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1.
Life Sci ; 242: 117241, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31891719

RESUMO

Signal transducer and activator of transcription 3 (STAT3) has been a protein target following its roles being found to play in the progression of cancer development, cancer stemness, chemoresistance and radioresistance. Two decades of research efforts in STAT3 has, however, not yielded a marketed anti-STAT3 drug. This review insightfully discusses structural views on the STAT3 domains (e.g. binding pockets and critical residues), approaches to discovering effective chemical structures (e.g. structure-based drug discovery, high-throughput screening, natural product derivatives, repurposing drugs and so on), how the domains were targeted (e.g. non-covalent or covalent inhibition), and rationale of domain targeting (e.g. prevention of homo-dimerization or DNA-binding). In addition, the assays that have been used for the discovery of STAT3 inhibitors will be discussed. Overall, with this review article, the progress of the development of STAT3 antagonists could be accelerated.


Assuntos
Fator de Transcrição STAT3/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Animais , Antineoplásicos Alquilantes/farmacologia , Sítios de Ligação , Humanos , Neoplasias/tratamento farmacológico , Fator de Transcrição STAT3/fisiologia
2.
Eur J Med Chem ; 186: 111885, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31784187

RESUMO

Constitutive activation of STAT3 can play a vital role in the development of melanoma. STAT3-targeted therapeutics are reported to show efficacy in melanomas harboring the BRAFV600E mutant and also in vemurafenib-resistant melanomas. We designed and synthesized a series of substituted nitric oxide (NO)-releasing quinolone-1,2,4-triazole/oxime hybrids, hypothesizing that the introduction of a STAT3 binding scaffold would augment their cytotoxicity. All the hybrids tested showed a comparable level of in vitro NO production. 7b and 7c exhibited direct binding to the STAT3-SH domain with IC50 of ∼ 0.5 µM. Also, they abrogated STAT3 tyrosine phosphorylation in several cancer cell lines, including the A375 melanoma cell line that carries the BRAFV600E mutation. At the same time, they did not affect the phosphorylation of upstream kinases or other STAT isoforms. 7c inhibited STAT3 nuclear translocation in mouse embryonic fibroblast while 7b and 7c inhibited STAT3 DNA-binding activity in the A375 cell line. Their anti-proliferating activity is attributed to their ability to trigger the production of reactive oxygen species and induce G1 cell cycle arrest in the A375 cell line. Interestingly, 7b and 7c showed robust cell growth suppression and apoptosis induction in two pairs of BRAF inhibitor-naïve (-S) and resistant (-R) melanoma cell lines containing a BRAF V600E mutation. Surprisingly, MEL1617-R cells that are known to be more resistance to MEK inhibition by GSK1120212 than MEL1617-S cells exhibit a similar response to 7b and 7c.


Assuntos
Antineoplásicos/farmacologia , Melanoma/tratamento farmacológico , Melanoma/patologia , Óxido Nítrico/metabolismo , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Fator de Transcrição STAT3/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Melanoma/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Óxido Nítrico/análise , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Fator de Transcrição STAT3/metabolismo , Relação Estrutura-Atividade
3.
Life Sci ; 242: 117221, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31881224

RESUMO

AIMS: Endothelial cell (EC) tube formation is crucial for tumor angiogenesis, which becomes a target for chemotherapy. The anti-malaria agent dihydroartemisinin (DHA) inhibited tumor growth and angiogenesis. The aim of this study was to investigate the effects of DHA on EC tube formation and the underlying mechanisms. MATERIALS AND METHODS: Human umbilical vein endothelial cells (HUVECs) were cultured with different concentrations of DHA, and the tube formation was measured by in vitro angiogenesis assay. The protein levels of signal transducer and activator of transcription factor 3 (STAT3), phosphorylated STAT3 and fatty acid synthase (FASN) were detected by Western blotting. The gene expression of FASN was determined by real time-polymerase chain reaction (RT-PCR). The FASN siRNA and STAT3 (Y705D) vector were introduced into HUVECs by lipofectin transfection. KEY FINDINGS: DHA treatment inhibited tube formation, and the phosphorylation of STAT3 on Y705 of HUVECs. The expression of FASN was down-regulated by DHA and STAT3 inhibitor. The inhibitory effect of DHA on FASN expression in HUVECs was eliminated by co-treatment with the STAT3 inhibitor. Over-expression of STAT3 (Y705D) relieved the inhibitory effect of DHA on tube-formation and FASN expression. Under hypoxia condition, expression of FASN was up-regulated but inhibited by DHA treatment in HUVECs through suppression of STAT3 phosphorylation. SIGNIFICANCE: We demonstrate that DHA inhibits the protein level of FASN via attenuation of the Y705 phosphorylation of STAT3, and subsequently inhibits tube formation of HUVECs. Our results support the therapeutic potential of DHA on angiogenesis.


Assuntos
Inibidores da Angiogênese/farmacologia , Artemisininas/farmacologia , Neovascularização Fisiológica/efeitos dos fármacos , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ácido Graxo Sintases/metabolismo , Expressão Gênica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Hylobatidae , Reação em Cadeia da Polimerase em Tempo Real , Fator de Transcrição STAT3/antagonistas & inibidores
4.
Cell Physiol Biochem ; 53(4): 701-712, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31592599

RESUMO

BACKGROUND/AIMS: Cholinergic signalling mediated by the activation of muscarinic and nicotinic receptors has been described in the literature as a classic and important signalling pathway in the regulation of the inflammatory response. Recent research has investigated the role of acetylcholine, the physiological agonist of these receptors, in the control of energy homeostasis at the central level. Studies have shown that mice that do not express acetylcholine in brain regions regulating energy homeostasis present with excessive weight gain and hyperphagia. However, it has not yet been well-described in the literature which cholinergic receptor subunits are involved in this response; moreover, the signalling pathways responsible for the observed effects are not fully delineated. The hypothalamus is the regulating centre of energy homeostasis, and the α7 subunit of the nicotinic acetylcholine receptor (α7nAChR) is highly expressed in this region. When active, α7nAChR recruits proteins such as JAK2/STAT3 to mediate its signalling; the same intracellular components are required by leptin, an anorexigenic hormone. The aim of the present study was to evaluate the role of the hypothalamic α7nAChR in the control of energy homeostasis. METHODS: The work was performed on Swiss male mice. Initially, using immunofluorescent staining on brain sections, the presence of α7nAChR in hypothalamic cells regulating energy homeostasis was evaluated. Animals were submitted to stereotaxis in the lateral ventricle and intracerebroventricular stimulation (ICV) was used for the administration of an agonist (PNU) or antagonist (α-bungarotoxin) of α7nAChR. Metabolic parameters were evaluated and the expression of neuropeptides was evaluated in the hypothalamus by real-time PCR and western blot. The expression of hypothalamic neuropeptides was evaluated in mice treated with siRNA or inhibitors of JAK2/STAT3 (AG490 and STATTIC) proteins. We also evaluated food intake in α7nAChR knockout animals (α7KO). Additionally, in mouse hypothalamic cell culture (the mypHoA-POMC/GFP lineage), we evaluated the expression of neuropeptides and pSTAT3 after stimulation with PNU. RESULTS: Our results indicate co-localisation of α7nAChR with α-MSH, AgRP and NPY in hypothalamic cells. Pharmacological activation of α7nAChR reduced food intake and increased hypothalamic POMC expression and decreased NPY and AgRP mRNA levels and the protein content of pAMPK. Inhibition of α7nAChR with an antagonist increased the mRNA content of NPY and AgRP. Inhibition of α7nAChR with siRNA led to the suppression of POMC expression and an increase in AgRP mRNA levels. α7KO mice showed no changes in food intake. Inhibition of proteins involved in the JAK2/STAT3 signalling pathway reversed the effects observed after PNU stimulation. POMC-GFP cells, when treated with PNU, showed increased POMC expression and nuclear translocation of pSTAT3. CONCLUSION: Thus, selective activation of α7nAChR is able to modulate important markers of the response to food intake, suggesting that α7nAChR activation can suppress the expression of orexigenic markers and favour the expression of anorexics using the intracellular JAK2/STAT3 machinery.


Assuntos
Proteína Relacionada com Agouti/metabolismo , Janus Quinase 2/metabolismo , Pró-Opiomelanocortina/metabolismo , Fator de Transcrição STAT3/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Proteína Relacionada com Agouti/genética , Animais , Benzamidas/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Bungarotoxinas/farmacologia , Linhagem Celular , Ingestão de Alimentos/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Janus Quinase 2/antagonistas & inibidores , Janus Quinase 2/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , Pró-Opiomelanocortina/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/genética , Transdução de Sinais/efeitos dos fármacos , Receptor Nicotínico de Acetilcolina alfa7/agonistas , Receptor Nicotínico de Acetilcolina alfa7/antagonistas & inibidores , Receptor Nicotínico de Acetilcolina alfa7/genética
5.
BMC Cancer ; 19(1): 959, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619200

RESUMO

BACKGROUND: HER3 mediates drug resistance against epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs), resulting in tumor relapse in lung cancers. Previously, we demonstrated that EGFR induces HER3 overexpression, which facilitates the formation of cancer stem-like tumorspheres. However, the cellular mechanism through which EGFR regulates HER3 expression remains unclear. We hypothesized that EGFR downstream of STAT3 participates in HER3 expression because STAT3 contributes to cancer stemness and survival of EGFR-TKI resistant cancers. METHODS: First, RNAseq was used to uncover potential genes involved in the formation of lung cancer HCC827-derived stem-like tumorspheres. EGFR-positive lung cancer cell lines, including HCC827, A549, and H1975, were individually treated with a panel containing 172 therapeutic agents targeting stem cell-associated genes to search for potential agents that could be applied against EGFR-positive lung cancers. In addition, gene knockdown and RNAseq were used to investigate molecular mechanisms through which STAT3 regulates tumor progression and the survival in lung cancer. RESULTS: BBI608, a STAT3 inhibitor, was a potential therapeutic agent that reduced the cell viability of EGFR-positive lung cancer cell lines. Notably, the inhibitory effects of BBI608 were similar with those associated with YM155, an ILF3 inhibitor. Both compounds reduced G9a-mediated HER3 expression. We also demonstrated that STAT3 upregulated G9a to silence miR-145-5p, which exacerbated HER3 expression in this study. CONCLUSIONS: The present study revealed that BBI608 could eradicate EGFR-positive lung cancers and demonstrated that STAT3 enhanced the expression of HER3 through miR-145-5p repression by G9a, indicating that STAT3 is a reliable therapeutic target against EGFR-TKI-resistant lung cancers.


Assuntos
Antígenos de Histocompatibilidade/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Neoplasias Pulmonares/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Receptor ErbB-3/metabolismo , Fator de Transcrição STAT3/metabolismo , Células A549 , Animais , Benzofuranos/farmacologia , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Técnicas de Silenciamento de Genes , Antígenos de Histocompatibilidade/genética , Histona-Lisina N-Metiltransferase/genética , Humanos , Imidazóis/farmacologia , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , MicroRNAs/genética , MicroRNAs/metabolismo , Naftoquinonas/farmacologia , Proteínas do Fator Nuclear 90/antagonistas & inibidores , Proteínas do Fator Nuclear 90/genética , Inibidores de Proteínas Quinases/efeitos adversos , Receptor ErbB-3/antagonistas & inibidores , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/genética , Ensaios Antitumorais Modelo de Xenoenxerto
6.
J Biosci ; 44(4)2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31502564

RESUMO

Vascular calcification is a common problem in the elderly with diabetes, heart failure and end-stage renal disease. The differentiation of vascular smooth muscle cells (VSMCs) into osteoblasts is the main feature, but the exact mechanism remains unclear. It is not clear whether adiponectin (APN) affects osteogenic differentiation of VSMCs. This study aims to explore the effect of APN on vascular calcification by using a cell model induced by beta-glycerophosphate (beta-GP). VSMCs were isolated and treated with beta-GP and APN in this study. The alkaline phosphatase (ALP) activity and expression levels of Runx2, BMP-2, collagen type I and osteocalcin were determined. The expression levels of STAT3 and p-STAT3 in nucleus and cytoplasm of VSMCs were analyzed. The results showed that APN significantly inhibited the expression of ALP, Runx2, BMP-2, collagen I, osteocalcin and the formation of the mineralized matrix in VSMCs induced by beta-GP. APN reduces the osteogenic differentiation of VSMCs induced by beta-GP and down-regulates the expression of the osteogenic transcription factor osterix by inhibiting STATS3 phosphorylation and nuclear transport. APN may be one of the potential candidates for clinical treatment of vascular calcification.


Assuntos
Adiponectina/genética , Osteogênese/genética , Fator de Transcrição STAT3/genética , Calcificação Vascular/genética , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Glicerofosfatos/farmacologia , Humanos , Janus Quinase 2/antagonistas & inibidores , Janus Quinase 2/genética , Camundongos , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Osteogênese/efeitos dos fármacos , RNA/genética , Fator de Transcrição STAT3/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição Sp7/genética , Calcificação Vascular/induzido quimicamente , Calcificação Vascular/patologia
7.
Invest Ophthalmol Vis Sci ; 60(12): 3776-3785, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31503282

RESUMO

Purpose: To investigate the therapeutic effects of targeting signal transducer and activator of transcription-3 (STAT3) activation on the ocular surface damage of dry eye in mice. Methods: Adult Balb/C and C57BL/6 mice with benzalkonium chloride (BAC) treatment, lacrimal gland excision, and meibomian gland dysfunction were used as dry eye models. The levels of phosphorylated STAT3 (p-STAT3) were detected with immunofluorescence staining and Western blotting. STAT3 inhibition was performed by topical application of STAT3 inhibitor S3I-201. Corneal epithelial barrier function, tear production, and conjunctival goblet cell density were quantified with fluorescein sodium staining, phenol red cotton test, and histochemical staining. The expressions of matrix metalloproteinase (MMP)-3/9, TUNEL, and inflammation cytokines were assessed with immunofluorescence staining, qPCR, and ELISA assays. The therapeutic effect of S3I-201 was further compared with the Janus kinase inhibitor tofacitinib and ruxolitinib. Results: Elevated levels of nuclear p-STAT3 were detected in the corneal and conjunctival epithelium of three dry eye models. Topical application of S3I-201 improved corneal epithelial barrier function, increased tear production and conjunctival goblet cell density in BAC-induced dry eye mice. Moreover, S3I-201 decreased the expression of MMP-3/9, suppressed the apoptosis of corneal and conjunctival epithelial cells, and reduced the levels of IL-1ß, IL-6, IL-17A, and IFN-γ. Compared with tofacitinib and ruxolitinib, the STAT3 inhibitor S3I-201 showed superior improvement of tear production and inflammatory cytokine expression in lacrimal gland. Conclusions: Elevated STAT3 activation is involved in the pathogenesis of dry eye, while targeting STAT3 effectively alleviates BAC-induced ocular surface damage.


Assuntos
Modelos Animais de Doenças , Síndromes do Olho Seco/tratamento farmacológico , Proteínas Inibidoras de STAT Ativados/uso terapêutico , Fator de Transcrição STAT3/antagonistas & inibidores , Administração Oftálmica , Animais , Western Blotting , Túnica Conjuntiva/metabolismo , Citocinas/metabolismo , Síndromes do Olho Seco/metabolismo , Síndromes do Olho Seco/patologia , Ensaio de Imunoadsorção Enzimática , Epitélio/metabolismo , Epitélio Anterior/metabolismo , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Células Caliciformes/patologia , Marcação In Situ das Extremidades Cortadas , Metaloproteinase 3 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Soluções Oftálmicas , Fosforilação , Reação em Cadeia da Polimerase em Tempo Real , Fator de Transcrição STAT3/metabolismo , Lágrimas/fisiologia
8.
Drug Dev Ind Pharm ; 45(11): 1835-1848, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31491363

RESUMO

Objective: In this study, we aimed to develop a candidate modifited polymeric nanoparticle (NP) system that will kill cancer cells by facilitated to apoptosis and also reduce pain. Significance: The primary goal of treatment, especially for metastatic cancers, is to control the growth of the cancer and to alleviate the symptoms. Pain is one of the commonest symptoms of cancer. In cancer treatment, directing cancer cells to death while simultaneously relieving pain will be a new approach. Methods: Chitosan-modified PLGA NPs were prepared using an nanoprecipitation technique. The NPs were loaded with flurbiprofen and decorated with folic acid. STAT3-siRNA was adsorbed to these polymeric NPs using antisense technology. Results: The NPs were small in size (176.9-220.3 nm) with positive zeta potential (+14.1 mV to +27.2 mV). They had high loading capacity and prolonged release properties over 144 hours. Cytotoxicity studies performed with siRNA showed effective electrostatic interaction due to the positively charged NPs. Folic acid facilitated entry into cancer cells and helped to kill them. Conclusion: The formulation we developed is a potential carrier system for both treatment of cancer and prevention of pain, especially for metastatic cancers.


Assuntos
Antineoplásicos/administração & dosagem , Dor do Câncer/prevenção & controle , Inibidores de Ciclo-Oxigenase/administração & dosagem , Portadores de Fármacos/química , Flurbiprofeno/administração & dosagem , Neoplasias/tratamento farmacológico , RNA Interferente Pequeno/administração & dosagem , Animais , Antineoplásicos/farmacocinética , Apoptose/efeitos dos fármacos , Apoptose/genética , Dor do Câncer/etiologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Quitosana/química , Inibidores de Ciclo-Oxigenase/farmacocinética , Flurbiprofeno/farmacocinética , Ácido Fólico/administração & dosagem , Ácido Fólico/farmacocinética , Humanos , Camundongos , Nanopartículas/química , Neoplasias/complicações , Neoplasias/patologia , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , RNA Interferente Pequeno/genética , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/genética
9.
Int J Mol Sci ; 20(18)2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31491838

RESUMO

Aberrantly high levels of tyrosine-phosphorylated signal transducer and activator of transcription 3 (p-STAT3) are found constitutively in ~50% of human lung and breast cancers, acting as an oncogenic transcription factor. We previously demonstrated that Manuka honey (MH) inhibits p-STAT3 in breast cancer cells, but the exact mechanism remained unknown. Herein, we show that MH-mediated inhibition of p-STAT3 in breast (MDA-MB-231) and lung (A549) cancer cell lines is accompanied by decreased levels of gp130 and p-JAK2, two upstream components of the IL-6 receptor (IL-6R) signaling pathway. Using an ELISA-based assay, we demonstrate that MH binds directly to IL-6Rα, significantly inhibiting (~60%) its binding to the IL-6 ligand. Importantly, no evidence of MH binding to two other cytokine receptors, IL-11Rα and IL-8R, was found. Moreover, MH did not alter the levels of tyrosine-phosphorylated or total Src family kinases, which are also constitutively activated in cancer cells, suggesting that signaling via other growth factor receptors is unaffected by MH. Binding of five major MH flavonoids (luteolin, quercetin, galangin, pinocembrin, and chrysin) was also tested, and all but pinocembrin could demonstrably bind IL-6Rα, partially (30-35%) blocking IL-6 binding at the highest concentration (50 µM) used. In agreement, each flavonoid inhibited p-STAT3 in a dose-dependent manner, with estimated IC50 values in the 3.5-70 µM range. Finally, docking analysis confirmed the capacity of each flavonoid to bind in an energetically favorable configuration to IL-6Rα at a site predicted to interfere with ligand binding. Taken together, our findings identify IL-6Rα as a direct target of MH and its flavonoids, highlighting IL-6R blockade as a mechanism for the anti-tumor activity of MH, as well as a viable therapeutic target in IL-6-dependent cancers.


Assuntos
Antineoplásicos/farmacologia , Produtos Biológicos/farmacologia , Mel , Receptores de Interleucina-6/antagonistas & inibidores , Fator de Transcrição STAT3/antagonistas & inibidores , Antineoplásicos/química , Comunicação Autócrina/efeitos dos fármacos , Produtos Biológicos/química , Linhagem Celular Tumoral , Humanos , Janus Quinase 2/metabolismo , Fosforilação/efeitos dos fármacos , Ligação Proteica , Fator de Transcrição STAT3/metabolismo , Células Tumorais Cultivadas
10.
Chem Biodivers ; 16(11): e1900421, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31487435

RESUMO

Phytochemical study on the fruit of Cornus officinalis Sieb. et Zucc. yielded two new iridoid glucosides, named cornusglucoside A (1) and cornusglucoside B (2). The structures of 1 and 2 were elucidated via comprehensive NMR and HR-ESI-MS data analysis. Additionally, their inhibitory effects on IL-6-induced STAT3 activation were assessed.


Assuntos
Cornus/química , Frutas/química , Glucosídeos Iridoides/isolamento & purificação , Células Hep G2 , Humanos , Interleucina-6/antagonistas & inibidores , Interleucina-6/metabolismo , Glucosídeos Iridoides/química , Glucosídeos Iridoides/farmacologia , Conformação Molecular , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/metabolismo
11.
Cancer Sci ; 110(12): 3761-3772, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31553107

RESUMO

Differentiation-inducing factor-1 (DIF-1) has been reported to inhibit the proliferation of various mammalian cells by unknown means, although some possible mechanisms of its action have been proposed, including the activation of glycogen synthase kinase-3 (GSK-3). Here, we report an alternative mechanism underlying the action of DIF-1 in human breast cancer cell line MCF-7, on which the effects of DIF-1 have not been examined previously. Intragastric administration of DIF-1 reduced the tumor growth from MCF-7 cells injected into a mammary fat pad of nude mice, without causing adverse effects. In cultured MCF-7, DIF-1 arrested the cell cycle in G0 /G1 phase and suppressed cyclin D1 expression, consistent with our previous results obtained in other cell species. However, DIF-1 did not inhibit the phosphorylation of GSK-3. Investigating an alternative mechanism for the reduction of cyclin D1, we found that DIF-1 reduced the protein levels of signal transducer and activator of transcription 3 (STAT3). The STAT3 inhibitor S3I-201 suppressed cyclin D1 expression and cell proliferation and the overexpression of STAT3 enhanced cyclin D1 expression and accelerated proliferation. Differentiation-inducing factor-1 did not reduce STAT3 mRNA or reduce STAT3 protein in the presence of cycloheximide, suggesting that DIF-1 inhibited STAT3 protein synthesis. Seeking its mechanism, we revealed that DIF-1 inhibited the activation of 70 kDa and/or 85 kDa ribosomal protein S6 kinase (p70S6K /p85S6K ). Inhibition of p70S6K /p85S6K by rapamycin also reduced the expressions of STAT3 and cyclin D1. Therefore, DIF-1 suppresses MCF-7 proliferation by inhibiting p70S6K /p85S6K activity and STAT3 protein synthesis followed by reduction of cyclin D1 expression.


Assuntos
Ciclina D1/antagonistas & inibidores , Hexanonas/farmacologia , Hidrocarbonetos Clorados/farmacologia , Proteínas Quinases S6 Ribossômicas/fisiologia , Fator de Transcrição STAT3/antagonistas & inibidores , Animais , Proliferação de Células/efeitos dos fármacos , Ciclina D1/análise , Feminino , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Fosforilação , Proteínas Quinases S6 Ribossômicas 70-kDa , Fator de Transcrição STAT3/biossíntese
12.
Med Hypotheses ; 129: 109241, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31371076

RESUMO

Oral Squamous Cell Carcinoma (OSCC) is one of the major causes of cancer related deaths worldwide. Presence of chemoresistant cancer stem cells is the major reason behind metastasis, tumor relapse and treatment resistance in OSCC. STAT 3 signalling plays a key role in survival of cancer stem cells (CSC's), Epithelial Mesenchymal Transition (EMT) mediated metastasis in OSCC. CD 133 is the surface marker for identification of cancer stem cells. In the present study we hypothesise the selective targeting of CSC's using CD 133 mediated delivery of STAT 3 inhibitor, Niclosamide to specifically target CSC's and Non CSC's.


Assuntos
Antígeno AC133/química , Carcinoma de Células Escamosas/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Neoplasias Bucais/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Niclosamida/administração & dosagem , Fator de Transcrição STAT3/antagonistas & inibidores , Apoptose , Portadores de Fármacos , Transição Epitelial-Mesenquimal , Humanos , Modelos Teóricos , Recidiva Local de Neoplasia , Transdução de Sinais
13.
Nat Commun ; 10(1): 3601, 2019 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-31399589

RESUMO

Intratumoral heterogeneity is a hallmark of glioblastoma (GBM) tumors, thought to negatively influence therapeutic outcome. Previous studies showed that mesenchymal tumors have a worse outcome than the proneural subtype. Here we focus on STAT3 as its activation precedes the proneural-mesenchymal transition. We first establish a STAT3 gene signature that stratifies GBM patients into STAT3-high and -low cohorts. STAT3 inhibitor treatment selectively mitigates STAT3-high cell viability and tumorigenicity in orthotopic mouse xenograft models. We show the mechanism underlying resistance in STAT3-low cells by combining STAT3 signature analysis with kinome screen data on STAT3 inhibitor-treated cells. This allows us to draw connections between kinases affected by STAT3 inhibitors, their associated transcription factors and target genes. We demonstrate that dual inhibition of IGF-1R and STAT3 sensitizes STAT3-low cells and improves survival in mice. Our study underscores the importance of serially profiling tumors so as to accurately target individuals who may demonstrate molecular subtype switching.


Assuntos
Predisposição Genética para Doença/genética , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Animais , Sobrevivência Celular , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/genética , Técnicas de Silenciamento de Genes , Humanos , Imidazóis/farmacologia , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Camundongos , Pirazinas/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Receptor IGF Tipo 1/antagonistas & inibidores , Receptor IGF Tipo 1/genética , Fator de Transcrição STAT3/antagonistas & inibidores , Temozolomida/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Phytomedicine ; 63: 153055, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31377585

RESUMO

BACKGROUND: Indoleamine 2,3-dioxygenase 1 (IDO1), an important intracellular rate-limiting enzyme in the development of Hepatic fibrosis (HF), and has been proposed as a hallmark of HF. Danshensu (DSS) is a major bioactive component that isolated from a edible traditional Chinese medicinal herb Salviae Miltiorrhizae Radix et Rhizoma (Danshen), while, the anti-HF mode and mechanism of action of DSS have not been fully elucidated. METHODS: Carbon tetrachloride (CCl4)-induced rat HF model and TGF-ß1-induced hepatic stellate cell (HSC) model were employed to assess the in vivo and in vitro anti-HF effects of DSS. HSC-T6 cells stably expressing IDO1, a constitutively active IDO1 mutant, was used to determine the role of JAK2-STAT3 signaling in the DSS's anti-HF effects. RESULTS: We found that intragastric administration of DSS potently reduced fibrosis, inhibited IDO1 expression and STAT3 activity both in vitro and in vivo. Using molecular docking and molecular dynamics analysis, DSS was identified as a novel IDO1 inhibitor. Mechanistic studies indicated that DSS inhibited JAK2-STAT3 signaling, it reduced IDO1 expression, STAT3 phosphorylation and STAT3 nuclear localization. More importantly, overexpression of IDO1 diminished DSS's anti-HF effects. CONCLUSION: Our findings provide a pharmacological justification for the clinical use of DSS in treating HF, and suggest that DSS has the potential to be developed as a modern alternative and/or complimentary agent for HF treatment and prevention.


Assuntos
Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Janus Quinase 2/metabolismo , Lactatos/farmacologia , Cirrose Hepática Experimental/tratamento farmacológico , Fator de Transcrição STAT3/metabolismo , Animais , Tetracloreto de Carbono/toxicidade , Linhagem Celular , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Células Estreladas do Fígado/efeitos dos fármacos , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/patologia , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Janus Quinase 2/antagonistas & inibidores , Lactatos/química , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/metabolismo , Masculino , Simulação de Acoplamento Molecular , Ratos Sprague-Dawley , Fator de Transcrição STAT3/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta1/farmacologia
15.
BMC Genomics ; 20(1): 677, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31455240

RESUMO

BACKGROUND: Brain-derived neurotrophic factor (BDNF) is a major signaling molecule that the brain uses to control a vast network of intracellular cascades fundamental to properties of learning and memory, and cognition. While much is known about BDNF signaling in the healthy nervous system where it controls the mitogen activated protein kinase (MAPK) and cyclic-AMP pathways, less is known about its role in multiple brain disorders where it contributes to the dysregulated neuroplasticity seen in epilepsy and traumatic brain injury (TBI). We previously found that neurons respond to prolonged BDNF exposure (both in vivo (in models of epilepsy and TBI) and in vitro (in BDNF treated primary neuronal cultures)) by activating the Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) signaling pathway. This pathway is best known for its association with inflammatory cytokines in non-neuronal cells. RESULTS: Here, using deep RNA-sequencing of neurons exposed to BDNF in the presence and absence of well characterized JAK/STAT inhibitors, and without non-neuronal cells, we determine the BDNF transcriptome that is specifically regulated by agents that inhibit JAK/STAT signaling. Surprisingly, the BDNF-induced JAK/STAT transcriptome contains ion channels and neurotransmitter receptors coming from all the major classes expressed in the brain, along with key modulators of synaptic plasticity, neurogenesis, and axonal remodeling. Analysis of this dataset has revealed a unique non-canonical mechanism of JAK/STATs in neurons as differential gene expression mediated by STAT3 is not solely dependent upon phosphorylation at residue 705 and may involve a BDNF-induced interaction of STAT3 with Heterochromatin Protein 1 alpha (HP1α). CONCLUSIONS: These findings suggest that the neuronal BDNF-induced JAK/STAT pathway involves more than STAT3 phosphorylation at 705, providing the first evidence for a non-canonical mechanism that may involve HP1α. Our analysis reveals that JAK/STAT signaling regulates many of the genes associated with epilepsy syndromes where BDNF levels are markedly elevated. Uncovering the mechanism of this novel form of BDNF signaling in the brain may provide a new direction for epilepsy therapeutics and open a window into the complex mechanisms of STAT3 transcriptional regulation in neurological disease.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/farmacologia , Encéfalo/metabolismo , Janus Quinases/metabolismo , Fator de Transcrição STAT3/metabolismo , Animais , Encéfalo/enzimologia , Células Cultivadas , Proteínas Cromossômicas não Histona/metabolismo , Epilepsia/genética , Epilepsia/metabolismo , Regulação da Expressão Gênica , Ontologia Genética , Humanos , Canais Iônicos/biossíntese , Canais Iônicos/genética , Inibidores de Janus Quinases/farmacologia , Janus Quinases/antagonistas & inibidores , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Neurotransmissores/biossíntese , Receptores de Neurotransmissores/genética , Fator de Transcrição STAT3/antagonistas & inibidores , Transdução de Sinais , Transcriptoma
16.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(6): 498-504, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31292053

RESUMO

Objective To observe the effect of selectively inhibiting STAT3 on the production of IL-8 and cell apoptosis of THP-1 cells by Stattic, and explore the underlying mechanism. Methods THP-1 cells were treated with different concentrations of Stattic ( 0, 1, 5, 10, 15, 20 µmol/L) for 0, 1, 3, 6, 12, 24 hours. Reverse transcription PCR or real-time PCR was performed to detect the mRNA expression of IL-8, IL-6, IL-1ß and tumor necrosis factor-α (TNF-α); ELISA was used to detect the protein expression of IL-8; flow cytometry was applied to evaluate the apoptosis of THP-1 cells; and Western blot analysis was performed to detect the phosphorylation of STAT3 and extracellular signal-regulated kinase (ERK). Reverse transcription PCR was used to test the effect of U0126 at different concentrations (0, 1, 5, 10 µmol/L) on the mRNA expression of IL-8 induced by Stattic in THP-1 cells. Results Stattic significantly up-regulated the mRNA and protein expression of IL-8 in THP-1 cells in a concentration range of 10~20 µmol/L, and induced cell apoptosis only at high concentration (15, 20 µmol/L). Treated with Stattic for 0, 1, 3, 6, 12, 24 hours, IL-8 mRNA was significantly up-regulated, and after 6 hours, the expression of IL-8 protein and apoptosis of THP-1 cells were up-regulated in a time-dependent manner. STAT3 phosphorylation was inhibited in a time- and dose-dependent manner by Stattic. ERK phosphorylation was induced by different concentrations of Stattic in a time-dependent manner. In addition, U0126, a selective inhibitor of ERK pathway, inhibited Stattic-induced IL-8 expression in a concentration-dependent manner. Conclusion Stattic, a selective STAT3 inhibitor, can induce the apoptosis and IL-8 production by activating ERK signaling pathway in THP-1 cells.


Assuntos
Apoptose , Óxidos S-Cíclicos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular , Interleucina-8/biossíntese , Fator de Transcrição STAT3/antagonistas & inibidores , Humanos , Sistema de Sinalização das MAP Quinases , Fosforilação , Células THP-1
17.
J Exp Clin Cancer Res ; 38(1): 289, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31277685

RESUMO

BACKGROUND: Glioblastoma (GBM) cells with stem cell-like properties are called glioma stem cells (GSCs). GSCs display highly treatment resistance and are responsible for tumor recurrence. Napabucasin (BBI608), a novel small molecule inhibitor of STAT3, has been identified to eliminate stemness-like tumor cells in some cancers. However, the influence of Napabucasin on GBM cells, especially on GSCs, is currently unclear. In this study, we explored the influence and underlying mechanisms of Napabucasin on GBM cells. METHODS: STAT3 expression and its correlation with the glioma grade and patient survival were analyzed using CGGA and TCGA glioma databases. The influence of Napabucasin on proliferation, stemness, the cell cycle, apoptosis, and invasion of human GBM cell lines U87MG and LN229 was tested by CCK8, EdU incorporation, colony formation, Transwell invasion, and three-dimensional spheroid assays as well as flow cytometry, qPCR, and western blot analysis. The ability of Napabucasin to inhibit cell proliferation of U87MG tumor xenografts in mice was assessed using a live animal bioluminescence imaging system and immunohistochemistry. RESULTS: Napabucasin suppressed the proliferation, colony formation, and invasion of U87MG and LN229 cells. Furthermore, Napabucasin induced cell cycle arrest and apoptosis. More importantly, Napabucasin treatment obviously inhibited expression of stemness-associated genes including STAT3 and suppressed the spheroid formation of glioma cells in vitro. Napabucasin also disrupted the NF-κB signaling pathway via downregulation of RelA (p65). Finally, glioma growth was effectively impaired by Napabucasin in nude mice bearing intracranial glioma xenografts. CONCLUSIONS: Napabucasin treatment may be a novel approach for the treatment of GBM, particularly GSCs.


Assuntos
Benzofuranos/uso terapêutico , Glioblastoma/tratamento farmacológico , Naftoquinonas/uso terapêutico , Fator de Transcrição STAT3/antagonistas & inibidores , Células-Tronco/metabolismo , Animais , Benzofuranos/farmacologia , Proliferação de Células/efeitos dos fármacos , Feminino , Glioblastoma/patologia , Humanos , Camundongos , Camundongos Nus , Naftoquinonas/farmacologia
18.
Oncol Rep ; 42(3): 1205-1213, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31322250

RESUMO

Signal transducer and activator of transcription 3 (STAT3) plays a key role in the transformation of normal cells to cancerous cells. Although inhibitors of STAT3 have been shown to suppress the growth of multiple cancer types in vitro and in vivo, such agents are of particular interest for the prevention of breast cancer, which affects over 200,000 women and claims more than 40,000 lives in the United States each year. In the present study, we employed the MMTV/Neu transgenic mouse model, which develops estrogen receptor (ER)­negative, Neu­overexpressing tumors, and the Sprague­Dawley (SD) rat model, which develops ER­positive tumors upon exposure to the carcinogen 7,12­dimethylbenz[a]anthracene (DMBA), to test the efficacy of the STAT3 inhibitor GLG­302 in the prevention of mammary cancer. Orally administered GLG­302 and its trizma salt derivative reduced mammary cancer incidence, multiplicity, and tumor weights in female MMTV/Neu mice, and GLG­302 reduced tumor multiplicity and weights in female DMBA­treated rats. Consistent with the mechanism of action of STAT3 inhibitors, the reductions in mammary tumors were correlated with decreases in STAT3 phosphorylation and cell proliferation. These data suggest that GLG­302 is a novel agent with potential for prevention of mammary cancer and support the further development of STAT3 inhibitors for this cause.


Assuntos
Benzenossulfonatos/farmacologia , Neoplasias Mamárias Experimentais/prevenção & controle , Receptor ErbB-2/metabolismo , Fator de Transcrição STAT3/antagonistas & inibidores , Ácidos Aminossalicílicos/farmacologia , Animais , Antracenos/toxicidade , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Neoplasias Mamárias Experimentais/etiologia , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/patologia , Vírus do Tumor Mamário do Camundongo/genética , Camundongos , Camundongos Transgênicos , Piperidinas/toxicidade , Ratos , Ratos Sprague-Dawley , Células Tumorais Cultivadas
19.
Prostate ; 79(14): 1611-1621, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31348843

RESUMO

BACKGROUND: The transcription factor signal transducer and activator of transcription 3 (STAT3) is implicated in cancer drug resistance, metastasis, and immunosuppression and has been identified as a promising therapeutic target for new anticancer drugs. Myeloid-derived suppressor cells (MDSCs) play a major role in the suppression of antitumor immunity and STAT3 is involved in the accumulation, generation, and function of MDSCs. Thus, targeting STAT3 holds the potential of reversing immunosuppression in cancer. This study aims to investigate the effect of the small molecule STAT3 inhibitor galiellalactone on prostate cancer cell- induced generation of MDSCs from monocytes and the effect on immunosuppressive factors and inflammatory cytokines. METHODS: Primary human monocytes were cocultured with prostate cancer cells (DU145, PC3, and LNCaP-IL6) or with conditioned medium (CM) from prostate cancer cells in the presence or absence of the STAT3 inhibitor galiellalactone. Monocytes were analyzed by flow cytometry for an MDSC-like phenotype (CD14+ HLA-DR-/lo ). The secretion and gene expression of immunosuppressive factors and inflammatory cytokines from prostate cancer cells and monocytes were investigated. RESULTS: Galiellalactone blocked the prostate cancer cell-induced generation of MDSC-like monocytes with an immunosuppressive phenotype ex vivo. Monocytes cultured with CM from prostate cancer cells showed increased expression of phosphorylated STAT3. Prostate cancer cells increased the expression of interleukin1ß (IL1ß), IL10, and IL6 in monocytes which was inhibited by galiellalactone. In addition, galiellalactone decreased indoleamine 2,3-dioxygenase gene expression in monocytes. Galiellalactone reduced the levels of IL8 and granulocyte macrophage-colony stimulating factor in prostate cancer cells per se. CONCLUSION: The STAT3 inhibitor galiellalactone may prevent the prostate cancer cell-induced generation of MDSCs and reverse the immunosuppressive mechanisms caused by the interplay between prostate cancer cells and MDSCs. This is a potential new immunotherapeutic approach for the treatment of prostate cancer.


Assuntos
Carcinógenos/antagonistas & inibidores , Imunossupressores/antagonistas & inibidores , Lactonas/farmacologia , Células Supressoras Mieloides/efeitos dos fármacos , Neoplasias da Próstata/patologia , Fator de Transcrição STAT3/antagonistas & inibidores , Carcinogênese/efeitos dos fármacos , Carcinógenos/metabolismo , Técnicas de Cocultura , Citocinas/antagonistas & inibidores , Citocinas/metabolismo , Humanos , Imunossupressores/metabolismo , Masculino , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Monócitos/patologia , Células Supressoras Mieloides/metabolismo , Células Supressoras Mieloides/patologia , Neoplasias da Próstata/metabolismo , Células Tumorais Cultivadas
20.
J Ethnopharmacol ; 243: 112121, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31356966

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Psoriasis is an immune system meditated disease, especially T cells. It disturbed many people around the world and hard to therapy. Paeonia lactiflora Pall has been used as a medicine in china for thousands of years. Recent studies found that the main component of Paeonia lactiflora Pall can alleviates the immune response in many diseases. In this study, we researched the effects and possible mechanisms of total glucosides of paeony (TGP) on animal psoriasis. AIM OF THE STUDY: To study the therapeutic effects and mechanisms of TGP in 5% propranolol cream-induced psoriasis in guinea pigs and Imiquimod (IMQ) cream-induced psoriasis in mice. MATERIALS AND METHODS: The effect of TGP was evaluated using a psoriasis-like model of guinea pigs and mice. Ear thickness was accessed, and pathology injury was observed by H&E staining. The levels of serum IL-1ß, IL-6, IL-12, IL-17, IL-23, TNF-α, and IFN-γ, skin IL-17A, IL-22 and orphan nuclear receptor (RORγt) mRNA expression, proliferating cell nuclear antigen (PCNA), total or phosphorylated signal transducers and activators of transcription (STAT1, STAT3) were determined by enzyme linked immunosorbent assays (ELISAs), real time PCR, immunohistochemical staining, and western blotting, respectively. RESULTS: Compared with model group, TGP treatment decreased the ear thickness, improved pathology of psoriasis, alleviated IMQ-induced keratinocyte proliferation, reduced the inflammatory cytokine, and downregulated IL-17A, IL-22, and RORγt mRNA in mice. Further study indicated that TGP inhibited STAT1 and STAT3 phosphorylation in lesion skins of psoriasis-like mice. CONCLUSIONS: TGP alleviates the symptoms of psoriasis-like guinea pigs and mice, and the possible mechanism may relate to inhibit T helper 17 (TH17) cell differentiation and keratinocytes proliferation by inhibiting STAT1 and STAT3 phosphorylation.


Assuntos
Glucosídeos/uso terapêutico , Paeonia , Psoríase/tratamento farmacológico , Fator de Transcrição STAT1/antagonistas & inibidores , Fator de Transcrição STAT3/antagonistas & inibidores , Animais , Citocinas/sangue , Citocinas/genética , Modelos Animais de Doenças , Feminino , Glucosídeos/farmacologia , Cobaias , Imiquimode , Masculino , Camundongos Endogâmicos BALB C , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Fosforilação/efeitos dos fármacos , Raízes de Plantas , Psoríase/sangue , Psoríase/induzido quimicamente , Psoríase/metabolismo , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT3/metabolismo
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