RESUMO
Proteasome-mediated degradation of chromatin-bound NF-κB is critical in terminating the transcription of pro-inflammatory genes and can be triggered by Set9-mediated lysine methylation of the RelA subunit. However, the E3 ligase targeting methylated RelA remains unknown. Here, we find that two structurally similar substrate-recognizing components of Cullin-RING E3 ligases, WSB1 and WSB2, can recognize chromatin-bound methylated RelA for polyubiquitination and proteasomal degradation. We showed that WSB1/2 negatively regulated a subset of NF-κB target genes via associating with chromatin where they targeted methylated RelA for ubiquitination, facilitating the termination of NF-κB-dependent transcription. WSB1/2 specifically interacted with methylated lysines (K) 314 and 315 of RelA via their N-terminal WD-40 repeat (WDR) domains, thereby promoting ubiquitination of RelA. Computational modeling further revealed that a conserved aspartic acid (D) at position 158 within the WDR domain of WSB2 coordinates K314/K315 of RelA, with a higher affinity when either of the lysines is methylated. Mutation of D158 abolished WSB2's ability to bind to and promote ubiquitination of methylated RelA. Together, our study identifies a novel function and the underlying mechanism for WSB1/2 in degrading chromatin-bound methylated RelA and preventing sustained NF-κB activation, providing potential new targets for therapeutic intervention of NF-κB-mediated inflammatory diseases.
Assuntos
Cromatina , Complexo de Endopeptidases do Proteassoma , Fator de Transcrição RelA , Ubiquitinação , Humanos , Cromatina/metabolismo , Células HEK293 , Lisina/metabolismo , Metilação , NF-kappa B/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Proteólise , Fator de Transcrição RelA/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genéticaRESUMO
Snail is a dedicated transcriptional repressor and acts as a master inducer of EMT and metastasis, yet the underlying signaling cascades triggered by Snail still remain elusive. Here, we report that Snail promotes colorectal cancer (CRC) migration by preventing non-coding RNA LOC113230-mediated degradation of argininosuccinate synthase 1 (ASS1). LOC113230 is a novel Snail target gene, and Snail binds to the functional E-boxes within its proximal promoter to repress its expression in response to TGF-ß induction. Ectopic expression of LOC113230 potently suppresses CRC cell growth, migration, and lung metastasis in xenograft experiments. Mechanistically, LOC113230 acts as a scaffold to facilitate recruiting LRPPRC and the TRAF2 E3 ubiquitin ligase to ASS1, resulting in enhanced ubiquitination and degradation of ASS1 and decreased arginine synthesis. Moreover, elevated ASS1 expression is essential for CRC growth and migration. Collectively, these findings suggest that TGF-ß and Snail promote arginine synthesis via inhibiting LOC113230-mediated LRPPRC/TRAF2/ASS1 complex assembly and this complex can serve as potential target for the development of new therapeutic approaches to treat CRC.
Assuntos
Argininossuccinato Sintase , Transição Epitelial-Mesenquimal , Arginina , Linhagem Celular Tumoral , Movimento Celular/genética , Transição Epitelial-Mesenquimal/genética , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição da Família Snail/metabolismo , UbiquitinaçãoRESUMO
Oral squamous cell carcinoma (OSCC), which is typically preceded by oral leukoplakia (OL), is a common malignancy with poor prognosis. However, the signaling molecules governing this progression remain to be defined. Based on microarray analysis of genes expressed in OL and OSCC samples, we discovered that the long non-coding RNA IFITM4P was highly expressed in OSCC, and ectopic expression or knockdown of IFITM4P resulted in increased or decreased cell proliferation in vitro and in xenografted tumors, respectively. Mechanistically, in the cytoplasm IFITM4P acted as a scaffold to facilitate recruiting SASH1 to bind and phosphorylate TAK1 (Thr187), and in turn to increase the phosphorylation of nuclear factor κB (Ser536) and concomitant induction of PD-L1 expression, resulting in activation of an immunosuppressive program that allows OL cells to escape anti-cancer immunity in cytoplasm. In nucleus, IFITM4P reduced Pten transcription by enhancing the binding of KDM5A to the Pten promoter, thereby upregulating PD-L1 in OL cells. Moreover, mice bearing tumors with high IFITM4P expression had notable therapeutic sensitivity to PD-1 monoclonal antibody (mAb) treatment. Collectively, these data demonstrate that IFITM4P may serve as a new therapeutic target in blockage of oral carcinogenesis, and PD-1 mAb can be an effective reagent to treat OSCC.
Assuntos
Carcinoma de Células Escamosas , Neoplasias Bucais , RNA Longo não Codificante , Animais , Anticorpos Monoclonais , Antígeno B7-H1/metabolismo , Carcinogênese/genética , Carcinoma de Células Escamosas/metabolismo , Linhagem Celular Tumoral , Camundongos , Neoplasias Bucais/genética , Neoplasias Bucais/metabolismo , Receptor de Morte Celular Programada 1 , RNA Longo não Codificante/genéticaRESUMO
Sulfation is an essential modification on biomolecules in living cells, and 3'-Phosphoadenosine-5'-phosphosulfate (PAPS) is its unique and universal sulfate donor. Human PAPS synthases (PAPSS1 and 2) are the only enzymes that catalyze PAPS production from inorganic sulfate. Unexpectedly, PAPSS1 and PAPSS2 do not functional complement with each other, and abnormal function of PAPSS2 but not PAPSS1 leads to numerous human diseases including bone development diseases, hormone disorder and cancers. Here, we reported the crystal structures of ATP-sulfurylase domain of human PAPSS2 (ATPS2) and ATPS2 in complex with is product 5'-phosphosulfate (APS). We demonstrated that ATPS2 recognizes the substrates by using family conserved residues located on the HXXH and PP motifs, and achieves substrate binding and releasing by employing a non-conserved phenylalanine (Phe550) through a never observed flipping mechanism. Our discovery provides additional information to better understand the biological function of PAPSS2 especially in tumorigenesis, and may facilitate the drug discovery against this enzyme.
Assuntos
Trifosfato de Adenosina/química , Complexos Multienzimáticos/química , Proteínas de Neoplasias/química , Fosfoadenosina Fosfossulfato/química , Sulfato Adenililtransferase/química , Trifosfato de Adenosina/metabolismo , Sequência de Aminoácidos , Domínio Catalítico , Clonagem Molecular , Cristalografia por Raios X , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Humanos , Modelos Moleculares , Complexos Multienzimáticos/genética , Complexos Multienzimáticos/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Fosfoadenosina Fosfossulfato/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Sulfato Adenililtransferase/genética , Sulfato Adenililtransferase/metabolismo , TermodinâmicaRESUMO
Estrogen/ERα signaling is critical for breast cancer progression and therapeutic treatments. Thus, identifying new regulators of this pathway will help to develop new therapeutics to overcome chemotherapy resistance of the breast cancer cells. Here, we report Ajuba directly interacts with ERα to potentiate ERα target gene expression, and biologically Ajuba promotes breast cancer cell growth and contributes to tamoxifen resistance of these cells. Ajuba constitutively binds the DBD and AF2 regions of ERα, and these interactions can be markedly enhanced by estrogen treatment. Mechanistically, Ajuba recruits DBC1 and CBP/p300 and forms a ternary complex to co-activate ERα transcriptional activity and concomitantly enhances ERα acetylation. Moreover, components of this complex can be found at endogenous promoters containing functional ERα responsive elements. Taken together, these data demonstrate that Ajuba functions as a novel co-activator of ERα and that Ajuba/DBC1/CBP/p300 ternary complex may be a new target for developing therapeutics to treat breast cancer.
Assuntos
Neoplasias da Mama/genética , Receptor alfa de Estrogênio/química , Receptor alfa de Estrogênio/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas com Domínio LIM/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Fatores de Transcrição de p300-CBP/metabolismo , Acetilação , Neoplasias da Mama/patologia , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Receptor alfa de Estrogênio/agonistas , Estrogênios/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas com Domínio LIM/genética , Proteínas do Tecido Nervoso , Ligação Proteica/efeitos dos fármacos , Tamoxifeno/antagonistas & inibidores , Tamoxifeno/farmacologia , Transcrição Gênica/efeitos dos fármacosRESUMO
The LIM protein Ajuba contains an unstructured proline/glycine-rich preLIM region in the N terminus and conserved tandem LIM motifs in the C terminus. Additionally, Ajuba contains both nuclear export sequences (NES) and nuclear localization sequences (NLS), which enable Ajuba shuttle between the cytoplasm and the nucleus. Thus, Ajuba can act as a versatile scaffold participating in assembly of variety of protein complexes to execute multiple cellular functions including cell adhesion, motility, mitosis, survival, gene expression, microRNA processing and mechanical force sensing. Numerous studies have demonstrated that Ajuba plays important roles in oncogenesis and progression by regulating major signalling pathways such as Wnt, RAS/ERK, JAK/STAT and Hippo, and by acting as a co-regulator of key transcription factors such as Snail, Sp1 and nuclear hormone receptors. Clinically, Ajuba is highly expressed in various types of tumors and can be a marker for prognosis and diagnosis. In this review, we aim to summarize the up-to-date literatures on the signaling pathways mediated by Ajuba and its associated protein complexes in oncogenesis, and to discuss Ajuba as a potential target for new therapeutics to treat cancers.
Assuntos
Carcinogênese/metabolismo , Proteínas com Domínio LIM/metabolismo , Transdução de Sinais , Animais , Apoptose , Carcinogênese/patologia , Adesão Celular , Humanos , Proteínas com Domínio LIM/análise , Mitose , Neoplasias/metabolismo , Neoplasias/patologia , Mapas de Interação de ProteínasRESUMO
Individuals with inflammatory bowel disease are at high risk of developing colitis-associated cancer (CAC). Strategies to block the process from inflammatory bowel disease to CAC should be considered. In the experiment, we aim to explore the chemopreventive efficacy of the probiotic cocktail Bifico and its potential mechanism in azoxymethane and dextran sodium sulphate-induced CAC in mice. Oral pretreatment of Bifico was adopted to evaluate its protective effect. The colorectums of 35 C57BL/6 mice were collected and examined for the degree of inflammation and tumorigenesis. Comparative 16S rRNA sequencing was carried out to observe Bifico-target alterations in gene expression and microbiota structure. We found that pretreatment of Bifico alleviated intestinal inflammation and reduced tumor formation. Furthermore, we identified a subset of genes as potential targets of Bifico treatment, including CXCL1, CXCL2, CXCL3, and CXCL5, which are all ligands of C-X-C motif receptor 2 (CXCR2). The 16S rRNA sequencing showed that Bifico decreased the abundance of genera Desulfovibrio, Mucispirillum, and Odoribacter, and a bloom of genus Lactobacillus was detected. Notably, we found that an abundance of these Bifico-target taxa was significantly associated with the expression of CXCR2 ligand genes. Our studies indicate that Bifico, given orally, can ameliorate CAC in mice through intervening with the possible link between Desulfovibrio, Mucispirillum, Odoribacter, Lactobacillus, and CXCR2 signaling.
Assuntos
Bactérias/classificação , Bactérias/efeitos dos fármacos , Colite/induzido quimicamente , Neoplasias Colorretais/tratamento farmacológico , Perfilação da Expressão Gênica/métodos , Probióticos/administração & dosagem , Administração Oral , Animais , Azoximetano , Bactérias/genética , Quimiocinas CXC/genética , Colite/complicações , Colite/genética , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/genética , Sulfato de Dextrana , Modelos Animais de Doenças , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Probióticos/farmacologia , RNA Ribossômico 16S/genética , Transdução de Sinais , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Optic pathway hypothalamic gliomas are intrinsic low-grade gliomas involving the optic nerve, chiasm, optic tract, and hypothalamus. The rarity of these tumors and their unpredictable course make assessment and standardization of treatment modalities difficult. Tumor debulking via various transcranial approaches was considered to be effective at controlling tumor growth, but with high rates of severe surgery-related complications. In the present case, endoscopic transsphenoidal surgery was initiated to debulk the exophytic chiasmatic/hypothalamic glioma with good preservation of hypothalamic and endocrine functions. The authors suggest transsphenoidal surgery with tumor debulking could be an effective and safe treatment for patients with chiasmatic/hypothalamic gliomas.
Assuntos
Astrocitoma/cirurgia , Endoscopia , Neoplasias Hipotalâmicas/cirurgia , Quiasma Óptico/cirurgia , Neoplasias do Nervo Óptico/cirurgia , Adulto , Astrocitoma/diagnóstico por imagem , Astrocitoma/patologia , Humanos , Neoplasias Hipotalâmicas/diagnóstico por imagem , Neoplasias Hipotalâmicas/patologia , Masculino , Quiasma Óptico/diagnóstico por imagem , Quiasma Óptico/patologia , Neoplasias do Nervo Óptico/diagnóstico por imagem , Neoplasias do Nervo Óptico/patologiaRESUMO
Surface expression of voltage-gated Ca(2+) (Cav) channels is important for their function in calcium homeostasis in the physiology of excitable cells, but whether or not and how the α1 pore-forming subunits of Cav channels are trafficked to plasma membrane in the absence of the known Cav auxiliary subunits, ß and α2δ, remains mysterious. Here we showed that 14-3-3 proteins promoted functional surface expression of the Cav2.2 α1B channel in transfected tsA-201 cells in the absence of any known Cav auxiliary subunit. Both the surface to total ratio of the expressed α1B protein and the current density of voltage step-evoked Ba(2+) current were markedly suppressed by the coexpression of a 14-3-3 antagonist construct, pSCM138, but not its inactive control, pSCM174, as determined by immunofluorescence assay and whole cell voltage clamp recording, respectively. By contrast, coexpression with 14-3-3τ significantly enhanced the surface expression and current density of the Cav2.2 α1B channel. Importantly, we found that between the two previously identified 14-3-3 binding regions at the α1B C terminus, only the proximal region (amino acids 1706-1940), closer to the end of the last transmembrane domain, was retained by the endoplasmic reticulum and facilitated by 14-3-3 to traffic to plasma membrane. Additionally, we showed that the 14-3-3/Cav ß subunit coregulated the surface expression of Cav2.2 channels in transfected tsA-201 cells and neurons. Altogether, our findings reveal a previously unidentified regulatory function of 14-3-3 proteins in promoting the surface expression of Cav2.2 α1B channels.
Assuntos
Proteínas 14-3-3/metabolismo , Canais de Cálcio Tipo N/metabolismo , Proteínas 14-3-3/genética , Animais , Western Blotting , Canais de Cálcio Tipo N/genética , Membrana Celular/metabolismo , Células Cultivadas , Eletrofisiologia , Retículo Endoplasmático/metabolismo , Imunoprecipitação , Ligação Proteica , Transporte Proteico/fisiologia , Ratos , Ratos Sprague-DawleyRESUMO
Corepressors play an essential role in nuclear receptor-mediated transcriptional repression. In general, corepressors directly bind to nuclear receptors via CoRNR boxes (L/I-X-X-I/V-I) in the absence of ligand and appear to act as scaffolds to further recruit chromatin remodeling complexes to specific target genes. Here, we describe the identification of the multiple LIM domain protein Ajuba as a unique corepressor for a subset of nuclear hormone receptors. Ajuba contains functional nuclear-receptor interacting motifs and selectively interacts with retinoic acid receptors (RARs) and rexinoid receptor (RXRs) subtypes in a ligand-dependent manner. Simultaneous mutation of these motifs abolishes RAR binding and concomitantly leads to loss of repression on RARE reporter genes. P19 cells depleted of Ajuba are highly sensitized to all-trans retinoic acid (atRA)-induced transcription and differentiation. In the absence of atRA, Ajuba can be readily found at the RARE control elements of RAR endogenous target genes. Stimulation of cells with atRA results in the dissociation of Ajuba from these regions. Moreover, we observed that coexpression of the known Ajuba binding partner Prmt5 (protein arginine methyltransferase-5) inhibited the Ajuba/RAR interaction. The high-affinity Ajuba-RAR/RXR interaction site overlaps the region responsible for Ajuba/Prmt5 binding, and thus binding appears to be mutually exclusive, providing a potential mechanism for these observations. Identification of Ajuba as a unique corepressor for nuclear receptors sheds new light on mechanisms for nuclear receptor-mediated repression and provides a unique target for developing more effective therapeutics to modulate this important pathway.
Assuntos
Proteínas Correpressoras/metabolismo , Regulação da Expressão Gênica/fisiologia , Proteínas de Homeodomínio/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Transdução de Sinais/fisiologia , Tretinoína/metabolismo , Motivos de Aminoácidos/genética , Motivos de Aminoácidos/fisiologia , Animais , Western Blotting , Linhagem Celular , Imunoprecipitação da Cromatina , Humanos , Imunoprecipitação , Proteínas com Domínio LIM , Luciferases , Camundongos , Microscopia de Fluorescência , Ligação Proteica , Proteína-Arginina N-Metiltransferases/metabolismo , Receptores do Ácido Retinoico/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Abnormal levels of some peripheral cytokines have been reported in children patients with tic disorders (TDs), but none of these cytokines can be a biomarker for this disease. Our aim was to systemically profile differentially expressed cytokines (DECs) in the blood of TD patients, examine their associations with TD development, and identify from them potential biomarkers for the prediction and management of the risk for TDs. In this study, a cytokine array capable of measuring 105 cytokines was used to screen for DECs in the plasma from 53 comorbidity-free and drug-naïve TD patients and 37 age-matched healthy controls. DECs were verified by ELISA and their associations with TD development were evaluated by binary logistic regression analysis. Elevation of a set of cytokines was observed in TD patients compared with controls, including previously uncharacterized cytokines in tic disorders, CCL5, Serpin E1, Thrombospondin-1, MIF, PDGF-AA, and PDGF-AB/BB. Further analysis of DECs revealed a significant association of elevated CCL5 with TD development (p = 0.005) and a significant ROC curve for CCL5 as a risk factor [AUC, 0.801 (95% CI: 0.707-0.895), p < 0.0001]. Conclusion: This study identifies associations of a set of circulating cytokines, particularly CCL5 with TD development, and provides evidence that high blood CCL5 has potential to be a risk factor for TD development. Clinical Trial Registration: identifier ChiCTR-2000029616.
RESUMO
Snail is a denoted transcriptional repressor that plays key roles in epithelial-mesenchymal transition (EMT) and metastasis. Lately, a plethora of genes can be induced by stable expression of Snail in multiple cell lines. However, the biological roles of these upregulated genes are largely elusive. Here, we report identification of a gene encoding the key GlcNAc sulfation enzyme CHST2 is induced by Snail in multiple breast cancer cells. Biologically, CHST2 depletion results in inhibition of breast cancer cell migration and metastasis, while overexpression of CHST2 promotes cell migration and lung metastasis in nude mice. In addition, the expression level of MECA79 antigen is elevated and blocking the cell surface MECA79 antigen with specific antibodies can override cell migration mediated by CHST2 upregulation. Moreover, the sulfation inhibitor sodium chlorate effectively inhibits the cell migration induced by CHST2. Collectively, these data provide novel insights into the biology of Snail/CHST2/MECA79 axis in breast cancer progression and metastasis as well as potential therapeutic strategy for the diagnosis and treatment of breast cancer metastasis.
Assuntos
Transição Epitelial-Mesenquimal , Transdução de Sinais , Animais , Camundongos , Fatores de Transcrição da Família Snail/metabolismo , Linhagem Celular Tumoral , Camundongos Nus , Movimento Celular/fisiologia , Metástase Neoplásica , Regulação Neoplásica da Expressão GênicaRESUMO
Inflammatory cytokines participate in the pathology of epilepsy and the development of drug resistance. In this study, we combined a cytokine array and enzyme-linked immunosorbent assay to identify new cytokines in the plasma from children on early stage of the onset of epilepsy (EOE) and children with drug-resistant epilepsy (DRE). Compared with healthy controls, a broad up-regulation of cytokines was observed in patients with EOE, and many of the cytokines were not previously reported. In patients with DRE, most of these up-regulated cytokines maintained at relatively low levels close to those in controls; only a few of them, including CCL5, Serpin E1, and IGFBP2, remained at high levels. The dramatic difference in cytokine profile could be a strong clue for the incidence of DRE, and DRE-associated cytokines appeared to have the potential to be new biomarkers for epilepsy prognosis and therapeutic targets.
RESUMO
Malignant breast cancer (BC) remains incurable mainly due to the cancer cell metastasis, which is mostly related to the status of Estrogen receptor alpha (ERα). However, our understanding of the mechanisms through which ERα regulates cancer cell metastasis remains limited. Here we identified a miR-29a-PTEN-AKT axis as a downstream signaling pathway of ERα governing breast cancer progression and metastasis. Two estrogen response element (ERE) half sites were identified in the promoter and enhancer regions of miR-29a, which mediated transcriptional regulation of miR-29a by ERα. Low level of miR-29a showed association with reduced metastasis and better survival in ERα+ luminal subtype of BC. In contrast, high level of miR-29a was detected in ERα- triple negative breast cancer (TNBC) in association with distant metastasis and poor survival. miR-29a overexpression in BC tumors increased the number of circulating tumor cells and promoted lung metastasis in mice. Targeted knockdown of miR-29a in TNBC cells in vitro or administration of a nanotechnology-based anti-miR-29a delivery in TNBC tumor-bearing mice in vivo suppressed cellular invasion, EMT and lung metastasis. PTEN was identified as a direct target of miR-29a, inducing EMT and metastasis via AKT signaling. A small molecular inhibitor of AKT attenuated miR-29a-induced EMT. These findings demonstrate a novel mechanism responsible for ERα-regulated breast cancer metastasis, and reveal the combination of ERα status and miR-29a levels as a new risk indicator in BC.
Assuntos
Neoplasias da Mama , Neoplasias Pulmonares , MicroRNAs , Neoplasias de Mama Triplo Negativas , Humanos , Animais , Camundongos , Feminino , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Neoplasias Pulmonares/genética , Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral , Proliferação de Células , Melanoma Maligno CutâneoRESUMO
The transcriptional repressor Snail induces EMT during embryonic development and tumor metastasis. Growing evidence indicates that Snail functions as a trans-activator to induce gene expression; however, the underlying mechanism remains elusive. Here, we report that Snail cooperates with GATA zinc finger protein p66ß to transactivate genes in breast cancer cells. Biologically, depletion of p66ß reduces cell migration and lung metastasis in BALB/c mice. Mechanistically, Snail interacts with p66ß and cooperatively induces gene transcription. Notably, a group of genes induced by Snail harbor conserved G-rich cis-elements (5'-GGGAGG-3', designated as G-box) in their proximal promoter regions. Snail directly binds to G-box via its zinc fingers and transactivates the G-box-containing promoters. p66ß enhances Snail binding affinity to G-box, whereas depletion of p66ß results in a decreased binding affinity of Snail to the endogenous promoters and concomitantly reduces the transcription of Snail-induced genes. Taken together, these data demonstrated that p66ß is critical for Snail-mediated cell migration by acting as a co-activator of Snail to induce genes containing G-box elements in the promoters.
Assuntos
Neoplasias Pulmonares , Fatores de Transcrição , Feminino , Gravidez , Animais , Camundongos , Fatores de Transcrição/genética , Movimento Celular/genética , Desenvolvimento Embrionário , Neoplasias Pulmonares/genética , Camundongos Endogâmicos BALB C , Dedos de ZincoRESUMO
Subsequently to the publication of the above paper, the authors have reviewed its content and the primary data, and have realized that the western blots selected to show the ßactin experiments featured in Fig. 4A and Fig. 3C were the same blot, albeit with a different exposure time. The control blots correctly presented for Fig. 3C were inadvertently copied into Fig. 4A owing to an error made during the figure compilation process. The revised version of Fig. 4, containing the correct ßactin blots for Fig. 4A, is shown below. Note that this error did not significantly affect the results or the conclusions reported in this paper, and all the authors agree to this Corrigendum. The authors thank the Editor of Molecular Medicine Reports for allowing them the opportunity to publish this corrigendum, and apologize to the readership for any inconvenience caused. [Molecular Medicine Reports 10: 28912897, 2014; DOI: 10.3892/mmr.2014.2614].
RESUMO
Adipogenesis is regulated by a complicated network of transcription factors among which PPARγ and C/EBP family members are the major regulators. During adipogenesis, C/EBPß is induced early and then transactivates PPARγ and C/EBPα, which cooperatively induce genes whose expressions give rise to the mature adipocyte phenotype. Identifying the factors that influence the expression and activity of C/EBPß should provide additional insight into the mechanisms regulating adipogenesis. Here, we demonstrate that depletion of Ajuba in 3T3-L1 cells significantly decreases mRNA and protein levels of PPARγ and C/EBPα and impairs adipocyte differentiation, while overexpression increases expression of these genes and promotes adipocyte differentiation. Moreover, restoration of C/EBPα or PPARγ expression in Ajuba-deficient 3T3-L1 cells improves the impaired lipid accumulation. Mechanistically, Ajuba interacts with C/EBPß and recruits CBP to facilitate the binding of C/EBPß to the promoter of PPARγ and C/EBPα, resulting in increased H3 histone acetylation and target gene expression. Collectively, these data indicate that Ajuba functions as a co-activator of C/EBPß, and may be an important therapeutic target for combating obesity-related diseases.
Assuntos
Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Proteínas com Domínio LIM/genética , PPAR gama/metabolismo , Células 3T3-L1 , Adipogenia , Animais , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Diferenciação Celular , Regulação da Expressão Gênica , Células HEK293 , Humanos , Proteínas com Domínio LIM/metabolismo , Metabolismo dos Lipídeos , Camundongos , PPAR gama/genéticaRESUMO
Lysyl oxidase-like 2 (LOXL2) is a member of the scavenger receptor cysteine-rich (SRCR) repeat carrying LOX family. Although LOXL2 is suspected to be involved in histone association and chromatin modification, the role of LOXL2 in epigenetic regulation during tumorigenesis and cancer progression remains unclear. Here, we report that nuclear LOXL2 associates with histone H3 and catalyzes H3K36ac deacetylation and deacetylimination. Both the N-terminal SRCR repeats and the C-terminal catalytic domain of LOXL2 carry redundant deacetylase catalytic activity. Overexpression of LOXL2 markedly reduced H3K36 acetylation and blocked H3K36ac-dependent transcription of genes, including c-MYC, CCND1, HIF1A, and CD44. Consequently, LOXL2 overexpression reduced cancer cell proliferation in vitro and inhibited xenograft tumor growth in vivo. In contrast, LOXL2 deficiency resulted in increased H3K36 acetylation and aberrant expression of H3K36ac-dependent genes involved in multiple oncogenic signaling pathways. Female LOXL2-deficient mice spontaneously developed uterine hypertrophy and uterine carcinoma. Moreover, silencing LOXL2 in cancer cells enhanced tumor progression and reduced the efficacy of cisplatin and anti-programmed cell death 1 (PD-1) combination therapy. Clinically, low nuclear LOXL2 expression and high H3K36ac levels corresponded to poor prognosis in uterine endometrial carcinoma patients. These results suggest that nuclear LOXL2 restricts cancer development in the female reproductive system via the regulation of H3K36ac deacetylation. SIGNIFICANCE: LOXL2 loss reprograms the epigenetic landscape to promote uterine cancer initiation and progression and repress the efficacy of anti-PD-1 immunotherapy, indicating that LOXL2 is a tumor suppressor.
Assuntos
Aminoácido Oxirredutases , Epigênese Genética , Humanos , Camundongos , Feminino , Animais , Aminoácido Oxirredutases/genética , Aminoácido Oxirredutases/metabolismo , Acetilação , Histonas/metabolismo , Hipertrofia/genética , Expressão GênicaRESUMO
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel strain of highly contagious coronaviruses that infects humans. Prolonged fever, particularly that above 39.5 °C, is associated with SARS-CoV-2 infection. However, little is known about the pathological effects of fever caused by SARS-CoV-2. Methods: Primary bovine alveolar macrophages (PBAMs), RAW264.7 mouse macrophages, and THP-1 human cells were transfected with plasmids carrying the genes encoding the SARS-CoV-2 spike (S) protein or receptor-binding domain (RBD). Proteins in the macrophages interacting with S-RBD at 39.5 °C or 37 °C were identified by immunoprecipitation-mass spectrometry. Glutathione S-transferase pulldown, surface plasmon resonance, and immunofluorescence were performed to evaluate the transient receptor potential vanilloid 2 (TRPV2) interaction with SARS-CoV-2-S-RBD at 39.5 °C. Using an RNA sequencing-based approach, cytokine gene expression induced by SARS-CoV-2 S transfection at 39.5 °C and 37.5 °C in primary alveolar macrophages was measured. Fluo-4 staining and enzyme-linked immunosorbent assays were used to assess the regulatory function of TRPV2 in intracellular Ca 2+ and cytokines under SARS-CoV-2-S-RBD at 39.5 °C. Additionally, cytokine release was examined after TRPV2 knockdown with shRNA oligonucleotides or inhibition using the SKF-96365 antagonist. Results: We identified an interaction between the primary alveolar macrophage receptor TRPV2 and S-RBD under febrile conditions. Febrile temperature promotes Ca2+ influx through SARS-CoV-2 infection in PBAMs, further activates the NF-κB p65 signaling pathway, and enhances the secretion of cytokines. Furthermore, knockdown or antagonist (with SKF-96365) of TRPV2 significantly decreased the release of cytokines that drive the inflammatory response. Conclusion: Collectively, our findings identified TRPV2 as a receptor of SARS-CoV-2 in conditions of febrile temperature, providing insight into critical interactions of SARS-CoV-2 with macrophages, as well as a useful resource and potential drug target for coronavirus disease 2019.
Assuntos
COVID-19/virologia , Febre/virologia , Macrófagos/metabolismo , Macrófagos/virologia , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Canais de Cátion TRPV/metabolismo , Internalização do Vírus , Animais , Cálcio/metabolismo , Bovinos , Células Cultivadas , Citocinas/metabolismo , Humanos , Imidazóis/farmacologia , Cinética , Macrófagos/efeitos dos fármacos , Camundongos , NF-kappa B/metabolismo , Ligação Proteica/efeitos dos fármacos , Células RAW 264.7 , SARS-CoV-2/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Células THP-1 , Temperatura , Internalização do Vírus/efeitos dos fármacosRESUMO
Dual specificity tyrosine phosphorylation regulated kinase 1A, DYRK1A, functions in multiple cellular pathways, including signaling, endocytosis, synaptic transmission, and transcription. Alterations in dosage of DYRK1A leads to defects in neurogenesis, cell growth, and differentiation, and may increase the risk of certain cancers. DYRK1A localizes to a number of subcellular structures including vesicles where it is known to phosphorylate a number of proteins and regulate vesicle biology. However, the mechanism by which it translocates to vesicles is poorly understood. Here we report the discovery of TRAF2, an E3 ligase, as an interaction partner of DYRK1A. Our data suggest that TRAF2 binds to PVQE motif residing in between the PEST and histidine repeat domain (HRD) of DYRK1A protein, and mediates K63-linked ubiquitination of DYRK1A. This results in translocation of DYRK1A to the vesicle membrane. DYRK1A increases phosphorylation of Sprouty 2 on vesicles, leading to the inhibition of EGFR degradation, and depletion of TRAF2 expression accelerates EGFR degradation. Further, silencing of DYRK1A inhibits the growth of glioma cells mediated by TRAF2. Collectively, these findings suggest that the axis of TRAF2-DYRK1A-Sprouty 2 can be a target for new therapeutic development for EGFR-mediated human pathologies.