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1.
PLoS Genet ; 11(12): e1005675, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26684013

RESUMO

Replication fork stalling and collapse is a major source of genome instability leading to neoplastic transformation or cell death. Such stressed replication forks can be conservatively repaired and restarted using homologous recombination (HR) or non-conservatively repaired using micro-homology mediated end joining (MMEJ). HR repair of stressed forks is initiated by 5' end resection near the fork junction, which permits 3' single strand invasion of a homologous template for fork restart. This 5' end resection also prevents classical non-homologous end-joining (cNHEJ), a competing pathway for DNA double-strand break (DSB) repair. Unopposed NHEJ can cause genome instability during replication stress by abnormally fusing free double strand ends that occur as unstable replication fork repair intermediates. We show here that the previously uncharacterized Exonuclease/Endonuclease/Phosphatase Domain-1 (EEPD1) protein is required for initiating repair and restart of stalled forks. EEPD1 is recruited to stalled forks, enhances 5' DNA end resection, and promotes restart of stalled forks. Interestingly, EEPD1 directs DSB repair away from cNHEJ, and also away from MMEJ, which requires limited end resection for initiation. EEPD1 is also required for proper ATR and CHK1 phosphorylation, and formation of gamma-H2AX, RAD51 and phospho-RPA32 foci. Consistent with a direct role in stalled replication fork cleavage, EEPD1 is a 5' overhang nuclease in an obligate complex with the end resection nuclease Exo1 and BLM. EEPD1 depletion causes nuclear and cytogenetic defects, which are made worse by replication stress. Depleting 53BP1, which slows cNHEJ, fully rescues the nuclear and cytogenetic abnormalities seen with EEPD1 depletion. These data demonstrate that genome stability during replication stress is maintained by EEPD1, which initiates HR and inhibits cNHEJ and MMEJ.


Assuntos
DNA Helicases/genética , Endodesoxirribonucleases/genética , Instabilidade Genômica , Recombinação Homóloga/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Reparo de DNA por Recombinação/genética , Quebras de DNA de Cadeia Dupla , Dano ao DNA/genética , Reparo do DNA por Junção de Extremidades/genética , Proteínas de Escherichia coli/genética , Regulação da Expressão Gênica , Células HEK293 , Histonas/genética , Humanos , Proteína 1 de Ligação à Proteína Supressora de Tumor p53
2.
Proc Natl Acad Sci U S A ; 111(11): 4173-8, 2014 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-24594601

RESUMO

The mechanism by which the 8q24 MYC enhancer region, including cancer-associated variant rs6983267, increases cancer risk is unknown due to the lack of protein-coding genes at 8q24.21. Here we report the identification of long noncoding RNAs named cancer-associated region long noncoding RNAs (CARLos) in the 8q24 region. The expression of one of the long noncoding RNAs, CARLo-5, is significantly correlated with the rs6983267 allele associated with increased cancer susceptibility. We also found the MYC enhancer region physically interacts with the active regulatory region of the CARLo-5 promoter, suggesting long-range interaction of MYC enhancer with the CARLo-5 promoter regulates CARLo-5 expression. Finally, we demonstrate that CARLo-5 has a function in cell-cycle regulation and tumor development. Overall, our data provide a key of the mystery of the 8q24 gene desert.


Assuntos
Cromossomos Humanos Par 8/genética , Regulação Neoplásica da Expressão Gênica/genética , Predisposição Genética para Doença/genética , Neoplasias/genética , RNA Longo não Codificante/genética , Sequência de Bases , Linhagem Celular Tumoral , Elementos Facilitadores Genéticos/genética , Citometria de Fluxo , Humanos , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único/genética , Regiões Promotoras Genéticas/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA
3.
J Biol Chem ; 288(13): 8966-76, 2013 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-23344954

RESUMO

Quality control of DNA double-strand break (DSB) repair is vital in preventing mutagenesis. Non-homologous end-joining (NHEJ), a repair process predominant in the G1 phase of the cell cycle, rejoins DSBs either accurately or with errors, but the mechanisms controlling its fidelity are poorly understood. Here we show that BRCA1, a tumor suppressor, enhances the fidelity of NHEJ-mediated DSB repair and prevents mutagenic deletional end-joining through interaction with canonical NHEJ machinery during G1. BRCA1 binds and stabilizes Ku80 at DSBs through its N-terminal region, promotes precise DSB rejoining, and increases cellular resistance to radiation-induced DNA damage in a G1 phase-specific manner. These results suggest that BRCA1, as a central player in genome integrity maintenance, ensures high fidelity repair of DSBs by not only promoting homologous recombination repair in G2/M phase but also facilitating fidelity of Ku80-dependent NHEJ repair, thus preventing deletional end-joining of chromosomal DSBs during G1.


Assuntos
Antígenos Nucleares/metabolismo , Proteína BRCA1/metabolismo , Proteínas de Ligação a DNA/metabolismo , Ciclo Celular , Imunoprecipitação da Cromatina , DNA/análise , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Fase G1 , Deleção de Genes , Glutationa Transferase/metabolismo , Células HEK293 , Humanos , Autoantígeno Ku , Mutagênese , Proteínas Nucleares/metabolismo , Ligação Proteica , Recombinação Genética , Transdução de Sinais
4.
Biochem J ; 441(1): 407-16, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21916846

RESUMO

The purpose of the present study was to investigate the role of PLD (phospholipase D) in bFGF (basic fibroblast growth factor)-induced Bcl-2 expression and to examine whether overexpressed Bcl-2 influences neurite outgrowth in immortalized hippocampal progenitor cells (H19-7 cells). We found that Bcl-2 expression was maximally induced by bFGF within 24 h, and that this effect was reduced by inhibiting PLD1 expression with PLD1 small interfering RNA or by overexpressing DN (dominant-negative)-PLD1, whereas PLD1 overexpression markedly induced Bcl-2 expression. bFGF treatment activated Ras, Src, PI3K (phosphoinositide 3-kinase), PLCγ (phospholipase Cγ) and PKCα (protein kinase Cα). Among these molecules, Src and PKCα were not required for Bcl-2 expression. PLD activity was decreased by Ras, PI3K or PLCγ inhibitor, suggesting that PLD1 activation occurred through Ras, PI3K or PLCγ. We found that Ras was the most upstream molecule among these proteins, followed by the PI3K/PLCγ pathway, indicating that bFGF-induced PLD activation took place through the Ras/PI3K/PLCγ pathway. Furthermore, PLD1 was required for activation of JNK (c-Jun N-terminal kinase), which led to activation of STAT3 (signal transducer and activator of transcription 3) and finally Bcl-2 expression. When Bcl-2 was overexpressed, neurite outgrowth was stimulated along with induction of neurotrophic factors such as brain-derived neurotrophic factor and neurotrophin 4/5. In conclusion, PLD1 acts as a downstream effector of bFGF/Ras/PI3K/PLCγ signalling and regulates Bcl-2 expression through JNK/STAT3, which leads to neurite outgrowth in H19-7 cells.


Assuntos
Fatores de Crescimento de Fibroblastos/metabolismo , Neuritos/fisiologia , Fosfolipase D/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Animais , Linhagem Celular , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação Enzimológica da Expressão Gênica , Humanos , MAP Quinase Quinase 4/genética , MAP Quinase Quinase 4/metabolismo , Fatores de Crescimento Neural/genética , Fatores de Crescimento Neural/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosfolipase C gama/genética , Fosfolipase C gama/metabolismo , Fosfolipase D/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Ratos , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismo
5.
Cells ; 12(19)2023 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-37830607

RESUMO

Non-small cell lung cancer (NSCLC) patients, accounting for approximately 85% of lung cancer cases, are usually diagnosed in advanced stages. Traditional surgical resection and radiotherapy have very limited clinical benefits. The objective of this study was to develop and evaluate a targeted therapy, antibody-drug conjugate (ADC), for NSCLC treatment. Specifically, the CD276 receptor was evaluated and confirmed as an ideal surface target of NSCLC in the immunohistochemistry (IHC) staining of seventy-three patient tumor microarrays and western blotting analysis of eight cell lines. Our anti-CD276 monoclonal antibody (mAb) with cross-activity to both human and mouse receptors showed high surface binding, effective drug delivery and tumor-specific targeting in flow cytometry, confocal microscopy, and in vivo imaging system analysis. The ADC constructed with our CD276 mAb and payload monomethyl auristatin F (MMAF) showed high anti-NSCLC cytotoxicity to multiple lines and effective anti-tumor efficacy in both immunocompromised and immunocompetent NSCLC xenograft mouse models. The brief mechanism study revealed the integration of cell proliferation inhibition and immune cell reactivation in tumor microenvironments. The toxicity study did not detect off-target immune toxicity or peripheral toxicity. Altogether, this study suggested that anti-CD276 ADC could be a promising candidate for NSCLC treatment.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Imunoconjugados , Neoplasias Pulmonares , Humanos , Camundongos , Animais , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Imunoconjugados/farmacologia , Imunoconjugados/uso terapêutico , Proliferação de Células , Fatores de Transcrição , Microambiente Tumoral , Antígenos B7
6.
STAR Protoc ; 4(1): 101871, 2023 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-36856767

RESUMO

Evaluation of autophagy flux could be challenging for muscle fibers due to the baseline expression of mCherry-EGFP-LC3 along the Z-line. We established a protocol to overcome this difficulty. We overexpress mChery-EGFP-LC3 in the FDB muscle of an adult mouse via electroporation. Then, we enzymatically digest FDB muscle to yield individual fibers for live cell imaging. Finally, we develop an ImageJ-based program to eliminate the baseline striation pattern and semi-automatically quantify autophagosomes (APs) and autolysosomes (ALs) for autophagy flux analysis.


Assuntos
Autofagia , Proteínas Associadas aos Microtúbulos , Camundongos , Animais , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Autofagia/genética , Fibras Musculares Esqueléticas/metabolismo , Autofagossomos/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Corantes/metabolismo
7.
Biochem J ; 436(1): 181-91, 2011 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-21284604

RESUMO

Decidualization is a biological and morphological process occurring in hES (human endometrial stromal) cells. Previously, we reported that PLD1 (phospholipase D1) plays an important role in cAMP-induced decidualization of hES cells. In the present study, we focused on how PLD1 expression is up-regulated during decidualization. Treatment with PKA (protein kinase A) inhibitors (Rp-cAMP or H89) or a Ras inhibitor (manumycin) partially inhibited PLD1 expression and decidua formation in response to cAMP treatment. Interestingly, dual inhibition of PKA and Ras completely inhibited PLD1 expression and cAMP-induced decidualization. These results suggest that PLD1 expression during decidualization is controlled additively by PKA and Ras. The use of inhibitors showed that extracellular-signal-regulated kinase, a downstream effector of Ras, was required for PLD activation and the morphological changes during decidualization, but not for the increase in PLD1 protein. Next, to investigate the regulator of the PLD1 gene at the transcriptional level, a promoter assay using deletion mutants of the PLD1 promoter was performed; the result indicated that PR (progesterone receptor) was a possible regulator of the PLD1 gene. In addition, chromatin immunoprecipitation assays on the PLD1 promoter identified PR as a transcription factor for PLD1 expression during 8-Br-cAMP-induced decidualization. Taken together, our findings demonstrate that PKA and Ras are novel regulators of PLD1 expression and also identify PR as a transcription factor for PLD1 expression during the decidualization of hES cells.


Assuntos
8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Endométrio/metabolismo , Fosfolipase D/genética , Receptores de Progesterona/metabolismo , Proteínas ras/metabolismo , Adulto , Endométrio/citologia , Endométrio/efeitos dos fármacos , Feminino , Humanos , Fosfolipase D/metabolismo , Regiões Promotoras Genéticas , Receptores de Progesterona/genética , Células Estromais/citologia , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
8.
Lung Cancer ; 146: 36-41, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32505734

RESUMO

INTRODUCTION: Recent clinical studies have identified tumor mutation burden (TMB) as a promising therapeutic biomarker of anti-tumor immune checkpoint blockade. However, given the relatively slow turnaround time and high expense in measuring TMB, tobacco smoking history (TSH) is an attractive replacement biomarker. The carcinogenic effects of tobacco smoking may be modified by the protective effects of genome stability genes. This study aims to test the associations between tobacco smoking, genome stability gene inactivation, and TMB. METHODS: Publicly available TSH and DNA somatic alteration data from NSCLC were downloaded from The Cancer Genome Atlas. Correlations and enrichments were calculated with Spearman and Fisher's exact test methods, respectively. Multivariate modeling of TMB was performed with penalized linear regression. RESULTS: 85% of never smokers in adenocarcinomas (LUAD) had low TMB, but a positive TSH was not predictive of hypermutancy. The limited utility of TSH in predicting TMB was reproduced on an independent LUAD dataset. To expand our search for predictors of TMB, we further investigated the contributions of genome stability related genes (GSGs) to TMB. 242/461 (52%) and 300/465 (65%) patients with LUAD and squamous carcinomas (LUSC), respectively, showed evidence of loss of function in at least one of the 182 GSGs. 182 GSGs from 16 pathways were assessed for associations with TMB high tumor status using Fisher's exact test. We performed univariate gene and pathway enrichments in TMB high tumors and found roles forPOLE, REV3L, and FANCE genes, as well as several key GSG pathways. CONCLUSIONS: This study comprehensively tested the association between GSG, tobacco smoking, and TMB in NSCLC. In LUAD, never-smoking status was predictive of low TMB, but overall TSH was not an adequate surrogate biomarker for TMB in NSCLC. Furthermore, we identified an association between GSG inactivation and TMB.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Antígeno B7-H1 , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Proteínas de Ligação a DNA , DNA Polimerase Dirigida por DNA , Humanos , Neoplasias Pulmonares/genética , Mutação
9.
Biochim Biophys Acta ; 1783(5): 912-23, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18190795

RESUMO

Phospholipase D (PLD) catalyzes the hydrolysis of phosphatidylcholine to generate phosphatidic acid (PA) and choline. There are at least two PLD isozymes, PLD1 and PLD2. Genetic and pharmacological approaches implicate both PLD isozymes in a diverse range of cellular processes, including receptor signaling, membrane transport control, and actin cytoskeleton reorganization. Several recent studies reported that PLD has a role in signaling pathways that oppose apoptosis and promote cell survival in cancer. In this study, we examined the role of PLD in taxotere-induced apoptosis in stomach cell lines; normal stomach (NSC) and stomach cancer cells (SNU 484). Taxotere treatment resulted in increase of PLD activity. To confirm the role of PLD in taxotere-induced apoptosis, PLDs were transfected into SNU 484 cells. Overexpression of PLD isozymes resulted in inhibition of taxotere-induced apoptotic cell death, evidenced by decreased degradation of chromosomal DNA, and increased cell viability. Concurrently, Bcl-2 expression was upregulated, and taxotere-induced activation of procaspase 3 was inhibited after PLD's transfection. However, when PLD was selectively inhibited by specific siRNA-PLD1 or -PLD2, taxotere-induced apoptosis was exacerbated in SNU 484 cells. On top of this, PA -- the product of PLDs, also resulted in upregulation of Bcl-2 in SNU 484. Although PA-induced Bcl-2 expression was blocked by mepacrine, an inhibitor of phospholipase A(2) (PLA(2)), increased Bcl-2 expression by PA was not abrogated by propranolol, an inhibitor of PA phospholyhydrolase (PAP). Taken together, PLD1 and PLD2 are closely related with Bcl-2 expression together with PLA(2), but not with PAP, during taxotere-induced apoptosis in SNU 484 cells.


Assuntos
Antineoplásicos/farmacologia , Apoptose , Fosfolipase D/metabolismo , Neoplasias Gástricas/enzimologia , Taxoides/farmacologia , Antineoplásicos/antagonistas & inibidores , Docetaxel , Expressão Gênica , Humanos , Ácidos Fosfatídicos/metabolismo , Fosfolipase D/antagonistas & inibidores , Fosfolipase D/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Interferência de RNA , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Taxoides/antagonistas & inibidores , Transfecção
10.
Exp Mol Med ; 41(2): 94-101, 2009 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-19287190

RESUMO

Phosphatidic acid (PA), the product of a PLD-mediated reaction, is a lipid second messenger that participates in various intracellular signaling events and is known to regulate a growing list of signaling proteins. We found that Bcl-2 was upregulated by PA treatment in HeLa cells. However, how PA upregulates Bcl-2 expression has not yet been studied. In this study, we tried to discover the mechanisms of Bcl-2 up-regulation by PA treatment in HeLa cells. Treatment with PA resulted in significantly increased expression of Bcl-2 in HeLa cells. Moreover, PA-induced Bcl-2 expression was blocked by mepacrine, an inhibitor of PLA2, but not by propranolol, an inhibitor of PA phospholyhydrolase (PAP). Treatment of 1,2-dipalmitoryl-sn-glycero-3- phosphate (DPPA) also increased Bcl-2 expression. These results indicate that Bcl-2 expression is mediated by lysophosphatidic acid (LPA), not by arachidonic acid (AA). Thereafter, we used MEK1/2 inhibitor, PD98059 to investigate the relationship between ERK1/2 MAPK and PA-induced Bcl-2 expression. PA-induced Bcl-2 expression was decreased when ERK1/2 was inhibited by PD98059. The transcription factor such as STAT3 which is controlled by ERK1/2 MAPK was increased along with Bcl-2 expression when the cells were treated with PA. Furthermore, STAT3 siRNA treatments inhibited PA-induced Bcl-2 expression, suggesting that STAT3 (Ser727) is involved in PA-induced Bcl-2 expression. Taken together, these findings indicate that PA acts as an important mediator for increasing Bcl-2 expression through STAT3 (Ser727) activation via the ERK1/2 MAPK pathway.


Assuntos
Ácidos Fosfatídicos/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Fator de Transcrição STAT3/genética , Inibidores Enzimáticos/farmacologia , Regulação Neoplásica da Expressão Gênica , Células HeLa , Humanos , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Ácidos Fosfatídicos/metabolismo , Propranolol/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Quinacrina/farmacologia , RNA Interferente Pequeno/genética , Fator de Transcrição STAT3/metabolismo
11.
World Allergy Organ J ; 12(1): 100004, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30937129

RESUMO

BACKGROUND: Periostin is induced by IL-13 and has been studied as a biomarker of asthma. The present study explored the relationship between serum levels of periostin and exercise-induced bronchoconstriction (EIB) in asthmatic children. METHODS: The study population consisted of 86 children 6-15 years old divided into an asthmatic group (n = 56) and healthy controls (n = 30). We measured the levels of periostin in serum and performed pulmonary function tests including baseline measurements, post-bronchodilator inhalation tests, exercise bronchial provocation tests (BPTs), and mannitol BPTs. RESULTS: The 56 asthmatic children were divided into four groups: asthmatics with positive exercise BPT and positive mannitol BPT (n = 30), asthmatics with positive exercise BPT but negative mannitol BPT (n = 7), asthmatics with negative exercise BPT but positive mannitol BPT (n = 10), and asthmatics with negative exercise BPT and negative mannitol BPT (n = 9). Serum levels of periostin in asthmatic children with both positive exercise and mannitol BPT were significantly greater than those in asthmatic children with both negative exercise and mannitol BPT (95.0 [75.0-104.0] vs. 79.0 [68.0-82.5] ng/mL, P = 0.008) and controls (74.0 [69.75-80.0] ng/mL, P < 0.001). Periostin levels were significantly correlated with both the maximum decrease in %FEV1 and mannitol PD15 value. CONCLUSION: Serum levels of periostin in asthmatic children with both positive exercise and mannitol BPT were significantly greater than those in asthmatic children with both negative exercise and mannitol BPT and also greater than in healthy controls.

12.
J Neurosci Res ; 86(7): 1557-65, 2008 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-18183620

RESUMO

Hippocalcin is a Ca2+-binding protein that is expressed mainly in pyramidal nerve cells of the hippocampus. However, its functions and mechanism in the brain remain unclear. To elucidate the role of hippocalcin, we used a conditionally immortalized hippocampal cell line (H19-7) and showed that bFGF treatment increased the expression of hippocalcin during bFGF-induced neurite outgrowth of H19-7 cells. Overexpression of hippocalcin dramatically elongated neurites and increased the expression of basic helix-loop-helix transcription factor, that is, NeuroD without bFGF stimulation. Treatment of the cells with hippocalcin siRNA completely blocked bFGF-induced neurite outgrowth and NeuroD expression. bFGF stimulation resulted in activation of phospholipase C-gamma (PLC-gamma) and an increased level of intracellular Ca2+. Hippocalcin expression by bFGF stimulation was fully blocked by both the PLC-gamma inhibitor U73122 and BAPTA-AM, a chelator of intracellular Ca2+, suggesting that hippocalcin expression by bFGF is dependent on PLC-gamma and Ca2+. Moreover, both U73122 and BAPTA-AM completely blocked bFGF-induced neurite outgrowth and NeuroD expression. Taken together, these results suggest for the first time that bFGF induces hippocalcin expression in H19-7 cells through PLC-gamma activation, which leads to neurite outgrowth.


Assuntos
Fator 2 de Crescimento de Fibroblastos/farmacologia , Regulação da Expressão Gênica/fisiologia , Hipocalcina/farmacologia , Neuritos/efeitos dos fármacos , Neurônios/citologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Cálcio/metabolismo , Linhagem Celular Transformada , Quelantes/farmacologia , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Estrenos/farmacologia , Fator 2 de Crescimento de Fibroblastos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/citologia , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neuritos/fisiologia , Neurônios/efeitos dos fármacos , Fosfolipase C gama/metabolismo , Pirrolidinonas/farmacologia , RNA Interferente Pequeno/metabolismo , RNA Interferente Pequeno/farmacologia , Ratos , Transfecção/métodos
13.
Cytokine ; 44(1): 126-34, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18723372

RESUMO

Lipopolysaccharide (LPS) has been known to produce inflammatory modulators such as tumor necrosis factor alpha (TNF-alpha) or nitric oxide (NO). In this study, we examined the effects of nicotine on LPS enhanced NO synthesis and inducible nitric oxide synthase (iNOS) expression in macrophages. LPS-induced NO synthesis and iNOS expression were significantly decreased by nicotine. To investigate the signaling mechanism of nicotine induced suppression of NO synthesis and iNOS expression induced by LPS, we focused on the possible roles of p42/44 MAPK, S6K1, and signal transducers and activators of transcription 3 (STAT3) signaling. LPS is known to activate p42/44 MAPK and S6K1, which in turn activates STAT3 to induce inflammatory regulators. Pretreatment of cells with nicotine blocked LPS-induced p42/44 MAPK and S6K1 as well as iNOS promoter activity. Furthermore, we found that LPS-induced phosphorylation of STAT3 at serine 727 is mediated by S6K1-p42/44 MAPK pathway, and this STAT3 phosphorylation was also blocked by nicotine. We also found that downregulation of STAT3 using STAT3 siRNA resulted in suppression of the NO synthesis and iNOS expression. Taken together, our results suggest that nicotine inhibits LPS-induced NO synthesis through suppression of S6K1-p42/44 MAPK pathway and phosphorylation of STAT3 in Raw 264.7 cells.


Assuntos
Lipopolissacarídeos/antagonistas & inibidores , Proteína Quinase 1 Ativada por Mitógeno/fisiologia , Proteína Quinase 3 Ativada por Mitógeno/fisiologia , Nicotina/farmacologia , Óxido Nítrico/biossíntese , Proteínas Quinases S6 Ribossômicas 90-kDa/fisiologia , Fator de Transcrição STAT3/metabolismo , Animais , Linhagem Celular , Ativação Enzimática/efeitos dos fármacos , Macrófagos , Camundongos , Óxido Nítrico Sintase Tipo II/biossíntese , Fosforilação , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional
14.
Cell Res ; 28(11): 1090-1102, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30297868

RESUMO

Resistance to genotoxic therapies is a primary cause of treatment failure and tumor recurrence. The underlying mechanisms that activate the DNA damage response (DDR) and allow cancer cells to escape the lethal effects of genotoxic therapies remain unclear. Here, we uncover an unexpected mechanism through which pyruvate kinase M2 (PKM2), the highly expressed PK isoform in cancer cells and a master regulator of cancer metabolic reprogramming, integrates with the DDR to directly promote DNA double-strand break (DSB) repair. In response to ionizing radiation and oxidative stress, ATM phosphorylates PKM2 at T328 resulting in its nuclear accumulation. pT328-PKM2 is required and sufficient to promote homologous recombination (HR)-mediated DNA DSB repair through phosphorylation of CtBP-interacting protein (CtIP) on T126 to increase CtIP's recruitment at DSBs and resection of DNA ends. Disruption of the ATM-PKM2-CtIP axis sensitizes cancer cells to a variety of DNA-damaging agents and PARP1 inhibition. Furthermore, increased nuclear pT328-PKM2 level is associated with significantly worse survival in glioblastoma patients. Combined, these data advocate the use of PKM2-targeting strategies as a means to not only disrupt cancer metabolism but also inhibit an important mechanism of resistance to genotoxic therapies.


Assuntos
Proteínas de Transporte/metabolismo , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Proteínas de Membrana/metabolismo , Hormônios Tireóideos/metabolismo , Animais , Linhagem Celular Tumoral , Sobrevivência Celular , Feminino , Humanos , Camundongos , Camundongos Nus , Proteínas de Ligação a Hormônio da Tireoide
15.
Immune Netw ; 17(6): 378-391, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29302251

RESUMO

Lung cancer is one of the leading causes of death worldwide. There are 2 major subtypes of lung cancer, non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). Studies show that NSCLC is the more prevalent type of lung cancer that accounts for approximately 80%-85% of cases. Although, various treatment methods, such as chemotherapy, surgery, and radiation therapy have been used to treat lung cancer patients, there is an emergent need to develop more effective approaches to deal with advanced stages of tumors. Recently, immunotherapy has emerged as a new approach to combat with such tumors. The development and success of programmed cell death 1 (PD-1)/program death-ligand 1 (PD-L1) inhibitors and cytotoxic T-lymphocyte antigen 4 (CTLA-4) blockades in treating metastatic cancers opens a new pavement for the future research. The current mini review discusses the significance of immune checkpoint inhibitors in promoting the death of tumor cells. Additionally, this review also addresses the importance of tumor-specific antigens (neoantigens) in the development of cancer vaccines and major challenges associated with this therapy. Immunotherapy can be a promising approach to treat NSCLC because it stimulates host's own immune system to recognize cancer cells. Therefore, future research should focus on the development of new methodologies to identify novel checkpoint inhibitors and potential neoantigens.

16.
Mol Cells ; 40(11): 805-813, 2017 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-29145720

RESUMO

The role of phospholipase D (PLD) in cancer development and management has been a major area of interest for researchers. The purpose of this mini-review is to explore PLD and its distinct role during chemotherapy including anti-apoptotic function. PLD is an enzyme that belongs to the phospholipase super family and is found in a broad range of organisms such as viruses, yeast, bacteria, animals, and plants. The function and activity of PLD are widely dependent on and regulated by neurotransmitters, hormones, small monomeric GTPases, and lipids. A growing body of research has shown that PLD activity is significantly increased in cancer tissues and cells, indicating that it plays a critical role in signal transduction, cell proliferation, and anti-apoptotic processes. In addition, recent studies show that PLD is a downstream transcriptional target of proteins that contribute to inflammation and carcinogenesis such as Sp1, NFκB, TCF4, ATF-2, NFATc2, and EWS-Fli. Thus, compounds that inhibit expression or activity of PLD in cells can be potentially useful in reducing inflammation and sensitizing resistant cancers during chemotherapy.


Assuntos
Neoplasias/enzimologia , Fosfolipase D/metabolismo , Regulação para Cima , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias/tratamento farmacológico , Fosfatidilcolinas/química , Fosfatidilcolinas/metabolismo , Transdução de Sinais , Regulação para Cima/efeitos dos fármacos
17.
Curr Pharmacol Rep ; 3(6): 360-373, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29503796

RESUMO

Lung cancer is the leading cause of cancer-related death in the United States and worldwide. Novel therapeutic developments are critically necessary to improve outcomes for this disease. Aberrant epigenetic change plays an important role in lung cancer development and progression. Therefore, drugs targeting the epigenome are being investigated in the treatment of lung cancer. Monotherapy of epigenetic therapeutics such as DNA methyltransferase inhibitors (DNMTi) and histone deacetylase inhibitors (HDACi) have so far not shown any apparent benefit while one of the clinical trials with the combinations of DNMTi and HDACi showed a small positive signal for treating lung cancer. Combinations of DNMTi and HDACi with chemotherapies have some efficacy but are often limited by increased toxicities. Preclinical data and clinical trial results suggest that combining epigenetic therapeutics with targeted therapies might potentially improve outcomes in lung cancer patients. Furthermore, several clinical studies suggest that the HDACi vorinostat could be used as a radiosensitizer in lung cancer patients receiving radiation therapy. Immune checkpoint blockade therapies are revolutionizing lung cancer management. However, only a minority of lung cancer patients experience long-lasting benefits from immunotherapy. The role of epigenetic reprogramming in boosting the effects of immunotherapy is an area of active investigation. Preclinical studies and early clinical trial results support this approach which may improve lung cancer treatment, with potentially prolonged survival and tolerable toxicity. In this review, we discuss the current status of epigenetic therapeutics and their combination with other antineoplastic therapies, including novel immunotherapies, in lung cancer management.

18.
PLoS One ; 12(7): e0181725, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28732081

RESUMO

INTRODUCTION: Although tumor metastases remain significant drivers of mortality, the genetic factors that increase the risks of metastases are not fully identified. Interleukin 6 (IL-6) has emerged as an important factor in breast cancer progression with IL-6 single nucleotide polymorphism (SNP) variants shown to affect survival. We hypothesized that SNPs of the IL-6 promoter at rs1800795 in breast cancer patients are associated with distant metastases. METHODS: We performed an initial case-control study using Vanderbilt University Medical Center's BioVU, a genomic biobank linked to de-identified electronic medical records in the Synthetic Derivative database, to identify germline SNPs that may predict the development of metastatic disease to any site from any solid tumor including breast cancer. We identified a SNP in IL-6: rs1800795 to be of significance and evaluated this finding using a separate, matched-pair cohort of breast cancer patients with and without metastases from The Ohio State University Wexner Medical Center. RESULTS: The initial study suggested that GG relative to CG at rs1800795 (OR 1.52; 95% CI 1.14-2.02; p = 0.004) was significantly associated with the development of metastases. This association was also observed in the Ohio State University cohort (OR 2.23; 95% CI 1.06-4.71; p = 0.001). There were no significant relationships between rs1800795 status and any patient or tumor characteristics, including estrogen receptor status. CONCLUSIONS: These findings suggest that GG SNP at IL-6: rs1800795 may indicate an increased risk of metastasis of primary breast cancer. Further studies in larger population sets are warranted as advanced screening and prophylactic intervention might be employed in GG carriers.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença/genética , Interleucina-6/genética , Polimorfismo de Nucleotídeo Único/genética , Idoso , Idoso de 80 Anos ou mais , Alelos , Estudos de Casos e Controles , Feminino , Frequência do Gene/genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Ohio , Regiões Promotoras Genéticas/genética , Fatores de Risco
19.
Cancer Cell ; 29(2): 201-13, 2016 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-26859459

RESUMO

Activation of nuclear factor κB (NF-κB) induces mesenchymal (MES) transdifferentiation and radioresistance in glioma stem cells (GSCs), but molecular mechanisms for NF-κB activation in GSCs are currently unknown. Here, we report that mixed lineage kinase 4 (MLK4) is overexpressed in MES but not proneural (PN) GSCs. Silencing MLK4 suppresses self-renewal, motility, tumorigenesis, and radioresistance of MES GSCs via a loss of the MES signature. MLK4 binds and phosphorylates the NF-κB regulator IKKα, leading to activation of NF-κB signaling in GSCs. MLK4 expression is inversely correlated with patient prognosis in MES, but not PN high-grade gliomas. Collectively, our results uncover MLK4 as an upstream regulator of NF-κB signaling and a potential molecular target for the MES subtype of glioblastomas.


Assuntos
Neoplasias Encefálicas/enzimologia , Glioma/enzimologia , MAP Quinase Quinase Quinases/metabolismo , Células-Tronco Mesenquimais/enzimologia , Células-Tronco Neoplásicas/enzimologia , Animais , Apoptose , Neoplasias Encefálicas/patologia , Inativação Gênica , Glioma/patologia , Humanos , MAP Quinase Quinase Quinases/genética , Células-Tronco Mesenquimais/patologia , Camundongos , NF-kappa B/metabolismo , Células-Tronco Neoplásicas/patologia , Fosforilação , Transdução de Sinais
20.
Int J Biomed Sci ; 8(2): 121-8, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23675264

RESUMO

Phospholipase D (PLD) has an important role in various biological functions including vesicular transport, endocytosis, exocytosis, cell migration, and mitosis. These cellular biological processes are deregulated in the development of various human tumors. In order to explore the relationship between the PLD1 gene and risk of non-small cell lung cancer (NSCLC), single nucleotide polymorphisms (SNP) in the PLD1 exon region were surveyed in 211 NSCLC patients and 205 normal controls. In this study, we identified six SNPs at exon 23 in the PLD1 gene. Among the six SNPs, the most notable was a heterozygous A to C transition at nucleotide 2698 (A2698C, p<0.001). In addition, the genotype frequencies of A2744C (AC+CC) and A2756C (AC+CC) were associated with gender (female, A2744C and A2756C: p=0.071) in NSCLC patients. Interestingly, although the SNP A2698C did not cause change in amino acid, correlation between odd ratio of NSCLC patients and the SNP A2698C was observed to be statistically significant.

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