LncRNA H19-Derived miR-675-5p Accelerates the Invasion of Extravillous Trophoblast Cells by Inhibiting GATA2 and Subsequently Activating Matrix Metalloproteinases.

The invasion of extravillous trophoblast (EVT) cells into the maternal decidua, which plays a crucial role in the establishment of a successful pregnancy, is highly orchestrated by a complex array of regulatory mechanisms. Non-coding RNAs (ncRNAs) that fine-tune gene expression at epigenetic, transcriptional, and post-transcriptional levels are involved in the regulatory mechanisms of EVT cell invasion. However, little is known about the characteristic features of EVT-associated ncRNAs. To elucidate the gene expression profiles of both coding and non-coding transcripts (i.e., mRNAs, long non-coding RNAs (lncRNAs), and microRNAs (miRNAs)) expressed in EVT cells, we performed RNA sequencing analysis of EVT cells isolated from first-trimester placentae. RNA sequencing analysis demonstrated that the lncRNA H19 and its derived miRNA miR-675-5p were enriched in EVT cells. Although miR-675-5p acts as a placental/trophoblast growth suppressor, there is little information on the involvement of miR-675-5p in trophoblast cell invasion. Next, we evaluated a possible role of miR-675-5p in EVT cell invasion using the EVT cell lines HTR-8/SVneo and HChEpC1b; overexpression of miR-675-5p significantly promoted the invasion of both EVT cell lines. The transcription factor gene GATA2 was shown to be a target of miR-675-5p; moreover, small interfering RNA-mediated GATA2 knockdown significantly promoted cell invasion. Furthermore, we identified MMP13 and MMP14 as downstream effectors of miR-675-5p/GATA2-dependent EVT cell invasion. These findings suggest that miR-675-5p-mediated GATA2 inhibition accelerates EVT cell invasion by upregulating matrix metalloproteinases.

Arsenite suppresses the transcriptional activity of EVI1 through the binding to CCHC-type Zn finger domain.

Transcription factor EVI1 is essential for normal hematopoiesis in embryos but is aberrantly elevated in bone marrow cells of myelodysplastic syndrome (MDS) patients. EVI1 and its downstream GATA-2 appear to be a possible therapeutic target of MDS. Here we found that treatment of EVI1-expressing K562 cells with arsenite (As(III)) reduced the mRNA and protein levels of EVI1 and GATA-2. A gel shift assay using the nuclear extract of K562 cells showed that As(III) suppressed the DNA-binding activity of EVI1. The DNA-binding activity of the recombinant EVI1 protein was also suppressed by As(III) but was recovered by excess amounts of dithiothreitol, suggesting the involvement of cysteine residues of EVI1. Since the 7th Zn finger domain of EVI1, having a motif of CCHC, is known to be involved in DNA-binding, the synthetic peptide of 7th Zn finger domain was reacted with As(III) and subjected to MALDI-TOF-MS analysis. The results showed that As(III) binds to this peptide via three cysteine residues. As(III)-induced reduction of the DNA-binding activity of the recombinant EVI1 was abolished by the mutations of each of three cysteine residues to alanine in the 7th Zn finger domain. These results demonstrate that As(III) causes the down-regulation of EVI1 and GATA-2 by inhibiting the transcriptional activity of EVI1 through the binding to the cysteine residues of CCHC-type Zn finger domain.

Shaping Chromatin States in Prostate Cancer by Pioneer Transcription Factors.

The androgen receptor (AR) is a critical therapeutic target in prostate cancer that responds to antagonists in primary disease, but inevitably becomes reactivated, signaling onset of the lethal castration-resistant prostate cancer (CRPC) stage. Epigenomic investigation of the chromatin environment and interacting partners required for AR transcriptional activity has uncovered three pioneer factors that open up chromatin and facilitate AR-driven transcriptional programs. FOXA1, HOXB13, and GATA2 are required for normal AR transcription in prostate epithelial development and for oncogenic AR transcription during prostate carcinogenesis. AR signaling is dependent upon these three pioneer factors both before and after the clinical transition from treatable androgen-dependent disease to untreatable CRPC. Agents targeting their respective DNA binding or downstream chromatin-remodeling events have shown promise in preclinical studies of CRPC. AR-independent functions of FOXA1, HOXB13, and GATA2 are emerging as well. While all three pioneer factors exert effects that promote carcinogenesis, some of their functions may inhibit certain stages of prostate cancer progression. In all, these pioneer factors represent some of the most promising potential therapeutic targets to emerge thus far from the study of the prostate cancer epigenome.

Molecular determinants for enzalutamide-induced transcription in prostate cancer.

Enzalutamide, a second-generation androgen receptor (AR) antagonist, has demonstrated clinical benefit in men with prostate cancer. However, it only provides a temporary response and modest increase in survival, indicating a rapid evolution of resistance. Previous studies suggest that enzalutamide may function as a partial transcriptional agonist, but the underlying mechanisms for enzalutamide-induced transcription remain poorly understood. Here, we show that enzalutamide stimulates expression of a novel subset of genes distinct from androgen-responsive genes. Treatment of prostate cancer cells with enzalutamide enhances recruitment of pioneer factor GATA2, AR, Mediator subunits MED1 and MED14, and RNA Pol II to regulatory elements of enzalutamide-responsive genes. Mechanistically, GATA2 globally directs enzalutamide-induced transcription by facilitating AR, Mediator and Pol II loading to enzalutamide-responsive gene loci. Importantly, the GATA2 inhibitor K7174 inhibits enzalutamide-induced transcription by decreasing binding of the GATA2/AR/Mediator/Pol II transcriptional complex, contributing to sensitization of prostate cancer cells to enzalutamide treatment. Our findings provide mechanistic insight into the future combination of GATA2 inhibitors and enzalutamide for improved AR-targeted therapy.

Gata2 as a Crucial Regulator of Stem Cells in Adult Hematopoiesis and Acute Myeloid Leukemia.

Subversion of transcription factor (TF) activity in hematopoietic stem/progenitor cells (HSPCs) leads to the development of therapy-resistant leukemic stem cells (LSCs) that drive fulminant acute myeloid leukemia (AML). Using a conditional mouse model where zinc-finger TF Gata2 was deleted specifically in hematopoietic cells, we show that knockout of Gata2 leads to rapid and complete cell-autonomous loss of adult hematopoietic stem cells. By using short hairpin RNAi to target GATA2, we also identify a requirement for GATA2 in human HSPCs. In Meis1a/Hoxa9-driven AML, deletion of Gata2 impedes maintenance and self-renewal of LSCs. Ablation of Gata2 enforces an LSC-specific program of enhanced apoptosis, exemplified by attenuation of anti-apoptotic factor BCL2, and re-instigation of myeloid differentiation--which is characteristically blocked in AML. Thus, GATA2 acts as a critical regulator of normal and leukemic stem cells and mediates transcriptional networks that may be exploited therapeutically to target key facets of LSC behavior in AML.

Clioquinol increases the expression of interleukin-8 by down-regulating GATA-2 and GATA-3.

Clioquinol was used in the mid-1900s as an amebicide to treat indigestion and diarrhea. However, it was withdrawn from the market in Japan because it was linked to subacute myelo-optic neuropathy (SMON). The pathogenesis of SMON has not yet been elucidated in detail. As reported previously, we performed a global analysis on human neuroblastoma cells using DNA chips. The global analysis and quantitative PCR demonstrated that the mRNA level of interleukin-8 (IL-8) was significantly increased when SH-SY5Y neuroblastoma cells were treated with clioquinol. An enzyme-linked immunosorbent assay also demonstrated that clioquinol induced the secretion of IL-8 into culture media. Promoter analyses on SH-SY5Y cells revealed that a region responsive to clioquinol exists between -152 and -144 of the human IL-8 gene, which contains a consensus GATA-binding site sequence. The introduction of mutations at this site or the activator protein (AP)-1 site sequence at -126/-120 significantly reduced clioquinol-induced transcriptional activation. Among the GATA transcription factors expressed in SH-SY5Y cells, GATA-2 and GATA-3 protein levels were significantly decreased by the addition of clioquinol. Electrophoresis mobility shift assays using a probe corresponding to -159/-113 of the human IL-8 gene revealed two major shifted bands, one of which was increased and the other was decreased by clioquinol. The introduction of mutations showed that the former corresponded to binding to the AP-1 site, and the latter to binding to the GATA site. Supershift analyses revealed that the binding of c-Jun and c-Fos was increased, whereas that of GATA-3 was decreased by clioquinol. Genome editing against GATA-2 or GATA-3, not GATA-4 significantly enhanced clioquinol-induced IL-8 mRNA expression. On the other hand, the stable expression of GATA-2 or GATA-3 attenuated clioquinol-induced IL-8 mRNA expression and IL-8 secretion. These results suggest that the clioquinol-induced suppression of GATA-2 and GATA-3 expression mediates the up-regulation of IL-8.

Up-regulation of POMC and CART mRNAs by intermittent hypoxia via GATA transcription factors in human neuronal cells.

Sleep apnea syndrome (SAS) is characterized by intermittent hypoxia (IH) during sleep. SAS and obesity are strongly related to each other. Here, we investigated the effect of IH on the expression of major appetite regulatory genes in human neuronal cells. We exposed NB-1, SH-SY5Y, and SK-N-SH human neuronal cells to IH (64 cycles of 5 min hypoxia and 10 min normoxia), normoxia, or sustained hypoxia for 24 h and measured the mRNA levels of proopiomelanocortin (POMC), cocaine- and amphetamine-regulated transcript (CART), galanin, galanin-like peptide, ghrelin, pyroglutamylated RFamide peptide, agouti-related peptide, neuropeptide Y, and melanocortin 4 receptor by real-time RT-PCR. IH significantly increased the mRNA levels of POMC and CART in all the neuronal cells. Deletion analysis revealed that the -705 to -686 promoter region of POMC and the -950 to -929 region of CART were essential for the IH-induced promoter activity. As possible GATA factor binding sequences were found in the two regions, we performed real-time RT-PCR to determine which GATA family members were expressed and found that GATA2 and GATA3 mRNAs were predominantly expressed. Therefore, we introduced siRNAs against GATA2 and GATA3 into NB-1 cells and found that GATA2 and GATA3 siRNAs abolished the IH-induced up-regulation of both POMC and CART mRNAs. These results indicate that IH stress up-regulates the mRNA levels of anorexigenic peptides, POMC and CART, in human neuronal cells via GATA2 and GATA3. IH can have an anorexigenic effect on SAS patients through the transcriptional activation of POMC and CART in the central nervous system.

Dynamically and epigenetically coordinated GATA/ETS/SOX transcription factor expression is indispensable for endothelial cell differentiation.

Although studies of the differentiation from mouse embryonic stem (ES) cells to vascular endothelial cells (ECs) provide an excellent model for investigating the molecular mechanisms underlying vascular development, temporal dynamics of gene expression and chromatin modifications have not been well studied. Herein, using transcriptomic and epigenomic analyses based on H3K4me3 and H3K27me3 modifications at a genome-wide scale, we analysed the EC differentiation steps from ES cells and crucial epigenetic modifications unique to ECs. We determined that Gata2, Fli1, Sox7 and Sox18 are master regulators of EC that are induced following expression of the haemangioblast commitment pioneer factor, Etv2. These master regulator gene loci were repressed by H3K27me3 throughout the mesoderm period but rapidly transitioned to histone modification switching from H3K27me3 to H3K4me3 after treatment with vascular endothelial growth factor. SiRNA knockdown experiments indicated that these regulators are indispensable not only for proper EC differentiation but also for blocking the commitment to other closely aligned lineages. Collectively, our detailed epigenetic analysis may provide an advanced model for understanding temporal regulation of chromatin signatures and resulting gene expression profiles during EC commitment. These studies may inform the future development of methods to stimulate the vascular endothelium for regenerative medicine.

GATA2 Inhibition Sensitizes Acute Myeloid Leukemia Cells to Chemotherapy.

Drug resistance constitutes one of the main obstacles for clinical recovery of acute myeloid leukemia (AML) patients. Therefore, the treatment of AML requires new strategies, such as adding a third drug. To address whether GATA2 could act as a regulator of chemotherapy resistance in human leukemia cells, we observed KG1a cells and clinical patients' AML cells with a classic drug (Cerubidine) and Gefitinib. After utilizing chemotherapy, the expression of GATA2 and its target genes (EVI, SCL and WT1) in surviving AML cells and KG1a cells were significantly enhanced to double and quadrupled compared to its original level respectively. Furthermore, with continuous chemotherapeutics, AML cells with GATA2 knockdown or treated with GATA2 inhibitor (K1747) almost eliminated with dramatically reduced expression of WT1, SCL, EVI, and significantly increased apoptotic population. Therefore, we propose that reducing GATA2 expression or inhibition of its transcription activity can relieve the drug resistance of acute myeloid leukemia cells and it would be helpful for eliminating the leukemia cells in patients.

MicroRNA-Based Therapy of GATA2-Deficient Vascular Disease.

BACKGROUND: The transcription factor GATA2 orchestrates the expression of many endothelial-specific genes, illustrating its crucial importance for endothelial cell function. The capacity of this transcription factor in orchestrating endothelial-important microRNAs (miRNAs/miR) is unknown. METHODS: Endothelial GATA2 was functionally analyzed in human endothelial cells in vitro. Endogenous short interfering RNA-mediated knockdown and lentiviral-based overexpression were applied to decipher the capacity of GATA2 in regulating cell viability and capillary formation. Next, the GATA2-dependent miR transcriptome was identified by using a profiling approach on the basis of quantitative real-time polymerase chain reaction. Transcriptional control of miR promoters was assessed via chromatin immunoprecipitation, luciferase promoter assays, and bisulfite sequencing analysis of sites in proximity. Selected miRs were modulated in combination with GATA2 to identify signaling pathways at the angiogenic cytokine level via proteome profiler and enzyme-linked immunosorbent assays. Downstream miR targets were identified via bioinformatic target prediction and luciferase reporter gene assays. In vitro findings were translated to a mouse model of carotid injury in an endothelial GATA2 knockout background. Nanoparticle-mediated delivery of proangiogenic miR-126 was tested in the reendothelialization model. RESULTS: GATA2 gain- and loss-of-function experiments in human umbilical vein endothelial cells identified a key role of GATA2 as master regulator of multiple endothelial functions via miRNA-dependent mechanisms. Global miRNAnome-screening identified several GATA2-regulated miRNAs including miR-126 and miR-221. Specifically, proangiogenic miR-126 was regulated by GATA2 transcriptionally and targeted antiangiogenic SPRED1 and FOXO3a contributing to GATA2-mediated formation of normal vascular structures, whereas GATA2 deficiency led to vascular abnormalities. In contrast to GATA2 deficiency, supplementation with miR-126 normalized vascular function and expression profiles of cytokines contributing to proangiogenic paracrine effects. GATA2 silencing resulted in endothelial DNA hypomethylation leading to induced expression of antiangiogenic miR-221 by GATA2-dependent demethylation of a putative CpG island in the miR-221 promoter. Mechanistically, a reverted GATA2 phenotype by endogenous suppression of miR-221 was mediated through direct proangiogenic miR-221 target genes ICAM1 and ETS1. In a mouse model of carotid injury, GATA2 was reduced, and systemic supplementation of miR-126-coupled nanoparticles enhanced miR-126 availability in the carotid artery and improved reendothelialization of injured carotid arteries in vivo. CONCLUSIONS: GATA2-mediated regulation of miR-126 and miR-221 has an important impact on endothelial biology. Hence, modulation of GATA2 and its targets miR-126 and miR-221 is a promising therapeutic strategy for treatment of many vascular diseases.

Cell-type phylogenetics and the origin of endometrial stromal cells.

A challenge of genome annotation is the identification of genes performing specific biological functions. Here, we propose a phylogenetic approach that utilizes RNA-seq data to infer the historical relationships among cell types and to trace the pattern of gene-expression changes on the tree. The hypothesis is that gene-expression changes coincidental with the origin of a cell type will be important for the function of the derived cell type. We apply this approach to the endometrial stromal cells (ESCs), which are critical for the initiation and maintenance of pregnancy. Our approach identified well-known regulators of ESCs, PGR and FOXO1, as well as genes not yet implicated in female fertility, including GATA2 and TFAP2C. Knockdown analysis confirmed that they are essential for ESC differentiation. We conclude that phylogenetic analysis of cell transcriptomes is a powerful tool for discovery of genes performing cell-type-specific functions.

Regulation of GATA-binding protein 2 levels via ubiquitin-dependent degradation by Fbw7: involvement of cyclin B-cyclin-dependent kinase 1-mediated phosphorylation of THR176 in GATA-binding protein 2.

A GATA family transcription factor, GATA-binding protein 2 (GATA2), participates in cell growth and differentiation of various cells, such as hematopoietic stem cells. Although its expression level is controlled by transcriptional induction and proteolytic degradation, the responsible E3 ligase has not been identified. Here, we demonstrate that F-box/WD repeat-containing protein 7 (Fbw7/Fbxw7), a component of Skp1, Cullin 1, F-box-containing complex (SCF)-type E3 ligase, is an E3 ligase for GATA2. GATA2 contains a cell division control protein 4 (Cdc4) phosphodegron (CPD), a consensus motif for ubiquitylation by Fbw7, which includes Thr(176). Ectopic expression of Fbw7 destabilized GATA2 and promoted its proteasomal degradation. Substitution of threonine 176 to alanine in GATA2 inhibited binding with Fbw7, and the ubiquitylation and degradation of GATA2 by Fbw7 was suppressed. The CPD kinase, which mediates the phosphorylation of Thr(176), was cyclin B-cyclin-dependent kinase 1 (CDK1). Moreover, depletion of endogenous Fbw7 stabilized endogenous GATA2 in K562 cells. Conditional Fbw7 depletion in mice increased GATA2 levels in hematopoietic stem cells and myeloid progenitors at the early stage. Increased GATA2 levels in Fbw7-conditional knock-out mice were correlated with a decrease in a c-Kit high expressing population of myeloid progenitor cells. Our results suggest that Fbw7 is a bona fide E3 ubiquitin ligase for GATA2 in vivo.

GATA2 promotes glioma progression through EGFR/ERK/Elk-1 pathway.

Among the gliomas, glioblastoma (GBM) is the highest grade and the most malignant glioma tumor. GATA2 is a hematopoietic factor that has been intensely studied in hematopoietic malignancies. Recently, the functions of GATA2 as an oncogene in other types of human cancer have been reported. However, no role for GATA2 in the development and progression of glioma has been reported to date. In the present study, we found that the expression level of GATA2 is upregulated in GBM and is correlated with GBM outcome. Ectopic expression of GATA2 or RNAi-mediated knockdown of GATA2 significantly enhanced or inhibited proliferation, migration and invasion of glioma cells. Moreover, we found that epidermal growth factor receptor and extracellular signal-regulated kinase, as upstream components of the signaling pathway, upregulate GATA2 expression; moreover, GATA2 promotes Elk-1 expression. Therefore, a genetic approach or pharmacological intervention targeting GATA2 could potentially serve as an effective strategy for treating glioma patients.

GATA-2 inhibits transforming growth factor-ß signaling pathway through interaction with Smad4.

GATA-2, a member of zinc finger GATA transcription factor family, plays key role in the hematopoietic stem cells self-renewal and differentiation. The transforming growth factor-ß (TGFß) signaling pathway is a major signaling network that controls cell proliferation, differentiation and tumor suppression. Here we found that GATA-2 negatively regulated TGF-ß signaling pathway in Smad4-dependent manner. GATA-2 specifically interacts with Smad4 with its N-terminal while the zinc finger domain of GATA-2 is essential for negative regulation of TGFß. Although GATA-2 did not affect the phosphorylation of Smad2/3 and the complex Smad2/3/4 formation in response to TGFß, the DNA binding activity of Smad4 was decreased significantly by GATA-2 overexpression. Overexpression of GATA-2 in K562 cells led to reduced TGFß-induced erythroid differentiation while knockdown of GATA-2 enhanced TGFß-induced erythroid differentiation. All these results suggest that GATA-2 is a novel negative regulator of TGFß signal pathway.

Expression and prognostic significance of GATA-binding protein 2 in colorectal cancer.

GATA-binding protein 2 (GATA2) is a nuclear transcription factor that plays a critical role in tumorigenesis. High levels of GATA2 expression are correlated with poor survival outcomes in many types of cancer. However, the expression and prognostic significance of GATA2 in colorectal cancer remain unknown. In this study, GATA2 protein expression was examined using immunohistochemistry in 307 colorectal cancer tissues, and its association with clinicopathological features and prognosis was analyzed. The expression of GATA2 was found to be significantly higher in colorectal cancer tissues than in matched adjacent noncancerous tissues (60.3 vs. 9.0 %, P < 0.0001). The expression of GATA2 was significantly correlated with tumor location (P = 0.005), histological type (P = 0.019), and recurrence (P = 0.009). Kaplan-Meier survival analysis demonstrated that patients with high levels of GATA2 expression had worse disease-free survival outcomes than those with low levels of GATA2 expression (P = 0.016). Univariate analysis showed high levels of GATA2 expression to be significantly associated with shorter periods of disease-free survival (HR 2.196; 95 % CI 1.142-4.226; P = 0.018). Multivariate analysis showed GATA2 expression to be an independent prognostic factor for patients with colorectal cancer (HR 1.952; 95 % CI 1.010-3.775; P = 0.047). These findings suggest that high levels of GATA2 expression may be a useful indicator of disease recurrence after curative colorectal cancer treatment.

Adenosine promotes GATA-2-regulated p53 gene transcription to induce HepG2 cell apoptosis.

BACKGROUND/AIMS: In our earlier study, adenosine induced apoptosis in HepG2 human hepatoma cells by tuning of apoptosis-mediator gene transcription. The present study aimed at understanding the regulatory mechanism underlying the apoptosis-mediator gene transcription under the control of adenosine. METHODS: For HepG2 cells with and without knocking-down p53 or GATA-2, cell viability, mitochondrial membrane potentials, caspase activity, and transcriptional activity were monitored, and Western blotting, RT-PCR, electrophoretic mobility shift assay (EMSA), and chromatin immunoprecipitation (ChIP) assay were carried out. RESULTS: Extracellular adenosine upregulated expression of the p53 mRNA and protein in HepG2 human hepatoma cells. Adenosine induced apoptosis, disrupted mitochondrial membrane potentials, and activated caspase-3, -8 and -9 in HepG2 cells, and those effects were inhibited by silencing the p53-targetd gene. In the assay of transcriptional activity using full-length p53 gene promoter and 5' deletion mutants combined with the luciferase reporter vector, adenosine enhanced transcriptional activity for full-length p53 gene promoter, that was prevented by deleting from -240 to -146 bp on the promoter. In the EMSA using a (32)P-labeled DNA probe to detect binding to the putative GATA-2 biding site on the p53 gene promoter, adenosine produced (32)P-positive signals in nuclear extracts from HepG2 cells. In the Western blot analysis, adenosine increased presence of GATA-2 in nuclear extracts. In the ChIP assay, adenosine increased PCR products for the p53 gene promoter in chromosomal extracts from HepG2 cells, immunoprecipitated using an anti-GATA-2 antibody. Adenosine-induced upregulation of the p53 mRNA expression was suppressed by knocking-down GATA-2. CONCLUSION: The results of the present study show that p53 is a transcriptional target of GATA-2 and that adenosine upregulates GATA-2-regulated p53 expression, thereby activating caspase-3, -8, and -9 to induce HepG2 cell apoptosis.

Antagonism of FOG-1 and GATA factors in fate choice for the mast cell lineage.

The zinc finger transcription factor GATA-1 requires direct physical interaction with the cofactor friend of GATA-1 (FOG-1) for its essential role in erythroid and megakaryocytic development. We show that in the mast cell lineage, GATA-1 functions completely independent of FOG proteins. Moreover, we demonstrate that FOG-1 antagonizes the fate choice of multipotential progenitor cells for the mast cell lineage, and that its down-regulation is a prerequisite for mast cell development. Remarkably, ectopic expression of FOG-1 in committed mast cell progenitors redirects them into the erythroid, megakaryocytic, and granulocytic lineages. These lineage switches correlate with transcriptional down-regulation of GATA-2, an essential mast cell GATA factor, via switching of GATA-1 for GATA-2 at a key enhancer element upstream of the GATA-2 gene. These findings illustrate combinatorial control of cell fate identity by a transcription factor and its cofactor, and highlight the role of transcriptional networks in lineage determination. They also provide evidence for lineage instability during early stages of hematopoietic lineage commitment.

Essential role of GATA transcriptional factors in the activation of mast cells.

Mast cells are pivotal effector cells in IgE-mediated allergic reactions. GATA transcriptional factors such as GATA-1 and GATA-2 are expressed in mast cells, and recent studies have revealed that both GATA-1 and GATA-2 are required for mast cell development. However, the role of GATA transcriptional factors in differentiated mast cells has remained largely unknown. In this study, we repressed the activity of GATA-1 and GATA-2 by using three different approaches (inducible overexpression of a dominant-negative form of GATA, pharmacological inactivation, or small interfering RNA technology), and analyzed the molecular mechanisms of GATA transcriptional factors in the activation of mast cells. Surprisingly, the repression of GATA activity in differentiated mast cells led to the impairment of cell survival, IgE-induced degranulation, and cytokine production. Signal transduction and histone modification in the chromatin related to protein kinase Cbeta were defective in these cells. These results identify that GATA has a critical role in the activation of mast cell.