Alternative mRNA splicing represents an effective mechanism of regulating gene function and is a key element to increase the coding capacity of the human genome. Today, an increasing number of reports illustrates that aberrant splicing events are common and functionally important for cancer development. However, more comprehensive analyses are warranted to get novel insights into the biology underlying malignancies like e.g. acute myeloid leukemia (AML). Here, we performed a genome-wide screening of splicing events in AML using an exon microarray platform. We analyzed complex karyotype and core binding factor (CBF) AML cases (n=64) in order to evaluate the ability to detect alternative splicing events distinguishing distinct leukemia subgroups. Testing different commercial and open source software tools to compare the respective AML subgroups, we could identify a large number of potentially alternatively spliced transcripts with a certain overlap of the different approaches. Selected candidates were further investigated by PCR and sequence analysis: out of 24 candidate genes studied, we could confirm alternative splice forms in 8 genes of potential pathogenic relevance, such as PRMT1 regulating transcription through histone methylation and participating in DNA damage response, and PTPN6, which encodes for a negative regulator of cell cycle control and apoptosis. In summary, this first large Exon microarray based study demonstrates that transcriptome splicing analysis in AML is feasible but challenging, in particular with regard to the currently available software solutions. Nevertheless, our results show that alternatively spliced candidate genes can be detected, and we provide a guide how to approach such analyses.
A robust estimation of exon expression to identify alternative spliced genes applied to human tissues and cancer samples.
Specimen part, Disease, Disease stage
View SamplesGene expression in NPM1 wildtype and mutated AML patients with high or low hsa_circ_0075001 expression
Circular RNAs of the nucleophosmin (NPM1) gene in acute myeloid leukemia.
Specimen part, Disease, Disease stage
View SamplesNeural cell adhesion molecule 1 (NCAM1; also known as CD56) is expressed in up to 20% of acute myeloid leukemia (AML) patients. Expression of NCAM1 is widely used as a marker of minimal residual disease; however, the biological function of this cell surface protein in AML remains elusive. In this study we investigated the impact of aberrant NCAM1 expression on leukemogenesis, drug resistance and its role as a biomarker to guide therapy.Gene expression profiling was performed with RNA-seq in three cell lines (SKM-1, NOMO-1, MOLM-14) after doxycycline-mediated induction of scrambled shRNA or shNCAM1 at timepoint 72 hours. Overall design: mRNA profiles of cell lines SKM-1, NOMO-1, MOLM-14 transfected either with scrambled shRNA or shRNA-NCAM1 were generated using TruSeq RNA Library Prep Kit v2 (Illumina) followed by sequencing with 100 bp paired-end reads on HiSeq 2000.
NCAM1 (CD56) promotes leukemogenesis and confers drug resistance in AML.
Cell line, Subject
View SamplesAcute myeloid leukemia (AML) is characterized by molecular heterogeneity. As commonly altered genomic regions point to candidate genes involved in leukemogenesis, we used microarray-based comparative genomic hybridization and single nucleotide polymorphism profiling data of 391 AML cases to further narrow down genomic regions of interest. Targeted-resequencing of 1000 genes located in the critical regions was performed in a representative cohort of 50 AML samples comprising all major cytogenetic subgroups. We identified 120 missense/nonsense mutations as well as 60 insertions/deletions affecting 73 different genes (~3.6 tumor-specific aberrations/AML). While most of the newly identified alterations were non-recurrent, we observed a number of mutations affecting genes involved in epigenetic regulation including known candidates like TET2, TET1, DNMT3A and DNMT1, as well as mutations in the histone methyltransferases NSD1, EZH2 and MLL3. Furthermore, we found mutations in the splicing factor SFPQ and in the non-classical regulators of mRNA-processing CTCF and RAD21. These splicing-related mutations affected 10% of AML patients in a mutually exclusive manner. In conclusion, we could identify a significant enrichment of alterations in genes involved in aberrant splicing and epigenetic regulation in genomic regions commonly altered in AML, highlighting their important role in the molecular pathogenesis of AML.
Commonly altered genomic regions in acute myeloid leukemia are enriched for somatic mutations involved in chromatin remodeling and splicing.
Specimen part, Disease
View SamplesPurpose: Mutations in several genetic loci lead to cardiac anomalies, with mutations in transcription factor NKX2-5 gene being one of the largest mutations known. Gestational hypoxia, such as seen in high-altitude pregnancy, has been known to affect cardiac development, and this paper aims to uncover information about the underlying mechanisms of this phenomena. Methods: Wild-type female mice were mated with Nkx2-5 mutant males, to produce offsprings. The pregnant females were then separated into two groups, one left in normal air and one breathing hypoxic, 14% oxygen, air from gestation day 10.5 to 12.5. Hearts were dissected from E12.5 embryos, subjected to RNA purification followed by RNA-seq. Wild-hypoxia and mutant-normoxia were compared to control wild-normoxia. Conclusions: The results of our study provide insights into a common molecular mechanism underlying non-genetic/epigenetic and genetic cardiac anomalies. Overall design: Embryonic mice were produced with either wild-type or mutant genomes, and some from each group were exposed to hypoxia during gestation, then physical analysis and RNA sequencing was done on the embryos.
Mechanism Sharing Between Genetic and Gestational Hypoxia-Induced Cardiac Anomalies.
Specimen part, Treatment, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
LEADeR role of miR-205 host gene as long noncoding RNA in prostate basal cell differentiation.
Cell line
View SamplesWe aimed at analyzing the transcriptome changes associated with the deletion of a portion of the Alu element from MIR205HG transcript
LEADeR role of miR-205 host gene as long noncoding RNA in prostate basal cell differentiation.
Cell line
View SamplesWe aimed at analyzing the transcriptome changes associated with MIR205HG knock-down in RWPE-1 cells
LEADeR role of miR-205 host gene as long noncoding RNA in prostate basal cell differentiation.
No sample metadata fields
View SamplesNeurotrophins are growth factors that are known to have a role in promoting cell survival and differentiation. The focus of the current study is to examine the role of neurotrophins in regulating ovarian primordial follicle development. Ovaries from 4-day old rats were placed into organ culture and cultured for 10 days in the absence or presence of neurotrophin-3 (NT3), brain-derived neurotrophic factor (BDNF), or nerve growth factor (NGF). Treatment of ovaries with NT3 resulted in a significant (P<0.01) increase in primordial follicle development (i.e. primordial to primary follicle transition). Treatment with BDNF at high doses of 100250 ng/ml also significantly (P<0.01) increased primordial follicle development, but NGF had no effect. Immunohistochemical studies determined that NT3 was present in granulosa cells, interstitial tissue, and in the oocytes of primordial and primary follicles. The NT3 receptor NTRK3 was present in oocytes at all stages of development. Analysis of ovaries that contain predominantly primordial follicles demonstrated the transcripts for NT3, NTRK3, NGF, and the BDNF/neurotrophin-4 (NT4) receptor NTRK2 are expressed, while BDNF, NT4, and the NGF receptor NTRK1 are not detectable. Inhibition of the NTRK3 receptor with the tyrophostin AG 879 resulted in oocyte death and a significant (P<0.01) reduction in follicle pool size. Inhibition of the NTRK receptors with K252a slowed primordial to primary follicle transition. A microarray analysis demonstrated that a small number of genes were differentially expressed after NT3 treatment. Observations indicate that the neurotrophin NT3, acting through the NTRK3 receptor in oocytes, promotes the primordial to primary follicle transition. Reproduction (2009) 138, pp. 697-707
Neurotrophin NT3 promotes ovarian primordial to primary follicle transition.
Sex, Specimen part
View SamplesAims to look at the targets of the bHLH transcription factor in Arabidopsis roots.
A basic helix-loop-helix transcription factor controls cell growth and size in root hairs.
Specimen part
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