NGX6基因联用5-Fu对人结肠癌细胞凋亡的影响

目的:探讨候选抑瘤基因NGX6联用5-Fu对结肠癌细胞凋亡的影响.方法:以稳定转染并表达NGX6基因的HT-29细胞与5-Fu联用作为实验组.以PDTC与5-Fu联用的HT-29细胞作为对照组.通过EMSA检测各组结肠癌HT-29细胞核转录因子-κB(NF-κB)的激活情况,利用MTT比色法检测各组细胞增殖的情况.吖啶橙(AO)/溴化乙啶(EB)双染法显微镜观测以及PI/Annexin-V双染流式细胞仪检测各组细胞凋亡情况.结果:稳定转染并表达NGX6基因的HT-29细胞以及应用了PDTC的HT-29细胞NF-κB的激活均明显受到抑制;与5-Fu作用的HT-29细胞组比较,5-Fu联合PDTC作用于HT-29细胞后,HT-29细胞增殖受到明显抑制,5-Fu诱导HT-29细胞凋亡作用增强;与5-Fu联合PDTC作用于HT-29细胞的对照组比较,在诱导细胞凋亡以及抑制细胞增殖方面,稳定转染并表达NGX6基因的HT-29细胞与5-Fu联用组和对照组所取得一致的效果,NGX6基因增强5-Fu对HT-29细胞增殖抑制的能力及诱导HT-29细胞凋亡的能力.结论:NGX6基因抑制了肿瘤细胞NF-κB的激活,具有增强5-Fu诱导结肠癌细胞凋亡的能力,其机制可能是抑制肿瘤细胞NF-κB的激活,NGX6基因对肿瘤的治疗及预后起积极作用.     

NDGA对HT-29结肠癌细胞生长抑制及对端粒酶表达影响的研究

目的:探讨脂氧合酶抑制剂NDGA在体外对结肠癌HT-29细胞株生长抑制、诱导凋亡,并对端粒酶表达的影响进行研究.方法:应用MTT法绘制生长曲线,倒置相差显微镜观察细胞形态变化;扫描电镜观察细胞超微结构变化,观察凋亡小体;RT-PCR检测端粒酶催化活性亚单位(hTERT)表达水平变化.结果:不同浓度NDGA处理HT-29结肠癌细胞,随着药物浓度加大,细胞形态变圆,体积缩小,从瓶壁上逐步脱落,肿瘤细胞生长抑制.应用扫描电镜可见凋亡小体形成.对照组结肠癌HT-29细胞hTERT mRNA呈阳性表达,随着药物浓度上升,hTERT mRNA表达水平逐步下降.结论:NDGA对结肠癌HT-29细胞具有抑制生长、诱导凋亡作用,并且具有剂量依赖效应.端粒酶参与其诱导凋亡的过程.     

靛玉红甲肟对HT-29细胞STAT3和Bcl-2/Bax表达的影响

目的检测靛玉红甲肟（Indirubin-3’-monoxime,IRO）作用前后人结肠癌HT-29细胞转录活化因子3（STAT3）和凋亡调节基因Bcl-2/Bax表达变化,探讨IRO抑制HT-29细胞增殖的机制。方法MTT法检测不同浓度、不同作用时间IRO对HT-29细胞增殖活性的影响。RT-PCR法检测10μmol/L的IRO作用不同时间对HT-29细胞STAT3、Bcl-2和BaxmRNA表达的影响。结果IRO对HT-29细胞生长具有明显的增殖抑制作用,且表现为剂量依赖性和时间依赖性（P〈0.01）。RT-PCR检测发现,以10μmol/L的IRO处理HT-29细胞后,STAT3和Bcl-2表达显著下降,而Bax表达上升,不同时间组间差异有统计学意义（P〈0.01）。结论IRO具有抑制人结肠癌HT-29细胞增殖的作用,其机制与下调STAT3、Bcl-2表达和升高Bax表达有关。     

改变细胞膜脂肪酸组成防治大肠癌的基因治疗研究*

目的:利用脂肪酸去饱和酶基因fat- 1 改变细胞膜脂肪酸组成,进行大肠癌的基因治疗研究。方法:将fat- 1 基因插入腺病毒载体中,与骨架载体同源重组,构建腺病毒重组载体（Ad-GFP-fat1）,通过包装细胞系（293）产生的腺病毒,感染人大肠癌株HT- 29细胞。提取细胞的总RNA,以fat- 1 基因的反义mRNA 作探针,用Northern Blot检测fat- 1 基因在HT- 29细胞内的表达。以流式细胞仪对HT- 29细胞G0/G1 期、S 期、G2/M期所占比例进行检测,分析fat- 1 基因对HT- 29细胞增殖和凋亡的影响。以气相色谱分析仪分析fat- 1 基因对HT- 29细胞细胞膜n-6 PUFAs 和n-3 PUFAs 含量及n-6/n- 3PUFAs 比例的影响。将HT- 29细胞皮下接种于裸鼠右前肢腋下,建立裸鼠HT- 29大肠癌细胞皮下移植瘤模型。成瘤后进行治疗实验,经连续5 次治疗,于最后一次治疗后第3 天处死小鼠,取肿瘤称重。分析fat- 1 基因裸鼠体内抗肿瘤效果。结果:通过基因重组技术,得到高滴度的含fat- 1 基因的重组病毒;腺病毒介导的fat- 1 基因能够在HT- 29细胞中有效表达;fat- 1 基因的表达可降低HT- 29细胞膜n-6/n- 3PUFAs 的比例,有效抑制HT- 29细胞增殖,促进细胞凋亡并能抑制裸鼠移植瘤的发展。结论:fat- 1 基因的表达,可抑制HT- 29细胞的体内外增殖并诱导细胞凋亡,在大肠癌基因治疗中可能具有良好利用价值。      

二烯丙基二硫对人结肠癌HT-29细胞周期的阻滞作用

[目的]探讨二烯丙基二硫(DADS)对人结肠癌HT-29细胞周期的阻滞作用及其分子机制.[方法]应用MTF法及细胞计数法测量HT-29细胞生长抑制,流式细胞术检测细胞时相分布,免疫细胞法测定p21、C-myc、Cyclin E表达.[结果]MTT法显示,不同浓度DADS作用HT-29细胞12、24、48h后,细胞生长抑制率及细胞群体倍增时间呈浓度、时间依赖性增加.流式细胞仪分析,30、60pmol/LL DADS阻滞HT29细胞在G1期,与对照组相比,可使G1期细胞增加约2倍,而90、120μmol/L DADS显著地将细胞阻滞在G2/M期.免疫细胞化学分析表明在细胞周期阻滞的同时有p21wafl蛋白表达上调,Cyclin E、C-myc蛋白表达下降.[结论]DADS对HT-29细胞的抑制增殖作用可能与细胞周期阻滞有关,DADS对HT-29细胞周期阻滞的分子机制可能与调节p21wafl、Cyclin E、C-myc表达相关.     

白藜芦醇对结肠癌细胞生长的影响及作用机制探讨

背景与目的:探讨白藜芦醇(Rev)对结肠癌细胞系HT-29生长的影响,并结合细胞内环氧酶-2(COX-2)以及凋亡相关蛋白Bcl-2和Bax的表达情况探讨白藜芦醇的作用机制.材料与方法:分别以含有0、12.5、25、50、100 μmol/L白藜芦醇(Rev)的完全培养液培养HT-29细胞.用MTT法检测HT-29细胞生长情况,用western blot法测定细胞内COX-2的含量,用免疫细胞化学法检测细胞内凋亡相关蛋白Bel-2和Bax的表达情况. 结果:与对照组相比,Rev能够抑制HT-29细胞的生长,且呈剂量和时间依赖性.以不同浓度的Rev作用HT-29细胞48 h后发现,Rev对细胞内Bel-2的表达水平没有明显影响,但50和100 μmol/L的Rev能够明显抑制细胞内COX-2的表达,并且100 μmol/L的Rev能够明显上调细胞内Bax的表达.结论:Rev能够抑制结肠癌细胞HT-29的增殖,且具有剂量和时间依赖性,其作用与Rev能够抑制细胞内COX-2的表达以及上调Bax的表达有关.     

靛玉红甲肟对HT-29细胞增殖和凋亡的影响及机制

背景与目的:近年来有报道称靛玉红甲肟(indirubin-3'-monoxime)在体内外实验中对部分实体肿瘤细胞具有明显的抑制作用,但尚未见其对人结肠癌HT-29细胞影响的研究报道,因而本文旨在研究其对HT-29细胞增殖和凋亡的影响及其机制.方法:MTT法检测不同浓度靛玉红甲肟处理HT-29细胞后细胞的增殖活性,制作生长抑制曲线.流式细胞仪检测凋亡率,RT-PCR检测细胞凋亡抑制基因survivin和bcl-2及凋亡促进基因Bax mRNA的变化.结果:靛玉红甲肟明显的抑制HT-29的增殖,其作用表现为剂量依赖性和时间依赖性(F=11.25,P<0.01).流式细胞仪检测发现:以10 μ mol/L的靛玉红甲肟处理HT-29细胞后,其凋亡率呈时间依赖性上升(F=195.25,P<0.01).RT-PCR检测发现HT-29细胞survivin(F=78.75,P<0.01)和Box(F=87.61,P<0.01)转录上升,而bcl-2转录显著下降(F=95.82,P<0.01).结论:靛玉红甲肟对人结肠癌HT-29细胞具有明显的增殖抑制和诱导凋亡作用,其作用机制与下调bcl-2/Bax比例有关.     

RNAi沉默整合素连接激酶基因表达对结肠癌细胞HT-29增殖的影响

目的:利用RNA干扰(RNA interference,RNAi)技术,阻断结肠癌细胞系HT-29中整合素连接激酶(integrin-linked kinase,ILK)基因的表达,研究ILK基因沉默后对HT-29细胞系增殖产生的影响。方法:构建针对ILK基因的真核表达质粒pSUPER-neo-EGFP-ILK(pSNE-ILK),在脂质体介导下稳定转染人结肠癌细胞系HT-29细胞(HT-29/pSNE-ILK组),同时以无关质粒pSUPER-neo-EGFP-C(pSNE-C)转染HT-29细胞(HT-29/pSNE-C组)和未转染细胞(HT-29组)作为对照,分别应用RT-PCR技术及蛋白印迹法检测ILK mRNA及蛋白表达水平,四甲基偶氮唑盐(MTT)比色法检测细胞增殖状况。结果:稳定转染后,HT-29/pSNE-ILK组ILK mRNA及蛋白表达水平分别为0.16±0.11和0.24±0.07,HT-29/pSNE-C组分别为0.53±0.10和0.56±0.08,HT-29组分别为0.64±0.11和0.77±0.02,前组ILK mRNA及蛋白表达水平分别与后两组比较,差异均有统计学意义(P<0.05);稳定转染pSNE-ILK质粒后HT-29细胞中ILK mRNA及蛋白表达抑制率分别为69.8%和57.1%。MTT比色法检测显示,HT-29/pSNE-ILK组细胞增殖率明显下降(P<0.05)。结论:RNA干扰技术能有效抑制靶基因ILK的表达,进而可抑制结肠癌细胞系HT-29的增殖。     

盐酸普鲁卡因对人结肠癌HT-29细胞的作用及其机制

目的探讨盐酸普鲁卡因对人结肠癌HT-29细胞生长的抑制作用及其机制。方法 应用不同浓度（0~10mmol/L）盐酸普鲁卡因处理HT-29细胞,通过倒置显微镜观察细胞形态学改变、四甲基偶氮唑盐比色法（MTT）检测细胞存活率、流式细胞术（FCM）观察细胞周期变化。结果倒置显微镜观察盐酸普鲁卡因处理后的HT-29细胞呈现缩小、皱缩、空泡、脱壁等增殖变慢的形态学特征;MTT结果分析表明盐酸普鲁卡因能显著抑制HT-29细胞增殖,其抑制率呈药物浓度及时间依赖性;FCM结果显示盐酸普鲁卡因可以使HT-29细胞的G0/G1期延长,S期缩短。结论盐酸普鲁卡因能够使HT-29细胞的生长阻滞在G0/G1期,从而显著抑制HT-29细胞的增殖,并且具有剂量、时间依赖效应。     

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.     

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.