核糖体蛋白 S7对宫颈癌 HeLa 细胞凋亡的影响

目的：初步探讨核糖体蛋白 S7（RPS7）对宫颈癌 HeLa 细胞凋亡的影响。方法用构建的带增强绿色荧光蛋白（EGFP）报告基因的 RPS7重组表达质粒 pIRES2-EGFP-RPS7转染 HeLa 细胞作为实验组,以转染空载体 pIRES2-EGFP 的细胞作为对照组,流式细胞仪检测带绿色荧光细胞的含量, Western blotting 检测细胞中 RPS7蛋白表达;用带有荧光染料藻蓝蛋白（APC）的磷脂结合蛋白-V （Annexin-V）试剂对瞬时过表达和稳定干扰 RPS7的细胞进行染色,流式细胞仪分析细胞凋亡水平。结果在获得的瞬时过表达RPS7的 HeLa 细胞中,细胞凋亡水平明显高于转染空载体的细胞[（10．00±0．60）％∶（5．73±0．61）％],差异有统计学意义（t ＝8．63,P ＝0．001）。另一方面,抑制 RPS7表达的Sh-RPS7细胞凋亡水平低于对照细胞[（3．08±0．49）％∶（5．97±0．63）％],差异有统计学意义（t ＝6．40,P ＝0．003）。结论上调 RPS7表达具有促进 HeLa 细胞凋亡的作用,而下调 RPS7表达可抑制HeLa 细胞的凋亡。     

维生素C在肿瘤细胞代谢与凋亡中的作用

维生素C（Vitamin C,Vc）是具有许多生物学功能的水溶性已糖衍生物,在多数生物环境中以抗坏血酸的形式存在。Vc在体内氧化成脱氢Vc,并与后者形成可逆的氧化还原系统。Vc是细胞内外液中广谱的抗氧化物,在人体组织细胞代谢中具有多种重要的生理功能。     

维生素C对A549细胞增殖、凋亡及Caspase-3、Survivin表达的影响

背景与目的维生素C作为一种抗氧化剂,对多种肿瘤均有抑制作用,本研究旨在探讨维生素C对肺癌细胞株A549的增殖、凋亡的影响及其诱导A549细胞凋亡的可能机制。方法在体外培养的肺癌A549细胞株中加入不同浓度的维生素C,采用细胞生长曲线及克隆形成实验检测细胞生长情况;用流式细胞仪检测细胞周期的影响及凋亡率;用RT-PCR方法检测肺癌细胞株A549中Caspase-3、Survivin的表达差异。结果400μg/mL、4mg/mL浓度组维生素C明显抑制A549细胞的增殖,流式细胞仪检测细胞被阻止在G0/G1期及S期,且随着时间的延长细胞凋亡逐渐增多,RT-PCR检测维生素C可以上调Caspase-3mRNA的表达,并且随着时间的延长Caspase-3mRNA的表达逐渐增强,对Survivin mRNA的表达无确切作用。结论维生素C呈时间和剂量依赖性抑制A549细胞的增殖,并使A549细胞阻止在G0/G1期及S期,并呈时间依赖性诱导A549细胞凋亡,其机制可能是通过上调Caspase-3的表达。     

棉酚联合放疗诱导宫颈癌HeLa细胞凋亡的研究

目的:研究棉酚(gossypol)联合放疗对宫颈癌HeLa细胞的增殖抑制与促细胞凋亡作用,以探讨棉酚的抗肿瘤作用机制.方法:利用MTT法检测棉酚对HeLa细胞生长抑制率的影响;采用丫啶橙/溴化乙锭双染色法、FCM观察细胞凋亡形态并检测细胞凋亡率;免疫细胞化学法检测Bcl-2和Bcl-xL蛋白的表达水平.结果:棉酚对HeLa细胞增殖有明显的抑制作用,且呈剂量及时间依赖性;棉酚、放疗、棉酚联合放疗能明显诱导HeLa细胞凋亡,且棉酚联合放疗组的诱导作用明显优于2者单独处理组.棉酚、放疗和棉酚联合放疗均可降低HeLa细胞内Bcl-2和Bcl-xL蛋白的表达水平,但棉酚联合放疗组的作用弱于2者单独处理组.结论:棉酚可抑制宫颈癌HeLa细胞的增殖并诱导细胞凋亡,可能增加放疗对宫颈癌HeLa细胞的敏感性.     

维生素C阻断MNNG毒性的实验细胞模型

食管癌高发地区环境病因的研究表明亚硝胺化合物可能是人类食管癌发病因素之一。为了探讨食管癌病因预防的措施,除了降低饮用水等亚硝胺类的含量和致癌活性作用外,阻断进入体内的或体内合成的亚硝胺类对细胞的毒性也是一个重要环节。 阻断亚硝胺类的毒性研究,以往以整体动物实验肿瘤为主要对象,而近年来,研究正迅速地转向细胞水平。建立维生素C阻断或亚阻断亚硝基胍(N-Metyl-N' -ntro-N-nitrosoguanidine,MNNG)毒性的实验细胞学研究模型,目的在于筛选阻断致癌物毒性的非细胞毒性药物,并为食管癌高发区的病     

NF-κB诱捕ODN促进宫颈癌HeLa细胞凋亡的实验研究

目的 探讨NF-κB在正常宫颈组织、宫颈上皮内瘤变组织以及宫颈癌组织中的表达情况以及NF-κB诱捕ODN对宫颈癌HeLa细胞增殖、凋亡的影响。方法 选取2013年2月至2014年2月南京医科大学第二附属医院妇产科收治的42例宫颈癌患者,以及同期诊治的宫颈上皮内瘤样病变患者22例、正常宫颈组织12例,进行免疫组织化学检测NF-κB信号激活情况;在体外培养的宫颈癌HeLa细胞株中,分别转染NF-κB特异诱捕ODN和错义ODN,使用MTT和流式细胞技术检测细胞增殖、凋亡情况。结果宫颈癌组织中NF-κB的表达明显增加;使用NF-κB诱捕ODN阻断NF-κB信号激活能够显著抑制宫颈癌HeLa细胞增殖,并增强顺铂诱导的细胞凋亡。结论 NF-κB诱捕ODN可以通过阻断NF-κB信号活化,从而抑制细胞增殖并增强顺铂诱导的细胞凋亡,为宫颈癌治疗提供了新的作用靶点和治疗方向。     

Bax-Bcl-2异源二聚体与胃癌细胞凋亡的关系

目的：明确Bax-Bcl-2异源二聚体与NSAIDs诱导胃癌细胞凋亡的关系。方法：以NSAIDs诱导胃癌细胞凋亡,并通过丫啶橙(AO)染色、共聚焦显微镜、流式细胞术、TUNEL法加以证实。应用Western blot方法检测Bax、Bcl-2蛋白的表达,应用免疫沉淀-蛋白印迹法检测Bax-Bcl-2异源二聚体水平的改变。结果：NSAIDs药物吲哚美辛(indomethacin,indo)800 mmol/L和阿司匹林(aspirin,Asp)8 mmol/L作用24 h后,AGS细胞发生显著的凋亡(Indo 800 mmol/L作用24 h凋亡率(9．34±1．99)%,48 h(38．97±3．36)%,Asp 8 mmol/L 48 h凋亡率(17．60±3．30)%。随着药物作用时间的延长,Bax-Bcl-2异源二聚体水平逐渐增高,在6～48 h内均呈现增强趋势,Bax蛋白表达的增强在6～24 h最为明显,Bcl-2蛋白未检测到。结论：NSAIDs可诱导胃癌细胞AGS凋亡；Bax-Bcl-2异源二聚体可能具有促进细胞凋亡的作用,也可能是NSAIDs调控肿瘤细胞凋亡的一个重要作用点。     

凋亡抑制新基因Livin与宫颈癌的关系

凋亡蛋白抑制因子(IAP)是一类抑制凋亡的调节分子,其成员Livin是新发现的凋亡抑制基因,能够与内源IAP抑制剂SMAC和caspase-3、caspase-7、caspase-9结合,发挥抗细胞凋亡的作用.近年来,研究发现Livin在宫颈癌细胞及组织中高表达,而且通过检测癌细胞凋亡有助于确定宫颈癌的发生机制及其疗效评价,因此研究Livin结构与功能及作用机制对于宫颈癌的发生、发展、诊断与治疗有积极意义.     

维生素C,E和硒与肺癌关系的流行病学证据

维生素Ｃ、Ｅ和硒与肺癌关系的流行病学证据钟礼杰，高玉堂上海市肿瘤研究所流行病室（上海２０００３２）近年来，饮食与癌症的关系引起了人们的极大兴趣，大量的动物实验和流行病学研究都显示β－胡萝卜素和维生素Ｃ、Ｅ以及硒等饮食成份对一些癌症有保护作用。尽管β胡...     

Glucocorticoid receptor antagonism promotes apoptosis in solid tumor cells

Background: Resistance to antiproliferative chemotherapies remains a significant challenge in the care of patients with solid tumors. Glucocorticoids, including endogenous cortisol, have been shown to induce pro-survival pathways in epithelial tumor cells. While pro-apoptotic effects of glucocorticoid receptor (GR) antagonism have been demonstrated under select conditions, the breadth and nature of these effects have not been fully established.Materials and Methods: To guide studies in cancer patients, relacorilant, an investigational selective GR modulator (SGRM) that antagonizes cortisol activity, was assessed in various tumor types, with multiple cytotoxic combination partners, and in the presence of physiological cortisol concentrations.Results: In the MIA PaCa-2 cell line, paclitaxel-driven apoptosis was blunted by cortisol and restored by relacorilant. In the OVCAR5 cell line, relacorilant improved the efficacy of paclitaxel and the potency of platinum agents. A screen to identify optimal combination partners for relacorilant showed that microtubule-targeted agents consistently benefited from combination with relacorilant. These findings were confirmed in xenograft models, including MIA PaCa-2, HeLa, and a cholangiocarcinoma patient-derived xenograft. In vivo, tumor-cell apoptosis was increased when relacorilant was added to paclitaxel in multiple models.Conclusions: These observations support recently reported findings of clinical benefit when relacorilant is added to paclitaxel-containing therapy in patients with ovarian and pancreatic cancers and provide a new rationale for combining relacorilant with additional cytotoxic agents.     

A new anticancer compound, oblongifolin C, inhibits tumor growth and promotes apoptosis in HeLa cells through Bax activation

Oblongifolin C (OC) was identified as a potent apoptosis inducer from an herbal plant, Garcinia yunnanensis, during our previous bioassay-guided drug screening. In this study, we investigated the signaling pathways through which OC activated apoptosis in HeLa cells. We also compared the IC(50) values of OC with that of etoposide, paclitaxel and vinblastine in multiple cancer cell lines including HER2 and P-glycoprotein overexpressing cells. In addition, the in vivo antitumor effect of OC was studied in nude mice model. Our results showed that OC induced a caspase-dependent apoptosis by triggering a series of events in HeLa cells including Bax translocation, cytochrome c release, caspase-3 activation, chromosome fragmentation followed by caspase-8 activation, Bid cleavage and eventually cell death. Addition of a pan-caspase inhibitor or overexpression of an anti-apoptotic protein, Bcl-xL, prevented OC-induced cell death. Moreover, OC exhibited a wide anticancer spectrum in multiple cancer cell lines with comparable IC(50) values, regardless of the expression levels of HER2 and P-glycoprotein. In contrast, the IC(50) values of three clinical anticancer drugs, etoposide, paclitaxel and vinblastine were significantly elevated in HER2 and/or P-glycoprotein overexpressing cells. Furthermore, OC showed a similar antitumor effect but lower general toxicity than etoposide against xenografted human tumors in nude mice model. All these data suggested that OC is a promising apoptosis inducer with the potential to be developed into a clinical anticancer drug.     

新型磺酰胺类肿瘤抑制剂DHW-51诱导宫颈癌细胞HeLa凋亡的作用机制

目的从新合成的甲磺酰胺类化合物库中筛选出一种新型肿瘤抑制剂DHW-51,初步探讨DHW-51对宫颈癌细胞HeLa凋亡的影响及其作用机制。方法采用细胞增殖抑制实验检测DHW-51作用HeLa细胞12、24和48h时的细胞存活率,分为对照组和10、15、20、25、30μmol/L实验组共6组;流式细胞术检测不同浓度DHW-51诱导HeLa细胞的凋亡率及细胞周期;检测细胞内Caspase 3、Caspase 8和Caspase 9活性及细胞凋亡相关蛋白pro-Caspase 3、pro-Caspase8和poly ADP-ribose polymerase-DNA修复酶(PARP)的表达,分析DHW-51的作用机制。结果DHW-51对HeLa细胞的增殖具有良好抑制作用。当DHW-51浓度为25μmol/L作用时间为24h时,HeLa细胞的存活率仅为(27.34±1.891)%,与对照组相比差异有统计学意义,F=1.369,P<0.001;随着浓度增加,作用时间延长细胞存活率更低。DHW-51能够有效诱导HeLa细胞凋亡,呈浓度和时间依赖关系;当DHW-51浓度为25μmol/L作用时间为24h时,细胞凋亡率为(92.10±1.683)%,与对照组相比差异有统计学意义,t=43.715,P<0.001;随着时间的延长,晚期凋亡的比例逐步增加,而对细胞周期则没有影响。当DHW-51浓度为20μmol/L时,Caspase 3[(1.87±0.063)%,t=12.43,P<0.001]和Caspase 9[(2.0±0.069)%,t=9.519,P<0.05]的活性增加,与对照组相比,差异有统计学意义;Caspase 8的活性无变化。蛋白质印迹结果显示,当DHW-51浓度为20μmol/L时,pro-Caspase 3[(0.33±0.005)%,t=-89.334,P<0.001]和pro-Caspase 9[(0.19±0.009)%,t=-48.308,P<0.001]蛋白表达量下调,pro-Caspase 8蛋白表达无变化,PARP[(0.35±0.012)%,t=14.961,P<0.001]出现断裂带。结论新型磺酰胺类化合物DHW-51可以诱导宫颈癌HeLa细胞凋亡。作用机制初步推测主要是通过由线粒体介导的Caspase依赖途径诱导HeLa细胞凋亡,进而实现抑制肿瘤细胞生长,这一过程与细胞周期阻滞无关。     

Self-renewal and solid tumor stem cells

Solid tumors arise in organs that contain stem cell populations. The tumors in these tissues consist of heterogeneous populations of cancer cells that differ markedly in their ability to proliferate and form new tumors. In both breast cancers and central nervous system tumors, cancer cells differ in their ability to form tumors. While the majority of the cancer cells have a limited ability to divide, a population of cancer stem cells that has the exclusive ability to extensively proliferate and form new tumors can be identified based on marker expression. Growing evidence suggests that pathways that regulate the self-renewal of normal stem cells are deregulated in cancer stem cells resulting in the continuous expansion of self-renewing cancer cells and tumor formation. This suggests that agents that target the defective self-renewal pathways in cancer cells might lead to improved outcomes in the treatment of these diseases.     

Enhancement of arsenic trioxide-mediated apoptosis using docosahexaenoic acid in arsenic trioxide-resistant solid tumor cells

It has been shown that the polyunsaturated fatty acid docosahexaenoic acid (DHA) can sensitize various tumor cells to reactive oxygen species (ROS)-inducing anticancer agents. Recently, we demonstrated that DHA also enhances the apoptotic effect of clinically achievable concentrations (1-2 microM) of arsenic trioxide (As2O3) in several As2O3-resistant human leukemic cell lines via a ROS-dependent mechanism. The aim of the present study was to evaluate whether this combined effect of As2O3 and DHA is also applicable to As2O3-resistant solid tumor cells. We have tested 12 different tumor cell lines, including MDA-MB-468, SK-BR-3, MCF-7 (breast cancer), ES-2, SKOV-3 (ovarian cancer), HT-29, SW-620, LS-174T (colon cancer), PC-3 (prostate cancer), HeLa (cervical cancer), PANC-1 (pancreatic cancer) and one primary melanoma cell line. With the exception of MDA-MB-468 and ES-2, all cells were resistant to treatment with either As2O3 or DHA alone. However, combined treatment with As2O3 and DHA significantly reduced viability in 7 of the 10 As2O3-resistant solid tumors tested. The cytotoxic effect of As2O3 and DHA was associated with the induction of apoptosis and a concomitant increase of intracellular lipid peroxidation products. Importantly, the combined effect of As2O3 and DHA was selectively toxic for malignant cells since no cytotoxic effect was observed in normal skin fibroblasts, human microvascular endothelial cells and peripheral blood mononuclear cells derived from healthy donors. Our data indicate that DHA may help to extend the therapeutic spectrum of As2O3 in the treatment of solid tumors since it may overcome de novo or acquired resistance to As2O3.     

Nuclear localization of Survivin renders HeLa tumor cells more sensitive to apoptosis by induction of p53 and Bax

Clinical studies have shown that nuclear expression of the inhibitor of apoptosis protein Survivin in tumor cells predicted a favorable prognosis whereas cytosolic-localized protein caused a decreased overall survival. Therefore Survivin’s subcellular localization may be important for its anti-apoptotic capacity. To address this question, we investigated localization and function of Survivin in normal human lung fibroblasts (NHLFs) and HeLa tumor cells. NHLFs of early passages expressed Survivin in the nucleus and were highly sensitive to C2 ceramide, which induces the mitochondrial apoptotic pathway. In contrast, NHLFs at higher passages relocated Survivin to the cytosol and became more resistant to C2 ceramide.

Blocking nuclear export of Survivin by leptomycin B in HeLa cells increased susceptibility to C2 ceramide. In addition, transduction of HeLa cells with Survivin fused to a nuclear localization signal augmented basal expression levels of p53 and Bax and enhanced sensitivity for intrinsic apoptosis. Those findings suggest that a predominant nuclear localization of Survivin increases the sensitivity for pro-apoptotic stimuli, whereas nuclear export enables Survivin to fulfill its inhibitor of apoptosis function. A therapeutic intervention which holds Survivin in the nucleus of tumor cells might improve cancer therapy.     

NLRP3炎症小体在槲皮素诱导宫颈癌HeLa细胞凋亡中的作用

目的:探讨槲皮素对人宫颈癌HeLa细胞增殖及凋亡的影响,并探讨其可能的机制。方法:以不同浓度槲皮素（20、40和80 μmol/L）处理HeLa细胞36 h,用噻唑蓝（MTT）法检测细胞增殖情况,流式细胞实验检测细胞凋亡情况,Western blot和实时定量PCR法检测NLRP3炎症小体的表达情况。结果:槲皮素能使HeLa细胞活力降低,差异具有统计意义（P<0.05)。流式细胞结果表明不同浓度槲皮素组均可诱导HeLa细胞凋亡,且能抑制NLRP3炎症小体相关蛋白NLRP3、ASC及Caspase-1的表达。结论:槲皮素能通过下调HeLa细胞中NLRP3炎症小体的表达发挥其促癌细胞凋亡作用。     

调节性B细胞与肿瘤免疫的关系

B细胞介导的体液免疫在肿瘤免疫系统中发挥着重要作用。研究发现,确实存在一种名为调节性B细胞（Bregs）的B淋巴细胞亚群,可与肿瘤细胞相互作用,通过分泌白细胞介素10和转化生长因子β等细胞因子,在肿瘤免疫系统中承担其特殊的调节性作用。针对Bregs的肿瘤诊断思路和治疗方法的研究也初步展开,并显示出其重要的研究价值和广阔的应用前景。