Core transcriptional regulatory circuit controlled by the TAL1 complex in human T-cell acute lymphoblastic leukemia
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE29181 | GEO | 2012/08/16
SECONDARY ACCESSION(S): PRJNA139987
REPOSITORIES: GEO
Similar Datasets
Project description:The oncogenic transcription factor TAL1/SCL is aberrantly expressed in over 40% of cases of human T cell acute lymphoblastic leukemia (T-ALL), emphasizing its importance in the molecular pathogenesis of T-ALL. Here we identify the core transcriptional regulatory circuit controlled by TAL1 and its regulatory partners HEB, E2A, LMO1/2, GATA3, and RUNX1. We show that TAL1 forms a positive interconnected autoregulatory loop with GATA3 and RUNX1 and that the TAL1 complex directly activates the MYB oncogene, forming a positive feed-forward regulatory loop that reinforces and stabilizes the TAL1-regulated oncogenic program. One of the critical downstream targets in this circuitry is the TRIB2 gene, which is oppositely regulated by TAL1 and E2A/HEB and is essential for the survival of T-ALL cells.
| S-EPMC3422504 | biostudies-literature
Project description:This SuperSeries is composed of the following subset Series: GSE29179: Identification of differentially expressed genes upon shRNA knockdown of TAL1 and its regulatory partners in T-ALL cells (Jurkat) GSE29180: ChIP-Seq of TAL1 and its regulatory partners in T-ALL cells (Jurkat) GSE33850: Core transcriptional regulatory circuit controlled by the tal1 complex in human t-cell acute lymphoblastic leukemia (Subseries) Refer to individual Series
2012-08-16 | E-GEOD-29181 | biostudies-arrayexpress
Project description:The oncogenic transcription factor TAL1/SCL is aberrantly overexpressed in over 40% of cases of T-cell acute lymphoblastic leukemia (T-ALL), emphasizing the importance of the TAL1-regulated transcriptional program in the molecular pathogenesis of T-ALL. Here we identify the core transcriptional regulatory circuit controlled by TAL1 and its regulatory partners HEB, E2A, GATA3, ETS1 and RUNX1 in T-ALL cells. We find that TAL1 forms an interconnected auto-regulatory loop with its partners, which contributes to the sustained upregulation of its direct target genes. Importantly, we also find the MYB oncogenic transcription factor is directly activated by the TAL1 complex and positively regulates many of the same target genes, thus forming a feed-forward positive regulatory loop that further promotes the TAL1-regulated oncogenic program. Human T-ALL cells were cross-linked with formaldehyde for 20 min. DNA was enriched by chromatin immunoprecipitation (ChIP) and analyzed by Solexa sequencing. A sample of whole cell extract (WCE) was sequenced and used as the background to determine enrichment. ChIP was performed using an antibody against total TAL1 (Santa Cruz SC-12984), TCF12/HEB (Santa Cruz SC-357),TCF3/E2A (Santa Cruz SC-349X), LMO1 (Santa Cruz SC-10494), LMO2 (R&D Systems AF2726), GATA3 (Santa Cruz SC-22206) and RUNX1 (Santa Cruz SC-8563). This represents the ChIP-seq portion of this dataset. Human Jurkat cells were cross-linked with formaldehyde for 20 min. DNA was enriched by chromatin immunoprecipitation (ChIP) and analyzed by Solexa sequencing. A sample of whole cell extract (WCE) was sequenced and used as the background to determine enrichment. ChIP was performed using an antibody against total TAL1 (Santa Cruz SC-12984), TCF12/HEB (Santa Cruz SC-357),TCF3/E2A (Santa Cruz SC-349X), LMO1 (Santa Cruz SC-10494), GATA3 (Santa Cruz SC-22206) and RUNX1 (Santa Cruz SC-8563). This represents the ChIP-seq portion of this dataset.
2012-03-14 | E-GEOD-33850 | biostudies-arrayexpress
Project description:The oncogenic transcription factor TAL1/SCL is aberrantly overexpressed in over 40% of cases of T-cell acute lymphoblastic leukemia (T-ALL), emphasizing the importance of the TAL1-regulated transcriptional program in the molecular pathogenesis of T-ALL. Here we identify the core transcriptional regulatory circuit controlled by TAL1 and its regulatory partners HEB, E2A, GATA3, ETS1 and RUNX1 in T-ALL cells. We find that TAL1 forms an interconnected auto-regulatory loop with its partners, which contributes to the sustained upregulation of its direct target genes. Importantly, we also find the MYB oncogenic transcription factor is directly activated by the TAL1 complex and positively regulates many of the same target genes, thus forming a feed-forward positive regulatory loop that further promotes the TAL1-regulated oncogenic program.
2012-03-14 | GSE33850 | GEO
Project description:Aberrant expression of 1 or more transcription factor oncogenes is a critical component of the molecular pathogenesis of human T-cell acute lymphoblastic leukemia (T-ALL); however, oncogenic transcriptional programs downstream of T-ALL oncogenes are mostly unknown. TAL1/SCL is a basic helix-loop-helix (bHLH) transcription factor oncogene aberrantly expressed in 60% of human T-ALLs. We used chromatin immunoprecipitation (ChIP) on chip to identify 71 direct transcriptional targets of TAL1/SCL. Promoters occupied by TAL1 were also frequently bound by the class I bHLH proteins E2A and HEB, suggesting that TAL1/E2A as well as TAL1/HEB heterodimers play a role in transformation of T-cell precursors. Using RNA interference, we demonstrated that TAL1 is required for the maintenance of the leukemic phenotype in Jurkat cells and showed that TAL1 binding can be associated with either repression or activation of genes whose promoters occupied by TAL1, E2A, and HEB. In addition, oligonucleotide microarray analysis of RNA from 47 primary T-ALL samples showed specific expression signatures involving TAL1 targets in TAL1-expressing compared with -nonexpressing human T-ALLs. Our results indicate that TAL1 may act as a bifunctional transcriptional regulator (activator and repressor) at the top of a complex regulatory network that disrupts normal T-cell homeostasis and contributes to leukemogenesis.
| S-EPMC1895859 | biostudies-literature
Project description:TAL1/SCL is one of the most prevalent oncogenes in T-cell acute lymphoblastic leukemia (T-ALL). TAL1 and its regulatory partners (GATA3, RUNX1, and MYB) positively regulate each other and coordinately regulate the expression of their downstream target genes in T-ALL cells. However, long non-coding RNAs (lncRNAs) regulated by these factors are largely unknown. Here we established a bioinformatics pipeline and analyzed RNA-seq datasets with deep coverage to identify lncRNAs regulated by TAL1 in T-ALL cells. Our analysis predicted 57 putative lncRNAs that are activated by TAL1. Many of these transcripts were regulated by GATA3, RUNX1, and MYB in a coordinated manner. We identified two novel transcripts that were activated in multiple T-ALL cell samples but were downregulated in normal thymocytes. One transcript near the ARID5B gene locus was specifically expressed in TAL1-positive T-ALL cases. The other transcript located between the FAM49A and MYCN gene locus was also expressed in normal hematopoietic stem cells and T-cell progenitor cells. In addition, we identified a subset of lncRNAs that were negatively regulated by TAL1 and positively regulated by E-proteins in T-ALL cells. This included a known lncRNA (lnc-OAZ3-2:7) located near the RORC gene, which was expressed in normal thymocytes but repressed in TAL1-positive T-ALL cells.
| S-EPMC8197659 | biostudies-literature
Project description:The transcription factor TAL1 is a proto-oncogene whose aberrant expression in committed T-cell precursors is associated with the development of T-cell acute lymphoblastic leukemia (T-ALL). The mechanisms leading to aberrant activation of TAL1 in T-ALL patients who lack chromosomal rearrangements involving the TAL1 locus remain largely unknown. We hypothesized that TAL1 levels decrease during normal T-cell development at least in part due to miRNA-dependent silencing, in which case TAL1 over-expression in some T-ALL cases could be the consequence of deregulated miRNA expression. By performing computational prediction of miRNAs that bind to the human TAL1 mRNA we compiled a list of miRNAs that are candidates to regulate TAL1. Using a luciferase reporter system and mutagenesis assays we confirmed the miRNA-TAL1 mRNA interactions and selected candidate miRNAs: miR-101, miR-520d-5p, miR-140-5p, miR-448 and miR-485-5p. Over-expression of these microRNAs in different T-ALL cell lines consistently resulted in the down-regulation of TAL1 protein. In accordance, inhibition of miR-101 and miR-520d-5p promoted TAL1 protein expression. Importantly, we found that miR-101, miR-140-5p, miR-448 and miR-485-5p were down-regulated in T-ALL patient specimens and T-ALL cell lines. Our results show for the first time the existence of epigenetic regulation of TAL1 by specific miRNAs which may contribute, at least in part, to the ectopic expression of TAL1 in some T-ALL cases.
| S-EPMC4884991 | biostudies-literature
Project description:The oncogenic transcription factor TAL1/SCL is aberrantly overexpressed in over 40% of cases of T-cell acute lymphoblastic leukemia (T-ALL), emphasizing the importance of the TAL1-regulated transcriptional program in the molecular pathogenesis of T-ALL. Here we identify regions occupied by TAL1 and its regulatory partners HEB, E2A, and GATA3 in a T-ALL cell line (RPMI-8402). Human T-ALL cells were cross-linked with formaldehyde for 20 min. DNA was enriched by chromatin immunoprecipitation (ChIP) and analyzed by Solexa sequencing. A sample of whole cell extract (WCE) was sequenced and used as the background to determine enrichment. ChIP was performed using an antibody against total TAL1 (Santa Cruz SC-12984), TCF12/HEB (Santa Cruz SC-357),TCF3/E2A (Santa Cruz SC-349X), and GATA3 (Santa Cruz SC-22206).
2012-07-09 | E-GEOD-39179 | biostudies-arrayexpress
Project description:The oncogenic transcription factor TAL1/SCL is aberrantly overexpressed in over 40% of cases of T-cell acute lymphoblastic leukemia (T-ALL), emphasizing the importance of the TAL1-regulated transcriptional program in the molecular pathogenesis of T-ALL. Here we identify regions occupied by TAL1 and its regulatory partners HEB, E2A, and GATA3 in a T-ALL cell line (RPMI-8402).
2012-07-09 | GSE39179 | GEO
Project description:The oncogenic transcription factor TAL1/SCL is aberrantly expressed in 60% of cases of human T cell acute lymphoblastic leukemia (T-ALL) and initiates T-ALL in mouse models. By performing global microRNA (miRNA) expression profiling after depletion of TAL1, together with genome-wide analysis of TAL1 occupancy by chromatin immunoprecipitation coupled to massively parallel DNA sequencing, we identified the miRNA genes directly controlled by TAL1 and its regulatory partners HEB, E2A, LMO1/2, GATA3, and RUNX1. The most dynamically regulated miRNA was miR-223, which is bound at its promoter and up-regulated by the TAL1 complex. miR-223 expression mirrors TAL1 levels during thymic development, with high expression in early thymocytes and marked down-regulation after the double-negative-2 stage of maturation. We demonstrate that aberrant miR-223 up-regulation by TAL1 is important for optimal growth of TAL1-positive T-ALL cells and that sustained expression of miR-223 partially rescues T-ALL cells after TAL1 knockdown. Overexpression of miR-223 also leads to marked down-regulation of FBXW7 protein expression, whereas knockdown of TAL1 leads to up-regulation of FBXW7 protein levels, with a marked reduction of its substrates MYC, MYB, NOTCH1, and CYCLIN E. We conclude that TAL1-mediated up-regulation of miR-223 promotes the malignant phenotype in T-ALL through repression of the FBXW7 tumor suppressor.
| S-EPMC3727321 | biostudies-literature