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1.
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.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Reguladoras de Apoptose/genética , Regulação da Expressão Gênica , Transtornos do Metabolismo de Glucose/prevenção & controle , Transcrição Gênica , Proteína Supressora de Tumor p53/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Apoptose , Proteínas Reguladoras de Apoptose/antagonistas & inibidores , Proteínas Reguladoras de Apoptose/metabolismo , Ciclo Celular , Movimento Celular , Proliferação de Células , Transtornos do Metabolismo de Glucose/etiologia , Transtornos do Metabolismo de Glucose/metabolismo , Transtornos do Metabolismo de Glucose/patologia , Células HCT116 , Humanos , Células MCF-7 , Proteína Supressora de Tumor p53/genética
2.
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
3.
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
4.
Biochim Biophys Acta Mol Cell Res ; 1864(10): 1668-1678, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28624440

RESUMO

Bcl-2 associated athanogene 3 (BAG3) contains a modular structure, through which BAG3 interacts with a wide range of proteins, thereby affording its capacity to regulate multifaceted biological processes. BAG3 is often highly expressed and functions as a pro-survival factor in many cancers. However, the oncogenic potential of BAG3 remains not fully understood. The cell cycle regulator, S-phase kinase associated protein 2 (Skp2) is increased in various cancers and plays an important role in tumorigenesis. The current study demonstrated that BAG3 promoted proliferation of ovarian cancer cells via upregulation of Skp2. BAG3 stabilized Skp2 mRNA via its 3'-untranslated region (UTR). The current study demonstrated that BAG3 interacted with Skp2 mRNA. In addition, miR-21-5p suppressed Skp2 expression, which was compromised by forced BAG3 expression. These results indicated that at least some oncogenic functions of BAG3 were mediated through posttranscriptional regulation of Skp2 via antagonizing suppressive action of miR-21-5p in ovarian cancer cells.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Reguladoras de Apoptose/genética , MicroRNAs/genética , Neoplasias Ovarianas/genética , Proteínas Quinases Associadas a Fase S/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Neoplasias Ovarianas/patologia , Processamento Pós-Transcricional do RNA/genética , RNA Mensageiro/genética , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Mol Cell Biochem ; 403(1-2): 73-83, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25673507

RESUMO

Autophagy is closely involved in vascular smooth muscle cell (VSMC) function, but little is known about the association between advanced glycation end products (AGEs) and autophagy and its role in AGEs-induced proliferation and migration of VSMCs. The current study investigated the effects of AGEs on the phenotypic modulation and autophagy of VSMCs, as well as the potential underlying mechanisms. Primary rat VSMCs were treated with bovine serum albumin or AGEs. Cell proliferation was detected by MTT assay, real-time cell analyzer and EdU incorporation. Cell cycle was analyzed by Hoechst staining and flow cytometry. The migration of VSMCs was detected by wound-healing assay and transwell migration assay. LC3 transition and p62 accumulation were detected using Western blotting. Acidic vacuoles were measured using AO and MDC staining. Cathepsin D (CatD) was transduced to VSMCs via lentiviral vectors. AGEs enhanced proliferation and migration of primary rat VSMC in a time-dependent manner. AGEs significantly increased LC3-II transition and p62 expression, as well as accumulation of acidic vacuole, which was not further increased by bafilomycin A1. AGEs decreased CatD expression in a time-dependent pattern, and overexpression of CatD prohibited autophagy attenuation mediated by AGEs. CatD overexpression suppressed AGEs-induced proliferation of VSMCs. Nevertheless, CatD exhibited no effects on AGEs-induced migration of VSMCs. AGEs promote proliferation of VSMCs and suppress autophagy, at least in part via CatD reduction.


Assuntos
Autofagia/efeitos dos fármacos , Catepsina D/metabolismo , Produtos Finais de Glicação Avançada/farmacologia , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/metabolismo , Animais , Animais Recém-Nascidos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Macrolídeos/farmacologia , Miócitos de Músculo Liso/efeitos dos fármacos , Fagossomos/efeitos dos fármacos , Fagossomos/metabolismo , Ratos
6.
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 , Chaperona BiP do Retículo Endoplasmático , Etoposídeo/farmacologia , Proteínas de Choque Térmico/química , Humanos , Ligação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína
7.
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 Gênica/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
8.
Cell Oncol (Dordr) ; 47(3): 1025-1041, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38345749

RESUMO

PURPOSE: Glucose not only provides energy for tumor cells, but also provides various biomolecules that are essential for their survival, proliferation and invasion. Therefore, it is of great clinical significance to understand the mechanism of how tumor cells adapt to metabolic stress and maintain their survival. The aim of this research was to study the critical role of OGT and TRIM29 O-GlcNAc modification driven adaptability of PDAC cells to low glucose stress, which might have important medical implications for PDAC therapy. METHODS: Western blotting, mass spectrometry and WGA-immunoprecipitation were used to examined the levels of OGT and O-GlcNAc glycosylated proteins in BxPC3 and SW1990 cells in normal culture and under glucose deprivation conditions. Crystal violet assay, flow cytometry, RIP, RT-qPCR, protein stability assay, biotin pull down were used to investigate the mechanism of OGT and TRIM29-mediated adaptive response to glucose deficiency in PDAC cells. RESULTS: The current study found that under the condition of low glucose culture, the levels of OGT and O-GlcNAc glycosylation in PDAC cells were significantly higher than those in normal culture. Moreover, the high expression of OGT has a protective effect on PDAC cells under low glucose stress. This study confirmed that there was no significant change in mRNA level and protein degradation of OGT under low glucose stress, which was mainly reflected in the increase of protein synthesis. In addition, O-GlcNAc modification at T120 site plays a critical role in the metabolic adaptive responses mediated by TRIM29. CONCLUSIONS: Taken together, our study indicated that O-GlcNAcylation of TRIM29 at T120 site and OGT translation forms a loop feedback to facilitate survival of PDAC under glucose deficiency.


Assuntos
Glucose , N-Acetilglucosaminiltransferases , Neoplasias Pancreáticas , Fatores de Transcrição , Humanos , Acetilglucosamina/metabolismo , Acilação , Adaptação Fisiológica/genética , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Retroalimentação Fisiológica , Glucose/metabolismo , Glicosilação , N-Acetilglucosaminiltransferases/metabolismo , N-Acetilglucosaminiltransferases/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/genética , Biossíntese de Proteínas , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética
9.
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
10.
Cancer Sci ; 104(1): 55-61, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23020756

RESUMO

Proteasome inhibitors represent a novel class of anticancer agents that are used in the treatment of hematologic malignancies and various solid tumors. However, mechanisms underlying their anticancer actions were not fully understood. It has been reported that strong 14-3-3 protein expression is observed and associated with tumor genesis and progression of astrocytoma. In addition, global inhibition of 14-3-3 functions with a general 14-3-3 antagonist difopein induces apoptosis of human astrocytoma cells, validating 14-3-3 as a potential molecular target for anticancer therapeutic management. In the current study, for the first time we demonstrated that proteasome inhibitors downregulated 14-3-3ε and 14-3-3θ/τ in U87 and SF295 glioma cells. Overexpression of 14-3-3ε and 14-3-3θ/τ significantly suppressed apoptosis of human glioma cells induced by proteasome inhibitors. We also demonstrated that MG132 activated ASK1 and siASK1 compromised the MG132-induced apoptosis of glioma cells. Furthermore, overexpression of 14-3-3ε and 14-3-3θ/τ markedly suppressed activation of ASK1. Collectively, the current study supported that proteasome inhibitors, at least in part, caused cytotoxicity of glioma cells via downregulation of 14-3-3ε and 14-3-3θ/τ and subsequent activation of ASK1.


Assuntos
Proteínas 14-3-3/metabolismo , Apoptose , Glioma/metabolismo , Leupeptinas/farmacologia , MAP Quinase Quinase Quinase 5/metabolismo , Inibidores de Proteassoma/farmacologia , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Regulação para Baixo , Glioma/patologia , Humanos , MAP Quinase Quinase Quinase 5/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Interferência de RNA , RNA Interferente Pequeno
11.
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
12.
EMBO J ; 27(18): 2432-43, 2008 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-18701920

RESUMO

Dominant mutations in leucine-rich repeat kinase 2 (LRRK2) are the most frequent molecular lesions so far found in Parkinson's disease (PD), an age-dependent neurodegenerative disorder affecting dopaminergic (DA) neuron. The molecular mechanisms by which mutations in LRRK2 cause DA degeneration in PD are not understood. Here, we show that both human LRRK2 and the Drosophila orthologue of LRRK2 phosphorylate eukaryotic initiation factor 4E (eIF4E)-binding protein (4E-BP), a negative regulator of eIF4E-mediated protein translation and a key mediator of various stress responses. Although modulation of the eIF4E/4E-BP pathway by LRRK2 stimulates eIF4E-mediated protein translation both in vivo and in vitro, it attenuates resistance to oxidative stress and survival of DA neuron in Drosophila. Our results suggest that chronic inactivation of 4E-BP by LRRK2 with pathogenic mutations deregulates protein translation, eventually resulting in age-dependent loss of DA neurons.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Dopamina/metabolismo , Proteínas de Drosophila/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Neurônios/metabolismo , Fatores de Iniciação de Peptídeos/fisiologia , Fosfoproteínas/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Ciclo Celular , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Fator de Iniciação 4E em Eucariotos/metabolismo , Genes Dominantes , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina , Modelos Biológicos , Mutação , Estresse Oxidativo , Fatores de Iniciação de Peptídeos/metabolismo , Fosfoproteínas/metabolismo , Fosforilação , Biossíntese de Proteínas
13.
BMC Cancer ; 12: 622, 2012 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-23270461

RESUMO

BACKGROUND: The ubiquitin-proteasome system and macroautophagy (hereafter referred to autophagy) are two complementary pathways for protein degradation. Emerging evidence suggests that proteasome inhibition might be a promising approach for tumor therapy. Accumulating data suggest that autophagy is activated as a compensatory mechanism upon proteasome activity is impaired. METHOD: Autophagy activation was measured using acridine orange staining and LC3 transition. Cell viability and apoptosis were measured using MTT assay and flow cytometry, respectively. Beclin 1 expression vectors or shRNA against Beclin 1 (shBeclin 1) were transfected to investigate the role of Beclin 1 in autophagy activation and cytotoxicity of ovarian cancer cells induced by proteasome inhibitors. RESULTS: Proteasome inhibitors suppressed proliferation and induced autophagy in ovarian cancer cells. Neither phosphoinositide 3-kinase (PI3K) inhibitors nor shRNA against Beclin 1 could abolish the formation of acidic vacuoles and the processing of LC3 induced by proteasome inhibitors. Moreover, Beclin 1 overexpression enhanced anti-proliferative effects of proteasome inhibitors in ovarian cancer cells. CONCLUSIONS: For the first time, the current study demonstrated that proteasome inhibitors induced PI3K and Beclin 1-independent autophagy in ovarian cancer cells. In addition, this study revealed autophagy-independent tumor suppressive effects of Beclin 1 in ovarian cancer cells.


Assuntos
Proteínas Reguladoras de Apoptose/fisiologia , Autofagia/fisiologia , Proteínas de Membrana/fisiologia , Neoplasias Ovarianas/tratamento farmacológico , Inibidores de Proteassoma/farmacologia , Análise de Variância , Apoptose/fisiologia , Proteínas Reguladoras de Apoptose/metabolismo , Autofagia/efeitos dos fármacos , Proteína Beclina-1 , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Proteínas de Membrana/metabolismo , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Inibidores de Proteínas Quinases/farmacologia
14.
Front Chem ; 10: 854664, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35360531

RESUMO

Zeolite SAPO-34 has been widely used in the industry because of its special pore structure and wide distribution of acid sites in the pore channel. However, traditional SAPO-34 with a small pore size suffers from carbon deposition and deactivation in catalytic reactions, and its inability to catalytically convert bulky organic molecules limits its industrial application. Meanwhile, impurities of SAPO-5, which have weak acidity leading to rapid catalyst deactivation, appear in SAPO-34 zeolite. Therefore, it is of great significance to synthesize SAPO-34 zeolite with a mesoporous pore structure, which can significantly improve the transfer of molecules in zeolites. In this paper, SAPO-34 zeolite with a hierarchical pore structure was synthesized, and its hydrodesulfurization performance for 4,6-dimethyldibenzothiophene (4,6-DMDBT) was studied in a fixed bed reactor. The characteristic results show that BET-specific surface area, micropore volume, and mesoporous volume of synthesized SAPO-34 are 754 m2 g-1, 0.25, and 0.23 cm3 g-1 respectively, and the pore size is mainly concentrated at 4 nm. The catalytic conversion of 4,6-DMDMT with Co- and Mo-supported SAPO-34 is about 83%, which is much higher than the catalytic performance of Al2O3.

15.
Cancer Lett ; 529: 85-99, 2022 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-34973391

RESUMO

Ovarian cancer (OC) is a common gynecological malignant tumor that seriously endangers the health of women worldwide. Tripartite motif containing 29 (TRIM29) is a TRIM family member that is frequently overexpressed in OC. However, the specific role of TRIM29 in OC remains obscure. To investigate the underlying molecular mechanism, a global proteomics analysis identified SET binding protein 1 (SETBP1) as a crucial target of TRIM29. Subsequently, the SETBP1/SET/Protein phosphatase 2 (PP2A) axis was confirmed to be required for the recovery of cancer stem cell (CSC)-like phenotype suppressed by TRIM29 knockdown. Mechanistically, TRIM29 facilitated SETBP1 transcriptional activation via the VEZF1 transcription factor. More importantly, TRIM29 promoted VEZF1 mRNA translation by recruiting RNA binding protein BICC1 to its 3'UTR. The clinical significance was established by the association of TRIM29 and SETBP1 expression with clinicopathological features in OC samples. The SETBP1/SET/PP2A axis driven by TRIM29 via transcription factor VEZF1 is at least one of the primary mechanisms underlying TRIM29 maintenance of the CSC-like characteristics in OC.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Ligação a DNA/metabolismo , Chaperonas de Histonas/metabolismo , Proteínas Nucleares/metabolismo , Neoplasias Ovarianas/metabolismo , Proteína Fosfatase 2/metabolismo , Fatores de Transcrição/metabolismo , Adulto , Idoso , Animais , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Suscetibilidade a Doenças , Ativação Enzimática , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Xenoenxertos , Humanos , Imuno-Histoquímica , Camundongos , Pessoa de Meia-Idade , Gradação de Tumores , Metástase Neoplásica , Estadiamento de Neoplasias , Proteínas Nucleares/genética , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/etiologia , Regiões Promotoras Genéticas , Transdução de Sinais , Fatores de Transcrição/genética
16.
BMC Cancer ; 11: 99, 2011 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-21418583

RESUMO

BACKGROUND: It was reported recently that resveratrol could sensitize a number of cancer cells to the antitumoral effects of some conventional chemotherapy drugs. The current study was designed to investigate whether resveratrol could sensitize leukemic cells to proteasome inhibitors. METHODS: Leukemic cells were treated with MG132 alone or in combination with resveratrol. Cell viability was investigated using MTT assay, and induction of apoptosis and cell cycle distribution was measured using flow cytometry. Western blot and real-time RT-PCR were used to investigate the expression of FOXO1 and p27Kip1. CHIP was performed to investigate the binding of FOXO1 to the p27 Kip1 promoter. RESULTS: Resveratrol strongly reduced cytotoxic activities of proteasome inhibitors against leukemic cells. MG132 in combination with resveratrol caused cell cycle blockade at G1/S transition via p27Kip1 accumulation. Knockdown of p27Kip1 using siRNA dramatically attenuated the protective effects of resveratrol on cytotoxic actions of proteasome inhibitors against leukemic cells. Resveratrol induced FOXO1 expression at the transcriptional level, while MG132 increased nuclear distribution of FOXO1. MG132 in combination with resveratrol caused synergistic induction of p27Kip1 through increased recruitment of FOXO1 on the p27Kip1 promoter. CONCLUSIONS: Resveratrol may have the potential to negate the cytotoxic effects of proteasome inhibitors via regulation of FOXO1 transcriptional activity and accumulation of p27Kip1.


Assuntos
Apoptose/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p27/genética , Fatores de Transcrição Forkhead/genética , Leucemia/patologia , Estilbenos/farmacologia , Apoptose/genética , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p27/fisiologia , Citoproteção/efeitos dos fármacos , Citoproteção/genética , Citotoxinas/farmacologia , Avaliação Pré-Clínica de Medicamentos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Inibidores Enzimáticos/farmacologia , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead/fisiologia , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Células K562 , Leucemia/genética , Inibidores de Proteassoma , Resveratrol , Células U937
17.
Mol Ther Nucleic Acids ; 24: 579-590, 2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-33898107

RESUMO

TRIM29 is dysregulated in pancreatic cancer and implicated in maintenance of stem-cell-like characters of pancreatic cancer cells. However, the exact mechanisms underlying oncogenic function of TRIM29 in pancreatic cancer cells remain largely unclarified. Using a global screening procedure, the current study found that adenylate kinase 4 (AK4) was profoundly reduced by TRIM29 knockdown. In addition, our data demonstrated that TRIM29 knockdown altered bioenergetics and suppressed proliferation and invasion of pancreatic cancer cells via downregulation of AK4 at the posttranscriptional level. The current study demonstrated that upregulation of microRNA-2355-3p (miR-2355-3p) upregulated AK4 expression via facilitating DDX3X recruitment to the AK4 transcript, and TRIM29 knockdown thereby destabilized the AK4 transcript via miR-2355-3p downregulation. Collectively, our study uncovers posttranscriptional stabilization of the AK4 transcript by miR-2355-3p interaction to facilitate DDX3X recruitment. Regulation of AK4 by TRIM29 via miR-2355-3p thereby provides additional information for further identification of attractive targets for therapy with pancreatic cancer.

18.
Biochim Biophys Acta Mol Cell Res ; 1868(9): 119076, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34126157

RESUMO

Ovarian cancer is the most frequent cause of gynecologic malignancies associated death. Primary or acquired cisplatin resistance is frequently occurred during ovarian cancer therapy. Cancer stem cells (CSC) tend to form minimal residual disease after chemotherapy and are implicated in relapse. The ability of cancer cells to reprogram their metabolism has recently been related with maintenance of CSC and resistance to chemotherapies. The current study found that BAG5 expression was decreased in cisplatin-resistant ovarian cancer cells and clinical tissues. Our data demonstrated that BAG5 knockdown was implicated in metabolic reprogramming and maintenance of cancer stem cell (CSC)-like features of ovarian cancer cells via regulation of Rictor and subsequent mTORC2 signaling pathway. In addition, the current study demonstrated that Bcl6 upregulation was responsible for repression of BAG5 transactivation via recruitment on the BAG5 promoter in cisplatin-resistant ovarian cancer. The current study also demonstrated reverse correlations between BAG5 and Bcl6, BAG5 and Rictor in ovarian serous adenocarcinoma tissues. Collectively, the current study identified the implication of Bcl6/BAG5/Rictor-mTORC2 signaling pathway in metabolic reprograming and maintenance of CSC-like features in cisplatin-resistant ovarian cancer cells. Therefore, further studies on the mechanism underlying regulation of metabolic reprogramming and CSC-like characteristics of cisplatin-resistant ovarian cancer cells may contribute to the establishment of novel therapeutic strategy for cisplatin-resistance.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Regulação para Baixo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Neoplasias Ovarianas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Antineoplásicos/farmacologia , Cisplatino/farmacologia , Regulação para Baixo/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas
19.
Biochim Biophys Acta Mol Cell Res ; 1868(9): 119077, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34111434

RESUMO

Ovarian cancer is the most lethal gynecologic malignant cancer, frequently due to its late diagnosis and high recurrence. Cancer stem cells (CSCs) from different malignancies including ovarian cancer have been linked to chemotherapy resistance and poor prognosis. Therefore, identifying the molecular mechanisms mediating therapy resistance is urgent to finding novel targets for therapy-resistant tumors. Aberrant O-glycosylation ascribed to subtle alteration of GALNT family members during malignant transformation facilitate metastasis in various cancers. The current study demonstrated that BAG3 was upregulated in platin-resistant ovarian cancer tissues and cells, and high BAG3 predicted dismal disease-free survival of patients with ovarian cancer. In addition, the current study showed that BAG3 facilitated CSC-like properties of ovarian cancer cells via regulation of GALTN10. In a term of mechanism, BAG3 epigenetically regulated GALNT10 transactivation via histone H3 lysine 4 (H3K4) presenter WDR5. We demonstrated that WDR5 increased H3K4 trimethylation (H3K4me3) modification at the promoter regions of GALNT10, facilitating recruitment of transcription factor ZBTB2 to the GALNT10 promoter. Collectively, our study uncovers an epigenetic upregulation of GALNT10 by BAG3 via WDR5 to facilitate CSCs of platin-resistant ovarian cancers, providing additional information for further identification of attractive targets with therapeutic significance in platin-resistant ovarian cancer.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Reguladoras de Apoptose/genética , Epigênese Genética/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , N-Acetilgalactosaminiltransferases/genética , Células-Tronco Neoplásicas/metabolismo , Neoplasias Ovarianas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/deficiência , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Antineoplásicos/farmacologia , Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/metabolismo , Carboplatina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , N-Acetilgalactosaminiltransferases/deficiência , N-Acetilgalactosaminiltransferases/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Células Tumorais Cultivadas , Polipeptídeo N-Acetilgalactosaminiltransferase
20.
Biochim Biophys Acta Mol Cell Res ; 1868(1): 118878, 2021 01.
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.


Assuntos
Proteínas de Ligação a DNA/genética , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Ovarianas/genética , Proteínas de Ligação a RNA/genética , Fatores de Transcrição/genética , Linhagem Celular Tumoral , Cisplatino/efeitos adversos , Cisplatino/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células-Tronco Neoplásicas/efeitos dos fármacos , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/terapia , Fenótipo
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