姜黄素诱导低分化鼻咽癌细胞株CNE-2Z的凋亡

背景与目的:鼻咽癌(nasopharyngealcarcinoma,NPC)是我国南方地区的高发肿瘤,发病早期的治疗主要是以放疗为主,而对晚期NPC患者则有必要进行适当的化疗。一些药物可通过诱导肿瘤细胞凋亡来达到治疗肿瘤的目的。本研究拟探讨姜黄素对人鼻咽癌细胞株CNE-2Z体外增殖抑制作用及凋亡的影响。方法:不同浓度姜黄素处理CNE-2Z细胞,用噻唑蓝(MTT)法测定增殖抑制率和IC50;用流式细胞术、Hoechest33258/碘化丙啶(PI)双染、琼脂糖电泳法观察细胞凋亡。结果:姜黄素能抑制CNE-2Z细胞的生长,其效果与姜黄素的浓度和作用时间有关,作用24h、48h、72h的IC50值为(24.05±0.47)、(19.20±0.17)、(7.35±0.50)μmol/L;5、10、20μmol/L姜黄素处理细胞24h后,流式细胞术观察到细胞凋亡率分别为(4.9±3.2)%、(10.7±2.7)%和(14.7±0.5)%;10、20μmol/L姜黄素处理细胞24h后,荧光染色可见细胞缩小,染色质固缩,核染色体碎裂等凋亡形态学改变,琼脂糖凝胶电泳可见DNA梯形条带。结论:姜黄素可诱导CNE-2Z细胞凋亡,姜黄素对CNE-2Z细胞具有增殖抑制作用。     

反义c-fos、c-jun对CNE-2Z细胞增殖及PKC-α表达的影响

为探讨反义c-fos、c-jun对CNE-2Z细胞生长的影响及与PKC-α表达的关系.本研究联合应用反义c-fos和c-jun寡核苷酸作用于CNE-2Z细胞,MTT法检测细胞生长指数,流式细胞仪(FCM)检测细胞PKC-α表达.结果显示,c-fos、c-jun反义寡核苷酸在Lipofectin(LP)最低有效浓度为1.7×10~(-6)μg/ml作用下,对CNE-2Z细胞抑制作用随浓度增大而增强,最低有效浓度为1.7×10~(-5)μg/ml;在一定时间内,对细胞生长的抑制作用,随作用时间延长而增强,最大抑制作用时间为20小时,其生长指数为63.9±5.0,较对照组明显降低(P<0.01).在以上浓度的LP和反义寡核苷酸作用于细胞20小时后,FCM检测发现PKC-α荧光强度明显低于各对照组,阳性细胞数百分比为10.40±5.23,较对照组29.87±7.41及其它各组均显著降低(P<0.01).结果表明,反义c-fos、c-jun寡核苷酸可抑制CNE-2Z细胞生长增殖,并呈明显的浓度和时间效应依赖关系,且明显抑制PKC-α蛋白的表达.     

趋化因子受体CXCR4在鼻咽癌细胞中的表达

背景与目的:研究表明,趋化因子受体CXCR4及其配体SDF-1(stromalcell-derivedfactor1)与肿瘤的增殖、分化和转移等恶性表现密切相关。本研究通过观察分化程度和增殖能力不同的鼻咽癌细胞中CXCR4的表达,初步了解CXCR4与鼻咽癌细胞恶性表现的关系。方法:分别以全反式维甲酸(all-trans-retinoicacid,RA)和端粒酶反义核酸处理鼻咽癌CNE1(高分化)和CNE2Z(低分化)细胞,原位杂交技术检测CXCR4mRNA表达,免疫组化法检测CXCR4蛋白表达,流式细胞仪检测细胞周期分布,MTT法检测细胞增殖能力。结果:CXCR4mRNA和CXCR4蛋白在鼻咽癌CNE1和CNE2Z细胞均呈强阳性表达,且CNE2Z细胞表达强度显著高于CNE1细胞。经1×10-5mol/L和1×10-4mol/LRA作用后,与对照组比较,CNE1细胞G1期细胞明显增多,CNE2Z细胞S期细胞明显增多,同时两者的CXCR4mRNA表达水平均显著低于对照组(P<0.01),其中1×10-4mol/LRA作用较1×10-5mol/LRA作用强(P<0.01)。经端粒酶反义核酸作用后,CNE1和CNE2Z细胞增殖均明显受抑制,CXCR4蛋白表达水平均显著低于对照组(P<0.01)。结论:CXCR4在鼻咽癌细胞高表达,其表达水平与鼻咽癌细胞的分化程度和增殖能力有关。     

EGFR的下调表达对鼻咽癌细胞粘附作用的实验研究

已有的研究表明:EGFR的过量表达增强了肿瘤的转移,但其确切的机理还知之甚少.同时,肿瘤细胞对胞外基质的粘附是肿瘤侵袭转移的重要步骤.为了探讨EGFR的表达改变是否影响肿瘤细胞对胞外基质的粘附作用,我们将构建的EGh反义序列表达质粒(pLXSN/AS)导入人过量表达EGFR的人类鼻咽癌细胞侏CNE-2Z中(pLXSN/AS)作对照转染).经G418筛选及125I-EGF结合分析,获得EGFR下调表达的CNE-2Z/AS克隆细胞,继而分别将CNE-2Z/AS,CNE-2Z及CNE-2Z/pLXSN细胞铺入含有层粘连蛋白(LN,10mg/ml)或纤粘连蛋白(FN,10mg/ml)的平皿中,于培养20min,40min,60min分别计数粘附于平的细胞数并绘制细胞生长曲线.结果表明:EGFR的下调表达能明显降低CNE-2Z细胞对FN,LN的粘附作用,而对照组细胞对FN,LN的粘附作用没有改变.这一结果提示:肿瘤细胞中EGFR的过量表达增强了肿瘤细胞对胞外基质的粘附作用,从而促进了肿瘤细胞分解基底膜和远端转移,这为进一步研究肿瘤转移机制奠     

奥沙利铂对人低分化鼻咽癌细胞系CNE2体外增殖的影响

背景与目的:奥沙利铂是第三代铂类化合物,与顺铂相比其作用机制有一些重要区别,且毒性较低。鼻咽癌以低分化癌为多见,虽放射治疗是基本手段,但对复法或转移鼻咽癌、化疗仍是重要的手段,因此,本实验通过探讨奥沙利铂体外对人低分化鼻咽癌细胞CNE2的影响研究其在鼻咽癌治疗中的可能价值。方法:将浓度分别为0.03、0.16、0.8、4.0、20.0、100μg/m l的奥沙利铂与CNE2细胞作用24、36、48 h,用MTT法计算细胞生长抑制率,流式细胞仪检测细胞周期改变和凋亡率,透射电镜观察其形态学变化。结果:奥沙利铂能够抑制CNE2细胞的增殖,并且这种作用呈时间和剂量依赖性。100μg/m l奥沙利铂作用48 h,CNE2细胞生长抑制率达(95.6±0.7)%。流式细胞仪分析显示CNE2细胞呈G2/M期阻滞;奥沙利铂浓度为0、0.03、4.0、100μg/m l时CNE2细胞的凋亡率分别为(0.19±0.17)%、(0.37±0.09)%、(5.50±1.08)%、(9.43±0.09)%。20μg/m l药物作用24 h后电镜观察发现CNE2细胞皱缩,染色质聚集于核膜周围,固缩,碎裂成多块;并有凋亡小体形成。结论:奥沙利铂能够抑制人低分化鼻咽癌细胞系CNE2的增殖,能够诱导CNE2细胞G2/M期阻滞,较高浓度的奥沙利铂才可诱导CNE2细胞凋亡。     

抗端粒酶核酶质粒的构建筛选及其对CNE-2Z细胞增殖与凋亡的影响

背景与目的:已证实端粒酶(telomerase,TLMA)对肿瘤的进展和肿瘤细胞的无限增殖起着重要的决定作用。核酶是具有特殊核酸内切酶活性的反义RNA,可序列特异性地与靶RNA分子配对并切割靶基因RNA。有报道人低分化鼻咽癌CNE-2Z细胞端粒酶阳性,本实验目的是构建抗端粒酶RNA模板区特异性核酶的真核表达载体并用电穿孔法将其导入人低分化鼻咽癌CNE-2Z细胞,研究该核酶对CNE-2Z细胞增殖、凋亡的影响。方法:设计合成针对端粒酶RNA模板区的锤头状核酶基因teloRZ作为端粒酶抑制剂,构建3种带有绿色荧光蛋白(greenfluorescentprotein,GFP)报道基因和嘌呤霉素(puromycin)抗性基因的teloRZ真核表达质粒pGFPuro-teloRZ2.1、pGFPuro-teloRZ7.1、pGFPuro-teloRZ7.7,这3种质粒的不同点在于teloRZ基因和puromycin抗性基因按3种不同方向设计,然后将上述3种质粒及载体质粒pPAT-GFP电转染CNE-2Z细胞,用荧光显微镜检测GFP表达情况;用流式细胞仪、荧光染色法检测细胞增殖指数及凋亡等指标。结果:CNE-2ZGTR7.1细胞(转染目的基因质粒pGFPuro-teloRZ7.1的CNE-2Z细胞)增殖指数(25.100±0.141)%明显低于CNE-2Z细胞(未转染质粒的细胞)的(53.663±16.981)%、CNE-2ZG细胞(转染空载质粒pPAT-GFP的CNE-2Z细胞)的(61.575±5.166)%、CNE-2ZGTR2.1     

长春新碱对鼻咽癌细胞增殖和周期的影响

[目的]探讨长春新碱(VCR)对鼻咽癌CNE鄄2Z细胞增殖和周期的影响。[方法]MTT法检测增殖抑制率和IC50,流式细胞术分析细胞周期。[结果]不同浓度的VCR分别处理细胞24h、48h、72h时,抑制率随浓度的增加和时间的延长而增加,其IC50分别为(2.01±0.26)、(1.59±0.23)、(0.92±0.11)μg/ml,各IC50间的差异有非常显著性意义(P<0.01)。0.5μg/ml、1μg/ml、2μg/mlVCR分别处理细胞6h、12h、24h时,G0/G1期细胞明显下降,G2/M期细胞明显升高,随时间的延长变化更明显(P<0.01)。[结论]VCR对CNE鄄2Z细胞具有增殖抑制作用,该抑制作用具有剂量和时间依赖性;阻滞细胞于G2/M期,此阻滞作用具有时间依赖性;一定剂量的VCR可能通过阻滞CNE鄄2Z于G2/M期而抑制其增殖。     

三氧化二砷诱导鼻咽癌CNE-2Z细胞凋亡及其作用机制的初步研究

目的:研究三氧化二砷(As2O3)对人鼻咽癌CNE2Z细胞的生物学效应及其作用机制。方法:台盼蓝计数法计算As2O3的IC50;CNE-2Z细胞经As2O3处理后,通过流式细胞仪、荧光染色及DNA电泳检测细胞凋亡;流式细胞仪测定bcl2和bax阳性细胞百分率;罗丹明123染色后进行线粒体膜电位分析。结果:As2O3在一定浓度范围内以浓度依赖的方式抑制CNE2Z细胞生长,其IC50为(1.35±0.30)μmol/L;0.5～2.0μmol/LAs2O3处理CNE2Z细胞后,流式细胞仪检测出凋亡峰,荧光显微镜下可见明显的细胞凋亡形态特征,琼脂糖凝胶电泳出现DNA梯形条带;As2O3对bcl2的表达没有影响(P>0.05),但能显著增加bax的表达(P<0.01)及降低线粒体膜电位(P<0.01)。结论:As2O3在体外可诱导鼻咽癌CNE2Z细胞凋亡,其机制可能与上调bax表达和降低线粒体膜电位有关。     

姜黄素对人鼻咽癌CNE-2Z细胞侵袭和转移的体外实验研究

背景与目的:鼻咽癌放射治疗后的局部复发和远处转移是患者死亡的主要原因之一。姜黄素(curcumin)是从姜科姜黄属植物姜黄(Curcuma longa)根茎中提取的一种酚性色素,具有抗菌、抗肿瘤及抗氧化作用。本研究旨在探讨姜黄素对人鼻咽癌CNE-2Z细胞侵袭和转移的影响,并探讨其可能的机制。方法:以10、20、40和80μmol/L姜黄素分别处理CNE-2Z细胞24、48 h后,MTT法检测其对细胞的生长抑制作用。应用Transwell小室进行人工重组基底膜(matrigel)侵袭和运动实验,观察姜黄素对CNE-2Z细胞侵袭和转移的影响。RT-PCR和Western blot分别检测不同浓度姜黄素作用后细胞中表皮生长因子受体(epidermal growth factor receptor,EGFR)表达水平的变化。结果:应用姜黄素处理后,人鼻咽癌CNE-2Z细胞生长受到抑制,且作用呈时效-量效依赖关系;同时细胞侵袭和迁移能力明显降低;EGFR基因和蛋白表达亦明显减弱。结论:姜黄素能够减弱人鼻咽癌CNE-2Z细胞的体外侵袭和转移能力,其机制可能与降低EGFR的表达有关。     

NK细胞对人鼻咽癌细胞CNE2裸鼠皮下移植瘤的抑制作用

 目的 研究同种异体NK细胞对人鼻咽癌细胞（CNE2）裸鼠皮下移植瘤的抑制作用。方法PCR-SSP法检测CNE2细胞HLA-A、B、Cw表型、NK细胞KIR表型（选择3例健康者为试验对象）,磁珠分离法分离NK细胞并进行体外培养扩增,LDH释放法测定NK细胞对CNE2细胞的体外杀伤活性。12只BALB/c裸鼠分为两组,每组6只,对照组裸鼠每只皮下接种1×106CNE2细胞,治疗组裸鼠每只皮下接种1×106CNE2细胞,同时每只经尾静脉注入3×107NK细胞,观察两组裸鼠成瘤时间、成瘤率、肿瘤体积变化、计算抑瘤率。结果 CNE2细胞表面HLA-A、B、Cw表型为A2,24;B18,35;Cw4,7,3例健康者均表达KIR2DL1、KIR2DL3、KIR3DL1、KIR3DL2。效靶比5∶1、10∶1、20∶1、30∶1时,NK细胞对CNE2细胞的杀伤活性分别为（9.37±2.14）%、（27.14±1.82）%、（36.40±4.28）%and（54.67±2.80）%。对照组和NK细胞治疗组肿瘤出现时间分别为（10.00±2.68）d、（18.80±1.64）d,（P〈0.01）,成瘤率分别为100%（6/6）、83.33%（5/6）,对照组和NK细胞治疗组裸鼠的瘤重分别为（2.22±0.09）g、（1.42±0.09）g,（P〈0.01）,NK治疗组的抑瘤率为36.04%。肿瘤组织石蜡切片病理学鉴定为低分化鳞状上皮细胞癌,NK细胞治疗组可见角化肿瘤细胞,较多的淋巴细胞浸润和大量细胞坏死区。结论 NK细胞对鼻咽癌裸鼠皮下移植瘤有明显的抑制作用,有希望成为治疗鼻咽癌的新方法。     

A functional epidermal growth factor (EGF) polymorphism, EGF serum levels, and esophageal adenocarcinoma risk and outcome.

PURPOSE: The epidermal growth factor (EGF) pathway is important in esophageal adenocarcinoma (EAC) tumorigenesis. We hypothesized that the EGF A61G homozygous variant genotype (GG) is (a) both a risk and poor prognostic factor for EAC and (b) associated with higher EGF serum levels in individuals with gastroesophageal reflux disease (GERD). EXPERIMENTAL DESIGN: Using unconditional logistic regression, we compared EGF A61G in 312 EAC cases and 447 GERD-free controls, adjusting for age, gender, smoking history, and healthy adult body mass index. Using the method of Kaplan and Meier, log-rank tests, and Cox proportional hazard models, we correlated EGF A61G with overall and failure-free survival in the EAC cases. Serum EGF levels and EGF genotype (G/G versus others) were correlated in 144 GERD patients using Wilcoxon rank sum tests. RESULTS: The EGF A61G G/G genotype conferred increased EAC risk, with an adjusted odds ratio of 1.81 (95% confidence interval, 1.2-2.7), and was even higher in the subgroup of EAC patients with concurrent Barrett's esophagus (adjusted odds ratio, 2.18; 95% confidence interval, 1.3-3.7). However, EGF A61G was not associated with a more aggressive phenotype or prognosis in EAC patients. Higher serum EGF levels were found in GERD patients carrying G/G compared with A/A or A/G (P = 0.03, Wilcoxon rank sum test). CONCLUSION: The EGF A61G G/G genotype is associated with a near 2-fold greater risk of EAC. The G/G allele was also associated with higher EGF levels in tumor-free patients with GERD. EGF genotyping can potentially identify high-risk patients with GERD and Barrett's metaplasia who might benefit from increased surveillance.     

EGF promoter SNPs, plasma EGF levels and risk of breast cancer in Chinese women

Epidermal growth factor (EGF), a potent mitogenic peptide, plays an important role in the development of cancers, including breast cancer. Previous studies showed that plasma EGF levels may influence the risk of cancer. In the current study, we hypothesized that genetic variants in the promoter region of EGF may influence plasma EGF levels and therefore are associated with breast cancer susceptibility. We genotyped three EGF polymorphisms (G61A, G-1380A, and A-1744G) in the promoter region by PCR-RFLP and measured plasma EGF levels using an enzyme immunoassay in a case-control study of Chinese women. We found that the mean plasma EGF levels in breast cancer patients (249.06 +/- 197.54 pg/ml) were significantly lower than those in controls (982.41 +/- 375.57 pg/ml, P < 0.001). There was a significant difference of plasma EGF levels among different genotypes carriers of the G-1380A locus in 654 controls (P = 0.007). After adjustment for age, body mass index, family history of cancer, age at menarche, and menopause status, EGF-1380AA carriers had significantly higher plasma EGF levels than -1380GG carriers did (P = 0.003). However, we did not find any significant associations between the three EGF polymorphisms (G61A, G-1380A, and A-1744G) and the risk of breast cancer. These findings indicated that plasma EGF levels served as a protective marker against breast cancer in our study and EGF G-1380A variant might be a modifier on it. Further studies are warranted to verify these findings.     

表皮生长因子及其受体与肝癌的关系

EGF、EGFR具有广泛的生理作用,体内分布广泛,在肝癌的形成、复发及转移过程中,EGF、EGFR与Ca2+通道、Na+-H+通道、磷脂酰肌醇信息传递通道、基因表达异常、肿瘤血管及间质的形成关系密切,提示了治疗肝癌的新方向.现就EGF、EGFR与肝癌的形成、转移、复发的关系及其在临床中的应用前景作一综述.     

Monoclonal antibodies directed against the EGF receptor show differential bindings of amphiregulin and EGF to the EGF receptor

Amphiregulin (AR), a new member of the EGF family of ligand, is a glycoprotein containing a 78 or 84 amino acid core polypeptide that was originally purified from the conditioned medium of the breast carcinoma cell line MCF-7 after treatment with phorbol 12-myristate 13-acetate. The aim of the present study was to determine whether, like EGF, TGF alpha, heparin binding EGF-related growth factor (HB-EGF) and betacellulin (ETC), the recombinant 78 amino acid form of mature human AR transmits its biological effects following binding to the EGF receptor (EGFR). We show that unlike EGF, TGF alpha, HB-EGF and BTC, the mature AR is not effective in blocking the binding of I-125-EGF or the iodinated anti-EGFR antibodies (mAbs) I-125-ICR62 and I-125-ICR80 to the external domain of the EGF receptor on EJ cells. Again, in contrast to other EGF ligands, AR is not effective in enhancing the binding of another anti-EGFR mAb ICR9 to the EGFR on EJ cells. Like EGF, TGF alpha and HB-EGF, AR could inhibit the growth in culture of EGFR overexpressing tumour cell lines, namely HN5, HSC-1 and MDA-MB468 cells, and again compared to other ligands AR was moderately effective at low concentration. Despite these differences, we show that like EGF, AR could induce the tyrosine phosphorylation of the 170 kDa EGF receptor on HN5 cells and that this effect could be blocked in the presence of anti-EGFR mAbs ICR62 and ICR80. Moreover, like EGF, the AR-induced growth inhibition of MDA-MB468 cells could also be reversed in the presence of anti-EGFR mAbs ICR62 and ICR80. On the basis of our results we conclude that, unlike the EGF, TGF alpha, HB-EGF and BTC, the AR-induced activation of the EGFR may involve another receptor.     

胃癌中幽门螺杆菌感染与表皮生长因子及其受体表达的研究

目的探讨幽门螺杆菌感染与表皮生长因子的表达与胃癌的关系。方法应用ＰＣＲ法及快速尿素酶法检测幽门螺杆菌（ＨＰ）,免疫组化法（ＡＢＣ法）检测表皮生长因子（ＥＧＦ）和表皮生长因子受体（ＥＧＦＲ）,对３０例胃癌,３０例癌前病变,３０例慢性胃炎的病理组织进行了检测。结果胃癌组ＨＰ的阳性率为４６７％,癌前病变组为７６７％,胃炎组为７０％,胃癌组的ＨＰ阳性率低于癌前病变组和慢性胃炎组,胃癌组的ＥＧＦ和ＥＧＦＲ表达明显强于其它两组,癌前病变组的ＥＧＦＲ表达强于胃炎组（Ｐ＜００１）。另外,ＨＰ阳性组的ＥＧＦＲ阳性表达强于ＨＰ阴性组（Ｐ＜０００５）。结论ＨＰ感染与胃癌及癌前病变有关,ＨＰ感染可能主要作用于癌变的起始阶段;ＥＧＦ和ＥＧＦＲ在胃癌有很强的表达。     

A common signaling cascade may underlie "addiction" to the Src, BCR-ABL, and EGF receptor oncogenes

"Oncogene addiction" describes an unexplained dependency of cancer cells on a particular cellular pathway for survival or proliferation. We report that differential attenuation rates of prosurvival and proapoptotic signals in oncogene-dependent cells contribute to cell death following oncogene inactivation. Src-, BCR-ABL-, and EGF receptor-dependent cells exhibit a similar profile of signal attenuation following oncogene inactivation characterized by rapid diminution of phospho-ERK, -Akt, and -STAT3/5, and a delayed accumulation of the proapoptotic effector phospho-p38 MAPK. These findings implicate a transient imbalance in survival and apoptotic oncogenic outputs in the apoptotic response to oncogene inactivation. Moreover, these observations implicate a common profile of signal attenuation for multiple oncogenes and suggest that "addiction" associated with apoptosis reflects an active rather than a passive process.     

The EGF receptor Hokey-Cokey

In cancer, the epidermal growth factor (EGF) receptor (EGFR) can be activated by mutations that disrupt the inactive conformation and allow the active conformation to predominate. Structural studies have elucidated the molecular events that lead to EGFR activation and shown that small-molecule anti-EGFR drugs can bind to either the inactive or the active conformation of the kinase domain. In this issue of Cancer Cell, Yun et al. present 12 crystal structures of the wild-type or mutant forms of the EGFR kinase domain bound to four different ligands. This study will prove invaluable to those developing novel anti-EGFR drugs.     

Growth Factors in Glioma Angiogenesis: FGFs,PDGF, EGF,and TGFs

It has become well accepted that solid tumors must create a vascular system for nutrient delivery and waste removal in order to grow appreciably. This process, angiogenesis, is critical to the progression of gliomas, with vascular changes accompanying the advancement of these tumors. The cascade of events in this process of blood vessel formation involves a complex interplay between tumor cells, endothelial cells, and their surrounding basement membranes in which enzymatic degradation of surrounding ground substance and subsequent endothelial cell migration, proliferation, and tube formation occurs. It is likely that a host of growth factors is responsible for mediating these key events. To date, a role for Vascular Endothelial Growth Factor (VEGF) in glioma angiogenesis has been convincingly demonstrated. This review explores the contribution of other growth factors–-Fibroblast Growth Factors (FGFs), Platelet-Derived Growth Factor (PDGF), Epidermal Growth Factor (EGF), and Transforming Growth Factors (TGFs)–-to glioma angiogenesis. These growth factors may influence glioma angiogenesis by directly stimulating endothelial cell proliferation, by mediating the expression of key proteases on endothelial cells necessary for angiogenesis, or by regulating the expression of VEGF and of each other.     

ABINs inhibit EGF receptor-mediated NF-kappaB activation and growth of EGF receptor-overexpressing tumour cells

The epidermal growth factor receptor (EGFR) is frequently overexpressed in various tumours of epidermal origin and is held responsible for tumourigenicity and tumour persistence. Increased nuclear factor (NF)-kappaB activity has been suggested to be involved in the malignant behaviour of EGFR-overexpressing cells. However, the mechanisms that regulate EGF-induced NF-kappaB activation are still largely unknown. Here we show that EGF can induce NF-kappaB-dependent gene expression independently from IkappaBalpha degradation or p100 processing in EGFR-overexpressing HEK293T cells. Moreover, EGF-induced NF-kappaB activation could be inhibited by overexpression of ABINs, which were previously identified as intracellular inhibitors of tumour necrosis factor, interleukin-1 and lipopolysaccharide-induced NF-kappaB activation. Knockdown of ABIN-1 by RNA interference boosted the NF-kappaB response upon EGF stimulation. The C-terminal ubiquitin-binding domain containing region of ABINs was crucial and sufficient for NF-kappaB inhibition. Adenoviral gene transfer of ABINs reduced constitutive NF-kappaB activity as well as the proliferation of EGFR-overexpressing A431 and DU145 human carcinoma cells. Altogether, these results demonstrate an important role for an ABIN-sensitive non-classical NF-kappaB signalling pathway in the proliferation of EGFR-overexpressing tumour cells, and indicate a potential use for ABIN gene therapy in the treatment of cancer.     

Relationship between VEGF, EGF and invasion, metastasis of gastric cancer cells

Objective: To investigate the relationship between expression of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF) and the biological properties of gastric cancer cells such as invasion and metastasis.Methods: RT-PCR was performed to semi-quantitatively detect the mRNA expressions of EGF, EGFR, VEGF and VEGFR in four kinds of gastric cancer cell lines BGC823, MGC803, HGC27 and SGC7901, which were classified by their differentiation degree in our experiment. We obtained cell line growth curves from MTT assays. The migration of gastric cancer cells was observed under inverted phase contrast microscope. The changes of invasion and adhesion were detected by a Transwell assay.Results: The growth rates slowed down sequentially in MGC803, HGC27, BGC823 and SGC7901(P＜0.05). The ability of migration, invasion and adhesion were reduced sequentially, and the difference was significant. The expressions of EGF, EGFR, VEGF and VEGFR were significantly stronger in MGC803 and HGC27 than in BGC823 and SGC7901 cells, and the difference was statistically significant(P＜0.05).Conclusion: The expressions of VEGF and EGF had close relationship with the properties of migration, adhesion and invasion of gastric cancer cells in vitro. Thus, targeting VEGF and EGF may be a potential therapeutic strategy for inhibiting peritoneal metastasis of gastric cancer.