变异型EBER2通过抑制PKR通路增强鼻咽癌细胞抗凋亡能力

目的：前期研究发现变异型EB病毒编码小RNA 2（EBER2）基因EB-8m可能与鼻咽癌（NPC）相关,本研究旨在探讨变异型EBER2是否通过增强对RNA激活蛋白激酶（PKR）的抑制作用从而提高NPC细胞的抗凋亡能力。方法：以野生型和EB-8m变异型EBER2基因稳定转染的EB病毒阴性NPC细胞系HONE1和CNE1为研究对象,以未转染EBER2基因细胞为对照,分别用10 000 IU/mLα-干扰素（IFN-α）和2μg/mL顺铂诱导凋亡后以流式细胞术检测细胞凋亡;采用Western blot检测IFN-α诱导凋亡细胞中PKR及下游eIF2α和c-Jun的磷酸化蛋白及Bcl-2蛋白表达水平。对EBER2基因转染细胞进行RNA和PKR蛋白免疫共沉淀,检测共沉淀产物中EBER2富集倍数。结果：EBER2基因转染细胞的凋亡率低于未转染EBER2基因细胞（P < 0.05或P < 0.01）,且变异型的细胞凋亡率低于野生型（P < 0.05）。与未转染EBER2基因细胞比较,EBER2转染细胞中磷酸化PKR、eIF2α和c-Jun减少,Bcl-2表达升高,且磷酸化PKR在变异型转染HONE1和CNE1细胞中的水平低于野生型转染细胞,磷酸化eIF2α在变异型转染HONE1细胞中的水平亦低于野生型转染细胞,差异均有统计学意义（P均 < 0.05）。EBER2基因转染细胞RNA和PKR免疫共沉淀产物中可检测到EBER2,且变异型的富集倍数高于野生型（P < 0.05）。结论：EB-8m变异型EBER2可能增强EBER2对PKR的结合作用,同时抑制eIF2α和c-Jun磷酸化并上调Bcl-2表达,进而增强NPC细胞抗凋亡能力。     

Silencing of hypoxia-inducible tumor suppressor lysyl oxidase gene by promoter methylation activates carbonic anhydrase IX in nasopharyngeal carcinoma

Lysyl oxidase (LOX) is an oxidative enzyme known to initiate the cross-linking of collagens and elastin, and suggested recently as a tumor suppressor for several tumor types including lung, pancreatic and gastric cancers. Previously we showed that LOX is strongly induced upon hypoxia in nasopharyngeal carcinoma (NPC) cell lines CNE2 and HONE1 but only slightly in HK1 and not in C666-1. Here, we further studied the regulatory mechanism and functions of LOX in NPC. LOX is widely expressed in human normal tissues with variations in expression levels. LOX was expressed in most NPC cell lines except for C666-1, while HK1 and FaDu (laryngeal cancer) only expressed low level of LOX. Methylation analysis showed that the LOX promoter was methylated in C666-1 and partially methylated in HK1. After demethylation with 5-aza-2’-deoxycytidine, LOX expression was reactivated along with increased unmethylated alleles. LOX promoter methylation was detected in 42/49 (85.7%) of NPC primary tumors but only 3/16 (18.75%) of nose swab samples from NPC patients. LOX overexpression reduced the clonogenicity and cell growth of NPC cells, and also inhibited the migration and invasion of the NPC cells. Carbonic anhydrase IX (CA9) mRNA level was obviously decreased in HK1 cells after transfection with LOX. The elevation of CA9 protein upon hypoxia was inhibited in LOX-transfected HK1 cells. The protein levels of an apoptosis marker cPARP were increased in LOX-transfected HK1 cells upon hypoxia treatment. Our data showed that silencing or down-regulation of LOX in NPC was due to its promoter methylation and LOX acts as a tumor suppressor in NPC. LOX silencing would facilitate NPC cells to escape from hypoxia-induced apoptosis and maintains a malignant and metastatic phenotype.     

Silencing of the retinoid response gene TIG1 by promoter hypermethylation in nasopharyngeal carcinoma

Tazarotene-induced gene 1 (TIG1) and Tazarotene-induced gene 3 (TIG3) are retinoid acid (RA) target genes as well as candidate tumor suppressor genes in human cancers. In our study, we have investigated the expression of TIG1 and TIG3 in nasopharyngeal carcinoma (NPC). Loss of TIG1 expression was found in 80% of NPC cell lines and 33% of xenografts, whereas TIG3 was expressed in all NPC samples and immortalized nasopharyngeal epithelial cells. In order to elucidate the epigenetic silencing of TIG1 in NPC, the methylation status of TIG1 promoter was examined by genomic bisulfite sequencing and methylation-specific PCR (MSP). We have detected dense methylation of TIG1 5'CpG island in the 5 TIG1-negative NPC cell lines and xenograft (C666-1, CNE1, CNE2, HONE1 and X666). Partial methylation was observed in 1 NPC cell line HK1 showing dramatic decreased in TIG1 expression. Promoter methylation was absent in 2 TIG1-expressed NPC xenografts and the normal epithelial cells. Restoration of TIG1 expression and unmethylated alleles were observed in NPC cell lines after 5-aza-2'-deoxycytidine treatment. Moreover, the methylated TIG1 sequence was detected in 39 of 43 (90.7%) primary NPC tumors by MSP. In conclusion, our results showed that TIG1 expression is lost in the majority of NPC cell lines and xenografts, while promoter hypermethylation is the major mechanism for TIG1 silencing. Furthermore, the frequent epigenetic inactivation of TIG1 in primary NPC tumors implied that it may play an important role in NPC tumorigenesis.     

Knockdown of Notch1 inhibits nasopharyngeal carcinoma cell growth and metastasis via downregulation of CCL2, CXCL16, and uPA

Notch pathway is a highly conserved cell signaling system that plays very important roles in controlling multiple cell differentiation processes during embryonic and adult life. Multiple lines of evidence support the oncogenic role of Notch signaling in several human solid cancers; however, the pleiotropic effects and molecular mechanisms of Notch signaling inhibition on nasopharyngeal carcinoma (NPC) remain unclear. In this study, we evaluated Notch1 expression in NPC cell lines (CNE1, CNE2, SUNE1, HONE1, and HK1) by real‐time quantitative PCR and Western blot analysis, and we found that CNE1 and CNE2 cells expressed a higher level of Notch1 compared with HONE1, SUNE1, and HK1 cells. Then Notch1 expression was specifically knocked down in CNE1 and CNE2 cells by Notch1 short hairpin RNA (shRNA). In Notch1 knockdown cells, cell proliferation, migration, and invasion were significantly inhibited. The epithelial‐mesenchymal transition of tumor cells was reversed in Notch1‐shRNA‐transfected cells, accompanied by epithelioid‐like morphology changes, increased protein levels of E‐cadherin, and decreased expression of vimentin. In addition, knockdown of Notch1 markedly inhibited the expression of urokinase plasminogen activator (uPA) and its receptor uPAR, and chemokines C‐C motif chemokine ligand 2 and C‐X‐C motif chemokine ligand 16, indicating that these factors are downstream targets of Notch1. Furthermore, deleting uPA expression had similar effects as Notch1. Finally, knockdown of Notch1 significantly diminished CNE1 cell growth in a murine model concomitant with inhibition of cell proliferation and induction of apoptosis. These results suggest that Notch1 may become a novel therapeutic target for the clinical treatment of NPC.     

STAT3 activation contributes directly to Epstein‐Barr virus–mediated invasiveness of nasopharyngeal cancer cells in vitro

Nasopharyngeal cancer (NPC) is an Epstein‐Barr virus (EBV)‐associated head and neck cancer prevalent in Asia. Although with reasons not fully understood, the intrinsic invasiveness of NPC is believed to be EBV‐linked. Recently, EBV was found to induce STAT3 activation. Constitutive STAT3 activation correlated with advanced clinical staging in NPC. We hypothesized that STAT3 activation by EBV directly contributes to the intrinsic invasiveness of NPC cells. Phospho‐STAT3‐Tyr705 was detected in high percentage of NPC tumors (7/10 cases). Using a paired NPC cell line model, HONE‐1 and the EBV‐infected counterpart, HONE‐1‐EBV, we found that HONE‐1‐EBV expressed a higher level of phospho‐STAT3‐Tyr705 and was ～11‐fold more invasive than HONE‐1. In HONE‐1‐EBV, STAT3 siRNA targeting inhibited both spontaneous and serum‐induced invasion, as well as cell growth. Conversely, activation of STAT3 (by expressing an activated STAT3 mutant, namely STAT3C) in the parental HONE‐1, mimicking EBV‐induced STAT3 activation, significantly enhanced its invasiveness and proliferation, which was accompanied by increased expression of markers of mesenchymal status, proliferation and anti‐apoptosis. Our results demonstrated that EBV‐induced STAT3 activation is responsible for NPC cell proliferation and invasion. This was further confirmed by a small molecule inhibitor of JAK/STAT3, JSI‐124. JSI‐124 inhibited STAT3 activation in HONE‐1‐EBV, with subsequent growth inhibition, induction of PARP cleavage, abrogation of anchorage‐independent growth and invasion. We found that EBV‐independent activation of STAT3 by a growth factor, EGF, also contributed to NPC invasion. In conclusion, EBV‐induced STAT3 activation directly contributes to the intrinsic invasiveness of NPC cells and STAT3 targeting may be beneficial in treating aggressive NPC. © 2009 UICC     

不同转移特性的人鼻咽癌细胞株中Tiam-1表达及其意义

目的探讨Tiam-1在不同转移特性的人鼻咽癌细胞株中的表达,分析Tiam-1表达与鼻咽癌侵袭转移特性的关系。方法采用免疫组化SP-9000法和RT-PCR方法 ,分别从蛋白表达水平和mRNA水平检测Tiam-1在人鼻咽癌细胞5-8F、6-10B、C666-1和CNE2中的表达。结果①Tiam-1蛋白分布于人鼻咽癌细胞胞质中,在具有高转移特性的5-8F细胞中呈棕黄、棕褐色强表达,在没有转移特性的6-10B细胞中呈淡黄色弱表达或不表达,在具有一定转移特性的C666-1、CNE2细胞株中呈黄色中度表达。②Tiam-1mRNA在5-8F细胞中灰度密度比值为（0.817±0.040）,在6-10B细胞中为（0.103±0.015）,在C666-1、CNE2细胞株中分别是（0.383±0.025、0.497±0.047）,各灰度密度比值比较具有统计学差异（F=220.770,P〈0.05）,且与细胞株转移特性呈正相关（γs=0.852,P〈0.05）。结论 Tiam-1在不同转移特性的人鼻咽癌细胞株中呈现不同程度的表达,与细胞株转移特性密切相关。提示Tiam-1可作为鼻咽癌恶性程度及其预后的判断指标。     

Downregulation of lncRNA ANRIL inhibits proliferation,induces apoptosis,and enhances radiosensitivity in nasopharyngeal carcinoma cells through regulating miR-125a

Increasing evidence demonstrated that long non-coding RNA ANRIL serves as a fatal oncogene in many cancers, including nasopharyngeal carcinoma (NPC). However, little is known whether ANRIL regulated NPC cell radioresistance. Quantitative real-time PCR (qRT-PCR) was performed to examine the expression of lncRNA ANRIL and miR-125a in NPC tissues and cell lines. MTT assay was conducted to measure the cell viability of CNE2 and HONE1 cells. The apoptotic rate of CNE2 and HONE1 cells was determined by flow cytometry analysis. Colony survival was determined by clonogenic assay. Luciferase reporter assay was performed to verity the direct target of miR-125a. LncRNA ANRIL was evidently elevated in NPC tissues and cell lines. ANRIL inhibition suppressed proliferation, induced apoptosis, and enhanced radiosensitivity in NPC. Moreover, ANRIL could negatively modulate miR-125a expression. Furethermore, ANRIL upregulation reserved the inhibited proliferation, induced apoptosis, and enhanced radiosensitivity triggered by miR-125a overexpression. The expression of lncRNA ANRIL was upregulated in NPC tissues and cells. Moreover, knockdown of ANRIL repressed proliferation, promoted apoptosis, and improved radiosensitivity in NPC via functioning as a miR-125a sponge.     

EB病毒miRNAs在鼻咽癌细胞株C666-1和CNE-2Z中的差异性表达分析

目的：探讨ebv-miRNA在低分化NPC细胞株C666-1（EBV＋）和CNE-2Z（EBV表达水平随传代次数增加而逐渐降低）中的差异性表达进而分析其功能.方法：常规培养NPC细胞株C666-1和CNE-2Z,分别提取总RNA并进行质检;RT-PCR检测LMP-1和LMP-2A mRNA的表达以判断EBV的感染情况;miRNA芯片技术检测EBV miRNAs的表达并对其表达谱进行差异性分析;荧光定量RT-PCR进行验证;复习文献了解ebv-miRNA调控的靶基因以了解其功能.结果：从C666-1和CNE-2Z两株细胞抽提的总RNA纯度高,A260/A280〉2.0,A260/A230〉2.1,RNA完整性好.C666-1具有比CNE-2Z更高的LMP-1和LMP-2A mRNA表达.ebv-miRNA表达谱的差异分析表明39个ebv-miRNAs中19个在两株细胞显著差异性表达;荧光定量RT-PCR结果证实ebv-miR-BHRF1-1和ebv-miR-BART14＊在C666-1中表达升高而ebv-miR-BART8＊表达降低,与芯片结果趋势一致;复习文献,EBV miRNAs功能远不清楚,少数已知的靶基因涉及信号转导、转录调控、细胞凋亡、增殖、免疫反应和病毒DNA复制等方面.结论：ebv-miRNA在低分化NPC中具有差异性表达并广泛参与基因调控.不同NPC细胞中EBV miRNA表达差异预示着基于ebv-miRNA的NPC个性化治疗的可能性.     

EB病毒感染鼻咽癌细胞后的增殖周期变化

背景与目的:EB病毒(Epstein-Barrvirus,EBV)在不同组织类型鼻咽癌细胞内的增殖周期特征决定了基因治疗所采取的策略。本研究探讨EBV感染鼻咽癌细胞后的增殖周期特征。方法:利用EBV阳性的B95-8细胞标准株与鼻咽癌细胞CNE2接触培养,通过补体激活的细胞毒性试验去除共培养体系中的B95-8细胞,并采用逆转录聚合酶链式反应及Southern印迹杂交的方法分析鼻咽癌细胞中病毒的初始感染状态。结果:B95-8细胞与CNE2细胞接触共培养的方法使EBV成功感染CNE2细胞,EBV裂解期标志性基因BZLF1转录时间平均为12d,病毒感染标志性基因EBER转录时间平均为22d。结论:EBV侵入CNE2细胞后可能多数病毒开始处于裂解期增殖,之后EBV从裂解期进入了相对稳定的潜伏期,并随着细胞的传代培养病毒逐渐丢失。     

TSLC1 is a tumor suppressor gene associated with metastasis in nasopharyngeal carcinoma

In up to 87% of nasopharyngeal carcinoma (NPC) clinical tumor specimens, there was either down-regulation or loss of TSLC1 gene expression. Using a tissue microarray and immunohistochemical staining, the frequency of down-regulated or loss of expression of TSLC1 in metastatic lymph node NPC was 83% and the frequency of loss of expression of TSLC1 was 35%, which was significantly higher than that in primary NPC (12%). To examine the possible growth-suppressive activity of TSLC1 in NPC, three NPC cell lines, HONE1, HNE1, and CNE2, were transfected with the wild-type TSLC1 gene cloned into the pCR3.1 expression vector; a reduction of colony formation ability was observed for all three cell lines. A tetracycline-inducible expression vector, pETE-Bsd, was also used to obtain stable transfectants of TSLC1. There was a dramatic difference between colony formation ability in the presence or absence of doxycycline when the gene is shut off or expressed, respectively, with the tetracycline-inducible system. Tumorigenicity assay results show that the activation of TSLC1 suppresses tumor formation in nude mice and functional inactivation of this gene is observed in all the tumors derived from tumorigenic transfectants. Further studies indicate that expression of TSLC1 inhibits HONE1 cell growth in vitro by arresting cells in G(0)-G(1) phase in normal culture conditions, whereas in the absence of serum, TSLC1 induced apoptosis. These findings suggest that TSLC1 is a tumor suppressor gene in NPC, which is significantly associated with lymph node metastases.     

洛铂对鼻咽癌抗肿瘤作用的体外实验研究

目的 探讨洛铂对鼻咽癌的体外抗肿瘤作用及其可能的机制,为洛铂用于鼻咽癌的临床治疗提供实验依据。方法 在体外将不同浓度洛铂分别作用于低分化鼻咽癌细胞株CNE2、HONE1和SUNE1,采用CCK-8法检测细胞活性;碘化丙啶（PI）染色分析细胞中DNA的含量,流式细胞仪检测细胞周期情况;采用Annexin V-FITC／PI双染法检测细胞凋亡情况;采用蛋白印迹法（Western blotting）检测细胞周期和细胞凋亡相关蛋白的表达。结果 在体外洛铂作用3种鼻咽癌细胞株48h具有明显的细胞抑制作用,并表现出浓度依赖性。洛铂作用鼻咽癌细胞株CNE2、HONE1、SUNE1的半数抑制浓度（IC₅₀）分别为（4.05±0.49）μmol/L、（4.32±1.17）μmol/L和（2.51±0.15）μmol／L。洛铂作用3种鼻咽癌细胞株48h后,在较低浓度（0.125倍IC₅₀）时将细胞周期阻滞在G₂期,同时伴随G₂期相关蛋白Cyclin B1和phospho-cdc2（Tyr15）表达增高;而在较高浓度（0.5倍IC₅₀）时则诱导细胞呈Caspase依赖性细胞凋亡,并具有浓度依赖性。结论 洛铂对鼻咽癌细胞具有明显的细胞毒作用,且呈浓度依赖性;其机制表现为双重作用,即在较低浓度时阻滞细胞于G₂期和在较高浓度时诱导细胞凋亡,这为洛铂用于鼻咽癌的临床治疗提供可能性。     

High expression of XPA confers poor prognosis for nasopharyngeal carcinoma patients treated with platinum-based chemoradiotherapy

In this study, we tried to explore if xeroderma pigmentosum complementation group-A (XPA) expression is likely a prognostic prediction factor for locally advanced nasopharyngeal carcinoma (NPC) patients treated with platinum-based chemoradiotherapy, which was considered to bring chemotherapy-related severe toxicity compared with radiotherapy alone. Firstly, MTT assay revealed that downregulating XPA expression in NPC HONE1 and CNE1 cells decreased IC₅₀ of cisplatin and sensitized cells to cisplatin. XPA expression was detected by immunohistochemistry in cancer tissues from locally advanced NPC patients treated with platinum-based chemoradiotherapy. The relationships between XPA expression and clinicopathologic features, overall survival and progression-free survival of patients were evaluated. The results showed that XPA expression was not associated with clinicopathologic parameters, but was likely an independent prognostic factor for patient survival. High XPA level predicts a poor prognosis, and the prediction values were higher in subgroups of younger, higher EBV antibody titer, or treated with concurrent chemoradiotherapy. Combining XPA levels and T/N classifications, we successfully classified these patients into low, medium and high risk groups for platinum-based chemoradiotherapy. These findings suggest that XPA levels may be a potential predictor of prognosis in locally advanced NPC patients treated with platinum-based chemoradiotherapy, and helpful for selecting patients likely to need and benefit from this treatment in future.     

鼻咽癌发生发展过程中EBER1表达的研究

目的：探讨ＥＢＶ与鼻咽癌发生发展的关系及其病理学意义。方法：应用原位杂交技术检测５０例鼻咽癌石蜡切片组织中ＥＢＥＲ１的表达及分布状况。结果：正常鼻咽粘膜上皮及其单纯性增生、鳞状化生上皮ＥＢＥＲ１表达均阴性,鼻咽癌组织中表达率为９８％（４９／５０）,且在转移灶中不丢失。鼻咽异型增生上皮亦可表达ＥＢＥＲ１阳性信号（１６／２０）,结论：ＥＢＶ与鼻咽癌关系密切,ＥＢＶ可能在鼻咽上皮的恶性转化过程中起重要作用,鼻咽上皮的异型性改变尤其是ＥＢＥＲ１阳性者可认为是癌前病变,随访监测可能有利于早期发现鼻咽癌。     

EB病毒LMP1对人鼻咽癌细胞转移能力的影响

背景与目的:EB病毒编码的潜伏膜蛋白1(latent membrane protein 1,LMP1)在鼻咽癌的浸润和转移过程中起重要的作用。本实验目的在于研究EB病毒LMP1对人鼻咽癌细胞转移能力的影响和探讨其中的相关机制。方法:应用免疫细胞化学RT-PCR法和Western blot检测LMP1、E-cadherin和intercellular adhesion molecule-1 (ICAM-1)在人高分化鼻咽癌细胞系CNE1和转染了LMP1基因的CNE1-GL细胞中的表达。应用细胞-细胞粘附实验、细胞-基质粘附实验、划痕实验和细胞运动实验观察LMP1对鼻咽癌细胞粘附和运动能力的影响。结果:免疫细胞化学结果显示:LMP1在CNE1和CNE1-GL细胞中的阳性率分别为0和(96.60±3.03)%(P<0.01);E-cadherin蛋白的阳性率分别为(37.47±1.50)%和(19.53±1.92)%(P<0.01);ICAM-1蛋白的阳性率分别为(5.27±1.45)%和(93.33±4.23)%(P<0.01)。RT-PCR和Westernblot结果表明,与CNE1细胞相比较,CNE1-GL细胞中E-cadherin的mRNA和蛋白表达明显降低(P<0.01),而ICAM-1的mRNA和蛋白表达则明显升高(P<0.01)。肿瘤细胞同质粘附实验显示,CNE1-GL细胞的同质粘附能力较CNE1细胞弱(P<0.05)。肿瘤细胞-基质粘附实验得出CNE1-GL细胞的异质粘附能力(A值=0.60±0.03)较CNE1细胞(A值=0.46±0.01)强(P<0.01)。肿瘤细胞运动实验显示,穿过PVPF膜的CNE1-GL细胞数多于CNE1细胞(119.3±6.0 vs 46.3±7.0,P<0.05)。结论:LMP1通过抑制E-cadherin表达、促进ICAM-1表达从而抑制肿瘤细胞的同质粘附能力、增强其异质粘附能力和运动能力来参与鼻咽癌的侵袭和转移。     

定量研究EB病毒潜在膜蛋白对人鼻咽癌细胞系CNE1的作用

目的研究ＥＢ病毒ＬＭＰ对人高分化鼻咽癌细胞株ＣＮＥ１细胞形态及ＤＮＡ含量的影响。方法采用电穿孔基因转染技术，将重组ＥＢＶ┐ＬＭＰ表达质粒转染鼻咽癌细胞株ＣＮＥ１细胞。以载体质粒转染及ＣＮＥ１细胞为对照，用免疫荧光和图像分析方法，观察细胞ＬＭＰ表达、细胞形态及ＤＮＡ含量的变化。结果ＬＭＰ表达质粒转染后细胞浆及细胞膜ＬＭＰ强阳性表达。形态定量及ＤＮＡ含量测定表明，ＬＭＰ表达后，ＣＮＥ１细胞明显变小（Ｐ＜０．０１），核浆比显著增大（Ｐ＜０．０１），核浆的变化主要由胞浆面积的增减所致，而与核面积的改变则无明显正比关系；ＤＮＡ含量明显增高（Ｐ＜０．０１／０．０５），且倍体分布更分散而右移。结论ＬＭＰ对ＣＮＥ１细胞生长有明显的促进作用，可致细胞恶性程度增高且分化受抑，有向低分化鳞癌发展倾向，提示ＬＭＰ在ＮＰＣ的发生发展过程及其演进中可能起重要作用     

海带多糖对人鼻咽癌细胞及其裸鼠移植瘤的抑制作用

  目的  通过观察海带多糖(laminaria japonica polysaccharides, LJP)在体内外对人鼻咽癌(nasopharyngeal carcinoma, NPC)细胞的抑制作用, 探讨其可能的抗癌机制。  方法  应用MTT法检测LJP对人NPC细胞株(HONE1和CNE2)增殖的抑制作用; 运用PI加Annexin V双染法检测LJP对HONE1细胞凋亡的影响; 以人NPC细胞株HONE1建立裸鼠皮下移植瘤模型及行体内抑瘤实验, 并在透射电镜(transmission electron microscopy, TEM)下观察移植瘤细胞超微结构。  结果  MTT显示LJP对人NPC细胞(HONE1和CNE2)的增殖有抑制作用, 且具有剂量相关性, 320 mg/L的LJP作用72h的抑制率分别为58.27%(P < 0.01)和55.00%(P < 0.01);流式细胞仪检测结果显示, LJP具有诱导HONE1细胞凋亡的作用, 凋亡率随着LJP浓度的增加而增高, 320mg/L的凋亡率为(49.51±1.89)%(P < 0.01)。体内实验中, LJP中、高剂量组抑瘤率分别为33.7%(P < 0.05)和47.0%(P < 0.01), 具有明显抑制移植瘤的作用, 而低剂量组的抑瘤率仅为16.4%(P > 0.05)。TEM结果提示癌细胞呈现凋亡特征的改变。  结论  LJP具有抑制NPC细胞生长的作用, 机制可能是通过诱导癌细胞凋亡而实现的。      

C2orf40蛋白在鼻咽癌中的表达及意义

目的 探讨C2orf40蛋白在鼻咽癌组织和细胞中的表达及其与细胞分化、临床病理特征的关系.方法 收集2001年1月至2003年12月在汕头大学医学院附属肿瘤医院诊断为鼻咽癌的122例病理活检组织石蜡标本及其病历资料,另外收集25例慢性鼻咽炎的石蜡标本作为对照.采用免疫组织化学法检测C2orf40蛋白表达情况,同时分析C2orf40表达水平与临床病理特征的关系.体外实验应用Western blotting对鼻咽癌细胞株CNE1、CNE2和C666-1进行C2orf40蛋白表达的测定,分析C2orf40表达与细胞分化程度的关系.结果 C2or40在对照组的阳性率为96.0％(24/25),且88.0％为高表达,病例组阳性率为58.2％ (71/122),但82.0％为低表达,二者差异有统计学意义(U=255.500,P＜0.001).C2orf40表达与淋巴结转移分期(N分期)和临床分期呈负相关(r=-0.058,P＜0.001;r=-0.202,P=0.026).C2orf40在高分化鼻咽癌细胞株CNE1中呈高表达,在低分化鼻咽癌细胞株CNE2和C666-1中呈低表达.结论 C2orf40蛋白表达下调与肿瘤细胞分化、淋巴结转移和临床分期相关,是鼻咽癌发生、发展的分子事件之一,可能成为抗肿瘤治疗的潜在靶点.