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1.
 NGX6 基因是我室利用定位候选克隆策略,在鼻咽癌的高频杂合性缺失区9p21-22克隆的新基因.前期研究结果提示,它与鼻咽癌细胞的侵袭转移密切相关.为了进一步阐明其作用的结构基础,本研究成功构建了含NGX6基因及突变体的pCMV-myc瞬时和pcDNA3.1-his-myc(-)B稳定表达载体.通过脂质体转染技术,构建了NGX6及突变体的稳定表达细胞系5-8F.用免疫荧光试验和免疫电镜观察了NGX6在5-8F细胞中的亚细胞定位主要位于胞膜、核膜以及胞浆中的膜质结构,缺失突变的功能域对其定位没有明显的影响.基质胶侵袭试验和划痕试验研究了NGX6及突变体对细胞运动的影响.NGX6能抑制高转移潜能的鼻咽癌细胞5-8F的运动和侵袭能力,缺失胞内区(CYTO)后NGX6不能抑制5-8F细胞的运动和侵袭,提示CYTO可能是其发挥作用的重要功能域.  相似文献   

2.
Nasopharyngeal carcinoma (NPC)-associated gene 6 (NGX6) is a novel candidate metastasis suppressor gene that can significantly decrease the growth, motility, and invasion of NPC cells. In this study, we generated a highly specific NGX6 polyclonal antibody and analyzed its distribution in the human fetus by Western blot and immunohistochemistry. The result of the Western blot showed the protein of NGX6 had two types of isoforms, isoform a (NGX6a) and isoform b (NGX6b). Isoform a is composed of 472 amino acids with a calculated molecular mass of 52 kDa, whereas isoform b is composed of 338 amino acids with a calculated molecular mass of 37 kDa. It is predicated that there is an epidermal growth factor domain in the N terminal of both a and b isoforms, and seven transmembrane domains in NGX6a, but only two transmembrane domains in NGX6b. The expression level of NGX6a was higher than that of NGX6b in human fetal tissue. Obvious high expression of NGX6a protein presents in the nervous system and epithelial tissues of the human fetus, but the NGX6b protein (37 kDa) is mainly expressed in the nervous system. We further analyzed the tissue microarray, which contained 154 NPC biopsies and 70 non-NPC biopsies, and found that NGX6a was significantly downregulated in NPC and associated with tumor metastasis. (J Histochem Cytochem 58:41–51, 2010)  相似文献   

3.
NGX6基因转染对鼻咽癌细胞基因表达谱的影响   总被引:4,自引:0,他引:4  
鼻咽癌是我国南方的常见肿瘤 .NGX6是新近克隆的定位于 9p2 1 2 2 ,在鼻咽癌组织中表达下调的基因 .初步的研究结果显示 ,NGX6基因转染鼻咽癌细胞HNE1能够延缓其生长速度 ,使肿瘤细胞更多地停留在G0 G1期 .为探索NGX6基因在鼻咽癌发病机制中的作用 ,建立了高表达NGX6的鼻咽癌细胞系 .利用包含 14 0 0 0个基因的cDNA微阵列分析了NGX6基因转染对HNE1细胞基因表达谱的影响 ,发现NGX6基因的转染能够上调p2 9、APC7、NEU1、RNasek6、αE catenin和TFⅡEα等基因的表达 ;同时也下调properdinP因子、G0S2、BAZ2B、ZHX1,OS4和PBX3等基因的表达 .研究结果提示 ,NGX6基因对鼻咽癌细胞的生物学行为的影响可能与它对一些细胞周期调控因子和转录调控因子的影响相关 .作为一种高通量的分析技术 ,cDNA微阵列为新基因的功能研究提供了重要的线索  相似文献   

4.
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   

5.
Nasopharyngeal carcinoma (NPC) is a common cancer in South China but is rare in other parts of the world. A novel NPC-related gene was isolated by location candidate cloning strategy, whose expression was down-regulated in NPC. This gene was designated human NGX6 (Genbank accession AF188239) and encoded a predicted protein of 338 amino acids that harbors an EGF-like domain. The effects of NGX6 on cells from human NPC cell line HNE1 were investigated. The cells transfected with NGX6 had a markedly high expression of NGX6, leading to significant decrease in cell proliferation and the capability to form colonies in soft agar, delaying the G0-G1 cell cycle progression. Flow cytometry assay indicated that the expression of cyclin D1 significantly decreased in NGX6-transfected HNE1 cells as well as cyclin A and E. There was a delay in tumor formation and a dramatic reduction in tumor size when cells transfected with NGX6 were injected into nude mice. In another way, we found NGX6 played a negative role in EGFR Ras/Mek/MAPK pathway. We propose that NGX6, as an EGF-like domain gene, could delay cell cycle G0-G1 progression and thus inhibit cell proliferation by negatively regulating EGFR pathway in NPC cells and down-regulating the expression of cyclin D1 and E.  相似文献   

6.
研究新的候选抑瘤基因NGX6在多种常见癌组织中的mRNA原位表达谱,分析NGX6 mRNA阳性率与肿瘤1临床病理特征的关系并评估其作为肿瘤转移、预后预测分子标志物的有效性.利用已制作的多肿瘤组织和鼻咽癌组织微阵列,原位杂交检测NGX6 mRNA在多种常见癌组织中的阳性率.结果显示.NGX6 mRNA在鼻咽癌、肺癌、胃癌和结、直肠癌中的阳性率低于其对应的正常组织(P<0.05,P<0.01).淋巴结转移性鼻咽癌、肺癌、结、直肠癌和喉癌组织中的NGX6 mR.NA阳性率显著降低(P<0.05,P<0.01).NGX6 mRNA阳性率与鼻咽癌、肺癌和结、直肠癌临床分期有关,临床Ⅱ期、Ⅲ期或Ⅳ期癌组织NGX6 mRNA阳性率明显低于其相应的临床Ⅰ期癌(P<0.05,P<0.01).研究表明,鼻咽癌、肺癌、胃癌和结、直肠癌中存在低水平的NGX6 mRNA,NGX6 mRNA可作为鼻咽癌、肺癌和结、直肠癌侵袭、转移和临床进展预测的分子标志.  相似文献   

7.
抑瘤基因NGX6对鼻咽癌细胞株HNE1细胞生长的影响(英文)   总被引:2,自引:2,他引:2  
鼻咽癌是我国南方多发恶性肿瘤 ,它的发生发展与遗传因素密切相关 .采用定位候选克隆策略在 9p上克隆出一个候选抑瘤基因 ,命名为NGX6 .为了进一步研究它的功能 ,将NGX6基因的全长cDNA片段亚克隆至pcDNA3.1(+ )的表达载体中 ,通过脂质体转染入鼻咽癌细胞系HNE1中 ,Northern杂交方法筛选高效表达NGX6的细胞株 ,并借助细胞生长曲线、软琼脂糖集落形成实验、裸鼠体内接种实验和流式细胞仪对转染细胞的生物学行为进行了检测 .结果显示 ,转染了NGX6基因的HNE1细胞的生长速度明显减慢 ,在软琼脂中集落形成率较对照组显著下降 (P〈0 0 5 ) ,裸鼠体内成瘤的时间较对照组明显延长 ,瘤体的大小和重量较对照组明显减少 ,流式细胞仪检测发现细胞的凋亡率无明显变化 .为了明确NGX6蛋白在细胞中发挥作用的部位 ,进一步将NGX6的开放阅读框架完整正确地克隆到pEGFPC1的荧光载体中 ,转染到COS7细胞中 ,用荧光显微镜观察细胞中荧光的分布 ,发现荧光主要分布在细胞浆中 ,说明NGX6蛋白可能是一种胞浆蛋白 .该研究表明 ,NGX6在NPC的发生发展中起重要作用 ,为全面阐述NGX6的功能提供重要的信息 ,为进一步的功能研究打下基础  相似文献   

8.
9.
目的 鼻咽癌是一种来源于鼻咽上皮的恶性肿瘤,其临床特征之一是易发生淋巴转移,但是目前鼻咽癌转移的分子机制尚未阐明。circPVT1是由PVT1基因2号外显子反向拼接形成的环状RNA (circRNA),在多种肿瘤中表达上调,本文探讨了circPVT1在鼻咽癌侵袭迁移中的作用和分子机制。方法 通过RT-qPCR检测circPVT1及其下游miRNA和FSCN1在鼻咽癌细胞的表达情况,Transwell和划痕愈合实验检测circPVT1对鼻咽癌细胞侵袭迁移的影响,RNA pull-down实验检测circPVT1结合的miRNA,双荧光素酶报告实验检测miR-24-3p和let-7a-5p靶向抑制FSCN1 mRNA表达。结果 在鼻咽癌细胞中过表达circPVT1可以促进鼻咽癌细胞侵袭迁移,而敲低circPVT1则可以抑制鼻咽癌细胞的侵袭迁移。进一步研究发现,circPVT1可以通过竞争性吸附miR-24-3p和let-7a-5p,上调FSCN1的表达,从而促进鼻咽癌细胞的侵袭迁移。结论 circPVT1通过miR-24-3p/let-7a-5p/FSCN1轴促进鼻咽癌细胞侵袭迁移,证实c...  相似文献   

10.
DEPDC1(DEP domain containing 1)是一个新的肿瘤相关基因,在多种恶性肿瘤的发生发展进程中起着重要作用。我们前期工作中在鼻咽癌细胞内沉默了DEPDC1的表达,发现抑制细胞增殖并诱发细胞凋亡。本研究旨在探讨沉默DEPDC1表达后,对鼻咽癌细胞HNE-1和CNE-1侵袭迁移能力的影响及其分子机制。结果显示,siRNA介导DEPDC1表达沉默后,细胞侧向运动能力、侵袭及迁移能力显著降低。qRT-PCR及Western印迹检测发现DEPDC1沉默导致EMT上游关键转录因子Twist1及间质细胞标志分子Vimentin表达显著下调。这些研究表明,鼻咽癌细胞中DEPDC1通过调节Twist1等EMT关键分子的表达在细胞侵袭转移过程中起关键作用。推测DEPDC1在鼻咽癌中高表达可能对于促进其侵袭转移具有重要作用,进而促进肿瘤发生发展,但具体分子机制仍有待更深入研究。  相似文献   

11.
In the present study, we investigated the roles and molecular mechanisms of miR-320a in human nasopharyngeal carcinoma (NPC). miR-320a expression was strongly reduced in NPC tissues and cell lines. Overexpression of miR-320a significantly suppressed NPC cell growth, migration, invasion and tumor growth in a xenograft mouse model. A luciferase reporter assay revealed that miR-320a could directly bind to the 3′ UTR of BMI-1. Overexpression of BMI-1 rescued miR-320a-mediated biological function. BMI-1 expression was found to be up-regulated and inversely correlated with miR-320a expression in NPC. Collectively, our data indicate that miR-320a plays a tumor suppressor role in the development and progression of NPC and may be a novel therapeutic target against NPC.  相似文献   

12.
The aim of this study is to determine the expression and roles of miR‐346 in nasopharyngeal carcinoma (NPC). We showed that miR‐346 was upregulated in NPC tissues compared with adjacent non‐tumorous nasopharyngeal tissues. Inhibition of miR‐346 significantly attenuated the migration and invasion of NPC cells. Luciferase reporter assay showed that miR‐346 targeted the 3′‐untranslated region (3′‐UTR) of breast cancer metastasis suppressor 1 (BRMS1). Overexpression of miR‐346 suppressed the endogenous expression of BRMS1 in NPC cells. There was a significant negative correlation between miR‐346 and BRMS1 protein expression in NPC tissues (r = ?0.372, P = 0.008). Rescue experiments demonstrated that overexpression of BRMS1 lacking the 3′‐UTR impaired the invasiveness of NPC cells transfected with miR‐346 mimic. Taken together, miR‐346 shows the ability to promote the migration and invasion of nasopharyngeal cancer cells via targeting BRMS1 and represents a potential therapeutic target for NPC.  相似文献   

13.
Nasopharyngeal carcinoma (NPC) is a highly invasive head-neck cancer derived from the nasopharyngeal epithelium, mainly prevalent in southern China and Southeast Asia. Radiotherapy and adjuvant cisplatin (DDP) chemotherapy are standard administrations applied in the treatment of NPC. However, resistance to chemotherapeutic drugs has recently become more common, resulting in worse treatment outcome for NPC therapy. To elucidate the underlying molecular basis of drug resistance to DDP in NPC cells, we examined the morphocytology, cell motility and molecular changes in DDP-resistant NPC cells with respect to epithelial-mesenchymal transition (EMT) features. We found that EMT is closely associated with DDP-induced drug resistance in NPC cells, as DDP-resistant cells displayed morphological and molecular markers changes consistent with EMT. Wound healing and Transwell Boyden chamber assays revealed an enhanced migration and invasion potential in DDP-resistant NPC cells. Mechanistically, upregulation of NEDD4 was observed to relate to EMT in DDP-resistant cells. More importantly, depletion of NEDD4 in resistant cells led to a partial reversion of EMT phenotypes to MET characteristics. These data suggest that NEDD4 is largely involved in EMT features and chemoresistance of NPC cancer cells. NEDD4 could be a novel therapeutic target to overcome drug resistance in successful administrations of NPC.  相似文献   

14.
Limb-bud and heart (LBH) gene has received increasing attention in recent cancer studies. Here we investigated the role of the LBH gene in regulating the metastasis capacity and epithelial-mesenchymal transition (EMT) of nasopharyngeal carcinoma (NPC) cells, and its potential mechanism. The expressions of LBH and αB-crystallin (CRYAB) were modulated by lentiviral infection, or plasmid/siRNA transfection, and the phosphorylation of p38 was suppressed by an inhibitor, to explore their functions in modulating NPC cell phenotypes, as well as the relationships of these factors with each other. Cellular proliferation, migration and invasion were examined by RTCA system, Transwell assays and Matrigel Transwell assays respectively. The EMT progression was indicated by RT-qPCR and Western blotting measuring the expressions of EMT biomarkers. NPC xenografts were constrcucted, and formed tumors were sectioned for morphology and immunohistofluorescence. The interaction between LBH and CRYAB was examined by colocalization and Fluorescence resonance energy transfer (FRET) analysis. We reached the conclusion that LBH inhibits the proliferation, migration, invasion and EMT of NPC cells, and its effects were partially achieved by suppressing p38 phosphorylation, which subsequently downregulates the mRNA expression and phosphorylation of CRYAB, while CRYAB directly interacts with LBH in NPC cells. This LBH-related pathway we revealed provides a novel therapeutic target for nasopharyngeal carcinoma research.  相似文献   

15.

Background

The role of CTGF varies in different types of cancer. The purpose of this study is to investigate the involvement of CTGF in tumor progression and prognosis of human nasopharyngeal carcinoma (NPC).

Experimental design

CTGF expression levels were examined in NPC tissues and cells, nasopharynx (NP) tissues, and NP69 cells. The effects and molecular mechanisms of CTGF expression on cell proliferation, migration, invasion, and cell cycle were also explored.

Results

NPC cells exhibited decreased mRNA expression of CTGF compared to immortalized human nasopharyngeal epithelial cell line NP69. Similarly, CTGF was observed to be downregulated in NPC compared to normal tissues at mRNA and protein levels. Furthermore, reduced CTGF was negatively associated with the progression of NPC. Knocking down CTGF expression enhanced the colony formation, cell migration, invasion, and G1/S cell cycle transition. Mechanistic analysis revealed that CTGF suppression activated FAK/PI3K/AKT and its downstream signals regulating the cell cycle, epithelial-mesenchymal transition (EMT) and MMPs. Finally, DNA methylation microarray revealed a lack of hypermethylation at the CTGF promoter, suggesting other mechanisms are associated with suppression of CTGF in NPC.

Conclusion

Our study demonstrates that reduced expression of CTGF promoted cell proliferation, migration, invasion and cell cycle progression through FAK/PI3K/AKT, EMT and MMP pathways in NPC.  相似文献   

16.
Cisplatin resistance is one of the main obstacles in the treatment of advanced nasopharyngeal carcinoma (NPC). AKR1C1 is a member of the Aldo-keto reductase superfamily (AKRs), which converts aldehydes and ketones to their corresponding alcohols and has been reported to be involved in chemotherapeutic resistance of multiple drugs. The expression and function of AKR1C1 in NPC have not been reported until now. The aim of this research was to investigate the expression of AKR1C1 and it is role in cisplatin resistance in NPC. AKR1C1 protein expression was detected by immunohistochemistry in human NPC tissues and by Western blot assays in NPC and immortalized nasopharyngeal epithelial cells. The effects of AKR1C1 knock-down by siRNA on proliferation, migration and invasion in NPC cells were evaluated by CCK8, wound healing and transwell assays. To evaluate the effects of AKR1C1 silencing on cisplatin sensitivity in NPC cells, CCK8 assays were used to detect cell proliferation, flow cytometry was used to detect cell cycle distribution, and flow cytometry and DAPI staining were used to detect cell apoptosis. AKR1C1 down-regulation was associated with advanced clinicopathological characters such as larger tumor size, more lymphatic nodes involvement, with metastasis and later clinical stages, while AKR1C1 down-regulation was a good prognostic factor for overall survival (OS) in NPC patients. In vitro study showed that AKR1C1 was not directly involved in the malignant biological behaviours such as proliferation, cell cycle progression and migration of NPC cells, whereas AKR1C1 knock-down could enhance cisplatin sensitivity of NPC cells. These results suggest that AKR1C1 is a potential marker for predicting cisplatin response and could serve as a molecular target to increase cisplatin sensitivity in NPC.  相似文献   

17.
Mounting evidence has reported that microRNA-143 (miR-143) is involved in the development of multiple cancers. To investigate the underlying mechanisms of miR-143 regulating proliferation and metastasis in nasopharyngeal carcinoma (NPC) cells, we evaluated the levels of miR-143 and formin-like protein 1 (FMNL1) in NPC tissues. The results of qRT-PCR and Western blot analysis showed that the expression of miR-143 was decreased, while FMNL1 was increased in NPC tissues. The expression of miR-143 was significantly elevated in NPC cells compared with that of human nasopharyngeal epithelial cells. The results of MiRcode prediction, dual-luciferase reporter, and Western blot analysis assays indicated that miR-143 negatively regulated the expression of FMNL1 (r2 = 0.4365P = 0.0001). Overexperssion of miR-143 or FMNL1 knockdown inhibited cell proliferation, migration, and invasion in NPC cells (P < 0.05). Ectopic expression of FMNL1 undermined the inhibition effect of miR-143 on proliferation, migration, and invasion in NPC cells. The findings of this study revealed that miR-143 functioned as a tumor suppressor and inhibited the NPC progression by targeting FMNL1.  相似文献   

18.
Nasopharyngeal carcinoma (NPC) is a kind of head-neck malignant tumor derived from the nasopharyngeal epithelium and is mainly prevalent in Southern China and Southeast Asia countries. Cisplatin (DDP) provides the first-line therapeutic administration in NPC patients. However, chemoresistance has been a main barrier and caused bad treatment outcome in NPC therapy. To understand the molecular mechanism of acquired resistance to DDP, multiple methods were performed to examine the morphocytology and molecular changes in DDP-resistant NPC cells. We found that drug resistance cells displayed epithelial-mesenchymal transition (EMT) characteristics. DDP-resistant NPC cells exhibited enhanced migration and invasion potential. Moreover, overexpression of TAZ, one key gene in Hippo pathway, is closely associated with the DDP resistance of NPC cells and its EMT properties. Depletion of TAZ in DDP-resistant cells reversed EMT phenotypes to MET characteristics and restored chemosensitivity of DDP-resistant cells to DDP treatment. These results suggest that inactivation of TAZ could be a promising approach for the treatment of NPC patients.  相似文献   

19.
The present study aimed to investigate the effects and mechanisms of PLAC8 on the epithelial-mesenchymal transition (EMT) of Nasopharyngeal carcinoma (NPC). The expression of PLAC8 in NPC and nasopharyngitis (NPG) tissues from 150 patients was determined using immunohistochemistry. The levels of PLAC8 in five NPC cell lines and nasopharyngeal permanent epithelial cell line were measured using western blotting. We then knocked out or overexpressed PLAC8 in CNE2 cells. Cell proliferation, wound healing, migration, and invasion assays were used to analyze the effects of PLAC8 on the proliferation, migration, and invasion in vivo and vitro. The results showed that the expression of PLAC8 was much higher in NPC tissues than in NPG tissues. The expression of PLAC8 was higher in all the cell lines than in the nasopharyngeal permanent epithelial cells. PLAC8 knockout resulted in significant decreases in cell proliferation, migration, and invasion; associated with lower protein levels of N-cadherin; and increased levels of E-cadherin. Overexpression of PLAC8 had the opposite effect. Furthermore, knockout of PLAC8 inactivated TGF-β/SMAD signaling pathway and suppressed the growth of NPC xenografts. PLAC8 may promote the carcinogenesis and EMT of NPC via the TGF-β/Smad pathway, which suggests that PLAC8 may be a potential biomarker for NPC.  相似文献   

20.
Salinomycin (Sal) is a polyether ionophore antibiotic that has recently been shown to induce cell death in various human cancer cells. However, whether salinomycin plays a functional role in nasopharyngeal carcinoma (NPC) has not been determined to date. The present study investigated the chemotherapeutic efficacy of salinomycin and its molecular mechanisms of action in NPC cells. Salinomycin efficiently inhibited proliferation and invasion of 3 NPC cell lines (CNE-1, CNE-2, and CNE-2/DDP) and activated a extensive apoptotic process that is accompanied by activation of caspase-3 and caspase-9, and decreased mitochondrial membrane potential. Meanwhile, the protein expression level of the Wnt coreceptor lipoprotein receptor related protein 6 (LRP6) and β-catenin was down-regulated, which showed that the Wnt/β-catenin signaling was involved in salinomycin-induced apoptosis of NPC cells. In a nude mouse NPC xenograft model, the anti-tumor effect of salinomycin was associated with the downregulation of β-catenin expression. The present study demonstrated that salinomycin can effectively inhibit proliferation and invasion, and induce apoptosis of NPC cells in vitro and inhibit tumor growth in vivo, probably via the inhibition of Wnt/β-catenin signaling, suggesting salinomycin as a potential candidate for the chemotherapy of NPC.  相似文献   

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