Papers by Andrew C Wakeham
PLOS ONE, Mar 18, 2011
Estrogen is a key regulator of normal function of female reproductive system and plays a pivotal ... more Estrogen is a key regulator of normal function of female reproductive system and plays a pivotal role in the development and progression of breast cancer. Here, we demonstrate that JMJD2B (also known as KDM4B) constitutes a key component of the estrogen signaling pathway. JMJD2B is expressed in a high proportion of human breast tumors, and that expression levels significantly correlate with estrogen receptor (ER) positivity. In addition, 17-beta-estradiol (E2) induces JMJD2B expression in an ERa dependent manner. JMJD2B interacts with ERa and components of the SWI/SNF-B chromatin remodeling complex. JMJD2B is recruited to ERa target sites, demethylates H3K9me3 and facilitates transcription of ER responsive genes including MYB, MYC and CCND1. As a consequence, knockdown of JMJD2B severely impairs estrogeninduced cell proliferation and the tumor formation capacity of breast cancer cells. Furthermore, Jmjd2b-deletion in mammary epithelial cells exhibits delayed mammary gland development in female mice. Taken together, these findings suggest an essential role for JMJD2B in the estrogen signaling, and identify JMJD2B as a potential therapeutic target in breast cancer.
Proceedings of the National Academy of Sciences of the United States of America, Aug 19, 2008
Genes & Development, Apr 1, 2000
Phosphorylation of IB, an inhibitor of NF-B, is an important step in the activation of the transc... more Phosphorylation of IB, an inhibitor of NF-B, is an important step in the activation of the transcription factor NF-B. Phosphorylation is mediated by the IB kinase (IKK) complex, known to contain two catalytic subunits: IKK␣ and IKK. A novel, noncatalytic component of this kinase complex called NEMO (NF-B essential modulator)/IKK␥ was identified recently. We have generated NEMO/IKK␥-deficient mice by gene targeting. Mutant embryos die at E12.5-E13.0 from severe liver damage due to apoptosis. NEMO/ IKK␥-deficient primary murine embryonic fibroblasts (MEFs) lack detectable NF-B DNA-binding activity in response to TNF␣, IL-1, LPS, and Poly(IC) and do not show stimulus-dependent IB kinase activity, which correlates with a lack of phosphorylation and degradation of IB␣. Consistent with these data, mutant MEFs show increased sensitivity to TNF␣-induced apoptosis. Our data provide in vivo evidence that NEMO/IKK␥ is the first essential, noncatalytic component of the IKK complex.
Genes & Development, 1998
Mutations in the SMAD4/DPC4 tumor suppressor gene, a key signal transducer in most TGF-related p... more Mutations in the SMAD4/DPC4 tumor suppressor gene, a key signal transducer in most TGF-related pathways, are involved in 50% of pancreatic cancers. Homozygous Smad4 mutant mice die before day 7.5 of embryogenesis. Mutant embryos have reduced size, fail to gastrulate or express a mesodermal marker, and show abnormal visceral endoderm development. Growth retardation of the Smad4-deficient embryos results from reduced cell proliferation rather than increased apoptosis. Aggregation of mutant Smad4 ES cells with wild-type tetraploid morulae rescues the gastrulation defect. These results indicate that Smad4 is initially required for the differentiation of the visceral endoderm and that the gastrulation defect in the epiblast is secondary and non-cell autonomous. Rescued embryos show severe anterior truncations, indicating a second important role for Smad4 in anterior patterning during embryogenesis.
Journal of Clinical Investigation, Sep 15, 2001
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Genes & Development, 2000
Phosphorylation of IκB, an inhibitor ofNF-κB, is an important step in the activation of the trans... more Phosphorylation of IκB, an inhibitor ofNF-κB, is an important step in the activation of the transcription factor NF-κB. Phosphorylation is mediated by the IκB kinase (IKK) complex, known to contain two catalytic subunits: IKKα andIKKβ. A novel, noncatalytic component of this kinase complex called NEMO(NF-κBessentialmodulator)/IKKγ was identified recently. We have generatedNEMO/IKKγ-deficient mice by gene targeting. Mutant embryos die at E12.5–E13.0 from severe liver damage due to apoptosis.NEMO/IKKγ-deficient primary murine embryonic fibroblasts (MEFs) lack detectableNF-κB DNA-binding activity in response to TNFα, IL-1, LPS, and Poly(IC) and do not show stimulus-dependent IκB kinase activity, which correlates with a lack of phosphorylation and degradation of IκBα. Consistent with these data, mutant MEFs show increased sensitivity to TNFα-induced apoptosis. Our data provide in vivo evidence that NEMO/IKKγ is the first essential, noncatalytic component of the IKK complex.
Cell Reports, 2021
Highlights d Typhoid toxin causes DNA fragmentation in vivo not associated with inflammation d In... more Highlights d Typhoid toxin causes DNA fragmentation in vivo not associated with inflammation d Infection with a genotoxin-producing bacterium induces senescence in vivo d The presence of senescent cells is associated with an antiinflammatory response d The anti-inflammatory effect is lost in mice with acute colitis
SummaryBacterial genotoxins cause DNA damage in eukaryotic cells, resulting in activation of the ... more SummaryBacterial genotoxins cause DNA damage in eukaryotic cells, resulting in activation of the DNA damage response (DDR) in vitro. These toxins are produced by Gram negative bacteria, enriched in the microbiota of Inflammatory Bowel Disease (IBD) and colorectal cancer (CRC) patients. However, their role in infection remains poorly characterized. We have addressed the role of the typhoid toxin in the modulation of the host-microbial interaction in health and disease.Infection with a genotoxigenic Salmonella protected mice from intestinal inflammation. The toxin-induced DNA damage caused senescence in vivo, which was uncoupled from the inflammatory response, and associated with the maintenance of an anti-inflammatory environment. This effect was lost when infection occurred in mice suffering from inflammatory conditions that mimic Ulcerative Colitis, a form of IBD.These data highlight a complex context-dependent crosstalk between bacterial genotoxins-induced DDR and the host immune ...
Nature, Jan 29, 2001
Programmed cell death is a fundamental requirement for embryogenesis, organ metamorphosis and tis... more Programmed cell death is a fundamental requirement for embryogenesis, organ metamorphosis and tissue homeostasis. In mammals, release of mitochondrial cytochrome c leads to the cytosolic assembly of the apoptosome-a caspase activation complex involving Apaf1 and caspase-9 that induces hallmarks of apoptosis. There are, however, mitochondrially regulated cell death pathways that are independent of Apaf1/caspase-9. We have previously cloned a molecule associated with programmed cell death called apoptosis-inducing factor (AIF). Like cytochrome c, AIF is localized to mitochondria and released in response to death stimuli. Here we show that genetic inactivation of AIF renders embryonic stem cells resistant to cell death after serum deprivation. Moreover, AIF is essential for programmed cell death during cavitation of embryoid bodies-the very first wave of cell death indispensable for mouse morphogenesis. AIF-dependent cell death displays structural features of apoptosis, and can be gene...
PloS one, Jan 18, 2011
Estrogen is a key regulator of normal function of female reproductive system and plays a pivotal ... more Estrogen is a key regulator of normal function of female reproductive system and plays a pivotal role in the development and progression of breast cancer. Here, we demonstrate that JMJD2B (also known as KDM4B) constitutes a key component of the estrogen signaling pathway. JMJD2B is expressed in a high proportion of human breast tumors, and that expression levels significantly correlate with estrogen receptor (ER) positivity. In addition, 17-beta-estradiol (E2) induces JMJD2B expression in an ERα dependent manner. JMJD2B interacts with ERα and components of the SWI/SNF-B chromatin remodeling complex. JMJD2B is recruited to ERα target sites, demethylates H3K9me3 and facilitates transcription of ER responsive genes including MYB, MYC and CCND1. As a consequence, knockdown of JMJD2B severely impairs estrogen-induced cell proliferation and the tumor formation capacity of breast cancer cells. Furthermore, Jmjd2b-deletion in mammary epithelial cells exhibits delayed mammary gland developme...
The Journal of Cell Biology, 2005
Tyrosine kinase growth factor receptor signaling influences proliferation, survival, and apoptosi... more Tyrosine kinase growth factor receptor signaling influences proliferation, survival, and apoptosis. Hair follicles undergo cycles of proliferation and apoptotic regression, offering an excellent paradigm to study how this transition is governed. Several factors are known to affect the hair cycle, but it remains a mystery whether Akt kinases that are downstream of growth factor signaling impact this equilibrium. We now show that an Akt relative, Sgk (serum and glucocorticoid responsive kinase) 3, plays a critical role in this process. Hair follicles of mice lacking Sgk3 fail to mature normally. Proliferation is reduced, apoptosis is increased, and follicles prematurely regress. Maintenance of the pool of transiently amplifying matrix cells is impaired. Intriguingly, loss of Sgk3 resembles the gain of function of epidermal growth factor signaling. Using cultured primary keratinocytes, we find that Sgk3 functions by negatively regulating phosphatidylinositol 3 kinase signaling. Our res...
The EMBO Journal, 2000
The hexosamine pathway provides UDP-N-acetylhexosamine donor substrates used in cytosolic and Gol... more The hexosamine pathway provides UDP-N-acetylhexosamine donor substrates used in cytosolic and Golgi-mediated glycosylation of proteins and for formation of glycosylphosphatidylinositol (GPI) anchors, which tether proteins to the outer plasma membrane. We have recently identi®ed the murine glucosamine-6-phosphate (GlcN6P) acetyltransferase, EMeg32, as a developmentally regulated enzyme on the route to UDP-N-acetylglucosamine (UDP-GlcNAc). Here we describe embryos and cells that have the EMeg32 gene inactivated by homologous recombination. Homozygous mutant embryos die at around embryonic day (E) 7.5 with a general proliferative delay of development. In vitro differentiated EMeg32 ±/± ES cells show reduced proliferation. Mouse embryonic ®broblasts (MEFs) de®cient for EMeg32 exhibit defects in proliferation and adhesiveness, which could be complemented by stable re-expression of EMeg32 or by nutritional restoration of intracellular UDP-GlcNAc levels. Reduced UDP-GlcNAc levels predominantly translated into decreased O-GlcNAc modi®cations of cytosolic and nuclear proteins. Interestingly, growth-impaired EMeg32 ±/± MEFs withstand a number of apoptotic stimuli and express activated PKB/AKT. Thus, EMeg32-dependent UDP-GlcNAc levels in¯uence cell cycle progression and susceptibility to apoptotic stimuli.
Proceedings of the National Academy of Sciences, 2008
CD83 is the major surface marker identifying mature dendritic cells (DCs). In this study, we repo... more CD83 is the major surface marker identifying mature dendritic cells (DCs). In this study, we report the generation of reporter mice expressing EGFP under the control of the CD83 promoter. We have used these mice to characterize CD83 expression by various immune system cell types bothin vivoandex vivoand under steady-state conditions and in response to stimulation with a Toll-like receptor (TLR) ligand. With those mice we could provein vivothat the CD83 promoter is highly active in all DCs and B cells in lymphoid organs. Interestingly, this promoter activity in B cells mainly depended on the stage of development, is up-regulated in the late pre-B cell stage, and was maintained on a high level in all peripheral B cells. We also confirmed that CD83 in those cells is mainly intracellular but is up-regulated after TLR stimulation. Otherwise, CD83 promoter activity in T cells seemed to depend on stimulation and could be found mainly in CD4+CD25+and CD8+CD25+T cells and in CD4+and CD8+memo...
Proceedings of the National Academy of Sciences, 2001
Functional inactivation of the tumor susceptibility gene tsg101 in NIH 3T3 fibroblasts results in... more Functional inactivation of the tumor susceptibility gene tsg101 in NIH 3T3 fibroblasts results in cellular transformation and the ability to form metastatic tumors in nude mice. The N-terminal region of tsg101 protein is structurally similar to the catalytic domain of ubiquitin-conjugating enzymes, suggesting a potential role of tsg101 in ubiquitin-mediated protein degradation. The C-terminal domain of TSG101 can function as a repressor of transcription. To investigate the physiological function of tsg101 , we generated a null mutation of the mouse gene by gene targeting. Homozygous tsg101 −/− embryos fail to develop past day 6.5 of embryogenesis (E6.5), are reduced in size, and do not form mesoderm. Mutant embryos show a decrease in cellular proliferation in vivo and in vitro but no increase in apoptosis. Although levels of p53 transcripts were not affected in tsg101 −/− embryos, p53 protein accumulated dramatically, implying altered posttranscriptional control of p53. In addition,...
Proceedings of the National Academy of Sciences, 2000
Regulators of G protein signaling (RGS) proteins accelerate the GTPase activity of Gα protein sub... more Regulators of G protein signaling (RGS) proteins accelerate the GTPase activity of Gα protein subunitsin vitro, negatively regulating G protein-coupled receptor signaling. The physiological role of mammalian RGS proteins is largely unknown. The RGS family memberrgs2was cloned as an immediate early response gene up-regulated in T lymphocytes after activation. To investigate the role of RGS2in vivo, we generatedrgs2-deficient mice. We show that targeted mutation ofrgs2in mice leads to reduced T cell proliferation and IL-2 production, which translates in an impaired antiviral immunityin vivo. Interestingly,rgs2−/−mice also display increased anxiety responses and decreased male aggression in the absence of cognitive or motor deficits. RGS2 also controls synaptic development and basal electrical activity in hippocampal CA1 neurons. Thus, RGS2 plays an important role in T cell activation, synapse development in the hippocampus, and emotive behaviors.
Nature Medicine, 2012
T cell immunoglobulin and mucin domain-containing-3 (Tim-3) is an inhibitory receptor expressed o... more T cell immunoglobulin and mucin domain-containing-3 (Tim-3) is an inhibitory receptor expressed on exhausted T cells during HIV-1 and HCV infection. By contrast, Tim-3 expression and function are defective in multiple human autoimmune diseases. However, the molecular mechanisms governing Tim-3 function remain poorly understood. Here we show that HLA-Bassociated transcript 3 (Bat3) binds to, and represses the function of Tim-3. Bat3-deficient T cells display elevated expression of exhaustion markers, and knocking down Bat3 in myelin antigenspecific CD4 + T cells dramatically inhibits the development of experimental autoimmune encephalomyelitis while promoting the expansion of a dysfunctional Tim-3 hi IFN γ lo CD4 + cell population. Furthermore, exhausted Tim-3 + T cells from murine tumors and HIV-1-infected individuals display substantially reduced Bat3 expression and targeted deletion of Bat3 induces an exhausted phenotype in T cells. These data indicate that Bat3 acts as a molecular safety catch that inhibits Tim-3-dependent cell death/exhaustion, suggesting that Bat3 may represent a viable therapeutic target in autoimmune disorders, chronic infections and cancers.
Molecular and Cellular Biology, 2000
TEP1 is a mammalian telomerase-associated protein with similarity to the Tetrahymena telomerase p... more TEP1 is a mammalian telomerase-associated protein with similarity to the Tetrahymena telomerase protein p80. Like p80, TEP1 is associated with telomerase activity and the telomerase reverse transcriptase, and it specifically interacts with the telomerase RNA. To determine the role of mTep1 in telomerase function in vivo, we generated mouse embryonic stem (ES) cells and mice lacking mTep1 . The mTep1 -deficient ( mTep1 −/− ) mice were viable and were bred for seven successive generations with no obvious phenotypic abnormalities. All murine tissues from mTep1 −/− mice possessed a level of telomerase activity comparable to that in wild-type mice. In addition, analysis of several tissues that normally lack telomerase activity revealed no reactivation of telomerase activity in mTep1 −/− mice. Telomere length, even in later generations of mTep1 −/− mice, was equivalent to that in wild-type animals. ES cells deficient in mTep1 also showed no detectable alteration in telomerase activity or ...
The Journal of Immunology, 2002
Negative selection is a process to delete potentially autoreactive clones in developing thymocyte... more Negative selection is a process to delete potentially autoreactive clones in developing thymocytes. Programmed cell death or apoptosis is thought to play an important role in this selection process. In this study, we investigated the role of apoptotic protease-activating factor 1 (Apaf1), a mammalian homologue of CED-4, in programmed cell death during the negative selection in thymus. There was no developmental abnormality in thymocytes from newborn Apaf1−/− mice in terms of CD4 and CD8 expression pattern and thymocyte number. Clonal deletion by endogenous male H-Y Ag of Apaf1-deficient thymocytes with transgenic expression of H-Y Ag-specific TCRs (H-Y Tg/Apaf1−/− thymocytes) was normally observed in lethally irradiated wild-type mice reconstituted with fetal liver-derived hemopoietic stem cells. Clonal deletion induced in vitro by a bacterial superantigen was also normal in fetal thymic organ culture. Thus, Apaf1-mediated pathway of apoptosis is dispensable for the negative selecti...
Journal of Clinical Investigation, 2001
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Papers by Andrew C Wakeham