Immediate Early Response 3 Research Articles

Correlation study of NF-κB, IER3, and Recurrence of Ovarian Endometrioid Cysts.

The study aimed to investigate the expression of nuclear actor-k-gene binding(NF-κB) and immediate early response 3(IER3) in ovarian endometrioid cysts and its correlation with the recurrence of the ovarian endometrioid cyst. From January 2018 to March 2019, a total of 88 patients who underwent laparoscopic ovarian cyst excision due to ovarian endometrioid cyst in Changzhou Maternity and Child Health Care Hospital were selected. Clinical data of the patients were collected. The patient's Revised American Fertility Society (R-AFS) score, least function(LF) score, and endometriosis fertility index (EFI) were calculated. Immunohistochemistry was performed to detect the expression of IER3 and NF-κB. The receiver-operating characteristic (ROC) curve was used to evaluate the predictive value of IER3 and NF-κB expression on postoperative recurrence. Cox regression was fitted to analyze the influencing factors of ovarian endometrioid cyst recurrence. The expression of NF-κB was positively correlated with IER3 (P < 0.001). ROC curve showed that NF-κB combined with IER3 had higher predictive value for disease recurrence. Multivariate Cox regression showed that the IER3 expression intensity > 4.5 (HR = 3.418,95%CI: 1.227 ~ 9.523, P = 0.019) and the NF-κB expression intensity > 4.5 (HR = 5.491,95%CI: 1.600 ~ 18.838, P = 0.007) were independent risk factors for recurrence, and EFI score (HR = 0.791,95%CI: 0.637 ~ 0.983, P = 0.035) was a protective factor for recurrence. Our results suggested that EFI score is a protective factor for recurrence. The expression levels of NF-κB and IER3 > 4.5 are correlated with the recurrence of ovarian endometrioid cysts and independent risk factors for recurrence.

Inflammatory priming of human mesenchymal stem cells induces osteogenic differentiation via the early response gene IER3.

Mesenchymal stem cells (MSCs) have gained tremendous interest due to their overall potent pro-regenerative and immunomodulatory properties. In recent years, various invitro and preclinical studies have investigated different priming ("licensing") approaches to enhance MSC functions for specific therapeutic purposes. In this study, we primed bone marrow-derived human MSCs (hMSCs) with an inflammation cocktail designed to mimic the elevated levels of inflammatory mediators found in serum of patients with severe injuries, such as bone fractures. We observed a significantly enhanced osteogenic differentiation potential of primed hMSCs compared to untreated controls. By RNA-sequencing analysis, we identified the immediate early response 3 (IER3) gene as one of the top-regulated genes upon inflammatory priming. Small interfering RNA knockdown experiments established IER3 as a novel positive regulator of osteogenic differentiation. Mechanistic analysis further revealed that IER3 deletion significantly downregulated bone marrow stromal cell antigen 2 (BST2) expression and extracellular signal-related kinase 1/2 (ERK1/2) phosphorylation in hMSCs, suggesting that IER3 regulates osteogenic differentiation through BST2 and ERK1/2 signaling pathway activation. On the basis of these findings, we propose IER3 as a novel therapeutic target to promote hMSC osteoblastogenesis, which might be of high clinical relevance, for example, in patients with osteoporosis or compromised fracture healing.

Comprehensive analysis of bulk, single-cell RNA sequencing, and spatial transcriptomics revealed IER3 for predicting malignant progression and immunotherapy efficacy in glioma

BackgroundAs part of stress-triggered molecules, immediate early response 3 (IER3) dysregulation has been reported to sustain pro-oncogenic pathways and precede malignant transformation. However, the role of IER3 in glioma pathology is ill-defined.MethodsImmunohistochemistry (IHC) assay and publicly available glioma datasets were used to calculate the IER3 expression level in glioma. Wound healing, invasion and cell counting kit-8 (CCK8) assays were applied to measure the cell viability and capacities of migration and invasion of glioma cells in vitro. The immunofluorescence (IF) assay was used to assess the expression associations of IER3 with CCL2 and TGFBI. Cox regression analysis and Kaplan-Meier (K-M) curve were introduced to compute the prognosis-predicting value of IER3. Variations in copy number (CNVs), single nucleotide (SNVs), and methylation profiles were analyzed to illustrate the epigenetic modifications of IER3. Gliomas were divided into two subgroups using the restricted cubic spline (RCS) method.Results IER3was overexpressed and hypomethylated in gliomas and significantly associated with the dismal prognosis of glioma samples. Samples in the high IER3 subgroup were characterized by increased infiltration of tumor-associated monocytes/macrophages (TAMMs), as well as the elevated sensitivity to Dabrafenib, an inhibitor of BRAF. In addition, this subgroup demonstrated a low mutation rate of IDH, high gain rates of BRAF, ELTD1, and PDGFA. Gliomas with relatively low IER3 expression demonstrated a less invasive subtype and were featured by favorable prognosis, increased response to immunotherapy, and adjuvant chemotherapy plus radiotherapy. The IF assay revealed that IER3 was co-localized and co-expressed with TGFBI. The glioma cells with small interfering RNA (siRNA)-silenced IER3 displayed lower migration, invasion, proliferation, and cell viability than the control group.ConclusionsIn this study, we identified IER3 upregulation as an essential biomarker that could assist in adjuvant therapy and prognosis prediction for gliomas.

Tumor-infiltrating monocytic myeloid-derived suppressor cells contribute to the development of an immunosuppressive tumor microenvironment in gastric cancer.

Gastric cancer (GC) is characterized by an immunosuppressive and treatment-resistant tumor immune microenvironment (TIME). Here, we investigated the roles of different immunosuppressive cell types in the development of the GC TIME. Single-cell RNA sequencing (scRNA-seq) and multiplex immunostaining of samples from untreated or immune checkpoint inhibitor (ICI)-resistant GC patients were used to examine the correlation between certain immunosuppressive cells and the prognosis of GC patients. The results of the scRNA-seq analysis revealed that tumor-infiltrating monocytic myeloid-derived suppressor cells (TI-M-MDSCs) expressed higher levels of genes with immunosuppressive functions than other immunosuppressive cell types. Additionally, M-MDSCs in GC tissues expressed significantly higher levels of these markers than adjacent normal tissues. The M-MDSCs were most enriched in GC tissues relative to adjacent normal tissues. Among the immunosuppressive cell types assessed, the M-MDSCs were most enriched in GC tissues relative to adjacent normal tissues; moreover, their presence was most strongly associated with a poor prognosis. Immediate early response 3 (IER3), which we identified as a differentially expressed gene between M-MDSCs of GC and adjacent normal tissues, was an independent poor prognostic factor in GC patients (P = 0.0003). IER3+ M-MDSCs expressed higher levels of genes with immunosuppressive functions than IER3- M-MDSCs and were abundant in treatment-resistant GC patients. The present study suggests that TI-M-MDSCs, especially IER3+ ones, may play a predominant role in the development of the immunosuppressive and ICI-resistant GC TIME.

Identify Key Genes Correlated to Ischemia-Reperfusion Injury in Aging Livers.

With the intensification of population aging, the proportion of aging livers in the donor pool is increasing rapidly. Compared with young livers, aging livers are more susceptible to ischemia-reperfusion injury (IRI) during liver transplantation, which greatly affects the utilization rate of aging livers. The potential risk factors associated with IRI in aging livers have not been fully elucidated. In this work, five human liver tissue expression profiling datasets (GSE61260, GSE107037, GSE89632, GSE133815, and GSE151648) and a total of 28 young and aging liver tissues of human (N = 20) and mouse (N = 8) were used to screen and verify the potential risk factors associated with aging livers being more prone to IRI. DrugBank Online was used to screen drugs with potential to alleviate IRI in aging livers. The gene expression profile and immune cell composition between young and aging livers had significant differences. Among the differentially expressed genes, aryl hydrocarbon receptor nuclear translocator-like (ARNTL), BTG antiproliferation factor 2 (BTG2), C-X-C motif chemokine ligand 10 (CXCL10), chitinase 3-like 1 (CHI3L1), immediate early response 3 (IER3), Fos proto-oncogene, AP-1 transcription factor subunit (FOS), and peroxisome proliferative activated receptor, gamma, coactivator 1 alpha (PPARGC1A), mainly involved in the regulation of cell proliferation, metabolism, and inflammation, were also dysregulated in liver tissues suffered from IRI and could form a FOS-centered interaction network. Nadroparin was screened out with the potential to target FOS in DrugBank Online. In addition, the proportion of dendritic cells (DCs) was significantly upregulated in aging livers. We combined the expression profiling datasets of liver tissues and samples collected in our hospital for the first time to reveal that the changes in the expression of ARNTL, BTG2, CXCL10, CHI3L1, IER3, FOS, and PPARGC1A and the proportion of dendritic cells may be associated with aging livers being more prone to IRI. Nadroparin may be used to mitigate IRI in aging livers by targeting FOS, and regulation of DC activity may also reduce IRI.

IER3 (IEX-1) dysregulation serves as a potential prognostic factor in acute myeloid leukemia patients.

IntroductionImmediate early response 3 (IER3) has association with hematological malignancies’ risk and prognosis, such as myelodysplastic syndrome, while its relation to acute myeloid leukemia (AML) is not clear. This study aimed to explore the correlation of IER3 with AML risk, clinical characteristics, complete remission (CR), event‐free survival (EFS), and overall survival (OS).MethodsA total of 93 de novo AML patients were included in this study. In addition, 30 patients with non‐hyperplasia hematologic malignancies requiring bone marrow testing (as disease controls) and 30 health donors (as health controls) were also recruited. Bone morrow samples of AML patients (before treatment), disease controls (before treatment), and health controls (at donation) were collected. IER3 in bone marrow mononuclear cells was detected by reverse transcription‐quantitative polymerase chain reaction.ResultsIER3 was increased in AML patients compared with disease controls and health donors (both P < .001), and receiver operating characteristic (ROC) curve showed that IER3 had certain capability of distinguishing AML patients from disease controls (area under curve (AUC): 0.735, 95% confidence interval (CI): 0.650‐0.820), and health donors (AUC: 0.789, 95% CI: 0.712‐0.866). Meanwhile, IER3 was correlated with FLT3‐ITD mutation (P = .030) and poor NCCN risk stratification (P = .031) in AML patients. Moreover, IER3 had negative association with CR in AML patients (P = .022), and showed certain potential in discriminating CR patients from non‐CR patients (AUC: 0.655, 95% CI: 0.533‐0.777). Besides, IER3 was negatively associated with EFS (P = .033), but not OS (P = .083) in AML patients.ConclusionIER3 dysregulation serves as a potential prognostic factor in AML patients.

Gene expression profiles of mitochondria-endoplasmic reticulum tethering in human gingival fibroblasts in response to periodontal pathogens

ObjectiveThe current study aimed to elucidate the potential involvement of mitochondria-endoplasmic reticulum contact genes in the pathogenesis of periodontal disease by monitoring levels of contact associated genes including Mitofusion 1 (MFN1) and MFN2, inositol 1,4,5-trisphosphate receptor (IP3R), chaperone glucose-regulated protein 75 (GRP75), sigma non-opioid intracellular receptor 1 (SIGMAR1) and phosphate and tensin homolog induced putative kinase 1 (PINK1) in human gingival fibroblasts in response to periodontal pathogens Fusobacterium nucleatum (F. nucleatum) and Porphyromonas gingivalis (P. gingivalis) in vitro. DesignPrimary human gingival fibroblasts were exposed to live cultures of P. gingivalis (W83; ATCC BAA-308) and F. nucleatum (subsp. Polymorphum; ATCC 10953) alone or in combination for 4 h at a 50 or 200 multiplicity of infection. Escherichia coli lipopolysaccharide (10 μg/mL) exposure was used as a positive control. Gene expression levels of contact genes (MFN1, MFN2, IP3R, GRP75, SIGMAR1 and PINK1) as well as a proinflammatory cytokine, Tumor necrosis factor-α (TNF-α), and the apoptosis associated gene, Immediate early response 3 (IER3), were evaluated by reverse transcription polymerase chain reaction analysis. ResultsMFN1, GRP75, IP3R and PINK1 were significantly upregulated by P. gingivalis with or without F. nucleatum. Only P. gingivalis with F. nucleatum caused a significant upregulation of SIGMAR1. TNF-α and IER3 gene expression positively correlated with the contact-associated gene expression changes. ConclusionF. nucleatum and P. gingivalis alone or in combination may differentially dysregulate the gene expression levels of contact-associated genes in human gingival fibroblasts. These host-microbiome interactions may mechanistically be important in the pathogenesis of periodontal disease.

Screening of key genes and pathways of ischemic stroke and prediction of traditional Chinese medicines based on bioinformatics

The aim of this paper was to explore the key genes and pathogenesis of ischemic stroke(IS) by bioinformatics, and predict the potential traditional Chinese medicines for IS. Based on the gene-chip raw data set of GSE22255 from National Center of Biotechnology Information(NCBI), the article enrolled in 20 patients with ischemic stroke and 20 sex-and age-matched controls, and differentially expressed genes(DEGs) were screened based on R language software. The DAVID tool and R language software were used to perform gene ontology(GO) biological process enrichment analysis and Kyoto encyclopedia of genes and gnomes(KEGG) pathway enrichment analysis. The DEGs were imported into STRING to construct a protein-protein interaction network, and the Molecular Complexity Module(MCODE) plug-in of Cytoscape software was used to visualize and analyze the key functional modules. Moreover, the core genes and the medical ontology information retrieval platform(Coremine Medical) were mapped to each other to screen the traditional Chinese medicines and construct drug-active ingredient-target network. Compared with healthy controls, 14 DEGs were obtained, of which 12 genes were up-regulated and 2 genes were down-regulated. DEGs were mainly involved in immune response, inflammatory process, signal transduction, and cell proliferation regulation. The interleukin-17(IL-17), nuclear factor kappaB(NF-κB), tumor necrosis factor(TNF), nucleotide binding oligomerization domain(NOD)-like receptor and other signaling pathways were involved in KEGG pathway enrichment analysis. The key modules of the DEGs-encoding protein interaction network mainly focused on 7 genes of TNF, JUN, recombinant immediate early response 3(IER3), recombinant early growth response protein 1(EGR1), prostaglandin-endoperoxide synthase 2(PTGS2), C-X-C motif chemokine ligand 8(CXCL8) and C-X-C motif chemokine ligand 2(CXCL2), which were involved in biological processes widely such as neuroinflammation and immunity. TNF and JUN were the key nodes in this module, which might become potential biological markers for diagnosis and prognosis evaluation of IS. The potential traditional Chinese medicines for the treatment of IS includes Salviae Miltiorrhizae Radix et Rhizoma, Croci Stigma, Scutellariae Radix, and Cannabis Fructus. The occurrence of stroke was the result of multiple factors. Dysregulation of genes and pathways related to immune regulation and inflammation may be the key link for the development of IS. This study provided research direction and theoretical basis for further exploring the mechanism of action of traditional Chinese medicine in the treatment of IS and searching for potential drug targets.

The Capacity of the Ovarian Cancer Tumor Microenvironment to Integrate Inflammation Signaling Conveys a Shorter Disease-free Interval.

Ovarian cancer has one of the highest deaths to incidence ratios across all cancers. Initial chemotherapy is effective, but most patients develop chemoresistant disease. Mechanisms driving clinical chemo-response or -resistance are not well-understood. However, achieving optimal surgical cytoreduction improves survival, and cytoreduction is improved by neoadjuvant chemotherapy (NACT). NACT offers a window to profile pre- versus post-NACT tumors, which we used to identify chemotherapy-induced changes to the tumor microenvironment. We obtained matched pre- and post-NACT archival tumor tissues from patients with high-grade serous ovarian cancer (patient, n = 6). We measured mRNA levels of 770 genes (756 genes/14 housekeeping genes, NanoString Technologies), and performed reverse phase protein array (RPPA) on a subset of matched tumors. We examined cytokine levels in pre-NACT ascites samples (n = 39) by ELISAs. A tissue microarray with 128 annotated ovarian tumors expanded the transcriptional, RPPA, and cytokine data by multispectral IHC. The most upregulated gene post-NACT was IL6 (16.79-fold). RPPA data were concordant with mRNA, consistent with elevated immune infiltration. Elevated IL6 in pre-NACT ascites specimens correlated with a shorter time to recurrence. Integrating NanoString (n = 12), RPPA (n = 4), and cytokine (n = 39) studies identified an activated inflammatory signaling network and induced IL6 and IER3 (immediate early response 3) post-NACT, associated with poor chemo-response and time to recurrence. Multiomics profiling of ovarian tumor samples pre- and post-NACT provides unique insight into chemo-induced changes to the tumor microenvironment. We identified a novel IL6/IER3 signaling axis that may drive chemoresistance and disease recurrence.

Abstract 5305: Characterization of the ovarian tumor transcriptome and microenvironment in pre and post-chemotherapy treated patients

Abstract Purpose: Ovarian cancer has one of the highest deaths to incidence ratios across all cancers. Initial chemotherapy is typically effective, but most patients will experience recurrence and enter a cycle of response and recurrence, ultimately developing resistant disease. Importantly, the understanding of mechanisms contributing to clinical chemoresistance in ovarian cancer is limited. Achieving optimal cytoreduction improves survival. Gynecologic oncologists therefore perform laparoscopy to evaluate resectability and collect tumor biopsies. Patients identified with un-resectable tumor receive three cycles of neoadjuvant platinum/taxane-based chemotherapy (NACT) to improve the likelihood of optimal cytoreductive surgery. NACT offers a previously unavailable window for identifying therapy-induced remodeling of the tumor, potentially providing insight into drivers of chemo-resistance. Experimental Design: We accessed formalin fixed (FFPE) tumor tissue from high-grade serous ovarian cancer NACT patients (n=6) pre- and post-chemotherapy. RNA was extracted and the mRNA transcript levels were examined for 791 genes via the Immunoncology 360 NanoString panel. Further, using the pre-treated ascites fluid we examined the cytokine environment through MesoScale Discovery multiplex ELISA. Transcriptional and cytokine profiles were correlated to clinical outcomes, such as days to recurrence. Results: Component analysis found that transcriptional profiles separated based on pre- and post-chemotherapy status. Comparing the pre- (n=6) and post-chemotherapy (n=6), the most upregulated gene following therapy was IL6 (4.1 log2 fold change, adj. p = 0.045) and the most downregulated gene was UBE2C (-3.9 log2 fold change, adj. p = 0.001). Elevated IL-6 within ascites correlated to a shorter time to recurrence. On the patient-by-patient basis we compared transcriptional changes between pre- and post therapy. We correlated these changes to IL6 expression and time to recurrence uncovered that an increase in Immediate Early Response 3 (IER3) is a poor prognostic indicator. IER3/IEX-1 is a NF-κB target gene involved in apoptosis and potentiates MAPK activation. Conclusion: Using ovarian cancer tumors from NACT patients provides a unique insight into chemo-induced transcriptional changes. To-date little is known of IER3's function in ovarian cancer thus future work will focus on a potential novel IL-6/IER3 signaling axis that protects tumors from chemotherapy-induced apoptosis. Also, computer modeling and integration of transcriptional and cytokine date could also provide an approach to predict recurrence. Citation Format: Kimberly R. Jordan, Jill Slansky, Angela Minic, Jennifer K. Richer, James C. Costello, Aaron J. Clauset, Rajendra T. Kumar, Kian Behbakht, Matthew J. Sikora, Benjamin G. Bitler. Characterization of the ovarian tumor transcriptome and microenvironment in pre and post-chemotherapy treated patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5305.

LncRNA GAS5 confers the radio sensitivity of cervical cancer cells via regulating miR-106b/IER3 axis

ObjectiveThe aim of the study was to investigate the biological role of growth arrest special 5 (GAS5) in the radio sensitivity of cervical cancer (CC). MethodsThe expressions of GAS5, miR-106b and immediate early response 3 (IER3) were detected in CC tissues and CC cell lines. RNA immunoprecipitation and RNA pull-down assays were performed to test the interaction of GAS5 and miR-106b. Dual-luciferase reporter assay was used to detect the regulatory relationship between miR-106b and IER3. The nude mouse model of CC was established for verifying the effects of GAS5 on the resistance of CC to radiation therapy in vivo. ResultsGAS5 and IER3 were low expressed in the radio-resistant human CC tissues and SiHa cells, while miR-106b expression was highly expressed. Overexpression of IER3 or GAS5 enhanced radio-sensitivity in SiHa cells, while knockdown of IER3 or GAS5 decreased radio-sensitivity in ME180 cells. Moreover, GAS5 served as a miR-106b sponge, and miR-106b negatively regulated IER3 expression. Besides, GAS5 could regulate IER3 expression through miR-106b, and GAS5 enhanced the radio-sensitivity in CC cells through inhibiting miR-106b both in vitro and in vivo. ConclusionOverexpression of GAS5 enhanced the sensitivity of CC cells to radiation treatment via up-regulating IER3 through miR-106b.

Molecular characterization of the bovine IER3 gene: Down-regulation of IL-8 by blocking NF-κB activity mediated by IER3 overexpression in MDBK cells infected with bovine viral diarrhea virus-1

The immediate early response 3 (IER3) is a key regulatory factor in the immune response, particularly as related to homeostasis immunomodulation via the nuclear factor kappa B (NF-κB) signaling pathway. The IER3 gene has been identified in mammals and, more recently, in other higher vertebrates. Nevertheless, relatively little is known about this regulator in bovines. Therefore, this study explored, characterized, and compared the genetic context of bovine IER3 to homologous genes in the human, mouse, and canine chromosomes. In silico analysis identified several regions of interest preserved in phylogenetically distant species. Similar analyses were also conducted for interleukin-8, a cytokine in which several putative cis elements were identified for the inducible transcription factor NF-κB. Subsequent challenge assays against the bovine viral diarrhea virus-1 revealed NF-κB signaling pathway activation just 15min post-infection, a process blocked by the BAY-117085 inhibitor. Similarly, infection strongly increased IER3 expression. Interestingly, IER3 down-regulated interleukin-8 expression, as confirmed by IER3 gene inhibition using small interfering RNA, RT-qPCR, and luciferase assays. In conclusion, this is the first report to present data indicating that bovine IER3 is a strong regulator of immune-marker expression, specifically modulating bovine interleukin-8 activation through the NF-κB/IER3 pathway in response to the bovine viral diarrhea virus.

Dual PI3K/ERK inhibition induces necroptotic cell death of Hodgkin Lymphoma cells through IER3 downregulation.

PI3K/AKT and RAF/MEK/ERK pathways are constitutively activated in Hodgkin lymphoma (HL) patients, thus representing attractive therapeutic targets. Here we report that the PI3K/ERK dual inhibitor AEZS-136 induced significant cell proliferation inhibition in L-540, SUP-HD1, KM-H2 and L-428 HL cell lines, but a significant increase in necroptotic cell death was observed only in two out of four cell lines (L-540 and SUP-HD1). In these cells, AEZS-136-induced necroptosis was associated with mitochondrial dysfunction and reactive oxygen species (ROS) production. JNK was activated by AEZS-136, and AEZS-136-induced necroptosis was blocked by the necroptosis inhibitor necrostatin-1 or the JNK inhibitor SP600125, suggesting that JNK activation is required to trigger necroptosis following dual PI3K/ERK inhibition. Gene expression analysis indicated that the effects of AEZS-136 were associated with the modulation of cell cycle and cell death pathways. In the cell death-resistant cell lines, AEZS-136 induced the expression of immediate early response 3 (IER3) both in vitro and in vivo. Silencing of IER3 restored sensitivity to AEZS-136-induced necroptosis. Furthermore, xenograft studies demonstrated a 70% inhibition of tumor growth and a 10-fold increase in tumor necrosis in AEZS-136-treated animals. Together, these data suggest that dual PI3K/ERK inhibition might be an effective approach for improving therapeutic outcomes in HL.

Scaffold protein FHL2 facilitates MDM2-mediated degradation of IER3 to regulate proliferation of cervical cancer cells.

The expression of immediate early response 3 (IER3), a protein with a short half-life, is rapidly induced by various cellular stimuli. We recently reported that IER3 induces the apoptosis of cervical cancer cells and that its expression is downregulated in patients with cervical cancer. However, the molecular mechanism involved in the rapid degradation of IER3 remains unknown. Here, we demonstrate that MDM2 is an E3 ligase that interacts with IER3 and promotes its ubiquitination, followed by proteasomal degradation. Polyubiquitination of the conserved lysine 60 of IER3 is essential for its degradation. In addition, four and a half LIM domains protein 2 (FHL2) binds to both IER3 and MDM2, allowing for efficient MDM2-mediated IER3 degradation by facilitating an association between MDM2 and IER3. Moreover, IER3 induces cell cycle arrest in cervical cancer cells and its activity is further enhanced in cells in which FHL2 or MDM2 was silenced, thereby preventing IER3 degradation. The E6 and E7 oncoproteins of human papilloma virus 18 regulated IER3 expression. FHL2 expression was significantly higher in the squamous epithelium of cervical carcinoma tissues than in non-cancerous cervical tissues, whereas cervical carcinoma expression of IER3 was downregulated in this region. Thus, we determined the molecular mechanism responsible for IER3 degradation, involving a ternary complex of IER3, MDM2 and FHL2, which may contribute to cervical tumor growth. Furthermore, we demonstrated that FHL2 serves as a scaffold for E3 ligase and its substrate during the ubiquitination reaction, a function that has not been previously reported for this protein.

Pharmacologic stabilization of hypoxia-inducible transcription factors protects developing mouse brain from hypoxia-induced apoptotic cell death

Objective: Accumulation of hypoxia-inducible transcription factors (HIFs) by prolyl-4-hydroxylase inhibitors (PHI) has been suggested to induce neuroprotection in the ischemic rodent brain. We aimed to investigate in vivo effects of a novel PHI on HIF-regulated neurotrophic and pro-apoptotic factors in the developing normoxic and hypoxic mouse brain. Methods: Neonatal mice (P7) were treated with PHI FG-4497 (30–100mg/kg, i.p.) followed by exposure to systemic hypoxia (8% O2, 6h) 4h later. Cerebral expression of HIFα-subunits, specific neurotrophic and vasoactive target genes (vascular endothelial growth factor (VEGF), adrenomedullin (ADM), erythropoietin (EPO), inducible nitric oxide synthase (iNOS)) as well as pro-apoptotic (BCL2/adenovirus E1B 19-kDa protein-interacting protein 3 gene (BNIP3), immediate early response 3 (IER3)) and migratory factors (chemokine receptor 4 (CXCR4), stromal cell-derived factor 1 (SDF-1)) was determined (quantitative real-time (RT)., Western blot analysis) in comparison to controls. Apoptotic cell death was analyzed by terminal desoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) and cleaved caspase 3 (CC3) staining. Results: Under normoxic conditions, FG-4497 treatment significantly induced the accumulation of both HIF-1α and HIF-2α isoforms in developing mouse brain. In addition, there was a significant up-regulation of HIF target genes (VEGF, ADM, EPO, CXCR4, p<0.01) with FG-4497 treatment compared to controls supporting functional activation of the HIF proteins. Under hypoxia, differential target gene activation was observed in the developing brain including additive effects of FG-4497 and hypoxia on mRNA expression of VEGF and ADM as well as a dose-dependent down-regulation of iNOS. BNIP3 but not IER3 mRNA levels significantly increased in hypoxic brains pre-treated with high-dose FG-4497 compared to controls. Of special interest, FG-4497 treatment significantly diminished apoptotic cell death, quantified by TUNEL and CC3-positive cells, in hypoxic developing brains compared to controls. Conclusions: PHI treatment modulates neurotrophic factors known to be crucially involved in hypoxia-induced cerebral adaptive mechanisms as well as early brain maturation. Pre-treatment with FG-4497 seems to protect the developing brain from hypoxia-induced apoptosis. Present observations provide basic information for further evaluation of neuroprotective properties of PHI treatment in hypoxic injury of the developing brain. However, potential effects on maturational processes need special attention in experimental research targeting HIF-dependent neuroprotective interventions during the very early stage of brain development.

Modulation of Nuclear Factor E2-related Factor-2 (Nrf2) Activation by the Stress Response Gene Immediate Early Response-3 (IER3) in Colonic Epithelial Cells: A NOVEL MECHANISM OF CELLULAR ADAPTION TO INFLAMMATORY STRESS

Although nuclear factor E2-related factor-2 (Nrf2) protects from carcinogen-induced tumorigenesis, underlying the rationale for using Nrf2 inducers in chemoprevention, this antioxidative transcription factor may also act as a proto-oncogene. Thus, an enhanced Nrf2 activity promotes formation and chemoresistance of colon cancer. One mechanism causing persistent Nrf2 activation is the adaptation of epithelial cells to oxidative stress during chronic inflammation, e.g. colonocytes in inflammatory bowel diseases, and the multifunctional stress response gene immediate early response-3 (IER3) has a crucial role under these conditions. We now demonstrate that colonic tissue from Ier3(-/-) mice subject of dextran sodium sulfate colitis exhibit greater Nrf2 activity than Ier3(+/+) mice, manifesting as increased nuclear Nrf2 protein level and Nrf2 target gene expression. Likewise, human NCM460 colonocytes subjected to shRNA-mediated IER3 knockdown exhibit greater Nrf2 activity compared with control cells, whereas IER3 overexpression attenuated Nrf2 activation. IER3-deficient NCM460 cells exhibited reduced reactive oxygen species levels, indicating increased antioxidative protection, as well as lower sensitivity to TRAIL or anticancer drug-induced apoptosis and greater clonogenicity. Knockdown of Nrf2 expression reversed these IER3-dependent effects. Further, the enhancing effect of IER3 deficiency on Nrf2 activity relates to the control of the inhibitory tyrosine kinase Fyn by the PI3K/Akt pathway. Thus, the PI3K inhibitor LY294002 or knockdown of Akt or Fyn expression abrogated the impact of IER3 deficiency on Nrf2 activity. In conclusion, the interference of IER3 with the PI3K/Akt-Fyn pathway represents a novel mechanism of Nrf2 regulation that may get lost in tumors and by which IER3 exerts its stress-adaptive and tumor-suppressive activity.

The PI3K/ERK Dual Inhibitor AEZS-136 Induces ROS-Dependent Necroptotic Cell Death and Exerts Potent Antitumor Effects In NOD/SCID Mice With Hodgkin Lymphoma Cell Line Xenografts

IntroductionDisease relapse and resistance to chemotherapy represent challenging issues for Hodgkin Lymphoma (HL) patients. PI3K/AKT and RAF/MEK/ERK pathways are constitutively activated in the majority of HL patients, thus representing attractive therapeutic targets. Previous results from our phase II study indicate that combining the PI3K/AKT inhibitor perifosine with the RAF/MEK/ERK inhibitor sorafenib can achieve significant clinical responses in relapsed/refractory HL. The present study was therefore aimed at characterizing the in vitro and in vivo activity and mechanism(s) of action of a novel PI3K/ERK dual inhibitor AEZS-136 (Æterna Zentaris GmbH, Germany, EU). MethodsFour HL cell lines (L-540, SUP-HD1, KM-H2 and L-428) were used to investigate the in vitro effects of AEZS-136 on cell growth, cell cycle distribution, gene expression profiling (GEP), and apoptosis. Live cell imaging experiments were performed to asses the production of reactive oxygen species (ROS). Western blotting (WB) was used to assess the effects of AEZS-136 on MAPK and PI3K/AKT pathways as well as apoptosis. The antitumor efficacy of AEZS-136 was investigated in vivo in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. ResultsExposure of L-540, SUP-HD1, KM-H2 and L-428 cell lines to AEZS-136 induced a marked, early and time-dependent dephosphorylation of PI3K/Akt and MAPK pathways that was associated with a significant time and dose-dependent cell growth inhibition [80 ± 3% (mean ±SEM) in the L-540 and SUP-HD1 responsive cell lines] and S phase cell cycle arrest. Indeed, upon AEZS-136 treatment the mean (±SEM) percentages of cells in S phase were reduced by 3-fold (13 ± 1%) as compared to control (33 ± 2%). Significant levels of cell death, as assessed by AnnexinV/PI staining, were only observed in L-540 (62 ± 9 vs 14 ± 3%, P ≤.0001) and SUP-HD1 (46 ± 2% vs 15 ± 2%, P ≤.0001) cell lines and were associated with severe mitochondrial dysfunction (up to 40%, P ≤.001). While no activation of caspase-3 and PARP cleavage were observed in L-540 and SUP-HD1 cells treated with AEZS-136, a potent generation of reactive oxygen species (ROS) was observed upon AEZS-136 treatment (up to 90%, P≤.0001). Pretreating cells with the ROS inhibitor YCG063 strongly inhibited AEZS-136-induced ROS generation, mitochondrial dysfunction and cell death, whereas the pan-caspase inhibitor Z-VADfmk did not. Since ROS generation has been implicated in mediating necroptosis, we tested if blocking programmed necrosis with Necrostatin-1 could prevent AEZS-136-induced cytotoxicity. When L-540 cells were treated with AEZS-136 in the presence of Necrostatin-1, cell death and ROS generation were completely prevented, suggesting that cell death was mechanistically related to necroptosis. Additionally, HL cells responsive to AEZS-136-induced cell death showed a pronounced JNK activation whose inhibition by the JNK inhibitor SP600125 reduced cell death and ROS generation. Furthermore, AEZS-136-increased JNK phosphorylation was inhibited by Necrostatin-1 or YCG063, suggesting that ROS-dependent necroptosis was linked to JNK. Interestingly, GEP analysis of L-540 and SUP-HD1 cell lines, but not KM-H2 and L-428 cells, indicated that AEZS-136 treatment induced upregulation of genes involved in positive regulation of cell death. In addition, in KM-H2 and L-428 cells, AEZS-136 strikingly induced the expression of the immediate early response 3 (IER3). Silencing of IER3 restored sensitivity of KM-H2 and L-428 cells to AEZS-136-induced necroptotic cell death, suggesting that IER3 acts as the signaling molecule that mediated AEZS-136-resistance to oxidative cell death. Finally, in vivo experiments were conducted to investigate the antitumor activity of AEZS-136. Treatment of NOD/SCID mice bearing L540 tumor nodules with increasing dose of AEZS-136 (30 – 60 mg/Kg body weight, PO, 5 days/2 weeks) resulted in a dose-dependent reduction of tumor growth (mean TGI of 70%, P ≤.0001) compared to vehicle-treated controls. No mice experienced any apparent treatment-related toxicity. ConclusionsThe PI3K/ERK dual inhibitor AEZS-136 demonstrates a potent antitumor activity against HL cell lines by targeting aberrant expression of MAPK and PI3K/Akt pathways. These data support further clinical evaluation of AEZS-136 in refractory/relapsed HL patients. Disclosures:No relevant conflicts of interest to declare.

Nuclear protein 1 promotes pancreatic cancer development and protects cells from stress by inhibiting apoptosis

Pancreatic ductal adenocarcinoma (PDAC) has the lowest survival rate of all cancers and shows remarkable resistance to cell stress. Nuclear protein 1 (Nupr1), which mediates stress response in the pancreas, is frequently upregulated in pancreatic cancer. Here, we report that Nupr1 plays an essential role in pancreatic tumorigenesis. In a mouse model of pancreatic cancer with constitutively expressed oncogenic Kras(G12D), we found that loss of Nupr1 protected from the development of pancreatic intraepithelial neoplasias (PanINs). Further, in cultured pancreatic cells, nutrient deprivation activated Nupr1 expression, which we found to be required for cell survival. We found that Nupr1 protected cells from stress-induced death by inhibiting apoptosis through a pathway dependent on transcription factor RelB and immediate early response 3 (IER3). NUPR1, RELB, and IER3 proteins were coexpressed in mouse PanINs from Kras(G12D)-expressing pancreas. Moreover, pancreas-specific deletion of Relb in a Kras(G12D) background resulted in delayed in PanIN development associated with a lack of IER3 expression. Thus, efficient PanIN formation was dependent on the expression of Nupr1 and Relb, with likely involvement of IER3. Finally, in patients with PDAC, expression of NUPR1, RELB, and IER3 was significantly correlated with a poor prognosis. Cumulatively, these results reveal a NUPR1/RELB/IER3 stress-related pathway that is required for oncogenic Kras(G12D)-dependent transformation of the pancreas.

IER3 Expression in Childhood Myelodysplastic Syndrome,

Abstract 3817 Background:Childhood myelodysplastic syndrome (MDS) is a rare disease accounting for less than 5% of all hematological malignancies. In about 50% of the MDS cases an abnormal karyotype is found by conventional karyotyping, of which chromosome 6 is involved in 10%. The immediate-early-response 3 (IER3) gene, which is located on chromosome 6p21, encodes for a glycoprotein that plays a role in the regulation of apoptosis and cell cycle progression. Recently, it was shown that IER3 gene aberrations frequently occur in adult MDS patients, which are not restricted to patients with chromosome 6 aberrations and that low IER3 expression was associated with a worse outcome. Therefore, we investigated the frequency and prognostic impact of IER3 expression in childhood MDS. Methods:IER3 mRNA expression was determined by quantitative real-time PCR in 58 childhood MDS patients of which 17 carried a chromosome 6 aberration, and in normal bone marrow (n=8). In addition, methylation-specific-PCR (MSP) was performed to investigate the methylation status of the promoter region of the IER3 gene, as a plausible cause for the downregulation of IER3. Results:Median IER3 mRNA expression was 0.9% in MDS (range 0.01–73.3% relative to GAPDH expression) and 3.3% in normal bone marrow (range 0.81–85.5% relative to GAPDH expression) (p=0.05). A more than 4-fold decrease in IER3 expression below the mean of healthy controls was found in 74% (43/58) of the childhood MDS patients. There was no difference in IER3 mRNA expression between MDS patients with or without chromosome 6 aberrations (MWU p= 0.89). Also, no difference in IER3 mRNA expression was found between the different WHO-subtypes or between primary versus secondary MDS. Three patients with a chromosome 6p21 rearrangements in the IER3 region based on genomic profiling (array-CGH) showed expression-levels in the range of normal bone marrow. Low IER3 mRNA expression was associated with adverse outcome in childhood MDS patients (Cox regression analysis estimated hazard ratio 0.73, p=0.027, 95% CI-interval 0.55–0.97). The low IER3 expression appeared not to be due to hypermethylation of its promoter region. Conclusion:IER3 expression is low in childhood MDS patients with and without chromosome 6 aberrations and this low expression is associated with poor outcome. However this seems to be due to therapy related mortality, rather than by the increased risk of relapse. The IER3 downregulation is not regulated by hypermethylation of the IER3 promoter region. Disclosures:Hasle:Pfizer: Research Funding.

IER3 (immediate early response 3)

Review on IER3 (immediate early response 3), with data on DNA, on the protein encoded, and where the gene is implicated.