes. Exosomes have been isolated from cell culture supernatant of BM-MSCs (MM=7; MGUS=2; Normal=4), and subsequently evaluated at ultrastructural level by using electron microscopy and immunogolf labeling. RNA was extracted; and miRNA profiling has been assessed by using TaqMan human miRNA profiling. Mean miRNA expression value has been used for miRNA RT-qPCR data normalization, as described (Mestdagh et al., 2009).
2013-07-24 | E-GEOD-39571 | biostudies-arrayexpress
Project description:We profile expression in serous epithelial ovarian carcinomas to assess the possibility of an miRNA signature associated with chemoresistance. Resistance to the available therapies is one of the main causes of low survival of patients with advanced epithelial ovarian cancer, thus representing an emergency in oncology. Here, we profiled miRNA expression in 86 naïve serous epithelial ovarian carcinomas (EOCs) to assess the possibility of miRNAs associated with chemoresistance. We identified 23 miRNAs associated with chemoresistance, of which three (miR-484, miR-642 and miR-217) were confirmed in the validation set (112 independent patients). The study of miR-484 role demonstrated that it regulated the chemoresistance of EOC cells acting not on cancer cells but on tumor vasculature. In particular, miR-484 is produced and secreted by chemosensitive EOC, therefore regulating the production of VEGFB by cancer cells and the expression of VEGFR2 in endothelial cells. Overall, we demonstrated that a three-miR signature can classify the response to chemotherapy and that chemoresistance in EOC relays, at least in part, on the control of tumor angiogenesis, indicating new options in the treatment of these patients. We analyzed tumor samples (<5% of normal tissue) from FFPE blocks of 86 patients with serous ovarian carcinomas.
2013-05-17 | E-GEOD-43867 | biostudies-arrayexpress
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.
2012-05-31 | E-GEOD-38364 | biostudies-arrayexpress
Project description:Purpose: To identify tissue microRNAs predictive of sunitinib activity in patients with metastatic renal-cell carcinoma (MRCC) and to validate them in a cellular model. Selected microRNAs were studied in serum from MRCC patients and healthy individuals. Methods: We screened 673 microRNAs using TaqMan Low-density Arrays (TLDAs) in tumors from MRCC patients with extreme phenotypes of marked efficacy and resistance to sunitinib, selected from an identification cohort (n=41). Differentially expressed microRNAs were selected using bioinformatics-based target prediction analysis and quantified by qRT-PCR in tumors from patients presenting similar phenoytpes selected from an independent cohort (n=117). Results were validated in a cellular model of sunitinib resistance and studied in serum from healthy individuals and MRCC patients. Results: TLDAs identified 64 microRNAs differentially expressed in the identification cohort. Seven candidates were quantified by qRT-PCR in the independent series. MiR-942 was the most accurate predictor of sunitinib efficacy (p=0.0074). High expression of miR-942, miR-133a, miR484, and miR-628-5p was significantly associated with decreased time-to-progression and overall survival. These microRNAs were overexpressed in the sunitinib resistant cell line Caki-2 in comparison with the sensitive parental cell line. Serum levels of miR-942, miR-133a, miR-484, miR-146a-5p, miR-374a and miR-486-5p were significantly reduced in MRCC patients compared to healthy controls. Conclusions: Our strategy identified differentially expressed microRNAs in MRCC patients presenting marked sensitivity and resistance to sunitinib. Mir-942 was the best predictor of efficacy. Results were confirmed in a cellular model of sunitinib resistance. We also identified exosome derived serum microRNAs differentially expressed in MRCC patients and healthy individuals. Taqman Low Density Array for 6 FFPE tissues obtained from extreme phenotype MRCC patients, (n=3 marked resistance to sunitinib treatment patients and n=3 marked sensitivity to sunitinib treatment patients), was performanced to screen 667 microRNAs.
2014-09-30 | E-GEOD-37766 | biostudies-arrayexpress
Project description:Chronic kidney disease is associated with progressive renal fibrosis, where perivascular cells give rise to the majority of α-SMA positive myofibroblasts. We sought to identify pericytic miRNAs that could serve as a target to decrease myofibroblast formation. We induced kidney fibrosis in FoxD1-GC;Z/Red-mice by unilateral ureteral obstruction (UUO) followed by FACS sorting of dsRed-positive FoxD1-derivative cells and miRNA profiling. MiR-132 selectively increased 21-fold during pericyte-to-myofibroblast formation whereas miR-132 was only 2.5-fold up in total kidney lysates (both in UUO and ischemia-reperfusion injury). MiR-132 silencing in UUO decreased collagen deposition (35%) and tubular apoptosis. Immunohistochemistry, western blot and qRT-PCR confirmed a similar decrease in interstitial α-SMA+ cells. Pathway analysis identified a rate-limiting role for miR-132 in myofibroblast proliferation that was confirmed in vitro. Indeed, antagomir-132 treated mice displayed a reduction in the number of proliferating, ki67+ interstitial myofibroblasts. Interestingly, this was selective for the interstitial compartment and did not impair the reparative proliferation of tubular epithelial cells, as evidenced by an increase in ki67+ epithelial cells, as well as increased (p-)RB1, Cyclin-A and decreased RASA1, p21 levels in kidney lysates. Taken together, silencing miR-132 counteracts the progression of renal fibrosis by selectively decreasing myofibroblast proliferation and could potentially serve as a novel antifibrotic therapy. Total RNA obtained from FACS sorted mouse FoxD1-derivative interstitial cells from healthy or fibrotic kidneys
2016-02-16 | E-GEOD-76549 | biostudies-arrayexpress
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2014-10-01 | E-MTAB-2618 | biostudies-arrayexpress
Project description:miRNA expression profiles for round spermatids of wild type and GRTH knock-out mice were determined by Rodent TaqMan® Low Density miRNA Arrays A v2.0 (TLDA, Applied Biosystem). Purified round spermatids were prepared from the testis of wild type and GRTH null mice (C57BL/6 strain). Equal amount of total RNA from 20 mice (wild type or GRTH KO) was pooled prior to gene expression analysis.
2012-01-31 | E-GEOD-33969 | biostudies-arrayexpress