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1.
J Exp Med ; 218(3)2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33616624

RESUMO

Frequent outbreaks of viruses have caused a serious threat to public health. Previous evidence has revealed that DNA methylation is correlated with viral infections, but its role in innate immunity remains poorly investigated. Additionally, DNA methylation inhibitors promote IFN-I by upregulating endogenous retrovirus; however, studies of intrinsically demethylated tumors do not support this conclusion. This study found that Uhrf1 deficiency in myeloid cells significantly upregulated Ifnb expression, increasing resistance to viral infection. We performed whole-genome bisulfite sequencing and found that a single-nucleotide methylation site in the Ifnb promoter region disrupted IRF3 recruitment. We used site-specific mutant knock-in mice and a region-specific demethylation tool to confirm that this methylated site plays a critical role in regulating Ifnb expression and antiviral responses. These findings provide essential insight into DNA methylation in the regulation of the innate antiviral immune response.

2.
Biochim Biophys Acta Mol Cell Res ; 1868(1): 118878, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33011193

RESUMO

Ovarian cancer is the deadliest gynaecologic malignancy, and the five-year survival rate of patients is less than 35% worldwide. Cancer stem cells (CSCs) are a population of cells with stem-like characteristics that are thought to cause chemoresistance and recurrence. TRIM29 is aberrantly expressed in various cancers and associated with cancer development and progression. Previous studies showed that the upregulation of TRIM29 expression in pancreatic cancer is related to stem-like characteristics. However, the role of TRIM29 in ovarian cancer is poorly understood. In this study, we found that TRIM29 expression was increased at the translational level in both the cisplatin-resistant ovarian cancer cells and clinical tissues. Increased TRIM29 expression was associated with a poor prognosis of patients with ovarian cancer. In addition, TRIM29 could enhance the CSC-like characteristics of the cisplatin-resistant ovarian cancer cells. Recruitment of YTHDF1 to m6A-modified TRIM29 was involved in promoting TRIM29 translation in the cisplatin-resistant ovarian cancer cells. Knockdown of YTHDF1 suppressed the CSC-like characteristics of the cisplatin-resistant ovarian cancer cells, which could be rescued by ectopic expression of TRIM29. This study suggests TRIM29 may act as an oncogene to promote the CSC-like features of cisplatin-resistant ovarian cancer in an m6A-YTHDF1-dependent manner. Due to the roles of TRIM29 and YTHDF1 in the promotion of CSC-like features, they may become potential therapeutic targets to combat the recurrence of ovarian cancer.

3.
Sci China Life Sci ; 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33141302

RESUMO

Interferon regulatory factors (IRFs) play pivotal and critical roles in innate and adaptive immune responses; thus, precise and stringent regulation of the stability and activation of IRFs in physiological processes is necessary. The stability and activities of IRFs are directly or indirectly targeted by endogenous and exogenous proteins in an ubiquitin-dependent manner. However, few reviews have summarized how host E3 ligases/DUBs or viral proteins regulate IRF stability and activity. Additionally, with recent technological developments, details about the ubiquitination of IRFs have been continuously revealed. As knowledge of how these proteins function and interact with IRFs may facilitate a better understanding of the regulation of IRFs in immune responses or other biological processes, we summarized current studies on the direct ubiquitination of IRFs, with an emphasis on how these proteins interact with IRFs and affect their activities, which may provide exciting targets for drug development by regulating the functions of specific E3 ligases.

4.
Biochim Biophys Acta Mol Cell Res ; 1867(4): 118647, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31926942

RESUMO

Cisplatin-based chemotherapies have long been considered as a standard chemotherapy in ovarian cancer. However, cisplatin resistance restricts beneficial therapy for patients with ovarian cancer. The ubiquitin-like protein interferon-stimulated gene 15 (ISG15) encodes a 15-kDa protein, that is implicated in the post-translational modification of diverse proteins. In this work, we found that ISG15 was downregulated in cisplatin resistant tissues and cell lines of ovarian cancer. Functional studies demonstrated that overexpression of wild type (WT) ISG15, but not nonISGylatable (Mut) ISG15 increased cell responses to cisplatin in resistant ovarian cancer cells. Furthermore, we found that WT ISG15 decreased ABCC2 expression at the protein level. Importantly, overexpression of ABCC2 blocked sensitizing effect of ISG15 on cisplatin. In addition, we identified that hnRNPA2B1 was recruited to 5'UTR of ABCC2 mRNA and promoted its translation, which was blocked by ISG15. We further demonstrated that hnRNPA2B1 could be ISGylated, and ISGylation blocked its recruitment to ABCC2 mRNA, thereby suppressed translation of ABCC2. Altogether, our data support targeting ISG15 might be a potential therapeutic strategy for patients with cisplatin-resistant ovarian cancer.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Citocinas/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Neoplasias Ovarianas/genética , Biossíntese de Proteínas , Ubiquitinas/metabolismo , Regiões 5' não Traduzidas , Adulto , Idoso , Linhagem Celular Tumoral , Citocinas/genética , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Pessoa de Meia-Idade , Proteínas Associadas à Resistência a Múltiplos Medicamentos/biossíntese , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Neoplasias Ovarianas/metabolismo , RNA Mensageiro/metabolismo , Ubiquitinas/genética
5.
Oncogene ; 39(3): 546-559, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31501523

RESUMO

TRIM family proteins are defined as E3 ubiquitin ligases because of their RING-finger domains. The ubiquitin-like protein interferon-stimulated gene 15 (ISG15) encodes a 15-kDa protein, that is implicated in the posttranslational modification of diverse proteins. Both TRIM29 and ISG15 play both pro-tumoral and anti-tumoral functions in cancer cells derived from different histology. In the current study, we demonstrated that correlation expression of TRIM29 and ISG15 in pancreatic ductal adenocarcinomas (PDACs). The current study demonstrated that TRIM29 knockdown destabilized ISG15 protein via promoting its processing by calpain 3 (CAPN3). Importantly, the current study found that TRIM29 knockdown suppressed cancer stem cell-like features of PDACs, which can be rescued by ISG15 independent of its conjugation function. In addition, the current study demonstrated that extracellular free ISG15 played an important role in maintenance of cancer stem cell-like features of PDACs. Thereby, the current study displayed a novel mechanism by which TRIM29 modulates ISG15 stability via CAPN3-mediated processing, and subsequently extracellular ISG15 maintains the cancer stem cell-like features of PDAC via autocrine mode of action.


Assuntos
Carcinoma Ductal Pancreático/patologia , Citocinas/metabolismo , Proteínas de Ligação a DNA/metabolismo , Células-Tronco Neoplásicas/patologia , Neoplasias Pancreáticas/patologia , Fatores de Transcrição/metabolismo , Ubiquitinas/metabolismo , Animais , Comunicação Autócrina , Calpaína/metabolismo , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Feminino , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Proteínas Musculares/metabolismo , Proteólise , Fatores de Transcrição/genética , Ensaios Antitumorais Modelo de Xenoenxerto
6.
J Cell Mol Med ; 24(1): 562-572, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31657880

RESUMO

Solid tumour frequently undergoes metabolic stress during tumour development because of inadequate blood supply and the high nutrient expenditure. p53 is activated by glucose limitation and maintains cell survival via triggering metabolic checkpoint. However, the exact downstream contributors are not completely identified. BAG3 is a cochaperone with multiple cellular functions and is implicated in metabolic reprogramming of pancreatic cancer cells. The current study demonstrated that glucose limitation transcriptionally suppressed BAG3 expression in a p53-dependent manner. Importantly, hinderance of its down-regulation compromised cellular adaptation to metabolic stress triggered by glucose insufficiency, supporting that BAG3 might be one of p53 downstream contributors for cellular adaptation to metabolic stress. Our data showed that ectopic BAG3 expression suppressed p53 accumulation via direct interaction under metabolic stress. Thereby, the current study highlights the significance of p53-mediated BAG3 suppression in cellular adaptation to metabolic stress via facilitating p53 accumulation.

7.
J Cell Mol Med ; 23(8): 5006-5016, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31119886

RESUMO

BAG3 is constitutively expressed in multiple types of cancer cells and its high expression is associated with tumour progression and poor prognosis of PDAC. However, little is known about the role of BAG3 in the regulation of stromal microenvironment of PDAC. The current study demonstrated that beside PDAC tumour cells, BAG3 was also expressed in some activated stroma cells in PDAC tissue, as well as in activated PSCs. In addition, the current study demonstrated that BAG3 expression in PSCs was involved in maintenance of PSCs activation and promotion of PDACs invasion via releasing multiple cytokines. The current study demonstrated that BAG3-positive PSCs promoted invasion of PDACs via IL-8, MCP1, TGF-ß2 and IGFBP2 in a paracrine manner. Furthermore, BAG3 sustained PSCs activation through IL-6, TGF-ß2 and IGFBP2 in an autocrine manner. Thereby, the current study provides a new insight into the involvement of BAG3 in remodelling of stromal microenvironment favourable for malignant progression of PDAC, indicating that BAG3 might serve as a potential target for anti-fibrosis of PDAC.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Neoplasias Pancreáticas/metabolismo , Células Estreladas do Pâncreas/metabolismo , Microambiente Tumoral/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Reguladoras de Apoptose/genética , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Citocinas/metabolismo , Humanos , Imuno-Histoquímica , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/genética , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucina-8/genética , Interleucina-8/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
8.
Biochem Biophys Res Commun ; 513(4): 852-856, 2019 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-31000199

RESUMO

Glucose limitation activates p53, which functions as an adaptive response to maintain cell survival. However, p53 is frequently deleted or mutated in a variety of tumors, while most cancer cells can acclimatize themselves to metabolically unfavorable surrounding, indicating that alternative mechanisms other than p53 transactivation underly adaptive response of cancer cells with p53 deletion or mutation to metabolically hostile environment. Sestrin 2 (SESN2) is a p53 downstream target, which plays a protective role against various stressful stimuli, such as genotoxic, energetic, and oxidative stress. In the current study, we demonstrated that SESN2 transcript was stabilized by glucose limitation at the posttranscriptional level irrespective of p53 status. Importantly, SESN2 also protected cells from metabolic stress triggered by glucose limitation in a p53-independent manner. Our data indicated that stabilization of SESN2 transcript might be an alternative adaptive response to metabolic stress other than p53 activation. Thereby, the current study highlights the significance of stabilization of SESN2 transcript in adaptation of cells with p53 deletion or mutation to metabolic stress.


Assuntos
Citoproteção , Proteínas Nucleares/metabolismo , Estresse Fisiológico , Proteína Supressora de Tumor p53/metabolismo , Animais , Linhagem Celular Tumoral , Glucose/deficiência , Camundongos , Estabilidade de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
9.
Cell Death Dis ; 10(4): 284, 2019 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-30910998

RESUMO

Bcl-2 associated athanogene 3 (BAG3) is an important molecule that maintains oncogenic features of cancer cells via diverse mechanisms. One of the important functions assigned to BAG3 is implicated in selective macroautophagy/autophagy, which attracts much attention recently. However, the mechanism underlying regulation of autophagy by BAG3 has not been well defined. Here, we describe that BAG3 enhances autophagy via promotion of glutamine consumption and glutaminolysis. Glutaminolysis initiates with deamination of glutamine by glutaminase (GLS), by which yields glutamate and ammonia in mitochondria. The current study demonstrates that BAG3 stabilizes GLS via prohibition its interaction with SIRT5, thereby hindering its desuccinylation at Lys158 and Lys164 sites. As an underlying molecular mechanism, we demonstrate that BAG3 interacts with GLS and decreases SIRT5 expression. The current study also demonstrates that occupation by succinyl at Lys158 and Lys164 sites prohibits its Lys48-linked ubiquitination, thereby preventing its subsequent proteasomal degradation. Collectively, the current study demonstrates that BAG3 enhances autophagy via stabilizing GLS and promoting glutaminolysis. For the first time, this study reports that succinylation competes with ubiquitination to regulate proteasomal GLS degradation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Autofagia/genética , Estabilidade Enzimática/genética , Glutaminase/metabolismo , Glutamina/metabolismo , Neoplasias/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Amônia/metabolismo , Proteínas Reguladoras de Apoptose/genética , Glutaminase/genética , Células Hep G2 , Humanos , Células MCF-7 , Mitocôndrias/metabolismo , Neoplasias/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Sirtuínas/metabolismo , Transfecção , Ubiquitinação
10.
Cell Death Dis ; 8(7): e2933, 2017 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-28703799

RESUMO

BAG3 is an evolutionarily conserved co-chaperone expressed at high levels and has a prosurvival role in many tumor types. The current study reported that BAG3 was induced under specific floating culture conditions that enrich breast cancer stem cell (BCSC)-like cells in spheres. Ectopic BAG3 overexpression increased CD44+/CD24- CSC subpopulations, first-generation and second-generation mammosphere formation, indicating that BAG3 promotes CSC self-renewal and maintenance in breast cancer. We further demonstrated that mechanically, BAG3 upregulated CXCR4 expression at the post-transcriptional level. Further studies showed that BAG3 interacted with CXCR4 mRNA and promoted its expression via its coding and 3'-untranslational regions. BAG3 was also found to be positively correlated with CXCR4 expression and unfavorable prognosis in patients with breast cancer. Taken together, our data demonstrate that BAG3 promotes BCSC-like phenotype through CXCR4 via interaction with its transcript. Therefore, this study establishes BAG3 as a potential adverse prognostic factor and a therapeutic target of breast cancer.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Neoplasias da Mama/patologia , Receptores CXCR4/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/deficiência , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Sistemas CRISPR-Cas/genética , Linhagem Celular Tumoral , Autorrenovação Celular , Feminino , Meia-Vida , Compostos Heterocíclicos/farmacologia , Humanos , Estimativa de Kaplan-Meier , Células MCF-7 , Proteína Homeobox Nanog/genética , Proteína Homeobox Nanog/metabolismo , Células-Tronco Neoplásicas/citologia , Células-Tronco Neoplásicas/metabolismo , Fenótipo , Prognóstico , Modelos de Riscos Proporcionais , Receptores CXCR4/genética , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Regulação para Cima/efeitos dos fármacos
11.
Oncotarget ; 7(43): 70364-70377, 2016 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-27683118

RESUMO

Beclin 1 has emerged as a haploinsufficient tumor suppression gene in a variety of human carcinomas. In order to clarify the role of Beclin 1 in thyroid cancer, Beclin 1 was knockdown in thyroid cancer cell lines. The current study demonstrated that knockdown of Beclin 1 resulted in morphological and molecular changes of thyroid cancer cells consistent with epithelial-mesenchymal transition (EMT), a morphogenetic procedure during which cells lose their epithelial characteristics and acquire mesenchymal properties concomitantly with gene expression reprogramming. In addition, the current study presented evidence demonstrating that Beclin 1 knockdown triggered this prometastatic process via stabilization of the EMT inducer ZEB1 mRNA through upregulation of AU-binding factor 1 (AUF1), which is recruited to the 3'-untranslated region (UTR) of the ZEB1 mRNA and decreases its degradation. We also found a negative correlation of Beclin 1 with AUF1 or ZEB1 in thyroid cancer tissues. These results indicated that at least some tumor suppressor functions of Beclin 1 were mediated through posttranscriptional regulation of ZEB1 via AUF1 in thyroid cancers.


Assuntos
Proteína Beclina-1/fisiologia , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Neoplasias da Glândula Tireoide/patologia , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Proteína Beclina-1/antagonistas & inibidores , Linhagem Celular Tumoral , Ribonucleoproteína Nuclear Heterogênea D0 , Ribonucleoproteínas Nucleares Heterogêneas Grupo D/fisiologia , Humanos , Proteínas Supressoras de Tumor/fisiologia , Regulação para Cima
12.
Oncotarget ; 7(1): 700-11, 2016 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-26621836

RESUMO

Bcl-2 associated athanogene 3 (BAG3) contains multiple protein-binding motifs to mediate potential interactions with chaperons and/or other proteins, which is possibly ascribed to the multifaceted functions assigned to BAG3. The current study demonstrated that BAG3 directly interacted with glucose 6 phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the pentose phosphate pathway (PPP). BAG3 suppressed the PPP flux, de novo DNA synthesis and cell growth in hepatocellular carcinomas (HCCs). The growth defect of HCCs with forced BAG3 expression can be rescued by enforced G6PD expression. However, BAG3 elevation did not cause a reduction in cellular NADPH concentrations, another main product of G6PD. In addition, supplement of nucleosides alone was sufficient to recover the growth defect mediated by BAG3 elevation. Collectively, the current study established a tumor suppressor-like function of BAG3 via direct interaction with G6PD in HCCs at the cellular level.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Reguladoras de Apoptose/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Glucosefosfato Desidrogenase/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Western Blotting , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Glucosefosfato Desidrogenase/metabolismo , Células HEK293 , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , NADP/metabolismo , Nucleosídeos/farmacologia , Via de Pentose Fosfato/genética , Ligação Proteica
13.
Asian Pac J Trop Med ; 7(12): 985-90, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25479628

RESUMO

OBJECTIVE: To investigate the effects of traditional Chinese medicine, Danzhi decoction, on the expression angiogenesis factors in human endometrial cells during the sequelae of pelvic inflammatory disease (SPID) and explore the role of Danzhi decction in improving the blood stasis microenvironment of SPID. METHODS: A three-dimensional (3D) co-culture system including human vascular endothelial cells (VECs), endometrial stromal cells and glandular epithelial cells was established in vitro and treated with Danzhi decoction, sterilized water and aspirin respectively. A Milliplex multifunctional liquid chip technique was used to measure the expression levels of vascular endothelial growth factor (VEGF)-A/C/D, fibroblast growth factor -1/2, angiopoietin-2, epidermal growth factor (EGF), HB-EGF, bone morphogenetic protein-9, endoglin, endothelin-1, granulocyte colony stimulating factor, hepatocyte growth factor, interleukin-8, follistatin, placenta growth factor and leptin. The location of angiogenesis factors was monitored by immunofluorescence labeling and confocal laser scanning microscope 3D reconstruction. RESULTS: Endometrial stromal cells and glandular epithelial cells were isolated and primary cultured for establishing a 3D co-culture system. The levels of VEGF-A/C/D in Danzhi decoction group and aspirin group were significantly lower than those in mock group (P<0.05), while there was no significant difference between Danzhi decoction group and aspirin group (P>0.05). Furthermore, the alterative location of VEGF-A/C/D was observed in the cytoplasm of endometrial glandular epithelial cells. CONCLUSIONS: Danzhi decoction may inhibit the expression of VEGF in the blood stasis microenvironment of SPID by targeting the cytoplasm of endometrial glandular epithelial cell.

14.
Fa Yi Xue Za Zhi ; 30(6): 416-8, 2014 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-25816569

RESUMO

OBJECTIVE: To establish the diagnosis of amniotic fluid embolism with blood samples by liquid-based cytology technique and to study the validity of method. METHODS: The blood samples were collected from patients who suffered from amniotic fluid embolism. The components of amniotic fluid in blood samples were examined with blood smear by two direct smear methods (supernatant smear, sediment smear) and two liquid-based cytology methods (automatic smear, manual smear). The positive detection rate of each method was calculated. RESULTS: The positive detection rates of two liquid-based cytology methods (84.6% and 92.3%, respectively) were much higher than those of two direct methods (53.8% and 61.5%, respectively). CONCLUSION: The liquid-based cytology technique could improve the positive detection rate of amniotic fluid embolism.


Assuntos
Técnicas Citológicas/métodos , Embolia Amniótica/sangue , Embolia Amniótica/diagnóstico , Líquido Amniótico , Feminino , Humanos , Gravidez
15.
Biochim Biophys Acta ; 1833(12): 3346-3354, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24140207

RESUMO

BAG3 plays a regulatory role in a number of cellular processes, including cell proliferation, apoptosis, adhesion and migration, epithelial-mesenchymal transition (EMT), autophagy activation, and virus infection. The AP-1 transcription factors are implicated in a variety of important biological processes including cell differentiation, proliferation, apoptosis and oncogenesis. Recently, it has been reported that AP-1 protein c-Jun inhibits autophagy and enhances apoptotic cell death mediated by starvation. However, the molecular mechanisms remain unclear. For the first time, the current study demonstrated that serum starvation downregulated BAG3 at the transcriptional level via c-Jun. In addition, the current study reported that BAG3 stabilized JunD mRNA, which was, at least in part, responsible for the promotion of serum starvation mediated-growth inhibition by BAG3.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Regulação para Cima/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Meios de Cultura Livres de Soro/farmacologia , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Humanos , Estabilidade Proteica/efeitos dos fármacos , Estabilidade de RNA/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição Genética/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
16.
Biochim Biophys Acta ; 1833(12): 3245-3253, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24080088

RESUMO

Bcl-2 associated athanogene 3 (BAG3) has a modular structure that contains a BAG domain, a WW domain, a proline-rich (PxxP) domain to mediate potential interactions with chaperons and other proteins that participate in more than one signal transduction. In search for novel interacting partners, the current study identified that 78kDa glucose-regulated protein (GRP78) was a novel partner interacting with BAG3. Interaction between GRP78 and BAG3 was confirmed by coimmunoprecipitation and glutathione S-transferase (GST) pulldown. We also identified that the ATPase domain of GRP78 and BAG domain of BAG3 mediated their interaction. Counterintuitive for a prosurvival protein, BAG3 was found to promote the cytotoxicity of breast cancer MCF7, thyroid cancer FRO and glioma U87 cells subjected to genotoxic stress. In addition, the current study demonstrated that BAG3 interfered with the formation of the antiapoptotic GRP78-procaspase-7 complex, which resulted in an increased genotoxic stress-induced cytotoxicity in cancer cells. Furthermore, overexpression of GRP78 significantly blocked the enhancing effects of BAG3 on activation of caspase-7 and induction of apoptosis by genotoxic stress. Overall, these results suggested that through direct interaction BAG3 could prevent the antiapoptotic effect of GRP78 upon genotoxic stress.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Dano ao DNA , Proteínas de Choque Térmico/metabolismo , Mutagênicos/toxicidade , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Reguladoras de Apoptose , Ligação Competitiva/efeitos dos fármacos , Caspase 7/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Etoposídeo/farmacologia , Proteínas de Choque Térmico/química , Humanos , Ligação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína
17.
Autophagy ; 9(6): 905-16, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23575457

RESUMO

Emerging lines of evidence have shown that blockade of ubiquitin-proteasome system (UPS) activates autophagy. The molecular players that regulate the relationship between them remain to be elucidated. Bcl-2 associated athanogene 3 (BAG3) is a member of the BAG co-chaperone family that regulates the ATPase activity of heat shock protein 70 (HSP70) chaperone family. Studies on BAG3 have demonstrated that it plays multiple roles in physiological and pathological processes, including antiapoptotic activity, signal transduction, regulatory role in virus infection, cell adhesion and migration. Recent studies have attracted much attention on its role in initiation of autophagy. The current study, for the first time, demonstrates that proteasome inhibitors elicit noncanonical autophagy, which was not suppressed by inhibitors of class III phosphatidylinositol 3-kinase (PtdIns3K) or shRNA against Beclin 1 (BECN1). In addition, we demonstrate that BAG3 is ascribed to activation of autophagy elicited by proteasome inhibitors and MAPK8/9/10 (also known as JNK1/2/3 respectively) activation is also implicated via upregulation of BAG3. Moreover, we found that noncanonical autophagy mediated by BAG3 suppresses responsiveness of HepG2 cells to proteasome inhibitors.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Autofagia/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Proteína Beclina-1 , Classe III de Fosfatidilinositol 3-Quinases/metabolismo , Citoproteção/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Células Hep G2 , Humanos , Proteínas de Membrana/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fagossomos/efeitos dos fármacos , Fagossomos/metabolismo , Fagossomos/ultraestrutura
18.
Biochim Biophys Acta ; 1823(8): 1395-404, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22691366

RESUMO

Proteasome inhibition may cause endoplasmic reticulum (ER) stress, which has been reported to be implicated in the antitumoral effects of proteasome inhibitors. CCAAT/enhancer-binding protein homologous protein (CHOP) is induced by a variety of adverse physiological conditions including ER stress and is involved in apoptosis. We have reported that distinct induction of CHOP contributes to the responsiveness of thyroid cancer cells to proteasome inhibitors. However, the mechanism underlying differential induction of CHOP by proteasome inhibitors in thyroid cancer cells has not been well characterized. In the current study, we characterized that proteasome inhibition primarily activated the amino acid response element 1 (AARE1) on the CHOP promoter. We also demonstrated that although proteasome inhibition caused similar accumulation of activating transcription factor 4 (ATF4) in a panel of thyroid cancer cells, distinct amounts of ATF4 were recruited to the AARE1 element of CHOP promoter. In addition, we demonstrated that NF-E2-related factor 2 (Nrf2) was also implicated in the induction of CHOP by precluding the binding of ATF4 to the CHOP promoter. This study highlights the molecular mechanisms by which ATF4 and Nrf2 can control CHOP induction in thyroid cancer cells by proteasome inhibition.


Assuntos
Fator 4 Ativador da Transcrição/metabolismo , Leupeptinas/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Inibidores de Proteassoma/farmacologia , Fator de Transcrição CHOP/genética , Ativação Transcricional/efeitos dos fármacos , Fator 4 Ativador da Transcrição/genética , Linhagem Celular Tumoral , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Genes Reporter , Humanos , Luciferases de Renilla/biossíntese , Luciferases de Renilla/genética , Estresse Oxidativo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Elementos de Resposta , Neoplasias da Glândula Tireoide , Fator de Transcrição CHOP/metabolismo
19.
Fa Yi Xue Za Zhi ; 28(1): 41-3, 2012 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-22435337

RESUMO

OBJECTIVE: To establish a whole genome amplification testing system based on degenerate oligonucleotide primed-PCR (DOP-PCR) and to explore its reliability and sensitivity. METHODS: DOP-PCR amplified production was detected by fluorescent labeled multiplex STR amplification and capillary electrophoresis detection system to determine reliability and sensitivity of DOP-PCR system. RESULTS: DOP-PCR system was successfully established and the detection sensitivity reached 5 cells (30 pg) by pretreatment of DOP-PCR and then detection of STR genotyping. CONCLUSION: The system established in this study is reliable and more testing sensitive for forensic trace evidence.


Assuntos
Primers do DNA , DNA/análise , DNA/genética , Reação em Cadeia da Polimerase/métodos , Sequências de Repetição em Tandem , Impressões Digitais de DNA/métodos , Eletroforese Capilar , Amplificação de Genes , Genótipo , Humanos , Técnicas de Amplificação de Ácido Nucleico , Oligonucleotídeos/genética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
Exp Cell Res ; 318(1): 16-24, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-22020323

RESUMO

Lipopolysaccharide (LPS) is an outer-membrane glycolipid component of Gram-negative bacteria known for its fervent ability to activate monocytic cells and for its potent proinflammatory capabilities. Bcl-2-associated athanogene 3 (BAG3) is a survival protein that has been shown to be stimulated during cell response to stressful conditions, such as exposure to high temperature, heavy metals, proteasome inhibition, and human immunodeficiency virus 1 (HIV-1) infection. In addition, BAG3 regulates replication of Varicella-Zoster Virus (VZV) and Herpes Simplex Virus (HSV) replication, suggesting that BAG3 could participate in the host response to infection. In the current study, we found that LPS increased the expression of BAG3 in a dose- and time-dependent manner. Actinomycin D completely blocked the LPS-induced BAG3 accumulation, as well as LPS activated the proximal promoter of BAG3 gene, supported that the induction by LPS occurred at the level of gene transcription. LPS-induced BAG3 expression was blocked by JNK or NF-κB inhibition, suggesting that JNK and NF-κB pathways participated in BAG3 induction by LPS. In addition, we also found that induction of BAG3 was implicated in monocytic cell adhesion to extracellular matrix induced by LPS. Overall, the data support that BAG3 is induced by LPS via JNK and NF-κB-dependent signals, and involved in monocytic cell-extracellular matrix interaction, suggesting that BAG3 may have a role in the host response to LPS stimulation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Lipopolissacarídeos/farmacologia , Monócitos/efeitos dos fármacos , NF-kappa B/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose , Adesão Celular , Fibronectinas/metabolismo , Humanos , Lipopolissacarídeos/imunologia , Monócitos/citologia , Monócitos/enzimologia , Monócitos/metabolismo , Regiões Promotoras Genéticas/genética , Células Tumorais Cultivadas
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