SATB1高表达通过促进上皮-间充质转化而介导鼻咽癌细胞侵袭和转移

目的:探讨鼻咽癌(NPC)中特殊富含AT序列结合蛋白1(SATB1)的表达及其与肿瘤侵袭和转移的关系。方法:免疫组化检测76例临床NPC及61例对照鼻咽黏膜慢性炎症(NPI)组织样本中SATB1、上皮型钙黏蛋白(E-cadherin)和波形蛋白(vimentin)的表达,并分析NPC中SATB1与患者临床参数、E-cadherin和vimentin表达的相关性。体外培养不同分化状态的NPC细胞系CNE1、CNE2Z及C666-1,筛选出SATB1高表达细胞系,采用小干扰RNA(siRNA)沉默SATB1表达后,分析上皮-间充质转化(EMT)相关分子的表达及细胞侵袭能力的改变。结果:临床鼻咽组织中SATB1表达定位于胞质和胞核,NPC组中SATB1阳性表达率显著高于对照NPI组(P0.01);E-cadherin在NPI黏膜上皮中呈膜阳性表达,NPC中膜表达水平下降,但出现胞质阳性。NPI中E-cadherin膜阳性率为100%,显著高于NPC的32.89%(P0.01)。Vimentin呈胞质阳性,NPI上皮细胞中均阴性,但NPC中阳性率为51.32%(P0.01)。NPC中SATB1高表达与患者性别、年龄及N分期无关,但与T分期和M分期均呈正相关(P0.05);SATB1高表达与vimentin呈正相关(r=0.358,P=0.009)。NPC细胞系中SATB1表达与细胞分化水平呈负相关。采用siRNA敲减C666-1细胞中SATB1表达后,E-cadherin表达上升,vimentin表达下降,且细胞侵袭能力下降。结论:SATB1高表达通过促进EMT而介导NPC临床进展。     

Reversal effect of GnT-V on the radioresistance of human nasopharyngeal carcinoma cells by alteration β1, 6-GlcNAc branched N-glycans

Radiotherapy is the primary treatment for human nasopharyngeal carcinoma (NPC), yet radioresistance remains a major obstacle to successful treatment in many cases. N-acetylglucosaminyltransferase V (GnT-V), which synthesizes β1, 6-GlcNAc branched N-glycans, is closely related to the radiosensitivity of NPC cells. However, a better understanding of the functional role of GnT-V in NPC radioresistance and the related mechanisms is urgently needed. In the present study, a radioresistant NPC cell line, CNE-2R, was established by repeated γ-irradiation. We found that GnT-V levels, as well as β1, 6-GlcNAc branched N-glycans were significantly increased in the CNE-2R cells as compared with that in the parental cells. Meanwhile, knockdown of GnT-V in the CNE-2R cells enhanced cell radiosensitivity and inhibited the formation of β1, 6-branched N-glycans. In addition, the regulated expression of GnT-V in the CNE-2R cells converted the heterogeneous N-glycosylated forms of CD147. Furthermore, swainsonine, an inhibitor of N-glycan biosynthesis, was also able to reverse the radioresistance of the CNE-2R cells. Taken together, the present study revealed a novel mechanism of GnT-V as a regulator of radioresistance in NPC cells, which may be useful for fully understanding the biological role of N-glycans in NPC radioresistance.     

Aberrant SATB1 expression is associated with Epstein-Barr virus infection,metastasis and survival in human nasopharyngeal cells and endemic nasopharyngeal carcinoma

Special AT-rich sequence-binding protein 1 (SATB1) has been identified as a key factor in the progression of some cancers, functioning as a global genome organizer and chromatin regulator. We examined the levels of SATB1 mRNA expression in NPC cell lines 5-8F (high metastasis) and 6-10B (low metastasis) and immortalized human nasopharyngeal epithelial cells NP69-SV40T by quantitative real-time PCR. We also examined the protein expression levels of SATB1 in 72 cases of nasopharyngeal carcinoma (NPC) tissues and 30 cases of normal nasopharyngeal (NNP) tissues by immunohistochemistry, and then assessed the correlations between SATB1 expression and clinicopathological factors. The expression level of SATB1 mRNA in 5-8F was much higher than those in 6-10B and NP69-SV40T (P < 0.05). The expression level of SATB1 mRNA in 6-10B was higher than in NP69-SV40T, but the difference was not statistically significant (P > 0.05). The positive expression rates of SATB1 protein in NPC (38/72, 52.8%) were significantly higher than in NNP (4/30, 13.3%) (P < 0.05). SATB1 protein levels in NPC were not associated with gender, age, and T stage (P > 0.05), but positively correlated with the titers of EBVCA-IgA, metastasis (N and M stage), recurrence, and survival (P < 0.05). Multivariate analysis showed that the overexpression of SATB1 protein is an independent prognostic factor for NPC. The expression levels of SATB1 were obviously upregulated in primary NPC tissues and human NPC cell lines. Therefore, SATB1 may be a valuable predictor in assessing the metastasis, recurrence, and prognosis of NPC.     

巨噬细胞移动抑制因子提高鼻咽癌细胞体外侵袭能力

目的　研究巨噬细胞移动抑制因子 (MIF)体外提高鼻咽癌细胞侵袭能力的原因 ,探讨鼻咽癌细胞早期发生侵袭和转移的机制。方法　采用微孔迁移分析法 (micron migrationassay)检测鼻咽癌细胞株CNE 1、CNE 2在细胞因子MIF诱导下通过 8μm直径微孔的细胞数量变化 ,采用Western蛋白印迹法、流式细胞术和酶联免疫吸附法检测侵袭转移相关因子基质金属蛋白酶 2、9(MMP2 ,MMP9)及白介素 8(IL 8)在此过程中的相应改变。结果　 (1)经MIF诱导后 ,CNE 1通过 8μm微孔的细胞数由原来的 2 3 7± 11 0 2增加至 113 7± 2 0 9,CNE 2则由原来的 3 4 7± 7 41增加至 3 11 3± 48 9,差异均呈显著性 (P =0 0 0 5,P =0 0 0 1)。 (2 )经MIF诱导后 ,癌细胞表达MMP9蛋白的细胞比例均明显增加 ,CNE 1细胞由 2 8 5%± 2 45%增加至 82 4%± 3 49% (P =0 0 0 1) ,而CNE 2细胞则由刺激前的 3 2 8%± 3 48%增加至 86 1%± 1 62 % (P =0 0 0 2 )。同时癌细胞MMP9蛋白表达强度也显著增强 ,CNE 1和CNE 2细胞MMP9蛋白的平均相对强度均比诱导前提高 3倍以上 (P <0 0 5)。但MIF刺激前后 ,MMP2蛋白的细胞表达数量和表达强度在两株细胞中却未见明显变化 (P值均大于 0 0 5)。 (3 )MIF诱导后 ,CNE 2细胞培养上清液中的IL 8浓度为 12     

稳定表达鼻咽癌来源潜伏膜蛋白1基因的鼻咽癌细胞系的建立

目的:建立稳定表达鼻咽癌(NPC)来源潜伏膜蛋白1(LMP1)的鼻咽癌细胞系。方法:利用基因重组技术构建NPC来源LMP1的一般性真核表达载体及上皮特异性表达载体,并将其转染鼻咽癌细胞系CNE-2,用PCR、RT-PCR及蛋白印迹等检测N-LMP1在CNE-2中的整合和表达。结果:①成功构建了N-LMP1的一般性和上皮特异性表达载体。②N-LMP1基因在CNE-2细胞中获得了正确表达。结论:成功建立了稳定表达NPC来源LMP1的鼻咽癌细胞系,为进一步研究LMP1在鼻咽癌细胞中的作用机制奠定基础。     

Detection of Epstein-Barr Virus DNA in well and pooly differentiated nasopharyngeal carcinoma cell lines

Undifferentiated and poorly differentiated nasopharyngeal carcinoma (NPC) were know to be tightly associated with Epstein-Barr Virus (EBV). Its association with well differentiated NPC was also reported. In the present study, the presence of EBV was investigated by nucleic acid hybridization, Polymerase Chain Reaction (PCR), Immunoblot andin situ hybridization in two well differentiated NPC cell lines (CNE-1 and HK-1) and two other poorly differentiated NPC cell line (CNE-2 and CNE-3). Contrary to previous report indicating the absence of EBV in these cell lines, EBV DNA and proteins were present in all cell lines. The detection of EBV became more easily when the investigation was carried out on the nude mice tumor induced by transplantation of each NPC epithelial cell line. The EBV latent membrane protein (LMP1) was found byin situ hybridization to be intergrated partly in the chromosomal DNA of these cell lines. The observations indicate that EBV could persist for a long time in the carcinoma cells established directly from well and poorly differentiated tumor biopsies and from transplantable NPC tumor in nude mice.     

The invasive behavior of two human nasopharyngeal carcinoma (NPC) cell lines CNE-1, CNE-2Z in vitro]

Method of co-culture of tumor cells with precultured heart fragments (PHF) in vitro was used in studying the invasive behavior of human nasopharyngeal carcinoma (NPC) cell lines CNE-land CNE-2Z respectively. This improved method was based on the gyrotory shaker organ culture technique originally established by Mareel in order to show NPC cell invasiveness in a rather identical image. Histopathological sections revealed that the tumor cells might invade into the cell layer of fibroblasts surrounding the heart tissue. This would make the heart muscle cells degenerated, atrophied and necrotic and finally displaced by the fibrotic tissue. Data also pointed out that CNE-2Z cells showed more active invasive ability than that of the CNE-1 cells in the organ culture.     

Antitumor activity of the pachymic acid in nasopharyngeal carcinoma cells

Objective: To investigate the antitumour efficacy of pachymic acid (PA), which is a fungal extract component, on nasopharyngeal carcinoma (NPC) cells CNE-1, CNE-2. Methods: We have chosen NPC cell line CNE-2 for the study, and the cells were treated with PA before the detection. CCK-8 assay was used to detect the proliferative ability, and Annexin V-PI double staining was used for the detection of apoptosis rate; and the nucleus damage was detected by transmission electron microscope, the protein expression of the DNA damage pathway were detected by Western blot. Results: PA can significantly inhibited proliferation of CNE-1, CNE-2 cells. The proportion of apoptotic cells of all cell lines gradually increased in a dose-dependent manner induced by PA, P < 0.05. Meanwhile, the nucleus could be caused morphological changes and the expression of DNA damage-related proteins was upregulated by PA in CNE-2. Conclusions: PA can significantly inhibit cell proliferation and increase the apoptosis rates and may induce the apoptosis of the human NPC cells.     

抑制NF-_κB对鼻咽癌细胞CNE-2中MMP-9表达的影响

目的　　为探讨高转移性和高复发性的鼻咽癌中ＭＭＰ－９的表达及ＮＦ－κＢ抑制剂ＰＤＴＣ对其表达的影响。方法　　采用常规培养的鼻咽癌细胞ＣＮＥ－２,通过流式细胞仪检测ＣＮＥ－２中ＭＭＰ－９的表达及核因子κＢ抑制剂ＰＤＴＣ对其表达的影响。结果　　ＣＮＥ－２中有高表达的ＭＭＰ－９,ＰＤＴＣ可有效抑制其ＭＭＰ－９的表达。结论　　ＭＭＰ－９在肿瘤转移过程中起重要作用,抑制ＮＦ－κＢ和ＭＭＰ－９可抑制肿瘤转移。     

不同辐射抗拒鼻咽癌细胞微小RNA差异表达的研究

目的: 在验证鼻咽癌（nasopharygycarcinoma, NPC）细胞CNE-1和CNE-2不同辐射抗拒性的基础上，探索微小RNA(miRNA)在CNE-1和CNE-2中的表达差异。方法: 通过观察X线照射对CNE-1和 CNE-2 细胞克隆形成数目的影响，利用SigmaPlot 软件进行分析及线性二次模型拟合存活曲线, 比较CNE-1和CNE-2 细胞剂量存活曲线及其生物学参数；采用Paraflo microfluidic microRNA芯片检测，用激光扫描器收集杂交的图像，经LOWESS 滤器规范信号后分析数据差异,根据Targetscan3.1数据库资料 (http:∥www.targetscan.org)，预测CNE-1和CNE-2细胞microRNA差异表达与NPC放射敏感性差异的关系。结果: 发现在CNE-1和CNE-2细胞中miRNA的差异表达，即与CNE-2细胞比，在检测的326个microRNA中，CNE-1细胞中有20个miRNA上调，13个miRNA下调，其中检测量的绝对值在2 000以上且两者相差在3倍以上的miRNA有hsa-miR-152、hsa-miR-7、hsa-miR-205和hsa-miR-572；分析结果提示明显差异表达的miRNA与放疗敏感性密切相关。结论: 不同辐射抗拒NPC细胞株CNE-1和CNE-2细胞的microRNA的表达有差异；差异表达的miRNA与放疗敏感有关。     

Niflumic acid exhibits anti-tumor activity in nasopharyngeal carcinoma cells through affecting the expression of ERK1/2 and the activity of MMP2 and MMP9

Niflumic acid (NFA) was known to inhibit cell proliferation or migration in several types of cancer. However, the function of NFA in human nasopharyngeal carcinoma (NPC) cells was not clarified. The proliferation of NPC cell line CNE-2Z cells with NFA treatment was detected using the cell counting kit-8 method and transwell assay was employed to assess the effect of NFA on the CNE-2Z cell migration and invasion. The activity of MMP2 and MMP9 was detected by Gelatin Zymography. Cell cycle distribution and apoptosis were detected using flow cytometry. In vitro pull-down assay, western blot, and computational technique were applied to investigate the NFA regulating signaling pathway. Our results indicated that the growth capacity and colony formation potential of CNE-2Z cells in soft agar were significantly suppressed by treatment with NFA. NFA inhibited the proliferation of CNE-2Z cells in a concentration and time-dependent manner. NFA exerted an S phase arrest on the CNE-2Z cells in a concentration-dependent manner, while promoting apoptosis in a dose-dependent manner. Migration and invasion potential of CNE-2Z cells were decreased by NFA treatment in vitro. In vitro pull-down assay and molecular modeling indicated that NFA directly bound with early respond kinase 1 (ERK1). Finally, the anti-tumor effect of NFA was suggested to be mediated by inhibiting early respond kinases (ERK) expression and the MMP2 and MMP9 activities. NFA has proliferation-inhibiting, invasion-suppressing, cell cycle-blocking and apoptosis-promoting effects on CNE-2Z cells through regulation of ERK/MAPK and our results indicates that NFA may serve as a candidate of anticancer drug for NPC.     

Ad-14-3-3σ对不同辐射抗拒的鼻咽癌细胞微小RNA表达的影响

目的： 在明确Ad-14-3-3σ对不同辐射抗拒鼻咽癌（nasopharygycarcinoma, NPC）细胞CNE-1和CNE-2治疗作用的基础上，检测Ad-14-3-3σ对CNE-1和CNE-2细胞中差异表达的微小RNA(microRNA, miRNA)的影响，探索CNE-1和CNE-2细胞中miRNA差异表达与NPC放射敏感性差异的关系。方法: 用Ad-14-3-3σ转染CNE-1和CNE-2细胞；采用Paraflo microfluidic microRNA芯片检测，用激光扫描器收集杂交的图像，经LOWESS滤器规范信号后分析数据差异，根据Targetscan3.1数据库资料（http://www.targetscan.org）探索Ad-14-3-3σ对CNE-1和CNE-2中的miRNA差异表达的影响，预测其差异表达与NPC放射敏感性差异的关系。结果: Ad-14-3-3σ处理细胞以后，CNE-1与CNE-2相比较，有37个microRNA有明显差异，CNE-1中有17个上调，20个下调。其中倍数变化在3倍以上且2者检测量数量差异达到1 000以上的有6个:hsa-miR-152、hsa-miR-205、 hsa-miR-203、 hsa-miR-7、hsa-miR-636和hsa-miR-100。结论: Ad-14-3-3σ能够改变微小RNA(microRNA, miRNA)在CNE-1和CNE-2中的表达模式，缩小CNE-1和CNE-2之间miRNA的表达差异，而这些miRNA可能跟肿瘤的发生和放疗敏感性有关。     

鼻咽癌复发的分子标志物Jab1 和Akt1 蛋白表达的差异*

 目的：通过筛查鼻咽癌病人复发组织与鼻咽癌初发组织分子标志物表达的差异,探讨差异表达的蛋白与鼻咽癌复发的关系,为干预鼻咽癌复发提供新的靶点。方法：免疫组织化学SABC 法检测Jab1、p-STAT3、 CHOP 和Akt1 在复发和初发病人鼻咽癌组织中的表达;Western blotting 法检测鼻咽癌细胞CNE-1、CNE-2、CNE-2R 和HONE1 中Jab1 和Akt1 蛋白的表达。结果：复发病人鼻咽癌组织Jab1和Akt1核表达水平均高于初发鼻咽癌组织（P<0.05）;Jab1 和Akt1 在CNE-1、CNE-2R 和HONE1细胞中的表达高于在CNE-2细胞中的表达,电离辐射能促进CNE-1、CNE-2、CNE-2R 和HONE1细胞中Jab1 蛋白的表达。结论：复发病人鼻咽癌组织或辐射抗拒鼻咽癌细胞中Jab1 和Akt1 核表达均高于初发鼻咽癌组织或辐射相对敏感的鼻咽癌细胞;电离辐射促进鼻咽癌细胞中Jab1 过表达。     

肝细胞生长因子/c-Met系统在鼻咽癌中的表达及意义

目的　探讨肝细胞生长因子(HGF)及其受体c- Met蛋白在鼻咽癌组织中的表达水平,研究HGF/c- Met系统对鼻咽癌细胞侵袭转移的影响。方法　收集1999—2003年期间45例确诊的鼻咽原发癌活检组织标本,采用免疫组织化学(LSAB)法检测鼻咽癌组织中HGF α亚单位和c- Met的表达,并与患者的病理及临床资料相联系。采用流式细胞术检测鼻咽癌细胞株CNE- 2在HGF刺激前后c- Met阳性癌细胞百分率的改变;蛋白印迹法和逆转录PCR法分别用于检测癌细胞株c -Met蛋白表达和mRNA表达的变化。结果　在45例鼻咽原发癌组织中,癌细胞c- Met的阳性表达率为91. 1% (41 /45),但仅有1例鼻咽癌细胞表达HGF( 2 .2%, 1 /45 )。HGF主要在鼻咽癌间质中的淋巴细胞表达。癌细胞c Met的表达水平与淋巴结转移有关(P=0 .024 ),且与淋巴细胞表达HGF呈正相关(rs=0 .450,P=0 .002)。癌细胞c Met表达量在间质淋巴细胞高表达HGF的病例中明显高于淋巴细胞低表达HGF的癌组织(P=0 .009)。但癌细胞c Met的表达与患者性别、年龄、病理组织学分型以及临床分期均未显示相关性。鼻咽癌细胞株CNE 2在HGF诱导24h后,c Met阳性的癌细胞比例即有明显增加,由(46 .6±9 .02)%增加至(85. 8±6. 05)% (P=0 .003 ),癌细胞c Met蛋白表达相对强度和mRNA表达水平均有显著提高,     

miR-346 在鼻咽癌中的表达及生物学功能

目的:探讨miR-346 在鼻咽癌中的表达及在鼻咽癌中的生物学功能。方法:收集63 例鼻咽癌组织以及34 例 鼻咽部非癌组织标本,Real-time PCR 检测组织和6 株人鼻咽癌细胞系及1 株人正常鼻咽部永生化上皮细胞株NP69 中miR- 346 表达量,选取人鼻咽癌细胞系中表达量居中的两种细胞系,并转染miR-346 inhibitor,设置对照组(NC 组)并转染阴性对照 质粒,Real-time PCR 检测两种细胞系转染miR鄄346 inhibitor 和对照组miR鄄346 表达量,细胞增殖、凋亡分别采用Brdu-ELISA 和 流式细胞术检测,Transwell 小室实验检测细胞迁移和侵袭。结果:与鼻咽非癌组织比较,鼻咽癌组织中miR-346 表达量显著升 高(P =0.000);以正常人鼻咽部上皮细胞NP69 比较,各鼻咽癌细胞株中miR-346 相对表达量均显著升高,差异有统计学意义 (P<0.05)。选择6 种鼻咽癌细胞株中miR-346 表达量居中的两种,分别为CNE-1 和CNE-2,转染miR-346 inhibitor 后,两种鼻 咽癌细胞株miR-346 相对表达量均显著降低,与NC 组比较差异均有统计学意义(P<0.05)。两种鼻咽癌细胞转染miR-346 inhibitor 下调miR-346 表达后鼻咽癌细胞的增殖受到抑制,均在转染第3 天差异具有统计学意义(P<0.05)。下调miR-346 表 达后鼻咽癌细胞CNE-1 和CNE-2 的凋亡显著增加,迁移细胞数和侵袭细胞数显著降低,与NC 组比较差异均有统计学意义 (P<0.05)。结论:miR-346 在鼻咽癌中高表达,下调miR-346 表达会抑制鼻咽癌细胞增殖、迁移和侵袭,促进凋亡,miR-346 可 能作为一种癌基因在鼻咽癌的发生和发展中发挥重要的作用。     

表没食子儿茶素没食子酸酯通过调控P53/miR-34a抑制鼻咽癌细胞的增殖

目的:观察表没食子儿茶素没食子酸酯(EGCG)对鼻咽癌细胞增殖的影响,并以微小RNA-34a(miR-34a)为靶点探讨其作用机制。方法:不同浓度的EGCG处理CNE-2Z细胞,CCK-8法、Ed U染色法和平板克隆形成实验检测细胞增殖能力的改变;流式细胞术检测细胞周期分布的改变;Western blot检测P53和Notch1蛋白水平的变化;real-time PCR检测miR-34a和Notch1 mRNA的表达。结果:EGCG处理后,CNE-2Z细胞的增殖受到明显抑制,克隆形成能力降低,细胞周期阻滞于G0/G1期,呈剂量依赖关系;随着EGCG浓度增高,P53和miR-34a的表达水平明显上调,而其下游Notch1 mRNA和蛋白的表达水平则明显下降。结论:EGCG可能通过调控P53/miR-34a/Notch1通路诱导细胞周期阻滞,抑制鼻咽癌细胞增殖。     

同源不同辐射抗拒NPC细胞间总甲基化水平及基因甲基化表达差异的探讨

目的:比较同源不同辐射抗拒能力的鼻咽癌细胞CNE2R/CNE2间总甲基化水平及其区域的差异。方法:采用赵存友博士改良的基于甲基化敏感酶全基因组甲基化法检测CNE2R/CNE2细胞全基因组甲基化水平;同时采用Me DIP-Seq测序法对CNE2R/CNE2细胞进行测序,分析比较DNA甲基化区域(主要包括6个基因功能元件即CDS、intron、downstream2k、upstream2k、3’UTR及5’UTR)的差异。结果:CNE2R细胞全基因组甲基化水平比CNE2细胞低约30%;在CNE2R和CNE2细胞中,虽然分布在6个基因功能元件上的峰值个数和峰值在各基因元件上的覆盖度均无明显差异,但2种细胞的6个基因功能元件上基因甲基化存在差异。结论:同源不同辐射抗拒能力的鼻咽癌细胞间总甲基化水平及基因甲基化存在差异,推测DNA甲基化的差异可能与鼻咽癌辐射抗拒相关。     

Upregulation of SATB1 is associated with the development and progression of glioma

ABSTRACT: BACKGROUND: Special AT-rich sequence-binding protein-1 (SATB1) has been reported to be expressed in several human cancers and may have malignant potential. This study was aimed at investigating the expression and potential role of SATB1 in human glioma. METHOD: The relationship between SATB1 expression, clinicopathological parameters, Ki67 expression and MGMT promoter methylation status was evaluated, and the prognostic value of SATB1 expression in patients with gliomas was analyzed. SATB1-specific shRNA sequences were synthesized, and U251 cells were transfected with SATB1 RNAi plasmids. Expression of SATB1 mRNA and protein was investigated by RT-PCR and immunofluoresence staining and western blotting. The expression of c-Met, SLC22A18, caspase-3 and bcl-2 protein was determined by western blotting. U251 cell growth and adherence was detected by methyl thiazole tetrazolium assay. The apoptosis of U251 cells was examined with a flow cytometer. The adherence, invasion, and in vitro angiogenesis assays of U251 cells were done. The growth and angiogenesis of SATB1 low expressing U251 cells was measured in an in vivo xenograft model. RESULTS: Of 70 tumors, 44 (62.9%) were positive for SATB1 expression. SATB1 expression was significantly associated with a high histological grade and with poor survival in univariate and multivariate analyses. SATB1 expression was also positively correlated with Ki67 expression but negatively with MGMT promoter methylation in glioma tissues. SATB1 shRNA expression vectors could efficiently induce the expression of SLC22A18 protein, increase the caspase-3 protein, inhibit the expression of SATB1, c-Met and bcl-2 protein, the growth, invasion, metastasis and angiogenesis of U251 cells, and induce apoptosis in vitro. Furthermore, the tumor growth of U251 cells expressing SATB1 shRNA were inhibited in vivo, and immunohistochemical analyses of tumor sections revealed a decreased vessel density in the animals where shRNA against SATB1 were expressed. CONCLUSION: SATB1 may have an important role as a positive regulator of glioma development and progression, and that SATB1 might be a useful molecular marker for predicting the prognosis of glioma.     

Expression of interleukin-18 by nasopharyngeal carcinoma cells: a factor that possibly initiates the massive leukocyte infiltration

Interleukin-18 (IL-18) is a single-chain cytokine that is produced by various cells. With interleukin-12 (IL-12), it synergistically stimulates activated T cells and natural killer (NK) cells to produce interferon-gamma (IFN-gamma). Nasopharyngeal carcinoma (NPC) is the most common form of nasal and nasopharyngeal malignancy, and in NPC tumor tissues there is an intense leukocyte infiltration comprising predominantly T cells and macrophages. We previously showed an increased expression of IFN-gamma in the infiltrating T cells. To identify the cells that provide IL-12 and IL-18 for stimulating the expression of IFN-gamma in activated T cells, NPC cell lines CNE-2 and HK-1, as well as biopsies obtained from NPC and control individuals, were examined. CNE-2 and HK-1 cells were found to express messenger RNA encoding IL-18, but not IL-12. Secreted IL-18 was detected in the culture supernatant. Addition of a caspase-1 inhibitor decreased the secretion level, indicating that this IL-18 secretion was caspase-1 dependent. Moreover, the in vitro IL-18 production in NPC cell lines correlated with the NPC tumor cells in situ. NPC tumor cells in the biopsies produced IL-18, as detected by immunohistochemistry and immunofluorescent double staining. In contrast, IL-18 expression was not observed in the control biopsies. We suggest that IL-18 secreted by NPC tumor cells plays a role in initiating the leukocyte infiltration process. IL-18 stimulates T cells and NK cells to produce IFN-gamma, which consequently activates macrophages and other immune cells to secrete chemokines to start a leukocyte recruitment cascade.