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1.
EB病毒LMP-1在鼻咽癌细胞中通过JNK介导AP-1活化   总被引:7,自引:0,他引:7  
 EB病毒潜伏膜蛋白 1 (latentmembraneprotein 1 ,LMP 1 )活化激活蛋白 1 (activatorprotein 1 ,AP 1 )信号传导途径与其致瘤作用密切相关 .为了探讨LMP 1活化AP 1信号传导的分子机制 ,在可诱导调控LMP 1表达的鼻咽癌细胞系L7中 ,首先通过荧光酶双报道系统确定了LMP 1表达能激活AP 1 ;在此基础上 ,用c JunPathDetect系统确定LMP 1表达活化AP 1是通过c Jun的磷酸化 (活化 )介导 .虽然LMP 1不能上调c Jun上游主要调节激酶c JunN端激酶 (c JunN terminalkinase ,JNK)的蛋白表达 ,但能显著促进JNK的磷酸化 (活化 ) ;在L7细胞中导入JNK相互作用蛋白 (JNK interactingprotein ,JIP)基因 ,抑制JNK的核移位能显著抑制LMP 1诱导的AP 1活化 ,同时对NFкВ活化也有部分抑制作用 .结果表明 ,EB病毒LMP 1在鼻咽癌细胞中通过JNK介导AP 1活化  相似文献   

2.
Chemotherapy is a crucial adjuvant therapy of advanced nasopharyngeal carcinoma (NPC). However, enhancing sensitivity and tolerance of chemotherapeutics in NPC treatment have been challenging. Both Bcl-2 and Mcl-1, 2 pro-survival proteins of Bcl-2 family, play essential roles on the chemotherapy tolerance of numerous cancers. In the present study, we explored the influences of TW-37, a small molecule inhibitor of Bcl-2 and Mcl-1, on the efficiency of chemotherapy for NPC. Oncomine cancer database shows that NPC tissues have higher expression of Bcl-2 and Mcl-1 than those of normal nasopharyngeal epithelial (NPE) tissues. And our results reveal that chemotherapeutics, Cisplatin (CDDP) and 5-Fluoracil (5-FU), result in the greater decrease of protein level of Bcl-2 and Mcl-1 in NPC cells than those in NPE cells. TW-37 does not have significant impact on the chemotherapeutics-treated NPE cell viability at a dosage that efficiently reduces chemotherapeutics-treated NPC cell viability. Moreover, impacts of TW-37 on the cell viability of chemotherapeutics-treated NPC cells are dependent on the expression of Bcl-2 and Mcl-1 in NPC cells. Further explorations suggest that TW-37 prominently promotes apoptosis in NPC cells under chemotherapeutics treatments but not in NPE cells. Meanwhile, TW-37 also remarkably reduces colony formation ability of chemotherapeutics-treated NPC cells. Importantly, in vivo models, TW-37 observably increases chemosensitivity of NPC tumors but has not markedly influence on the normal tissues in mice. In conclusion, our results point to TW-37 as a promising ancillary drug for the chemotherapy of NPC.  相似文献   

3.
4.
Chondrosarcoma is a type of highly malignant tumour with a potent capacity to invade locally and cause distant metastasis. Chondrosarcoma shows a predilection for metastasis to the lungs. Tumour necrosis factor (TNF)‐α is a key cytokine involved in inflammation, immunity, cellular homeostasis and tumour progression. Integrins are the major adhesive molecules in mammalian cells and have been associated with metastasis of cancer cells. However, the effects of TNF‐α in migration and integrin expression in chondrosarcoma cells are largely unknown. In this study, we found that TNF‐α increased the migration and the expression of αvβ3 integrin in human chondrosarcoma cells. Activations of MAPK kinase (MEK), extracellular signal‐regulating kinase (ERK) and nuclear factor‐κB (NF‐κB) pathways after TNF‐α treatment were demonstrated, and TNF‐α‐induced expression of integrin and migration activity was inhibited by the specific inhibitor and mutant of MEK, ERK and NF‐κB cascades. Taken together, our results indicated that TNF‐α enhances the migration of chondrosarcoma cells by increasing αvβ3 integrin expression through the MEK/ERK/NF‐κB signal transduction pathway. J. Cell. Physiol. 226: 792–799, 2011. © 2010 Wiley‐Liss, Inc.  相似文献   

5.
Follistatin‐like protein 1 (FSTL1) is a newly characterized protein that can regulate the immune response in various ways. Dendritic cells (DCs) are central to immune regulation. In this study, we explored the impact of FSTL1 on DC activity in nasopharyngeal carcinoma (NPC) patients. The surface expression of CD40, CD86, and HLA‐DR on DCs was analyzed and showed significantly elevated expression levels, indicating DC maturity. After FSTL1 was added to DCs collected from NPC patients (n = 50), controls (n = 47), and healthy donors (n = 10), interferon γ secretion and T‐cell receptor expression in cytotoxic T lymphocytes were also investigated. In the experimental groups, the expression of the critical immune protein nuclear factor (NF)‐κb was upregulated, whereas Jun N‐terminal kinase (JNK) was downregulated. Our findings demonstrate that FSTL1 plays a critical role in immune regulation, enhancing the antigen presentation ability of DCs by up‐regulating NF‐κb expression and down‐regulating JNK expression.  相似文献   

6.
Invasion of tumor cells is the primary cause of therapeutic failure in malignant chondrosarcomas treatment. Receptor activator of nuclear factor‐κB ligand (RANKL) and its receptor, RANK, play a key roles in osteoclastogenesis and tumor metastasis. We found that the RANKL and RANK expression in human chondrosarcoma tissues was higher than that in normal cartilage. We also found that RANKL directed the migration and increased cell surface expression of β1 integrin in human chondrosarcoma cells (JJ012 cells). Pretreatment of JJ012 cells with MAPK kinase (MEK) inhibitors, PD98059 or U0126, inhibited the RANKL‐induced migration and integrin expression. Stimulation of cells with RANKL increased the phosphorylation of MEK and extracellular signal‐regulating kinase (ERK). In addition, NF‐κB inhibitor (PDTC) or IκB protease inhibitor (TPCK) also inhibited RANKL‐induced cells migration and integrin up‐regulation. Taken together, these results suggest that the RANKL acts through MEK/ERK, which in turn activates IKKα/β and NF‐κB, resulting in the activation of β1 integrin and contributing to the migration of human chondrosarcoma cells. J. Cell. Biochem. 111: 138–147, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   

7.
Nasopharyngeal carcinoma (NPC) is a head and neck malignant tumor rare throughout most of the world but common in Southeast Asia, especially in Southern China. Flotillin-2 (Flot-2) is not only an important component of cellular membrane, but also involves in various cellular processes such as membrane trafficking, T cell and B cell activation, regulation of several signaling pathways associated with cell growth and malignant transformation, keeping structure and junction of epidermal cells and formation of filopodia. Although such molecular effects of Flot-2 have been reported, whether the expression of Flot-2 protein is associated with clinicopathologic implication for NPC has not been reported. The purpose of this research is to investigate the expression of Flot-2 protein in NPC and control nasopharyngeal epithelial tissues by immunohistochemistry and elucidate the association between the expression of Flot-2 protein and clinicopathological characteristics of NPC. The results showed that the positive percentage of Flot-2 expression in the NPC, nasopharyngeal epithelia with atypical hyperplasia and in the control nasopharyngeal mucosa epithelia was 88.8% (119/134), 76.9% (10/13) and 5.7% (5/88), respectively. There was significantly higher expression of Flot-2 protein in NPC and nasopharyngeal epithelia with atypical hyperplasia compared to the control nasopharyngeal mucosa epithelia (P<0.001, respectively). The positive percentage of Flot-2 protein expression in NPC patients with lymph node metastasis was significantly higher than those without lymph node metastasis. Increasing of Flot-2 expression was obviously correlated with clinical stages of NPC patients. The expression of Flot-2 was proved to be the independent predicted factor for lymph node metastasis by multivariate analysis. The sensitivity of Flot-2 for predicting lymph node metastasis of NPC patients was 93%. Taken together, our results suggest that the increased expression of Flot-2 protein is a novel higher sensitivity biomarker that can predict lymph node metastases in NPC.  相似文献   

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9.
Bradykinin (BK) is an inflammatory mediator, and shows elevated levels in regions of severe injury and inflammatory diseases. BK has recently been shown to be involved in carcinogenesis and cancer progression. In this study, we found that BK increased the migration and the expression of α2β1 integrin in human chondrosarcoma cells. We also found that human chondrosarcoma tissues had significantly higher expression of the B1 and B2 receptors comparing to normal cartilage. BK‐mediated migration and integrin up‐regulation was attenuated by B1 and B2 BK receptor siRNA or antagonist. Activations of phospholipase C (PLC), protein kinase Cδ (PKCδ), and NF‐κB pathways after BK treatment was demonstrated, and BK‐induced integrin expression and migration activity was inhibited by the specific inhibitor of PLC, PKCδ, and NF‐κB cascades. Taken together, our results indicated that BK enhances the migration of chondrosarcoma cells by increasing α2β1 integrin expression through the BK receptors/PLC/PKCδ/NF‐κB signal transduction pathway. J. Cell. Biochem. 109: 82–92, 2010. © 2009 Wiley‐Liss, Inc.  相似文献   

10.
Tumor malignancy is associated with several features such as proliferation ability and frequency of metastasis. Connective tissue growth factor (CTGF), a secreted protein that binds to integrins, modulates the invasive behavior of certain human cancer cells. However, the effect of CTGF on migration activity in human chondrosarcoma cells is mostly unknown. Here we found that CTGF increased the migration and expression of matrix metalloproteinase (MMP)‐13 in human chondrosarcoma cells (JJ012 cells). RGD peptide, αvβ3 monoclonal antibody (mAb) and MAPK kinase (MEK) inhibitors (PD98059 and U0126) but not RAD peptide inhibited the CTGF‐induced increase of the migration and MMP‐13 up‐regulation of chondrosarcoma cells. CTGF stimulation increased the phosphorylation of focal adhesion kinase (FAK) and extracellular signal‐regulated kinase (ERK). In addition, treatment of JJ012 cells with NF‐κB inhibitor (PDTC) or IκB protease inhibitor (TPCK) inhibited CTGF‐induced cell migration and MMP‐13 up‐regulation. Stimulation of JJ012 cells with CTGF also induced IκB kinase α/β (IKK α/β) phosphorylation, IκBα phosphorylation, p65 Ser536 phosphorylation, and κB‐luciferase activity. The CTGF‐mediated increases in κB‐luciferase activities were inhibited by RGD, PD98059, U0126 or FAK, and ERK2 mutant. Taken together, our results indicated that CTGF enhances the migration of chondrosarcoma cells by increasing MMP‐13 expression through the αvβ3 integrin, FAK, ERK, and NF‐κB signal transduction pathway. J. Cell. Biochem. 107: 345–356, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

11.
Invasion of tumor cells is the primary cause of therapeutic failure in the treatment of malignant chondrosarcomas. Glial cell‐derived neurotrophic factor (GDNF) plays a crucial role in migration and metastasis of human cancer cells. Integrins are the major adhesive molecules in mammalian cells. Here we found that GDNF directed the migration and increased cell surface expression of αv and β3 integrin in human chondrosarcoma cells. Pretreated of JJ012 cells with MAPK kinase (MEK) inhibitors PD98059 or U0126 inhibited the GDNF‐mediated migration and integrin expression. Stimulation of cells with GDNF increased the phosphorylation of MEK and extracellular signal‐regulating kinase (ERK). In addition, NF‐κB inhibitor (PDTC) or IκB protease inhibitor (TPCK) also inhibited GDNF‐mediated cells migration and integrin up‐regulation. Stimulation of cells with GDNF induced IκB kinase (IKKα/β) phosphorylation, IκB phosphorylation, p65 Ser536 phosphorylation, and κB‐luciferase activity. Furthermore, the GDNF‐mediated increasing of κB‐luciferase activity was inhibited by PD98059, U0126, PDTC and TPCK or MEK, ERK, IKKα, and IKKβ mutants. Taken together, these results suggest that the GDNF acts through MEK/ERK, which in turn activates IKKα/β and NF‐κB, resulting in the activations of αvβ3 integrin and contributing the migration of human chondrosarcoma cells. J. Cell. Physiol. 220: 499–507, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

12.
Deng W  Pang PS  Tsang CM  Hau PM  Yip YL  Cheung AL  Tsao SW 《PloS one》2012,7(6):e39095
Nasopharyngeal carcinoma (NPC) is a common cancer in Southeast Asia, particularly in southern regions of China. EBV infection is closely associated with NPC and has long been postulated to play an etiological role in the development of NPC. However, the role of EBV in malignant transformation of nasopharyngeal epithelial cells remains enigmatic. The current hypothesis of NPC development is that premalignant nasopharyngeal epithelial cells harboring genetic alterations support EBV infection and expression of EBV genes induces further genomic instability to facilitate the development of NPC. The latent membrane protein 1 (LMP1) is a well-documented EBV-encoded oncogene. The involvement of LMP1 in human epithelial malignancies has been implicated, but the mechanisms of oncogenic actions of LMP1, particularly in nasopharyngeal cells, are unclear. Here we observed that LMP1 expression in nasopharyngeal epithelial cells impaired G2 checkpoint, leading to formation of unrepaired chromatid breaks in metaphases after γ-ray irradiation. We further found that defective Chk1 activation was involved in the induction of G2 checkpoint defect in LMP1-expressing nasopharyngeal epithelial cells. Impairment of G2 checkpoint could result in loss of the acentrically broken chromatids and propagation of broken centric chromatids in daughter cells exiting mitosis, which facilitates chromosome instability. Our findings suggest that LMP1 expression facilitates genomic instability in cells under genotoxic stress. Elucidation of the mechanisms involved in LMP1-induced genomic instability in nasopharyngeal epithelial cells will shed lights on the understanding of role of EBV infection in NPC development.  相似文献   

13.
Osteosarcoma is characterized by a high malignant and metastatic potential. The chemokine stromal‐derived factor‐1α (SDF‐1α) and its receptor, CXCR4, play a crucial role in adhesion and migration of human cancer cells. Integrins are the major adhesive molecules in mammalian cells, and has been associated with metastasis of cancer cells. Here, we found that human osteosarcoma cell lines had significant expression of SDF‐1 and CXCR4 (SDF‐1 receptor). Treatment of osteosarcoma cells with SDF‐1α increased the migration and cell surface expression of αvβ3 integrin. CXCR4‐neutralizing antibody, CXCR4 specific inhibitor (AMD3100) or small interfering RNA against CXCR4 inhibited the SDF‐1α‐induced increase the migration and integrin expression of osteosarcoma cells. Pretreated of osteosarcoma cells with MAPK kinase (MEK) inhibitor PD98059 inhibited the SDF‐1α‐mediated migration and integrin expression. Stimulation of cells with SDF‐1α increased the phosphorylation of MEK and extracellular signal‐regulating kinase (ERK). In addition, NF‐κB inhibitor (PDTC) or IκB protease inhibitor (TPCK) also inhibited SDF‐1α‐mediated cell migration and integrin up‐regulation. Stimulation of cells with SDF‐1α induced IκB kinase (IKKα/β) phosphorylation, IκB phosphorylation, p65 Ser536 phosphorylation, and κB‐luciferase activity. Furthermore, the SDF‐1α‐mediated increasing κB‐luciferase activity was inhibited by AMD3100, PD98059, PDTC and TPCK or MEK1, ERK2, IKKα and IKKβ mutants. Taken together, these results suggest that the SDF‐1α acts through CXCR4 to activate MEK and ERK, which in turn activates IKKα/β and NF‐κB, resulting in the activations of αvβ3 integrins and contributing the migration of human osteosarcoma cells. J. Cell. Physiol. 221: 204–212, 2009. © 2009 Wiley‐Liss, Inc  相似文献   

14.
N,N'-Dinitrosopiperazine (DNP) is a carcinogen for nasopharyngeal carcinoma (NPC), which shows organ specificity to nasopharyngeal epithelium. Herein, we demonstrate that DNP induces fiber formation of NPC cells (6-10B) and also increases invasion and motility of 6-10B cells. DNP-mediated NPC metastasis also was confirmed in nude mice. Importantly, DNP induced the expression of phosphorylated ezrin (phos-ezrin) at threonine 567 (Thr-567) dose- and time-dependently but had no effect on the total ezrin expression at these concentrations. Furthermore, DNP-induced phos-ezrin expression was dependent on increased Rho kinase and protein kinase C (PKC) activity. DNP may activate Rho kinase through binding to its pleckstrin homology and may activate PKC through promoting its translocation to the plasma membrane in vivo. DNP-induced phos-ezrin was associated with induction of fiber growth in 6-10B cells. However, DNP could not induce motility and invasion of NPC cells containing ezrin mutated at Thr-567. Similarly, DNP could not induce motility and invasion of the cells containing siRNAs against Rho or PKC. These results indicate that DNP induces ezrin phosphorylation at Thr-567, increases motility and invasion of cells, and promotes tumor metastasis. DNP may be involved in NPC metastasis through regulation of ezrin phosphorylation at Thr-567.  相似文献   

15.
The Epstein-Barr virus (EBV)-encoded LMP1 protein is an important component of the process of transformation by EBV. LMP1 is essential for transformation of B lymphocytes, most likely because of its profound effects on cellular gene expression. Although LMP1 is expressed in the majority of nasopharyngeal carcinoma (NPC) tumors, the effect of LMP1 on cellular gene expression and its contribution to the development of malignancy in epithelial cells is largely unknown. In this study the effects of LMP1 on the expression and tyrosine kinase activity of the epidermal growth factor receptor (EGFR) were investigated in C33A human epithelial cells. Stable or transient expression of LMP1 in C33A cells increased expression of the EGFR at both the protein and mRNA levels. In contrast, expression of the EGFR was not induced by LMP1 in EBV-infected B lymphocytes. Stimulation of LMP1-expressing C33A cells with epidermal growth factor (EGF) caused rapid tyrosine phosphorylation of the EGFR (pp170) as well as several other proteins, including pp120, pp85, pp75, and pp55, indicating that the EGFR induced by LMP1 is functional. LMP1 also induced expression of the A20 gene in C33A epithelial cells. In C33A cells, LMP1 expression increased the proliferative response to EGF, as LMP1-expressing C33A cells continued to increase in number when plated in serum-free media supplemented with EGF, while the neo control cells exhibited very low levels of viability and did not proliferate. Immunoblot analysis of protein extracts from nude mouse-passaged NPC tumors also demonstrated that the EGFR is overexpressed in primary NPC tumors as well as those passaged in nude mice. This study suggests that the alteration in the growth patterns of C33A cells expressing LMP1 is a result of increased proliferative signals due to enhanced EGFR expression, as well as protection from cell death due to LMP1-induced A20 expression. The induction of EGFR and A20 by LMP1 may be an important component of EBV infection in epithelial cells and could contribute to the development of epithelial malignancies such as NPC.  相似文献   

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18.
The anti-inflammatory effect of acetylsalicylic acid (ASA) has been thought to be secondary to the inhibition of prostaglandin synthesis. Because doses of ASA necessary to treat chronic inflammatory diseases are much higher than those needed to inhibit prostaglandin synthesis, a prostaglandin-independent pathway has been emerging as the new anti-inflammatory mechanism of ASA. Here, we examined the effect of ASA on the interleukin (IL)-1 beta- and tumor necrosis factor (TNF)-alpha-induced proinflammatory cytokine expression and evaluated whether this effect is closely linked to the nuclear factor (NF)-kappa B/I kappa B-alpha pathway. A high dose of ASA blocked IL-1 beta- and TNF-alpha-induced TNF-alpha and IL-8 expression, respectively. ASA inhibited TNF-alpha-induced activation of NF-kappa B by preventing phosphorylation and subsequent degradation of I kappa B-alpha in a prostanoid-independent manner. TNF-alpha-induced activation of I kappa B kinase was also suppressed by ASA pretreatment. These observations suggest that the anti-inflammatory effect of ASA in lung epithelial cells may be due to suppression of I kappa B kinase activity, which thereby inhibits subsequent phosphorylation and degradation of I kappa B-alpha, activation of NF-kappa B, and proinflammatory cytokine expression in lung epithelial cells.  相似文献   

19.

Background

To determine the correlation of cyclin-dependent kinase inhibitor 1B (p27) expression with clinicopathologic features in nasopharyngeal carcinoma (NPC), including patient prognosis.

Methods

Real-time PCR and immunohistochemistry were used to examine the mRNA and protein expressions of p27 in NPC and nasopharyngeal tissues. The relationship of p27 expression levels with clinical features and prognosis of NPC patients was analyzed.

Results

The expression level of p27 mRNA was markedly lower in NPC tissues than that in the nasopharyngeal tissues (P?=?0.0006). Specific p27 protein staining by immunohistochemistry was found in the nuclei and cytoplasm of nasopharyngeal and malignant epithelial cells but decreased expression was observed in NPC samples compared to normal epithelium samples (P?=?0.002). In addition, low levels of p27 protein were inversely correlated with the status of T classification (p?=?0.002) and clinical stage (p?=?0.019) of NPC patients. Patients with lower p27 expression had a significantly shorter overall survival time than did patients with high p27 expression. Multivariate analysis suggested that the level of p27 expression was not an independent prognostic indicator (p?=?0.682) for NPC survival.

Conclusion

Low level of p27 expression is a potential unfavorable prognostic factor for patients with NPC.

Virtual slides

The virtual slide (s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1915282782109343.
  相似文献   

20.
Tumor malignancy is associated with several features such as proliferation ability and frequency of metastasis. Osteopontin (OPN), which abundantly expressed in bone matrix, is involved in cell adhesion, migration, invasion and proliferation via interaction with its receptor, that is, αvβ3 integrin. However, the effect of OPN on migration activity in human chondrosarcoma cells is mostly unknown. Here we found that OPN increased the migration and expression of matrix metalloproteinase (MMP)‐9 in human chondrosarcoma cells (JJ012 cells). RGD peptide, αvβ3 monoclonal antibody and MAPK kinase (MEK) inhibitors (PD98059 and U0126) but not RAD peptide inhibited the OPN‐induced increase of the migration and MMP‐9 up‐regulation of chondrosarcoma cells. OPN stimulation increased the phosphorylation of focal adhesion kinase (FAK), MEK and extracellular signal‐regulated kinase (ERK). In addition, treatment of JJ012 cells with NF‐κB inhibitor (PDTC) or IκB protease inhibitor (TPCK) inhibited OPN‐induced cell migration and MMP‐9 up‐regulation. Stimulation of JJ012 cells with OPN also induced IκB kinase α/β (IKK α/β) phosphorylation, IκBα phosphorylation, p65 Ser536 phosphorylation, and κB‐luciferase activity. The OPN‐mediated increases in MMP‐9 and κB‐luciferase activities were inhibited by RGD peptide, PD98059 or FAK and ERK2 mutant. Taken together, our results indicated that OPN enhances the migration of chondrosarcoma cells by increasing MMP‐9 expression through the αvβ3 integrin, FAK, MEK, ERK and NF‐κB signal transduction pathway. J. Cell. Physiol. 221: 98–108, 2009. © 2009 Wiley‐Liss, Inc  相似文献   

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