Breast cancer cells facilitate distant metastasis through the induction of immunosuppressive regulatory B cells, designated tBregs. We report here that, to do this, breast cancer cells produce metabolites of the 5-lipoxygenase (5-LO) pathway such as leukotriene B4 (LTB4) to activate the proliferator-activated receptor alpha (PPARalpha) in B cells. Inactivation of LTB4 signaling or genetic deficiency of PPARalpha in B cells blocks the generation of tBregs and thereby abrogates lung metastasis in mice with established breast cancer. Thus, in addition to eliciting fatty acid oxidation and metabolic signals, PPARalpha initiates programs required for differentiation of tBregs. We propose that PPARalpha in B cells or/and tumor 5-LO pathways represents new targets for pharmacological control of tBreg-mediated cancer escape.
Cancer-produced metabolites of 5-lipoxygenase induce tumor-evoked regulatory B cells via peroxisome proliferator-activated receptor α.
Specimen part
View SamplesLong noncoding RNAs (lncRNAs) have been found to regulate the expression of mRNAs with which they share partial complementarity. We sought to identify the mechanism through which the lncRNA OIP5-AS1, which is abundant in the cytoplasm, suppressed cell proliferation. Silencing of OIP5-AS1 in human cervical carcinoma cells revealed the appearance of many aberrant (monopolar, multipolar, misaligned) mitotic spindles. By biotin-oligomer affinity pulldown, proteomic, and bioinformatic analyses, we identified a subset of human cell cycle regulatory proteins encoded by mRNAs that were capable of interacting with OIP5-AS1. Further investigation revealed that GAK mRNA, which encodes a cyclin G-associated kinase important for mitotic progression, was a prominent target of OIP5-AS1. The interaction between these two transcripts led to a reduction in GAK mRNA stability and GAK protein abundance, as determined in cells in which OIP5-AS1 levels were increased or decreased. Importantly, the aberrant mitotic cell division seen after silencing OIP5-AS1 was partly rescued if GAK was simultaneously silenced. These findings indicate that the abnormal mitoses seen after silencing OIP5-AS1 was caused by an untimely rise in GAK levels and suggest that OIP5-AS1 suppresses cell proliferation at least in part by reducing GAK levels
LncRNA OIP5-AS1/cyrano suppresses GAK expression to control mitosis.
Specimen part, Disease, Disease stage, Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Blast traumatic brain injury-induced cognitive deficits are attenuated by preinjury or postinjury treatment with the glucagon-like peptide-1 receptor agonist, exendin-4.
Sex, Specimen part, Treatment, Time
View SamplesBlast traumatic brain injury (B-TBI) affects military and civilian personnel. Presently there are no approved drugs for blast brain injury. Exendin-4, administered subcutaneously, was evaluated as a pre-treatment (48 hours) and post-injury treatment (2 hours) on neurodegeneration, behaviors and gene expressions in a murine open field model of blast injury. B-TBI induced neurodegeneration, changes in cognition and genes expressions linked to dementia disorders. Exendin-4, administered pre- or post-injury ameliorated B-TBI-induced neurodegeneration at 72 hours, memory deficits from days 7-14 and attenuated genes regulated by blast at day 14 post-injury. The present data suggest shared pathological processes between concussive and B-TBI, with endpoints amenable to beneficial therapeutic manipulation by exendin-4. B-TBI-induced dementia-related gene pathways and cognitive deficits in mice somewhat parallel epidemiological studies of Barnes and co-workers who identified a greater risk in US military veterans who experienced diverse TBIs, for dementia in later life.
Blast traumatic brain injury-induced cognitive deficits are attenuated by preinjury or postinjury treatment with the glucagon-like peptide-1 receptor agonist, exendin-4.
Sex, Specimen part
View SamplesTraumatic brain injury (TBI) is a global problem reaching near epidemic numbers that manifests clinically with cognitive problems that decades later may result in dementias like Alzheimers disease (AD). Presently, little can be done to prevent ensuing neurological dysfunctions by pharmacological means. Recently, it has become apparent that several CNS diseases share common terminal features of neuronal cell death. The effects of exendin-4 (Ex-4), a neuroprotective agent delivered via a subcutaneous micro-osmotic pump, were examined in the setting of mild TBI (mTBI). Utilizing a model of mTBI, where cognitive disturbances occur over time, animals were subjected to four treatments: sham; Ex-4; mTBI and Ex-4/mTBI. mTBI mice displayed deficits in novel object recognition, while Ex-4/mTBI mice performed similar to sham. Hippocampal gene expression, assessed by gene array methods, showed significant differences with little overlap in co-regulated genes between groups. Importantly, changes in gene expression induced by mTBI, including genes associated with AD were largely prevented by Ex-4. These data suggest a strong beneficial action of Ex-4 in managing secondary events induced by a traumatic brain injury.
Exendin-4, a glucagon-like peptide-1 receptor agonist prevents mTBI-induced changes in hippocampus gene expression and memory deficits in mice.
Sex, Specimen part, Treatment, Time
View SamplesDeregulation of the translational machinery is emerging as a critical contributor to lymphomagenesis. Various miRNA alterations have been identified in lymphoma, but their role in disrupting the cap-dependent translation regulation complex remains poorly understood. Here, we demonstrate the translation initiation factor, eIF4GII, as a direct target and major mediator of miR-520c-3p function through 3UTR of eIF4GII mRNA. We established that elevated miR-520c-3p represses translation, initiates premature senescence and blocks cell proliferation in diffuse large B-cell lymphoma (DLBCL). Moreover, miR-520c-3p overexpression diminishes DLBCL cells colony formation and reduces tumor growth in a lymphoma xenograft mouse model. miR-520c-3p overexpressing cells display lowered eIF4GII levels. Consequently, downregulation of eIF4GII by siRNA induces cellular senescence, decreases cell proliferation and ability to form colonies. Our in vitro and in vivo findings we further validated in patient samples; DLBCL primary cells demonstrated low miR-520c-3p levels with reciprocally highly up-regulated eIF4GII protein expression. In contrast, normal donor B-cell lymphocytes had low levels of eIF4GII protein and elevated miR-520c-3p levels. Our results provide evidence that the tumor suppressor effect of miR-520c-3p is mediated through repression of cap-dependent translation while inducing senescence and that eIF4GII is a key effector of this anti-tumor activity. These findings may have implications for therapeutic interventions in patients with DLBCL.
Down-regulation of eIF4GII by miR-520c-3p represses diffuse large B cell lymphoma development.
Cell line
View SamplesNAD(P)H:quinone Oxidoreductase (NQO1) is essential for cell defense against reactive oxidative species, cancer, and metabolic stress. Recently, NQO1 was found in ribonucleoprotein (RNP) complexes, but NQO1-interacting mRNAs and the functional impact of such interactions are not known. Here, we used ribonucleoprotein immunoprecipitation (RIP) and microarray analysis to identify comprehensively the subset of NQO1 target mRNAs in human hepatoma HepG2 cells. One of its main targets, SERPINA1 mRNA, encodes the serine protease inhibitor -1-antitrypsin, A1AT, which is associated with disorders including obesity-related metabolic inflammation, chronic obstructive pulmonary disease (COPD), liver cirrhosis and hepatocellular carcinoma. Biotin pulldown analysis indicated that NQO1 can bind the 3 untranslated region (UTR) and the coding region (CR) of SERPINA1 mRNA. NQO1 did not affect SERPINA1 mRNA levels; instead, it enhanced the translation of SERPINA1 mRNA, as NQO1 silencing decreased the size of polysomes forming on SERPINA1 mRNA and lowered the abundance of A1AT. Luciferase reporter analysis further indicated that NQO1 regulates SERPINA1 mRNA translation through the SERPINA1 3UTR. Accordingly, NQO1-KO mice had reduced hepatic and serum levels of A1AT and increased activity of neutrophil elastase, one of the main targets of A1AT. We propose that this novel mechanism of action of NQO1 as RNA-binding protein may help to explain its pleiotropic biological effects.
Novel RNA-binding activity of NQO1 promotes SERPINA1 mRNA translation.
Specimen part, Cell line, Treatment
View SamplesLong non-coding RNAs (lncRNAs) regulate vital biological processes, including cell proliferation, differentiation and development. A subclass of lncRNAs is synthesized from microRNA host genes (MIRHGs) due to pre-miRNA processing, and is categorized as miRNA-host gene lncRNAs (lnc-miRHGs). Presently, it is not clear whether lnc-miRHG perform additional functions. We demonstrate a miRNA-independent role for a nuclear-enriched lnc-miRHG in cell cycle progression. MIR100HG produces spliced and stable lncRNAs (lnc-MIR100HG) that display elevated levels during the G1 phase of the cell cycle. Depletion of lnc-MIR100HG in human cells results in aberrant cell cycle progression with out altering the levels of miRNA encoded within MIR100HG. Notably, lnc-MIR100HG interacts with the HuR/Elav as well as with several of HuR-target mRNAs. Further, lnc-MIR100HG-depleted cells show reduced interaction between HuR and its target mRNAs, indicating that lnc-MIR100HG facilitates interaction between HuR and target mRNAs. Our studies have unearthed novel roles played by miRHG-encoded lncRNAs in regulating RNA binding protein activity, thereby underscoring the importance of determining the function of several hundreds of miRHG lncRNAs that are present in human genome.
MIR100 host gene-encoded lncRNAs regulate cell cycle by modulating the interaction between HuR and its target mRNAs.
Cell line, Treatment
View SamplesNeuroendocrine prostate cancer (NEPC) is rare historically but may be increasingin prevalence as patients potentially develop resistance to contemporary anti-androgen treatment through a neuroendocrine phenotype. Diagnosis can be straightforward when classic morphological features are accompanied by a prototypical immunohistochemistry profile, however there is increasing recognition of disease heterogeneity and hybrid phenotypes. In the primary setting, small cell prostatic carcinoma (SCPC) is frequently admixed with adenocarcinomas that may be clonally related, while a small fraction of SCPCs express markers typical of prostatic adenocarcinoma. Gene expression patterns may eventually help elucidate the biology underlying equivocal cases with discordant IHC, however studies to date have focused on prototypical cases and been based on few patients due to disease rarity.
Gene expression signatures of neuroendocrine prostate cancer and primary small cell prostatic carcinoma.
Subject
View SamplesInterleukin-1 receptor associated kinase 1 (IRAK1) is an important component of the IL-1R and TLR signaling pathways, which influence Th cell differentiation. Here, we show that IRAK1 promotes Th17 development by mediating IL-1 induced upregulation of IL-23R and subsequent STAT3 phosphorylation, thus enabling sustained IL-17 production. Moreover, we show that IRAK1 signaling fosters Th1 differentiation by mediating T-bet induction and counteracts Treg generation. Cotransfer experiments revealed that Irak1-deficient CD4+ T cells have a cell-intrinsic defect in generating Th1 and Th17 cells under inflammatory conditions in spleen, mesenteric lymph nodes and colon tissue. Furthermore, IRAK1 expression in T cells was shown to be essential for T cell accumulation in the inflamed intestine and mLNs. Transcriptome analysis ex vivo revealed that IRAK1 promotes T cell activation and induction of gut-homing molecules in a cell-intrinsic manner. Accordingly, Irak1-deficient T cells failed to upregulate surface expression of 47 integrin after transfer into Rag1-/- mice and their ability to induce colitis was greatly impaired. Lack of IRAK1 in recipient mice provided additional protection from colitis. Therefore, IRAK1 plays an important role in intestinal inflammation by mediating T cell activation, differentiation and their accumulation in the gut. Thus, IRAK1 is a promising novel target for therapy of inflammatory bowel diseases.
IRAK1 Drives Intestinal Inflammation by Promoting the Generation of Effector Th Cells with Optimal Gut-Homing Capacity.
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