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1.
J Med Virol ; 96(5): e29634, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38682578

RESUMO

Metabolic reprogramming induced by Epstein-Barr virus (EBV) often mirrors metabolic changes observed in cancer cells. Accumulating evidence suggests that lytic reactivation is crucial in EBV-associated oncogenesis. The aim of this study was to explore the role of metabolite changes in EBV-associated malignancies and viral life cycle control. We first revealed that EBV (LMP1) accelerates the secretion of the oncometabolite D-2HG, and serum D-2HG level is a potential diagnostic biomarker for NPC. EBV (LMP1)-driven metabolite changes disrupts the homeostasis of global DNA methylation and demethylation, which have a significantly inhibitory effect on active DNA demethylation and 5hmC content. We found that loss of 5hmC indicates a poor prognosis for NPC patients, and that 5hmC modification is a restriction factor of EBV reactivation. We confirmed a novel EBV reactivation inhibitor, α-KG, which inhibits the expression of EBV lytic genes with CpG-containing ZREs and the latent-lytic switch by enhancing 5hmC modification. Our results demonstrate a novel mechanism of which metabolite abnormality driven by EBV controls the viral lytic reactivation through epigenetic modification. This study presents a potential strategy for blocking EBV reactivation, and provides potential targets for the diagnosis and therapy of NPC.


Assuntos
Metilação de DNA , Infecções por Vírus Epstein-Barr , Herpesvirus Humano 4 , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas , Ativação Viral , Humanos , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/fisiologia , Carcinoma Nasofaríngeo/virologia , Carcinoma Nasofaríngeo/metabolismo , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/virologia , Neoplasias Nasofaríngeas/metabolismo , Neoplasias Nasofaríngeas/patologia , Infecções por Vírus Epstein-Barr/virologia , Infecções por Vírus Epstein-Barr/complicações , Proteínas da Matriz Viral/metabolismo , Proteínas da Matriz Viral/genética , Epigênese Genética , Progressão da Doença
3.
Nucleic Acids Res ; 48(19): 10940-10952, 2020 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-33010150

RESUMO

ATR functions as a master regulator of the DNA-damage response. ATR activation requires the ATR activator, topoisomerase IIß-binding protein 1 (TopBP1). However, the underlying mechanism of TopBP1 regulation and how its regulation affects DNA replication remain unknown. Here, we report a specific interaction between TopBP1 and the histone demethylase PHF8. The TopBP1/PHF8 interaction is mediated by the BRCT 7+8 domain of TopBP1 and phosphorylation of PHF8 at Ser854. This interaction is cell-cycle regulated and phosphorylation-dependent. PHF8 is phosphorylated by CK2, which regulates binding of PHF8 to TopBP1. Importantly, PHF8 regulates TopBP1 protein level by preventing its ubiquitination and degradation mediated by the E3 ligase UBR5. Interestingly, PHF8pS854 is likely to contribute to regulation of TopBP1 stability and DNA replication checkpoint. Further, both TopBP1 and PHF8 are required for efficient replication fork restart. Together, these data identify PHF8 as a TopBP1-binding protein and provide mechanistic insight into how PHF8 regulates TopBP1 stability to maintain DNA replication.


Assuntos
Proteínas de Transporte/metabolismo , Replicação do DNA , Proteínas de Ligação a DNA/metabolismo , Histona Desmetilases/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Caseína Quinase II/metabolismo , Linhagem Celular , Humanos , Fosforilação , Ligação Proteica , Domínios Proteicos
4.
Theranostics ; 8(15): 4050-4061, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30128035

RESUMO

Hotspot mutations of isocitrate dehydrogenase 1 and 2 (IDH1/2) have been studied in several cancers. However, the function of wild-type IDH2 in lung cancer and the mechanism of its contribution to growth of cancer cells remain unknown. Here, we explored the role and mechanism of wild-type IDH2 in promoting growth of lung cancer. Methods: Information regarding genomic and clinical application focusing on IDH2 in cancer was examined in several databases of more than 1,000 tumor samples. IDH2 expression was assessed by immunohistochemistry in tissues from lung cancer patients. The biological functions of IDH2 were evaluated by using cell-based assays and in vivo xenograft mouse models. Results: Here we reported that wild-type IDH2 is up-regulated and is an indicator of poor survival in lung cancer and several other cancers. Targeting IDH2 with shRNA resulted in decreased HIF1α expression, leading to the attenuation of lung cancer cell proliferation and tumor growth. Treatment of lung cancer cells with AGI-6780 (a small molecule inhibitor of IDH2), PX-478 (an inhibitor of HIF1α) or incubation with octyl-α-KG inhibited lung cancer cell proliferation. Conclusion: IDH2 promotes the Warburg effect and lung cancer cell growth, which is mediated through HIF1α activation followed by decreased α-KG. Therefore, IDH2 could possibly serve as a novel therapeutic target for lung cancer.


Assuntos
Proliferação de Células , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Isocitrato Desidrogenase/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/fisiopatologia , Células A549 , Animais , Modelos Animais de Doenças , Xenoenxertos , Humanos , Imuno-Histoquímica , Camundongos , Microscopia , Modelos Teóricos , Transplante de Neoplasias
5.
Theranostics ; 8(9): 2329-2347, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29721083

RESUMO

Nasopharyngeal carcinoma (NPC) has a particularly high prevalence in southern China, southeastern Asia and northern Africa. Radiation resistance remains a serious obstacle to successful treatment in NPC. This study aimed to explore the metabolic feature of radiation-resistant NPC cells and identify new molecular-targeted agents to improve the therapeutic effects of radiotherapy in NPC. Methods: Radiation-responsive and radiation-resistant NPC cells were used as the model system in vitro and in vivo. Metabolomics approach was used to illustrate the global metabolic changes. 13C isotopomer tracing experiment and Seahorse XF analysis were undertaken to determine the activity of fatty acid oxidation (FAO). qRT-PCR was performed to evaluate the expression of essential FAO genes including CPT1A. NPC tumor tissue microarray was used to investigate the prognostic role of CPT1A. Either RNA interference or pharmacological blockade by Etomoxir were used to inhibit CPT1A. Radiation resistance was evaluated by colony formation assay. Mitochondrial membrane potential, apoptosis and neutral lipid content were measured by flow cytometry analysis using JC-1, Annexin V and LipidTOX Red probe respectively. Molecular markers of mitochondrial apoptosis were detected by western blot. Xenografts were treated with Etomoxir, radiation, or a combination of Etomoxir and radiation. Mitochondrial apoptosis and lipid droplets content of tumor tissues were detected by cleaved caspase 9 and Oil Red O staining respectively. Liquid chromatography coupled with tandem mass spectrometry approach was used to identify CPT1A-binding proteins. The interaction of CPT1A and Rab14 were detected by immunoprecipitation, immunofluorescence and in situ proximity ligation analysis. Fragment docking and direct coupling combined computational protein-protein interaction prediction method were used to predict the binding interface. Fatty acid trafficking was measured by pulse-chase assay using BODIPY C16 and MitoTracker Red probe. Results: FAO was active in radiation-resistant NPC cells, and the rate-limiting enzyme of FAO, carnitine palmitoyl transferase 1 A (CPT1A), was consistently up-regulated in these cells. The protein level of CPT1A was significantly associated with poor overall survival of NPC patients following radiotherapy. Inhibition of CPT1A re-sensitized NPC cells to radiation therapy by activating mitochondrial apoptosis both in vitro and in vivo. In addition, we identified Rab14 as a novel CPT1A binding protein. The CPT1A-Rab14 interaction facilitated fatty acid trafficking from lipid droplets to mitochondria, which decreased radiation-induced lipid accumulation and maximized ATP production. Knockdown of Rab14 attenuated CPT1A-mediated fatty acid trafficking and radiation resistance. Conclusion: An active FAO is a vital signature of NPC radiation resistance. Targeting CPT1A could be a beneficial regimen to improve the therapeutic effects of radiotherapy in NPC patients. Importantly, the CPT1A-Rab14 interaction plays roles in CPT1A-mediated radiation resistance by facilitating fatty acid trafficking. This interaction could be an attractive interface for the discovery of novel CPT1A inhibitors.


Assuntos
Carnitina O-Palmitoiltransferase/metabolismo , Ácidos Graxos/metabolismo , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/radioterapia , Apoptose/efeitos da radiação , Linhagem Celular Tumoral , Humanos , Metabolismo dos Lipídeos/efeitos da radiação , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Carcinoma Nasofaríngeo/metabolismo , Neoplasias Nasofaríngeas/metabolismo , Oxirredução , Tolerância a Radiação/efeitos da radiação
6.
Oncotarget ; 8(39): 64984-64998, 2017 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-29029406

RESUMO

The Fip1-like1 (FIP1L1)-platelet-derived growth factor receptor alpha (PDGFRA) (F/P) oncogene can cause chronic eosinophilic leukemia (CEL), but requires IL-5 cytokine participation. In this study, we investigate the mechanism of F/P in collaboration with IL-5 in CEL. The results showed that Lyn, a key effector in the IL-5-motivated eosinophil production, is extensively activated in F/P-positive CEL cells. Lyn can associate and phosphorylate IL-5 receptor α (IL-5RA) in F/P-positive cells. Moreover, the activation of Lyn and IL-5R kinase were strengthened when the cells were stimulated by IL-5. Lyn inhibition in F/P-positive CEL cells attenuated cellular proliferation, induced apoptosis, and blocked cell migration and major basic protein (MBP) release. We identified the FIP1L1-PDGFRA/JAK2/Lyn/Akt complex in the F/P-expressing cells which can be disrupted by dual inhibition of JAK2 and Lyn, repressing cell proliferation in both EOL-1(F/P-positive human eosinophilic cell line) and imatinib-resistance (IR) cells. Altogether, our data demonstrate that Lyn is a vital downstream kinase activated by F/P converged with IL-5 signals in CEL cells. Lyn activate and expand IL-5RA intracellular signaling through FIP1L1-PDGFRA/JAK2/Lyn/Akt network complex, provoking eosinophils proliferation and exaggerated activation manifested as CEL.

7.
Genet Test Mol Biomarkers ; 21(11): 641-648, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28910191

RESUMO

BACKGROUND: Peritoneal carcinomatosis (PC) is an important cause of morbidity and mortality among patients with gastric cancer. Thus, it is important to identify an ideal biomarker for PC. METHODS: Plasma and ascites samples were collected from gastric cancer patients with PC and a control group. Lysophosphatidic acid (LPA) levels were tested and analyzed. RESULTS: The plasma LPA levels of gastric cancer patients with PC were significantly higher than those in gastric cancer patients after radical resection (p = 0.046) and healthy volunteers (p < 0.001). Besides, plasma LPA levels were statistically lower after chemotherapy in gastric cancer patients with PC (p = 0.028). Furthermore, the ascites LPA levels were significantly higher in gastric cancer patients with peritoneal carcinomatosis than those in liver cirrhosis patients (p < 0.001). Moreover, ascites LPA levels were statistically lower after intraperitoneal chemotherapy injection than before (p < 0.001). In addition, the plasma LPA levels were significantly associated with serum CA125 levels (p = 0.032) and TNM stage in gastric cancer patients (p = 0.009). Individuals with plasma LPA levels >20,000 ng/mL had significantly worse overall survival (OS) than those with plasma LPA levels <20,000 ng/mL group (p = 0.006). In addition the group with ascites LPA levels >24,000 ng/mL showed significantly worse progression-free survival (PFS) and OS (p < 0.001 in PFS and OS). CONCLUSIONS: This study demonstrated that LPA levels in plasma and ascites may be useful diagnostic biomarkers for PC of gastric cancer and that higher levels are associated with poor prognosis.


Assuntos
Lisofosfolipídeos/metabolismo , Neoplasias Peritoneais/genética , Adulto , Idoso , Ascite/genética , Ascite/metabolismo , Biomarcadores Tumorais/genética , China , Intervalo Livre de Doença , Feminino , Humanos , Lisofosfolipídeos/análise , Lisofosfolipídeos/sangue , Masculino , Pessoa de Meia-Idade , Neoplasias Peritoneais/metabolismo , Prognóstico , Neoplasias Gástricas/genética , Neoplasias Gástricas/mortalidade
8.
Mol Carcinog ; 56(5): 1414-1426, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27996164

RESUMO

Neoalbaconol, derived from Albatrellus confluens, shows anti-cancer activities in the previously study, but its role in angiogenesis is unknown. Here, we determined whether neoalbaconol could attenuate angiogenesis and how does it occur. Data demonstrated that neoalbaconol could inhibit the proliferation of breast cancer cells and induce apoptosis. Also, neoalbaconol suppressed vascular endothelial growth factor (VEGF)-induced human umbilical vascular endothelial cells (HUVECs) proliferation, migration, invasion, and capillary-like tube formation in vitro and reduced tumor angiogenesis in vivo. VEGF receptor activation and the downstream signal transduction cascades activation were inhibited by neoalbaconol. Additionally, neoalbaconol blocked EGFR-mediated VEGF production. EGFR overexpression reversed the neoalbaconol-induced VEGF reduction, confirming the importance of the EGFR inhibition in anti-angiogenesis of neoalbaconol. Furthermore, neoalbaconol inhibited tumor growth and tumor angiogenesis in a breast cancer xenograft model in vivo. Taken together, these results indicate that neoalbaconol could inhibit tumor angiogenesis and growth through direct suppression effects on vascular endothelial cells and reduction of proangiogenic factors in cancer cells.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Receptores ErbB/metabolismo , Neovascularização Patológica/tratamento farmacológico , Sesquiterpenos/farmacologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/patologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Receptores ErbB/genética , Feminino , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Camundongos Nus , Neovascularização Patológica/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Mol Carcinog ; 56(3): 1082-1087, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27649069

RESUMO

Recently, mutations in isocitrate dehydrogenase 1/2 (IDH1/2) were discovered in 70% of low-grade glioma and secondary glioblastoma multiforme. The discovery of an oncogenic function and the identification of onco-metabolites of IDH1/2 support new roles for metabolism in cancer. For example, some evidence indicates that IDH2 might also exhibit oncogenic functions by promoting cellular metabolism and cancer cell growth. We examined the association between IDH2 rs11540478 and lung cancer risk in 262 lung cancer patient cases and 602 healthy control subjects and also investigated the biological function of rs11540478 in vivo. We found that a higher risk was observed in lung cancer patient carriers of rs11540478 TT and CT compared with CC carriers (OR = 1.44; 95%CI = 1.04-2.00; P = 0.03). The frequency of IDH2 rs11540478 TT and CT carriers was decreased in healthy individuals between the ages of 50-77 compared to those aged 30-49 (OR = 0.67; 95%CI = 0.47-0.96; P = 0.03). Functional analysis showed the effect of rs11540478 on IDH2 expression and lung cancer cell viability, with higher IDH2 expression and cell viability among T allele compared with C allele. IDH2 mRNA was higher in peripheral blood lymphocytes from lung cancer patients compared to healthy subjects. Herein, for the first time we identified IDH2 rs11540478 as a new susceptibility locus for lung cancer. The effect of rs11540478 on mRNA expression of IDH2 and lung cancer cell viability might provide new insight for the genetic basis of lung cancer. © 2016 Wiley Periodicals, Inc.


Assuntos
Isocitrato Desidrogenase/genética , Neoplasias Pulmonares/genética , Polimorfismo de Nucleotídeo Único , Células A549 , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Sobrevivência Celular , Feminino , Regulação Neoplásica da Expressão Gênica , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade
10.
Cancer Lett ; 380(1): 191-200, 2016 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-27255972

RESUMO

We conducted this research to explore the role of latent membrane protein 1 (LMP1) encoded by the Epstein-Barr virus (EBV) in modulating the DNA damage response (DDR) and its regulatory mechanisms in radioresistance. Our results revealed that LMP1 repressed the repair of DNA double strand breaks (DSBs) by inhibiting DNA-dependent protein kinase (DNA-PK) phosphorylation and activity. Moreover, LMP1 reduced the phosphorylation of AMP-activated protein kinase (AMPK) and changed its subcellular location after irradiation, which appeared to occur through a disruption of the physical interaction between AMPK and DNA-PK. The decrease in AMPK activity was associated with LMP1-mediated glycolysis and resistance to apoptosis induced by irradiation. The reactivation of AMPK significantly promoted radiosensitivity both in vivo and in vitro. The AMPKα (Thr172) reduction was associated with a poorer clinical outcome of radiation therapy in NPC patients. Our data revealed a new mechanism of LMP1-mediated radioresistance and provided a mechanistic rationale in support of the use of AMPK activators for facilitating NPC radiotherapy.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Carcinoma/radioterapia , Quebras de DNA de Cadeia Dupla , Proteína Quinase Ativada por DNA/metabolismo , Infecções por Vírus Epstein-Barr/virologia , Herpesvirus Humano 4/metabolismo , Neoplasias Nasofaríngeas/radioterapia , Proteínas Nucleares/metabolismo , Tolerância a Radiação , Proteínas da Matriz Viral/metabolismo , Animais , Apoptose/efeitos da radiação , Carcinoma/enzimologia , Carcinoma/patologia , Carcinoma/virologia , Linhagem Celular Tumoral , Reparo do DNA , Relação Dose-Resposta à Radiação , Ativação Enzimática , Feminino , Glicólise , Interações Hospedeiro-Patógeno , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/enzimologia , Neoplasias Nasofaríngeas/patologia , Neoplasias Nasofaríngeas/virologia , Fosforilação , Transdução de Sinais/efeitos da radiação , Fatores de Tempo , Carga Tumoral/efeitos da radiação , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Oncotarget ; 6(18): 15995-6018, 2015 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-26201446

RESUMO

microRNAs (miRNAs) are involved in the various processes of DNA damage repair and play crucial roles in regulating response of tumors to radiation therapy. Here, we used nasopharyngeal carcinoma (NPC) radio-resistant cell lines as models and found that the expression of miR-504 was significantly up-regulated. In contrast, the expression of nuclear respiratory factor 1 (NRF1) and other mitochondrial metabolism factors, including mitochondrial transcription factor A (TFAM) and oxidative phosphorylation (OXPHOS) complex III were down-regulated in these cell lines. At the same time, the Seahorse cell mitochondrial stress test results indicated that the mitochondrial respiratory capacity was impaired in NPC radio-resistant cell lines and in a miR-504 over-expressing cell line. We also conducted dual luciferase reporter assays and verified that miR-504 could directly target NRF1. Additionally, miR-504 could down-regulate the expression of TFAM and OXPHOS complexes I, III, and IV and impaired the mitochondrial respiratory function of NPC cells. Furthermore, serum from NPC patients showed that miR-504 was up-regulated during different weeks of radiotherapy and correlated with tumor, lymph nodes and metastasis (TNM) stages and total tumor volume. The radio-therapeutic effect at three months after radiotherapy was evaluated. Results indicated that patients with high expression of miR-504 exhibited a relatively lower therapeutic effect ratio of complete response (CR), but a higher ratio of partial response (PR), compared to patients with low expression of miR-504. Taken together, these results demonstrated that miR-504 affected the radio-resistance of NPC by down-regulating the expression of NRF1 and disturbing mitochondrial respiratory function. Thus, miR-504 might become a promising biomarker of NPC radio-resistance and targeting miR-504 might improve tumor radiation response.


Assuntos
Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/radioterapia , Fator 1 Nuclear Respiratório/antagonistas & inibidores , Tolerância a Radiação/genética , Trifosfato de Adenosina/metabolismo , Animais , Apoptose , Western Blotting , Carcinoma , Proliferação de Células , Humanos , Metástase Linfática , Camundongos , MicroRNAs/sangue , NAD/metabolismo , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/sangue , Neoplasias Nasofaríngeas/patologia , Estadiamento de Neoplasias , Fator 1 Nuclear Respiratório/genética , Fator 1 Nuclear Respiratório/metabolismo , Prognóstico , RNA Mensageiro/genética , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas
12.
Cell Biochem Biophys ; 73(1): 205-12, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25716338

RESUMO

SOX9 gene encodes a transcription factor essential for a central role in the development and differentiation of multiple cell lineages, such as in neurogenesis, neural crest development, etc. Recent study reported that overexpression of SOX9 mRNA is closely associated with poor clinical outcome of patients with malignant gliomas. In the present study, we have explored the regulatory role of SOX9 in glioma metastasis. To investigate the role of SOX9 in glioma metastasis, SOX9 overexpressed in human glioma cell line U251 on cell migration and invasion was evaluated via wound scratch, Transwell assay without or with Matrigel. SOX9-induced changes in EMT process were evaluated by Western blot. Furthermore, the role of ß-catenin in the regulatory effect of SOX9 on cell migration and invasion, and EMT process was explored by suppressing ß-catenin expression in SOX9-overexpressed U251 cells. SOX9 overexpression in U251 cells resulted in a significant increase in cell migration and invasion. SOX9 overexpression also markedly promoted the EMT process. More importantly, our results revealed that SOX9 stimulated metastasis through activating Wnt/ß-catenin signaling. In summary, this study indicated that the promoting effect of SOX9 on glioma metastasis was, at least in part, through Wnt/ß-catenin signaling. The findings in this study highlight the effectiveness and therapeutic potential to utilize SOX9 targeted strategies in the treatment of glioma.


Assuntos
Movimento Celular , Glioma/metabolismo , Fatores de Transcrição SOX9/genética , Via de Sinalização Wnt , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal , Glioma/genética , Humanos , Fatores de Transcrição SOX9/metabolismo , Proteínas Wnt/metabolismo , beta Catenina/metabolismo
13.
Oncotarget ; 6(8): 5804-17, 2015 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-25714020

RESUMO

LMP1, which is encoded by the Epstein-Barr virus, is proposed to be one of the major oncogenic factors involved in nasopharyngeal carcinoma (NPC). Previous studies demonstrated that down-regulation of LMP1 by LMP1-targeted DNAzyme (DZ1) increases the radiosensitivity of NPC. However, the mechanism by which DZ1 contributes to this radiosensitivity remains unclear. In this study, we determined whether a DZ1 blockade of LMP1 expression has an overall positive effect on the radiotherapy of NPCs by repressing HIF-1/VEGF activity and to investigate the mechanisms underlying LMP1-induced HIF-1 activation in NPC cells. The results showed that DZ1 inhibited the microtubule-forming ability of HUVECs co-cultured with NPC cells, which occurs with the down-regulation of VEGF expression and secretion. Moreover, LMP1 increases phosphorylated JNKs/c-Jun signaling, which is involved in the regulation of HIF-1/VEGF activity. After silencing LMP1 and decreasing phosphorylation of JNKs, NPC cells exhibited an enhanced radiosensitivity. Furthermore, in vivo experiments revealed a significant inhibition of tumor growth and a marked reduction of the Ktrans parameter, which reflects the condition of tumor micro-vascular permeability. Taken together, our data suggested that VEGF expression is increased by LMP1 through the JNKs/c-Jun signaling pathway and indicated that DZ1 enhances the radiosensitivity of NPC cells by inhibiting HIF-1/VEGF activity.


Assuntos
Inibidores da Angiogênese/farmacologia , DNA Catalítico/farmacologia , Neoplasias Nasofaríngeas/tratamento farmacológico , Neoplasias Nasofaríngeas/radioterapia , Proteínas da Matriz Viral/antagonistas & inibidores , Animais , Carcinoma , Linhagem Celular Tumoral , Técnicas de Cocultura , Feminino , Xenoenxertos , Células Endoteliais da Veia Umbilical Humana , Humanos , Fator 1 Induzível por Hipóxia/metabolismo , Sistema de Sinalização das MAP Quinases , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/irrigação sanguínea , Fosforilação , Tolerância a Radiação , Proteínas da Matriz Viral/genética , Proteínas da Matriz Viral/metabolismo
14.
Cell Biochem Biophys ; 72(2): 551-7, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25564360

RESUMO

Although aggressive therapeutic regimen has been applied in the treatment of Glioblastoma (GBM), the prognosis of patients with GBM remains poor. Preclinical studies have demonstrated the efficacy of Suntinib in GBM both in vitro and in vivo. In this study, we showed that the cytotoxicity was enhanced by transfection with miR-145 mimic. In addition, we suggested that the enhanced cytotoxicity of Sunitinib by miR-145 mimic was mediated by inhibition of both P-gp and Bcrp.


Assuntos
Inibidores da Angiogênese/toxicidade , Glioblastoma/metabolismo , Indóis/toxicidade , MicroRNAs/metabolismo , Pirróis/toxicidade , Apoptose/efeitos dos fármacos , Linhagem Celular , Glioblastoma/genética , Humanos , MicroRNAs/genética , Sunitinibe
15.
Cancer Biol Ther ; 15(1): 61-8, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24145206

RESUMO

The latent membrane protein 1 (LMP1), which is encoded by the Epstein-Barr virus (EBV), has been suggested to be one of the major oncogenic factors in nasopharyngeal carcinoma (NPC). In previous studies, we experimentally demonstrated that downregulation of LMP1 expression by targeting EBV-LMP1 DNAzyme (Dz1) could increase the radiosensitivity of NPC. However, how Dz1 contributes to the radiosensitivity in NPC is still not clear. In the present study, we confirmed that Dz1 decreases LMP1 expression and downregulates the expression of the catalytic subunit of telomerase (hTERT), both at the protein and mRNA levels (P<0.01), and therefore, consequently inhibits telomerase activity (P<0.05) in LMP1-positive NPC cells. We also observed that LMP1 mediated Akt phosphorylation is involved in the regulation of hTERT expression and phosphorylation. After LMP1 and hTERT expression was silenced by Dz1 and hTERT-targeted siRNA, respectively, the radiosensitivity increased in CNE1-LMP1 cells (P<0.05). The inhibition was more significant after Dz1 treatment was combined with siRNA (P<0.01). We concluded that hTERT expression and phosphorylation could be regulated by LMP1 through the Akt pathway, and Dz1 enhances radiosensitivity of LMP1-positive NPC cells by inhibiting telomerase activity.


Assuntos
DNA Catalítico/metabolismo , Neoplasias Nasofaríngeas/patologia , Tolerância a Radiação , Telomerase/metabolismo , Proteínas da Matriz Viral/metabolismo , Carcinoma , Linhagem Celular Tumoral/efeitos da radiação , DNA Catalítico/genética , Humanos , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/enzimologia , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Interferente Pequeno/genética , Transdução de Sinais , Telomerase/genética , Proteínas da Matriz Viral/genética
16.
Artigo em Inglês | MEDLINE | ID: mdl-24120648

RESUMO

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

17.
Int J Oncol ; 43(5): 1541-8, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24042231

RESUMO

This study aimed to determine the molecular mechanisms underlying the effect of the LMP1-targeted DNAzyme 1 (DZ1) on cell cycle progression in nasopharyngeal carcinoma (NPC) cells. We showed that the active DZ1 inhibited the expression of latent membrane protein 1 (LMP1) and induced a G1 phase arrest. In addition, this cell cycle deregulation was shown to be accompanied by upregulation of the DNA damage marker γ-H2AX, downregulation of the DNA damage response factor p-p53-Ser15 and cell proliferation inhibition. To investigate what affected the cell cycle progression, we examined the expression of two checkpoint-related cyclins and cyclin-dependent kinases (CDKs). We found a decrease of cyclin D1 and cyclin E protein levels at 24 h from the DZ1 treatment. Moreover, we observed inhibition of CDK4 activity and decreased cyclin D1 expression in the complexes immunoprecipitated with CDK4 antibody. We also found a reduction in cdc2 phosphorylation at Thr161 which partially stands for the cdc2 kinase activity in DZ1-treated CNE1-LMP1 cells, although the downregulation of LMP1 expression had no effect on the cyclin B1 and cdc2 expression. Further, we analyzed changes in cdc2 kinase activity induced by DZ1 and found that the downregulation of the LMP1 expression resulted in a 5-fold reduction in cdc2 kinase activity in CNE1-LMP1. The data suggest that the downregulation of the LMP1 expression by DZ1 was able to induce DNA damage, which then further inhibited the cell proliferation and resulted in malfunction of cell cycle checkpoints that led to G1 phase arrest and the decrease in number of cells in G2/M phase.


Assuntos
Carcinoma de Células Escamosas/patologia , Pontos de Checagem do Ciclo Celular , Dano ao DNA , DNA Catalítico/antagonistas & inibidores , Neoplasias Nasofaríngeas/patologia , Proteínas da Matriz Viral/metabolismo , Apoptose , Western Blotting , Proteína Quinase CDC2 , Carcinoma , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Proliferação de Células , Ciclina B/metabolismo , Ciclina D1/metabolismo , Ciclina E/metabolismo , Quinases Ciclina-Dependentes , DNA Catalítico/metabolismo , Imunofluorescência , Histonas/metabolismo , Humanos , Técnicas Imunoenzimáticas , Imunoprecipitação , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/metabolismo , Proteínas Oncogênicas/metabolismo , Fosforilação , Células Tumorais Cultivadas
18.
PLoS One ; 7(4): e34912, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22523564

RESUMO

The Fip1-like1 (FIP1L1)-platelet-derived growth factor receptor alpha fusion gene (F/P) arising in the pluripotent hematopoietic stem cell (HSC),causes 14% to 60% of patients with hypereosinophilia syndrome (HES). These patients, classified as having F/P (+) chronic eosinophilic leukemia (CEL), present with clonal eosinophilia and display a more aggressive disease phenotype than patients with F/P (-) HES patients. The mechanisms underlying predominant eosinophil lineage targeting and the cytotoxicity of eosinophils in this leukemia remain unclear. Given that the Janus tyrosine kinase (JAK)/signal transducers and activators of transcription (Stat) signaling pathway is key to cytokine receptor-mediated eosinophil development and activated Stat3 and Stat5 regulate the expression of genes involved in F/P malignant transformation, we investigated whether and how JAK proteins were involved in the pathogenesis of F/P-induced CEL. F/P activation of JAK2, Stat3 and Stat5, were confirmed in all the 11 F/P (+) CEL patients examined. In vitro inhibition of JAK2 in EOL-1, primary F/P(+) CEL cells (PC) and T674I F/P Imatinib resistant cells(IR) by either JAK2-specific short interfering RNA (siRNA) or the tryphostin derivative AG490(AG490), significantly reduced cellular proliferation and induced cellular apoptosis. The F/P can enhance the IL-5-induced JAK2 activation, and further results indicated that JAK2 inhibition blocked IL-5-induced cellular migration and activation of the EOL-1 and PC cells in vitro. F/P-stimulation of the JAK2 suppressed cells led to a significantly reduction in Stat3 activation, but relatively normal induction of Stat5 activation. Interestingly, JAK2 inhibition also reduced PI3K, Akt and NF-κB activity in a dose-dependent manner, and suppressed expression levels of c-Myc and Survivin. These results strongly suggest that JAK2 is activated by F/P and is required for F/P stimulation of cellular proliferation and infiltration, possibly through induction of c-Myc and Survivin expression via activation of multiple signaling pathways, including NF-κB, Stat3, and PI3K/Akt.


Assuntos
Eosinófilos/fisiologia , Síndrome Hipereosinofílica/genética , Janus Quinase 2/metabolismo , Proteínas de Fusão Oncogênica/fisiologia , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/fisiologia , Fatores de Poliadenilação e Clivagem de mRNA/fisiologia , Benzamidas , Regulação para Baixo , Ativação Enzimática , Células-Tronco Hematopoéticas/metabolismo , Humanos , Síndrome Hipereosinofílica/enzimologia , Síndrome Hipereosinofílica/fisiopatologia , Mesilato de Imatinib , Interleucina-5/fisiologia , Janus Quinase 2/antagonistas & inibidores , NF-kappa B/metabolismo , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , RNA Interferente Pequeno/farmacologia , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT5/antagonistas & inibidores , Fator de Transcrição STAT5/metabolismo , Células Tumorais Cultivadas , Tirfostinas/farmacologia
19.
J Gastrointest Surg ; 15(9): 1526-31, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21717282

RESUMO

BACKGROUND: Lymphatic vessel invasion (LV) has been regarded as a prognostic factor in some solid tumors. The aim was to clarify the impact of lymphatic vessel invasion on survival in curative resected gastric cancer. METHODS: In this retrospective study, we reviewed the records of 1,024 patients who underwent curative resection for gastric cancer. Among all of the studied patients, 285 of them (27.8%) had lymphatic vessel invasion. RESULTS: There were significant differences in tumor size, tumor location, depth of invasion, and lymph node metastasis (LN) between the patients with lymphatic vessel invasion and those without. The 5-year survival rates in patients were 80.1%, 59.2%, 40.9%, and 30.5% for LN-LV-, LN-LV+, LN+LV-, and LN+LV+ group, respectively. Multivariate analysis revealed that age, tumor location, the depth of invasion, and lymph node metastasis were independent prognostic factors for curative resected gastric cancer. Lymphatic vessel invasion was not an independent prognostic factor in node-positive gastric cancer; however, it was true in node-negative gastric cancer. CONCLUSION: Lymphatic vessel invasion is one of the independent prognostic factors for node-negative gastric cancer after curative resection.


Assuntos
Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Vasos Linfáticos/patologia , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Adenocarcinoma/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Estimativa de Kaplan-Meier , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Invasividade Neoplásica , Prognóstico , Modelos de Riscos Proporcionais , Neoplasias Gástricas/cirurgia , Carga Tumoral
20.
Zhonghua Er Ke Za Zhi ; 45(1): 51-4, 2007 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-17349153

RESUMO

OBJECTIVE: To explore the mode of intervention for children with language developmental delay under the current condition of China. METHOD: The study population consisted of a cross-sectional convenience sample of 206 children, ages 13 - 24 months, from six communities of Qingpu in Shanghai. Parents were asked to complete detailed questionnaires about their child's spontaneous use of vocabularies. Fourteen children with vocabularies less than 5 percentile of every age group were identified as having language developmental delay. During the 12-month intervention, developmental pediatricians did the developmental assessment for every child and set goals of intervention for everybody according to their language abilities and family situation. Then kindergarten teachers who got the training in language therapy carried out the intervention. Gesell development scale was used for developmental assessment before and after the intervention. RESULTS: The developmental quotient (DQ) in areas of language and personal-social behavior was elevated significantly after 12 months of intervention (P < 0.01). The developmental quotient (DQ) in the area of adaptive behavior was also elevated (P < 0.05). There was an obvious catching up effect in both areas of language and personal-social behavior. Increased developmental age in both areas was (18.0 +/- 5.3) months and (16.2 +/- 5.9) months, respectively. The language ability of 71.4% samples was in the normal range at the end. CONCLUSIONS: The mode of medical and educational cooperation to give early intervention for children with language developmental delay is feasible. It can significantly improve the abilities in language and communication of children 1 - 2 years of age.


Assuntos
Intervenção Educacional Precoce , Transtornos do Desenvolvimento da Linguagem/terapia , China , Estudos Transversais , Humanos , Lactente , Transtornos do Desenvolvimento da Linguagem/diagnóstico , Testes de Linguagem , Inquéritos e Questionários
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