组蛋白去乙酰化酶在食管鳞癌中的表达及其表达下调对EC9706细胞生物特性的影响

目的:探讨组蛋白去乙酰化酶(histone deacetylase2,HDAC2)在食管鳞癌组织中的表达,并研究其表达下调对食管鳞癌EC9706细胞增殖、细胞周期和细胞凋亡的影响,以及分析其相关的分子机制。方法:采用免疫组织化学法检测食管鳞癌组织中HDAC2蛋白的表达。将特异性针对HDAC2基因的小分子干扰RNA(small interfering RNA,siRNA)和对照siRNA分别转染食管鳞癌EC9706细胞,实验分3组:未处理组、对照siRNA组和HDAC2siRNA组。蛋白质印迹法检测各组EC9706细胞中HDAC2蛋白的表达。CCK-8计数法检测转染前后细胞的增殖情况。FCM法检测细胞周期和细胞凋亡的变化。蛋白质印迹法检测与细胞增殖、细胞周期和细胞凋亡相关蛋白的表达变化。结果:HDAC2蛋白在食管鳞癌组织中表达的阳性率为79.71%,显著高于癌旁不典型增生组织的51.11%和正常食管黏膜组织的23.19%,3者之间差异具有统计学意义(χ2=44.121,P=0.000);此外,HDAC2蛋白表达与患者的年龄和性别无关(P均>0.05),但是与组织学分级、浸润深度、TNM分期和淋巴结转移均显著相关(P均<0.05)。HDAC2siRNA能有效下调食管鳞癌EC9706细胞中HDAC2蛋白的表达,明显抑制食管鳞癌EC9706细胞的增殖,促使细胞周期静止在G0/G1期,并诱导细胞凋亡。蛋白质印迹法检测结果显示,HDAC2表达下调能明显提高p21和凋亡相关蛋白bax的表达量,同时降低细胞周期蛋白cyclin D1和bcl-2的表达量。结论:HDAC2可能在食管鳞癌的发生、发展中具有重要作用,其表达下调介导的食管鳞癌细胞增殖抑制、细胞周期静止以及细胞凋亡可能与p21、bax的表达升高和cyclin D1、bcl-2表达降低密切相关。     

下调HDAC6表达对食管鳞癌细胞周期、细胞迁移的影响及其分子机制探讨

目的:探讨组蛋白去乙酰化酶6（HDAC6）表达的下调对食管鳞癌细胞周期、细胞迁移的影响及其分子机制。方法:将食管鳞癌EC9706细胞分为三组,即未处理组、对照siRNA组和HDAC6 siRNA组,后两组分别转染对照siRNA和HDAC6 siRNA。采用半定量反转录-聚合酶链反应、蛋白印迹方法检测各组细胞中细胞增殖和周期相关因子p21 mRNA和蛋白以及细胞迁移相关因子E-cadherin mRNA和蛋白的表达水平的变化。结果:HDAC6 siRNA组中p21及E-cadherin mRNA和蛋白的表达水平分别是0.440±0.120、0.840±0.070和0.580±0.090、0.450±0.080,且均明显高于未处理组（0.165±0.090、0.090±0.020;0.088±0.009、0.054±0.011）和对照siRNA组（0.163±0.021、0.070±0.040;0.820±0.070、0.066±0.007）中p21及E-cadherin mRNA和蛋白的表达水平,其表达差异均具有统计学意义（P均<0.05）,而未处理组和对照siRNA组之间p21及E-cadherin mRNA和蛋白的表达无差异（P＞0.05）。结论:HDAC6表达下调对食管鳞癌细胞周期的影响可能与p21表达的升高相关;对细胞迁移的影响可能与E-cadherin表达的上调有关。     

Notch1信号途径在食管鳞癌细胞中的激活及对细胞周期的影响

目的 观察Notch1信号途径在食管鳞癌EC9706细胞中的激活状态及 其对细胞周期的影响。方法 通过免疫细胞化学检测Notch1基因在 食管鳞癌细胞株EC9706细胞中的表达,并通过免疫荧光方法研究 Notch1基因在EC9706细胞中的激活状态。并且利用CCK-8试剂检测食管癌细胞的增殖状态。此外,采用RT-PCR和Western blot技术检 测与细胞周期相关基因的表达,最后通过流式细胞仪进一步探索激 活的Notch1信号途径对细胞周期的影响。结果 转染pcNICD后的食 管鳞癌细胞株中发现Notch1基因的表达。免疫荧光结果显示,转染 pcNICD后的食管鳞癌细胞株中Notch1信号途径处于激活状态。与未处理和转染pcDNA3.1的EC9706细胞相比,稳定表达NICD的EC9706细 胞的生长速率明显受到抑制（P<0.01）。此外,与未处理的和转染pcDNA3.1的EC9706细胞相比,稳定表达NICD的EC9706细胞的CDK2, cyclin D1和E基因的mRNA和蛋白的表达明显下调（P<0.05）。转染pcNICD的EC9706细胞在G0/G1期的比率高达74.5%,而未处理的和转染pcDNA3.1的EC9706细胞在G0/G1期的比率分别为59.1%和59.0%。细胞周期分析显示瞬时表达NICD的EC9706细胞在G0/G1期比率的增加,提示激活的Notch1信号途径能够诱导细胞静止在G₀/G₁ 期。结论 Notch1信号途径的激活引起食管鳞癌细胞的细胞周期 静止,提示Notch1基因有可能成为治疗食管鳞癌的新靶点。     

干扰mTOR表达增强食管鳞癌EC9706细胞对雷帕霉素的敏感性

目的：观察哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin,mTOR)特异性小干扰RNA（mTOR-siRNA）干扰mTOR表达后,食管鳞癌EC9706细胞对雷帕霉素(rapamycin)敏感性的变化。方法：mTOR-siRNA转染EC9706细胞, RT-PCR检测干扰效果。mTOR-siRNA转染前后的EC9706细胞用雷帕霉素处理,Western blotting检测EC9706细胞中mTOR及其下游p70S6K蛋白的表达;流式细胞术检测EC9706细胞的周期及凋亡,CCK-8试剂盒检测EC9706细胞的增殖。结果：mTOR-siRNA下调EC9706细胞中mTOR mRNA的表达（P<0.05或P<0.01);雷帕霉素抑制EC9706细胞中mTOR和p-p70S6K蛋白的表达（P<0.05),并促进p70S6K蛋白表达(P<0.01),且mTOR-siRNA转染后此作用更明显（P<0.05）。雷帕霉素可诱导EC9706细胞凋亡(P<0.01)、抑制EC9706细胞增殖(P<0.05或P<0.01)、使EC9706细胞阻滞于G1期(P<0.01),且mTOR-siRNA转染后这些作用更强（P<0.05）。结论：mTOR-siRNA能特异性下调食管鳞癌EC9706细胞中mTOR表达,提高EC9706细胞对雷帕霉素的敏感性。     

沉默锌指蛋白217基因对食管鳞癌EC9706细胞增殖和侵袭能力的影响

目的 探讨锌指蛋白217基因(ZNF217)在食管鳞癌侵袭转移中的作用.方法 合成ZENF217基因的siRNA序列并转染对数生长期食管鳞癌EC9706细胞.设置转染无义序列siRNA和未转染EC9706细胞为阴性对照和空白对照.半定量RT-PCR和Western blot方法分别检测转染48 h后3组细胞ZNF217 mRNA和蛋白的表达变化;侵袭小室检测3组细胞穿膜细胞数变化;MTT法分析3组细胞增殖能力的变化.结果 与空白对照组和阴性对照组比较,转染ZNF217 siRNA组EC9706细胞ZNF217 mRNA和蛋白表达均显著下降,差异有统计学意义(P＜0.05);转染ZNF217 siRNA组EC9706细胞穿膜细胞数显著下降,差异有统计学意义(P ＜0.05);ZNF217 siRNA能明显抑制EC9706细胞体外增殖能力(P＜0.05).结论 ZNF217基因表达下降能显著抑制EC9706细胞体外侵袭力和增殖能力,ZNF217基因有望成为食管癌基因治疗的有效靶点.     

下调DNMT1对食管鳞癌EC9706增殖、迁移的影响及相关机制的研究

背景与目的：已有研究显示在多种肿瘤组织或细胞中均能检测出特异性DNA甲基转移酶1（DNA methyltransferase 1,DNMT1）的高表达,提示DNMT1的高表达与肿瘤的发生发展密切相关。本研究旨在通过下调DNMT1基因的表达,研究其对食管鳞癌EC9706细胞的增殖及浸润转移能力的影响,并探讨相关的分子作用机制。方法：利用CCK-8试剂盒研检测下调DNMT1对EC9706细胞增殖能力的影响,并利用Boyden室法检测下调DNMT1对EC9706细胞浸润转移能力,进一步通过Real-time PCR和Western印迹法检测转染DNMT1 siRNA后细胞中DNMT1及MMP-2基因的转录及其蛋白表达。结果：DNMT1 siRNA转染后,能明显抑制食管鳞癌EC9706细胞的增殖,降低其浸润转移能力,引起MMP-2表达下调,提示DNMT1下调引起的浸润转移能力的降低可能与MMP-2表达下调密切相关。结论：DNMT1可能成为食管鳞癌治疗新的分子靶点。     

MRE11对食管鳞癌细胞凋亡和增殖的作用研究

目的 探讨MRE11对食管鳞癌细胞增殖和凋亡的影响及其分子机制。方法 MRE11 siRNA转染食管鳞癌细胞,下调MRE11表达;AKT激动剂SC79（0、0.1、0.5、1、1.5、1.8和2 μg/ml）分别孵育24 h;构建过表达载体pcDNA.3.1-c-myc,与MRE11 siRNA共转染细胞;Western blot法检测食管鳞癌细胞Ec9706和TE-1中MRE11、p-AKT和c-myc的蛋白表达量;Annexin-V FITC/PI试剂盒检测Ec9706和TE-1细胞凋亡;Caspase-3活性检测试剂盒检测caspase-3活性;BrdU方法检测Ec9706和TE-1细胞增殖能力。结果 Ec9706和TE-1细胞中MRE11的蛋白表达较人食管上皮细胞Het-1A明显升高;MRE11 siRNA转染后,Ec9706和TE-1细胞中AKT磷酸化水平及MRE11和c-myc的蛋白表达量显著降低;下调MRE11显著促进Ec9706和TE-1细胞凋亡,提高caspase-3活性,抑制食管鳞癌细胞增殖能力;下调MRE11后,SC79（1.5、1.8和2 μg/ml）显著提高AKT磷酸化水平,同时逆转下调MRE11对c-myc蛋白表达量和细胞增殖的抑制作用及对细胞凋亡的促进作用。过表达c-myc抑制下调MRE11对细胞增殖的抑制作用和对细胞caspase-3活性的促进作用。结论 下调MRE11可通过调控AKT和c-myc抑制食管鳞癌细胞增殖 及促进细胞凋亡。     

抑制酰基-辅酶A去饱和酶1表达对食管鳞癌细胞增殖和凋亡的影响及其分子机制探讨

目的:检测酰基-辅酶A去饱和酶1(stearoyl-CoA desaturase-1,SCD-1)在食管鳞癌组织和细胞中的表达,分析其表达下调对食管鳞癌EC1细胞增殖和凋亡的影响,并探讨其相关的分子机制.方法:采用免疫组织化学和原位杂交法检测60例食管鳞癌组织及其相应癌旁正常食管黏膜组织中SCD-1 mRNA和蛋白的表达,实时荧光定量PCR和蛋白质印迹法检测正常食管组织(作为阴性对照)和食管鳞癌细胞株中SCD-1 mRNA和蛋白的表达.不同浓度SCD-1小干扰RNA (small interfering RNA,siRNA)转染食管鳞癌EC1细胞后,采用实时荧光定量PCR和蛋白质印迹法检测SCD-1 mRNA和蛋白的表达,应用CCK-8法检测转染前后EC1细胞增殖的变化,FCM检测转染前后EC1细胞凋亡的改变,蛋白质印迹法检测总Akt、p-Akt、bcl-2和bax蛋白的表达.结果:食管鳞癌组织中SCD-1 mRNA和蛋白表达的阳性率显著高于正常食管黏膜组织(P＜0.05),其表达上调与肿瘤组织分级、TNM分期和淋巴结转移密切相关(P＜0.05).此外,与正常食管组织相比,食管鳞癌EC9706、Eca109和EC1细胞中SCD-1 mRNA和蛋白表达均显著上调(P＜0.05),其中EC1细胞中SCD-1的表达水平最高.50 nmol/L SCD-1 siRNA能显著下调EC1细胞中SCD-1 mRNA和蛋白的表达.SCD-1表达下调可显著抑制EC1细胞的增殖,诱导细胞凋亡;同时,显著上调bax蛋白的表达,并下调p-Akt和bcl-2蛋白的表达,但不改变总Akt的表达水平.结论:SCD-1可能在食管鳞癌的发生和发展中具有重要作用,抑制SCD-1的表达有望成为食管鳞癌重要的分子治疗策略之一.     

Survivin反义寡核苷酸抑制EC9706细胞增殖并诱导细胞凋亡

目的 观察Sunrivin反义寡核苷酸(ASODN)对人食管癌细胞系EC9706细胞增殖和凋亡的影响.方法 人工合成Survivin基因反义和正义ODN,并进行硫代磷酸化修饰,通过脂质体途径分别转染 EC9706 细胞;应用 RT-PCR 和 Western Blot 检测 SurvivinmRNA和蛋白表达;应用MTT法检测 Survivin ASODN 对 EC9706 细胞增殖的影响;流式细胞仪检测细胞周期变化及细胞凋亡比率.结果 体外培养的 EC9706 细胞可表达较强的 Survivin mRNA 和蛋白;Survivin ASODN 可呈浓度依赖性地抑制 Survivin mRNA 和蛋白表达,50μmoL/L ASODN 几乎可以完全抑制.MTT 研究结果表明,Survivin ASODN 可呈浓度依赖性地抑制 EC9706 细胞增殖,50μmol/L ASODN 对细胞生长的抑制率可达78.5%,诱导细胞凋亡,使细胞阻滞于G2/M 期.Survivin SODN 对 Survivin mRNA 和蛋白以及 EC9706 细胞的增殖和细胞周期无明显的抑制作用.结论 脂质体介导转染 Survivin 反义寡核苷酸可抑制细胞增殖、诱导细胞G2/M 期阻滞而促进细胞凋亡.     

哺乳动物雷帕霉素靶蛋白小分子干扰RNA对食管鳞癌细胞中mTOR-p70S6K信号通路及裸鼠移植瘤生长的影响

目的 检测哺乳动物雷帕霉素靶蛋白(mTOR)小分子干扰RNA(siRNA)对食管鳞癌中mTOR-p70S6K信号通路的阻断作用以及对裸鼠移植瘤生长的影响.方法 以食管鳞癌细胞株EC9706为研究对象,采用siRNA干扰、逆转录聚合酶链反应(RT-PCR)、Western blot、流式细胞术及CCK-8等方法,观察mTOR-p70S6K信号通路被阻断后,通路中各因子蛋白及mRNA表达的变化,及其对细胞增殖和凋亡的影响.进行裸鼠成瘤实验,观察mTOR siRNA对肿瘤生长的影响.结果 与未转染细胞相比,转染mTOR siRNA的细胞中mTOR和磷酸化p70S6K的表达水平降低(P<0.05),而pTOS6K的表达水平升高(P<0.05).转染mTOR siRNA后,细胞凋亡增加,细胞增殖能力降低,且对顺铂的敏感性增高,细胞被阻滞在G,期(P<0.05).mTOR siRNA能明显抑制裸鼠移植瘤的生长,siRNA组和siRNA+顺铂组的肿瘤抑制率分别为50.9%和62.3%.结论 mTOR siRNA能有效抑制mTOR-pTOS6K信号通路,抑制细胞增殖,促进细胞凋亡,在裸鼠体内能显著抑制肿瘤的生长.mTOR-pVOSSK信号通路在食管鳞癌发生发展中起重要作用.     

桥接整合因子1通过AKT-mTOR通路诱导非小细胞肺癌H1975细胞周期阻滞

目的：研究桥接整合因子1（bridging intergrator 1,Bin1）基因过表达后对非小细胞肺癌细胞株H1975细胞周期的影响及其作用机制。方法：构建携带Bin1基因的CMV-MCS-GFP-SV40-Neomycin-Bin1质粒,并转染H1975细胞（Bin1+组）,另设置空白质粒转染组（Bin1-组）及空白对照组（Ctrl组）,利用RT-PCR和Western blotting分别检测3组细胞中Bin1在mRNA和蛋白质水平的表达情况。流式细胞术检测不同处理组H1975细胞周期的变化,Western boltting分别检测各组中AKT、mTOR磷酸化水平及细胞周期相关蛋白（周期蛋白D1、CDK4、Rb）的表达情况。结果：与Bin1-组、Ctrl组比较,Bin1+组H1975细胞中Bin1在mRNA、蛋白水平表达明显上调（均P<0.05）; H1975细胞阻滞在G1期\[（60.53±1.89）% vs（46.14±1.56）%、（47.33±2.07）%,均P<0.05\]; Bin1+组H1975细胞内p-AKT、p-mTOR表达下调（均P<0.05）,AKT、mTOR表达变化无统计学差异（P>0.05）;周期蛋白D1、CDK4的表达量均明显下调(P<0.05),Rb表达量明显增加（P<0.05）。结论：Bin1基因在H1975细胞株过表达后明显诱导细胞周期阻滞,其机制可能是通过抑制AKT-mTOR通路及其细胞周期相关蛋白实现的。     

Radiation sensitivity of merkel cell carcinoma cell lines

: Merkel cell carcinoma (MCC), being a small cell carcinoma, would be expected to be sensitive to radiation. Clinical analysis of patients at our center, especially those with macroscopic disease, would suggest the response is quite variable. We have recently established a number of MCC cell lines from patients prior to radiotherapy, and for the first time are in a position to determine their sensitivity under controlled conditions.     

Mechanisms of kaposis-sarcoma cell supernatant-induced vascular cell invasion

Kaposi's sarcoma (KS) is a highly angiogenic lesion frequently associated with acquired immune deficiency syndrome. Histologically the lesions appear to contain proliferative 'spindle shaped' cells with a mixed smooth muscle-endothelial-fibroblastic histotype and a conspicuous neovascularization, derived from host cell recruitment. Media conditioned by cultured KS cells (KS-CM) have angiogenic properties. KS-CM is able to promote endothelial and smooth muscle cell migration and invasion. The mechanisms of this KS-CM activity are still unknown. We hypothesize that KS-CM contains numerous factors with different roles in inducing the neo angiogenic process. We show that AIDS-IST-KS cell supernatants induce gelatinase A production and plasminogen activator (PA) up-regulation in vascular cells. KS-CM activity in vivo is heparin dependent. Also bFGF alone, a heparin dependent factor, alone can induce endothelial and smooth muscle cell invasion, MMP-2 production and PA activity. However, antibodies to bFGF do not block KS-CM activity and do not reduce the effect on PA up-regulation. This evidence suggests that heparin-binding factors other than bFGF may be present. Chromatography of KS-CM on heparin-sepharose demonstrates the presence of two heparin-binding fractions with chemotactic and gelatinase A inducing activity. The flow through was also active. KS-CM absorption on heparin-sepharose beads did not modify its induction of PA activity, further evidence for the presence of non heparin-binding factors as well.     

NDRG2 suppresses the proliferation of clear cell renal cell carcinoma cell A-498

Background

Recently, the anti-tumor activity of N-myc downstream-regulated gene 2 (NDRG2) was shown decreased expression in clear cell renal cell carcinoma (CCRCC), but the role of the down-expression of NDRG2 has not been described.

Methods

The NDRG2 recombinant adenovirus plasmid was constructed. The proliferation rate and NDRG2 expression of cell infected with recombinant plasmid were mesured by MTT, Flow cytometry analysis and western blot.

Results

The CCRCC cell A-498 re-expressed NDRG2 when infected by NDRG2 recombinant adenovirus and significantly decreased the proliferation rate. Fluorescence activated cell sorter analysis showed that 25.00% of cells expressed NDRG2 were in S-phase compared to 40.67% of control cells, whereas 62.08% of cells expressed NDRG2 were in G1-phase compared to 54.39% of control cells (P < 0.05). In addition, there were much more apoptotic cells in NDRG2-expressing cells than in the controls (P < 0.05). Moreover, upregulation of NDRG2 protein was associated with a reduction in cyclin D1, cyclin E, whereas cyclinD2, cyclinD3 and cdk2 were not affected examined by western blot. Furthermore, we found that p53 could upregulate NDRG2 expression in A-498 cell.

Conclusions

We found that NDRG2 can inhibit the proliferation of the renal carcinoma cells and induce arrest at G1 phase. p53 can up-regulate the expression of NDRG2. Our results showed that NDRG2 may function as a tumor suppressor in CCRCC.     

Inhibition of S-adenosylhomocysteine hydrolase decreases cell mobility and cell proliferation through cell cycle arrest

S-adenosylhomocysteine hydrolase (AHCY) hydrolyzes S-adenosylhomocysteine to adenosine and l-homocysteine, and it is already known that inhibition of AHCY decreased cell proliferation by G2/M arrest in MCF7 cells. However, the previous study has not indicated what mechanism the cell cycle arrest is induced by. In this study, we aimed to investigate the different cell cycle mechanisms in both p53 wild-typed MCF7 and p53 mutant-typed MCF7-ADR by suppressing AHCY. We extensively proved that AHCY knockdown has an anti-proliferative effect by using the WST-1 assay, BrdU assay, and cell cytometry analysis and an anti-invasive, migration effect by wound-healing assay and trans-well analysis. Our study showed that down-regulation of AHCY effectively suppressed cell proliferation by regulating the MEK/ERK signaling pathway and through cell cycle arrests. The cell cycle arrest occurred at the G2/M checkpoint by inhibiting degradation of cyclinB1 and phosphorylation of CDC2 in MCF7 cells and at the G1 phase by inhibiting cyclinD1 and CDK6 in MCF7-ADR cells. Finally, we determined that AHCY regulates the expression of ATM kinase that phosphorylates p53 and affects to arrest of G2/M phase in MCF7 cells. The findings of this study significantly suggest that AHCY is an important regulator of cell proliferation through different mechanism in between MCF7 and MCF7-ADR cells as p53 status.     

Landscape of immune cell infiltration in clear cell renal cell carcinoma to aid immunotherapy

The tumor microenvironment, comprised of tumor cells and tumor-infiltrating immune cells, is closely associated with the clinical outcome of clear cell renal cell carcinoma (ccRCC) patients. However, the landscape of immune infiltration in ccRCC has not been fully elucidated. Herein, we applied multiple computational methods and various datasets to reveal the immune infiltrative landscape of ccRCC patients. The tumor immune infiltration (TII) levels of 525 ccRCC patients using a single-sample gene were examined and further categorized into immune infiltration subgroups. The TII score was characterized by distinct clinical traits and showed a significant divergence based on gender, grade, and stage. A high TII score was associated with the ERBB signaling pathway, the TGF-β signaling pathway, and the MTOR signaling pathway, as well as a better prognosis. Furthermore, patients with high TII scores exhibited greater sensitivity to pazopanib. The low TII score was characterized by a high immune infiltration level of CD8⁺ T cells, T follicular helper cells, and regulatory T cells (Tregs). Moreover, the immune check point genes, including CTLA-4, LAG3, PD-1, and IDO1, presented a high expression level in the low TII score group. Patients in the high TII score group demonstrated significant therapeutic advantages and clinical benefits. The findings in this study have the potential to assist in the strategic design of immunotherapeutic treatments for ccRCC.     

Characterisation of four merkel cell carcinoma adherent cell lines

We have previously described the establishment of a number of cell lines from Merkel cell carcinoma (MCC), also known as small cell cancer of the skin or neuroendocrine carcinoma of the skin. These cells, all of which grew as suspension cultures, were found to resemble small cell lung cancer (SCLC) lines types 1, 2 and 3 by their morphology and growth characteristics. We now report 4 more MCC cell lines which resemble the SCLC type 4 cell lines in that they grow as adherent monolayers. These MCC lines would belong to the variant subgroup as they no longer express most neuroendocrine markers, grow at low cell density and have population doubling times of 1–5 days in contrast to the MCC suspension lines which have doubling times of 6–12 days. MCC 14/1 and MCC 14/2 were established from the same metastatic node and would appear to represent 2 clones of the tumour which differ in morphology, histochemical markers and DNA content. We present details of the morphology, DNA content and immunohistochemistry of these 4 lines and com-pare their growth patterns with those of SCLC and MCC lines which grow in suspension. © 1995 Wiley-Liss, Inc.