Nultin-3联合顺铂对口腔鳞状细胞癌细胞的抑制作用及机制研究

目的 探讨MDM2抑制剂Nultin-3联合顺铂对口腔鳞状细胞癌Tca8113细胞的抑制作用及其机制。方法 将人口腔鳞状细胞癌Tca8113细胞分为对照组、顺铂组、Nultin-3组及Nultin-3联合顺铂组(联合组), 采用噻唑蓝(MTT)法分别检测各组Tca8113细胞处理48 h后的增殖率;采用蛋白质印迹法检测各组细胞MDM2、p53及凋亡相关蛋白Caspase-3和Caspase-9的表达。结果 联合组处理后口腔鳞状细胞癌Tca8133细胞的增殖率明显低于其它各组, 差异具有统计学意义(P＜0.05)。联合组Caspase-9、Caspase-3及p53蛋白的相对表达量明显高于顺铂组和Nultin-3组(P＜0.05);此外, 联合组MDM2蛋白的相对表达量显著低于顺铂组和Nultin-3组(P＜0.05)。结论 Nultin-3联合顺铂作用于口腔鳞癌细胞Tca8113时具有协同增效作用。Nultin-3通过调控MDM2-p53信号通路并上调促凋亡蛋白Caspase-9及Caspase-3的表达水平, 以达到增强顺铂抑制口腔鳞状细胞癌的作用, 从而为相关临床研究及治疗提供坚实的理论基础。     

细胞色素c 介导的半胱天冬氨酸蛋白酶-3活性改变与人卵巢癌顺铂耐药的关系

目的：探讨人卵巢癌顺铂耐药细胞株A2780／DDP、COC1／DDP中抗凋亡基因bcl-XL、细胞色素c的表达和半胱天冬氨酰蛋白酶－3（caspase-3)活性对人卵巢癌顺铂耐药的影响。方法：采用逆转录聚合酶链反应（RT－PCR）和Western blot检测人卵巢癌顺铂敏感细胞株A2780、COC1和顺铂耐药株A2780／DDP、COC1／DDP中bcl-XL的表达,以及顺铂作用后细胞色素c的含量和caspase-3活性的变化,并应用流式细胞仪测定顺铂作用后A2780、COC1、A2780／DDP、COC1／DDP细胞的凋亡率。结果：bcl-XL在A2780/DDP、COC1／DDP细胞中的表达明显高于A2780、COC1细胞;顺铂作用后,细胞色素c在A2780／DDP、COC1／DDP细胞中的表达明显减少,caspase-3活性和凋亡率也较A2780和COC1细胞明显降低（P＜0．05）。结论：人卵巢部细胞对顺铂产生耐药可能与细胞内bcl-XL过度表达、细胞色素c释放受抑制和caspase-3活性下降有关。     

转染PDCD5基因促进顺铂诱导前列腺癌细胞的凋亡作用

目的探讨过表达细胞程序性死亡基因5（PDCD5）对顺铂诱导人前列腺癌DU145细胞凋亡以及细胞凋亡相关蛋白表达的影响。方法CCK-8法检测顺铂处理DU145细胞后对细胞生长增殖的影响;构建稳定过表达PDCD5的DU145细胞系;Annexin V-FITC﹠PI 双染法检测细胞的凋亡率、电子显微镜观察细胞凋亡的形态学变化;Western blot法检测细胞凋亡相关蛋白的表达。结果顺铂对DU145细胞的生长有抑制作用,且呈时间-剂量依赖性;成功构建稳定过表达PDCD5的DU145细胞;流式细胞术和电子显微镜都显示PDCD5联合顺铂（25 μmol/L）促进细胞的凋亡作用比联合顺铂（10 μmol/L）和单独使用顺铂明显,Western blot结果显示,顺铂联合PDCD5能明显降低Bcl-2的表达,而Bax的表达变化不明显。结论单独PDCD5过表达不引起DU145细胞的凋亡,但PDCD5能显著增强顺铂诱导DU145细胞凋亡的作用,其机制之一是通过降低Bcl-2/Bax的表达比率实现的。     

奥沙利铂诱导人小细胞肺癌NCI-H446细胞凋亡的研究

目的:研究奥沙利铂对人肺癌细胞株NCI-H446生长抑制及诱导凋亡的作用并探讨其机制。方法:以不同浓度的奥沙利铂作用于NCI-H446细胞,应用采用噻唑蓝(MTT)法检测奥沙利铂对NCI-H446细胞生长的抑制作用。Hoechst33258荧光染色法观察细胞凋亡形态学变化;流式细胞术检测细胞周期和凋亡;分光光度法检测caspase-3、caspase-8、caspase-9的活性。结果:奥沙利铂可抑制NCI-H446细胞的生长并具有时间和剂量依赖性,Hoechst 33258荧光染色可见典型的细胞凋亡特征,流式细胞仪检测到细胞阻滞于S期和sub-G1峰。经过奥沙利铂诱导,caspase-3、caspase-9活性被上调,较对照组明显升高(P<0.05),caspase-8活性未见明显改变(P>0.05)。结论:奥沙利铂具有抑制肺癌细胞株NCI-H446增殖及诱导凋亡作用,此作用可能通过激活内源性凋亡途径实现。     

奥沙利铂诱导人小细胞肺癌NCI-H446细胞凋亡的研究

目的：研究奥沙利铂对人肺癌细胞株NCI-H446生长抑制及诱导凋亡的作用并探讨其机制。方法：以不同浓度的奥沙利铂作用于NCI-H446细胞,应用采用噻唑蓝（MTT）法检测奥沙利铂对NCI-H446细胞生长的抑制作用。Hoechst33258荧光染色法观察细胞凋亡形态学变化;流式细胞术检测细胞周期和凋亡;分光光度法检测caspase-3、caspase-8、caspase-9的活性。结果：奥沙利铂可抑制NCI-H446细胞的生长并具有时间和剂量依赖性,Hoechst 33258荧光染色可见典型的细胞凋亡特征,流式细胞仪检测到细胞阻滞于S期和sub-G1峰。经过奥沙利铂诱导,caspase-3、caspase-9活性被上调,较对照组明显升高（P〈0.05）,caspase-8活性未见明显改变（P〉0.05）。结论：奥沙利铂具有抑制肺癌细胞株NCI-H446增殖及诱导凋亡作用,此作用可能通过激活内源性凋亡途径实现。     

塞来昔布联合顺铂对人舌鳞癌Tca8113细胞移植瘤的生长抑制作用

目的:通过动物实验观察COX-2抑制剂塞菜昔布与顺铂联合应用后对人舌鳞癌Tca8113细胞移植瘤的生长抑制作用.方法:将Tca8113细胞接种于裸鼠皮下,分别给予塞来昔布、顺铂及两者联合应用,35 d后处死裸鼠,测移植瘤质量,计算抑瘤率,光镜及电镜观察移植瘤组织学变化,免疫组化染色观察COX-2蛋白的表达,RT-PCR检测COX-2 mRNA表达.结果:COX-2抑制剂塞来昔布除抑制Tca8113细胞移植瘤生长及COX-2蛋白的表达外,还显著增强顺铂对移植瘤的生长抑制作用.塞来昔布组、顺铂组及塞来昔布+顺铂组的抑瘤率分别为15.63%、37.50%和82.81%,与对照组相比差异有统计学意义,P＜0.01;塞来昔布+顺铂组与塞来昔布及顺铂单独用药组相比,其抑制移植瘤生长差异有统计学意义,P＜0.01;塞来昔布对Tca8113细胞COX-2mRNA表达的抑制作用较弱,与对照组相比差异无统计学意义,P=0.073.结论:塞来昔布除了可以抑制裸鼠移植瘤生长外,还可以增强顺铂对Tca8113细胞裸鼠移植瘤生长抑制作用,其作用机制可能与抑制COX-2蛋白的表达有关,为进一步探索抑制COX-2酶的活性与防治头颈肿瘤的作用机制方面,提供了有益的参考.     

全反式维甲酸诱导食管癌细胞凋亡的实验研究

目的探讨全反式维甲酸(ATRA)诱导食管癌EC9706细胞凋亡的作用及其机制。方法用不同浓度的ATRA处理EC9706细胞,采用四甲基偶氮唑盐(MTT)法检测ATRA对EC9706细胞的增殖抑制效应;采用流式细胞仪和原位末端标记(TUNEL)法检测细胞周期的变化和凋亡率;采用免疫组化S-P法,检测凋亡相关基因caspase-3和bcl-2的蛋白表达,并用病理图像分析软件进行半定量分析。结果ATRA对EC9706细胞有增殖抑制和诱导凋亡的作用;流式细胞仪检测显示,在G1期之前可出现Sub-G1峰,凋亡率最高为(32.6±0.4)%,并有浓度和时间依赖性;TUNEL法显示凋亡小体形成;EC9706细胞在凋亡过程中,凋亡相关基因caspase-3的蛋白表达增强,bcl-2的蛋白表达减弱。结论ATRA作用于食管癌EC9706细胞后将引起细胞凋亡的增加,这主要与ATRA能促进caspase-3的活化,并下调bcl-2的蛋白表达有关。     

咖啡酸联合顺铂对肺腺癌A549细胞增殖与凋亡的影响

目的:研究咖啡酸(caffeic acid)与化疗药物顺铂(cisplatin,DDP)联合应用对人肺腺癌A549细胞增殖及凋亡的影响,并初步探讨其可能的分子作用机制。方法:体外培养A549细胞,采用MTT法检测咖啡酸与DDP单药或联合用药对A549细胞增殖抑制率的影响;Hoechst33258染色观察细胞凋亡形态学的变化,FCM检测细胞凋亡率;蛋白质印迹法检测凋亡相关蛋白Bcl-2、Bax及caspase-3表达水平的改变。结果:咖啡酸或DDP单药或联合用药均对A549细胞有抑制细胞增殖和诱导细胞凋亡的作用,且两药联合应用具有协同作用。蛋白质印迹法检测结果表明,咖啡酸与DDP联合用药可协同抑制Bcl-2蛋白的表达,增强Bax的表达,活化caspase-3蛋白的表达。结论:咖啡酸联合DDP作用于肺腺癌A549细胞可以抑制其增殖并诱导细胞凋亡,两者联合应用有一定的协同效应。     

全反式维甲酸诱导人肝癌细胞HepG2凋亡的初步研究

[目的]研究全反式维甲酸（ATRA）体外诱导人肝癌细胞株HepG2的凋亡及其作用机制。[方法]ATRA处理HepG2细胞。MTT法分析细胞增殖反应;Hoechst染色法检测细胞凋亡情况;Western blot检测细胞中caspase-9、caspase-3和NF-κB蛋白表达情况。[结果]A-TRA可抑制HepG2细胞增殖并诱导细胞凋亡,可上调细胞中caspase-9、caspase-3表达水平（P〈0.05）。[结论]ATRA可抑制HepG2细胞增殖并诱导细胞凋亡,其作用机制可能与cas-pase-9、caspase-3表达上调有关。     

吴茱萸碱联合射线对舌鳞状细胞癌Tca-8113细胞增殖、黏附和迁移的影响

目的:探讨吴茱萸碱(evodiamine,EVO)联合射线对舌鳞状细胞癌Tca-8113细胞放射增敏、黏附和迁移的影响。方法:采用MTT比色法检测EVO对Tca-8113细胞增殖及放射增敏的影响;克隆形成实验检测EVO联合射线对Tca-8113细胞克隆形成能力的影响;细胞黏附和划痕实验检测EVO联合射线作用后细胞黏附和迁移能力的改变。结果:Tca-8113细胞的存活率随EVO作用浓度及作用时间的增加而降低,而不同放射剂量和处理不同时间后EVO+放射组的细胞存活率均显著低于单纯放射组(P<0.01)。克隆形成实验结果显示,EVO的放射增敏比(sensitizing enhancement ratio,SER)Do=1.35,SERDq=1.75,SERSF2=1.67。同质黏附实验显示,20、40和60min时单纯放射组及EVO+放射组与对照组相比,黏附细胞数显著增加(P<0.01);且在40和60min时,EVO+放射组与单纯放射组相比,黏附细胞数亦显著增加(P<0.01)。与血管内皮细胞的黏附实验显示,在20、40和60min时,EVO+放射组与单纯放射组及对照组相比,黏附率均明显下降(P<0.05)。划痕实验结果显示,EVO联合放射组的细胞迁移率显著低于对照组和单纯放射组(P<0.01)。结论:EVO对Tca-8113细胞有明显的放射增敏作用,并能改变Tca-8113细胞的黏附和迁移能力。     

白皮杉醇增强顺铂杀伤喉癌Hep-2细胞的作用及其机制

目的 探讨白皮杉醇增强顺铂对喉癌细胞的杀伤作用及其分子机制。方法 体外培养喉癌细胞Hep-2,联合使用白皮杉醇及顺铂,CCK8法检测喉癌Hep-2细胞的增殖能力,流式细胞术检测喉癌Hep-2细胞的凋亡率,Hoechst染色检测喉癌Hep-2细胞中细胞核固缩比例,蛋白印迹法检测BCL-2家族蛋白表达变化。结果 白皮杉醇在50 μmol/L时对喉癌Hep-2细胞的增殖凋亡并无显著影响。与顺铂组相比,白皮杉醇联合顺铂组细胞的增殖能力显著降低,48 h细胞吸光度值白皮杉醇联合顺铂组较顺铂组降低60%,流式细胞术检测发现48 h时,白皮杉醇联合顺铂组喉癌Hep-2细胞的凋亡率显著高于顺铂组（P<0.05）,Hoechst染色发现白皮杉醇联合顺铂组喉癌Hep-2细胞的细胞核固缩比例显著增高,差异有统计学意义。蛋白印迹检测发现,白皮杉醇可以显著下调BCL-2蛋白表达水平,上调BAX蛋白表达水平。结论 白皮杉醇可以有效增强顺铂对喉癌细胞的杀伤作用,其分子机制与白皮杉醇可以显著调控BCL-2家族蛋白表达有关。     

miR-126在口腔鳞状细胞癌组织中的表达及其临床意义

目的:检测miR-126在口腔鳞状细胞癌(oral squamous cell carcinoma,OSCC)中的表达,分析其表达与患者临床病理特征及预后的关系,探讨其过表达对Tca8113细胞恶性生物学行为的影响。方法:选取2016年6月至2018年6月在郑州大学第一附属医院手术治疗的62例OSCC患者的癌及癌旁组织标本,以及人舌鳞癌细胞株Tca8113和人口腔角质细胞株HOK,用qPCR法检测癌组织及细胞中miR-126的表达,分析miR-126表达与患者临床病理特征和预后的关系。利用脂质体转染技术,将miR-126 mimics、miR-NC质粒分别转染进Tca8113细胞,分别采用MTT法、流式细胞术及Trasnwell小室法检测细胞增殖、凋亡、迁移及侵袭能力,WB法检测凋亡、迁移和侵袭相关蛋白的表达水平。结果:miR-126在OSCC组织和Tca8113细胞中的表达水平明显低于癌旁组织和HOK细胞(均P<0.01)。miR-126表达与OSCC患者的TNM分期、淋巴结转移相关联(均P<0.05),miR-126高表达患者的总生存率显著高于低表达组(P<0.05)。转染miR-126 mimics后,Tca8113细胞的增殖、迁移及侵袭能力明显降低(P<0.05或P<0.01),凋亡率明显升高(P<0.01);细胞中Bcl-2、N-cadherin和vimentin表达水平明显降低(均P<0.01),Bax和E-cadherin表达水平明显升高(均P<0.01)。结论:miR-126在OSCC组织及Tca8113细胞中低表达,上调miR-126可抑制Tca8113细胞的增殖、迁移和侵袭能力,并促进细胞凋亡。     

All-trans-retinoic acid inhibits growth of head and neck cancer stem cells by suppression of Wnt/β-catenin pathway

Differentiation therapy is a novel approach to eradicate cancer stem cells (CSCs), including head and neck squamous carcinoma CSC (HNSC CSC). All-trans-retinoic acid (ATRA) is a potent differentiating agent. We studied the anti-tumour effect of ATRA on HNSC CSC. HNSC CSCs were differentiated by ATRA in a serum-free conditioned medium. The effect of differentiation on tumour growth was assessed in vitro and in vivo, and chemosensitisation was examined using a colorimetric viability assay. In addition, the involvement of Wnt/β-catenin signalling as an underlying mechanism of the anti-tumour effect of retinoic acid (RA) on HNSC CSCs was assessed. ATRA suppressed the expression of the stem cell markers Oct4, Sox2, Nestin and CD44 in HNSC CSCs and inhibited the proliferation of HNSC CSCs in vitro and in vivo. Furthermore, ATRA treatment augmented the chemosensitising effects of cisplatin. The anti-tumour effects of ATRA may be associated with down-regulation of Wnt/β-catenin signalling. In conclusion, ATRA may be potentially valuable in treatment of HNSC CSC, especially in combination with cisplatin.     

Docetaxel suppresses invasiveness of head and neck cancer cells in vitro

The combination of docetaxel, cisplatin, and fluorouracil significantly enhances the survival of head and neck cancer patients compared to cisplatin and fluorouracil. We hypothesized that docetaxel may affect invasiveness of the head and neck cancer cells in addition to its tumor‐killing effect. Two different head and neck cancer cell lines (HEp‐2 and Ca9‐22) were treated with docetaxel at IC₁₀ and IC₅₀ concentrations. Cell migration and invasive growth was evaluated by wound healing assay and three‐dimensional (3D) culture of multicellular tumor spheroids, respectively. Expression levels of possible downstream effectors for cell migration/invasiveness were measured by immunoblotting in conditions with or without docetaxel. Docetaxel, but not cisplatin, suppressed filopodia formation compared with no treatment (control) condition. Consistent with this, docetaxel suppressed two‐dimensional (2D) cell migration and 3D cell invasion compared with control or cisplatin. Only docetaxel treated cells exhibited thick tubulin bundle and had lower activity of Cdc42, a member of the Rho family of small GTPases. In conclusion, Docetaxel treatment suppressed migration and invasiveness of head and neck cancer cells in vitro, which is likely to be mediated by regulating Cdc42 activity. (Cancer Sci 2010; 00: 000–000)     

2-Deoxy-D-glucose combined with cisplatin enhances cytotoxicity via metabolic oxidative stress in human head and neck cancer cells

Glucose deprivation has been hypothesized to cause cytotoxicity by inducing metabolic oxidative stress in human cancer cells. The current work tests the hypothesis that 2-deoxy-d-glucose (2DG) combined with cisplatin [cis-diamminedichloroplatinum(II)] can enhance cytotoxicity in human head and neck cancer cells (FaDu) by mechanisms involving oxidative stress. Exposure of FaDu cells to the combination of 2DG and cisplatin resulted in a significant decrease in cell survival when compared with 2DG or cisplatin alone. Treatment with 2DG and cisplatin also caused perturbations in parameters indicative of oxidative stress, including decreased intracellular total glutathione and increased percentage of glutathione disulfide. Simultaneous treatment with the thiol antioxidant N-acetylcysteine (NAC) inhibited parameters indicative of oxidative stress, as well as protected FaDu cells from the cytotoxic effects of cisplatin alone and the combination of 2DG and cisplatin. In addition, polyethylene glycol-conjugated antioxidant enzymes (PEG-superoxide dismutase and PEG-catalase) also protected FaDu cells from 2DG toxicity. An inhibitor of glutathione synthesis, l-buthionine-[S,R]-sulfoximine (BSO), sensitized FaDu cells to the cytotoxic effects of 2DG and cisplatin, and these effects were inhibited by NAC. Furthermore, the combination of 2DG, cisplatin, and BSO significantly increased the percentage of glutathione disulfide, which was also inhibited by NAC. These results support the hypothesis that exposure of human head and neck cancer cells to 2DG combined with cisplatin enhances cytotoxicity via metabolic oxidative stress. These findings provide a strong biochemical rationale for evaluating inhibitors of glucose and hydroperoxide metabolism in combination with cisplatin for the treatment of head and neck cancer.     

Interon-gamma enhances the antitumor effect of all-trans retinoic acid on hepatocellular carcinoma cells by inhibiting the expression of nuclear factor-kappaB

Objective： To explore the combination effects of all-trans retinoic acid （ATRA） with interferon-gamma （IFN-γ） on human hepatocarcinoma cell line SMMC-7721 and the mechanism of action. Methods： SMMC-7721 cells were divided into treated group and control group. The cells were treated with ATRA or ATRA＋ IFN-γ in the former and added with PBS in the latter. The inhibition rate of SMMC-7721 cell proliferation was detected by MTT, the cell change in morphology was observed by electron microscope. The apoptosis was detected by flow cytometry and the expression changes of nuclear factor-kappaB （NF-κB） was analyzed by Western blotting when the SMMC-7721 cells were treated with ATRA and IFN-γ. Results： The SMMC-7721 cell proliferation was suppressed and apoptosis was induced after the cells were treated with ATRA treatment, and these effects were enhanced when ATRA was combined with IFN-γ. The expression of NF-κB was reduced after SMMC-7721 cell was treated with ATRA, and reduced significantly when the cells were treated with the combination of ATRA and IFN-γ. Conclusion： IFN-γ can enhance the inhibiting effects of ATRA on cell proliferation and inducing apoptosis on SMMC-7721 cell and these effects might be mediated by inhibiting the expression of NF-κB.     

Using attenuated Salmonella typhi as tumor targeting vector for MDR1 siRNA delivery

OBJECTIVE: To investigate the feasibility of using attenuated Salmonella typhi as an in vivo delivery vector for multidrug-resistance gene (MDR1) small interference RNA (siRNA) in a mouse model bearing human tongue squamous cell cancer. This technique may represent a novel and effective route for the in vivo administration of siRNA against malignant tumors. METHODS: The cisplatin (DDP)-resistant human tongue squamous cell carcinoma cell line Tca8113/DDP, which highly expresses the MDR1 gene, was established by exposure to gradually increasing concentrations of cisplatin. A plasmid MDR1 siRNAwas constructed and transformed into attenuated Salmonella typhi strain SL7207. Tca8113/ DDP cells were infected with recombinant salmonella and expression of the MDR1 gene encoding P-glycoprotein (P-gp) product was detected. Tca8113/DDP tumor-bearing nude mice were established by inoculation by gavage administration of recombinant salmonella and were simultaneously injected intraperitoneally with cisplatin. Tumor growth was observed. RESULTS: Recombinant salmonella-bearing MDR1 siRNA expression plasmids can infect Tca8113/DDP cells in vitro and suppress P-gp expression and reverse DDP tolerance in Tca8113/DDP cells. Oral administration of recombinant salmonella in tumor-bearing nude mice can suppress tumor proliferation and enhance the therapeutic effect of DDP. CONCLUSION: Attenuated Salmonella typhi is expected to act as an in vivo targeting delivery vector for siRNA in tumor tissues.     

Apoptosis of human pancreatic carcinoma cells induced by all-trans retinoic acid and interferon

Objective  To investigate the apoptosis of human pancreatic carcinoma PC3 cells induced by the combination of all-trans retinoic acid (ATRA) with interferon alpha (IFN-α). Methods  PC3 cells were treated with ATRA and IFN-α. The inhibitory rate of PC3 cell proliferation was detected using MTT method. Cellular apoptosis was determined with flow cytometry. The percentage of PC3 cell apoptosis was assayed using TUNEL methods. Results  ATRA and IFN-α could inhibit cellular proliferation and induces cellular apoptosis of PC3 cells. The inhibitory effect was stronger when the ATRA and IFN-α were combined as a therapy. Conclusion  ATRA inhibits the proliferation of PC3 cells and induce the apoptosis of PC3 cells. The combination of IFN-α with ATRA may enhance these effects on PC3 cells.