Inhibition of Cell Proliferation and Induction of Apoptosis During Azoxymethane Induced Colon Carcinogenesis by Black Tea

Tea (Camellia sinensis) is one of the most popular beverages, consumed worldwide. The health promotingproperties of tea have been attributed to its antioxidative polyphenolic constituents and their oxidative products.The aim of the present study was to evaluate the chemopreventive efficacy of a black tea infusion on azoxymethaneinduced colonic preneoplastic lesions, the aberrant crypt foci in Sprague-Dawley rats. Rats were injected withazoxymethane (15mg/kg.b.w.) and received oral administration of 1% and 2% (w/v) tea infusions from the 1st day ofcarcinogen application. The treatment was continued for 12 weeks. The colons were then assessed for aberrant cryptfoci and compared with the untreated carcinogen control group. In situ cell proliferation and in situ apoptosis werealso estimated using Brdu incorporation and the TUNEL method, respectively. Aberrant crypt foci were reducedsignificantly (by 44% in the 1% tea-treated and by about 40% in 2% tea-treated group). Significant decrease inproliferation and increase in apoptosis suggest a possible interplay between the two processes resulting in inhibitionof colon carcinogenesis by black tea.     

阻断mTOR表达对结肠癌LoVo细胞增殖的影响及机制

目的观察RNA干扰(RNAi)特异性阻断哺乳动物雷帕霉素靶蛋白(mTOR)基因表达对结肠癌LoVo细胞体内外增殖的影响及机制。方法实验分3组：正常培养组：未转染的正常培养LoVo细胞;阳性实验组：转染mTOR-RNA干扰质粒的LoVo细胞;阴性对照组：转染空载体质粒的LoVo细胞。MTT法检测LoVo细胞体外生长曲线;平板克隆形成试验分析细胞克隆形成能力;流式细胞仪检测细胞周期和凋亡;高效液相色谱法(HPLC)测定细胞内三磷酸腺苷(ATP)含量。结果阳性实验组细胞生长速度较正常对照组减慢。正常培养组、阳性实验组和阴性对照组细胞克隆形成率分别为(26.8±4.9)%、(11.8±2.1)%和(21.3±4.7)%;与正常培养组比较,阳性实验组细胞克隆形成率显著减少(P<0.01)。与正常培养组相比,阳性实验组G₁期细胞数增加8.6%,S期的细胞数减少8.0%,细胞凋亡率增加7.0%(均P<0.01)。正常培养组、阳性实验组和阴性对照组细胞内ATP含量分别为（2.47±0.20）nmol/106 、（1.62±0.18）nmol/106和（2.37±0.21）nmol/106;阳性实验组ATP含量明显低于正常培养组(P<0.01)。结论特异性阻断mTOR基因表达可通过遏制能量代谢和诱导细胞凋亡来抑制结肠癌LoVo细胞增殖。     

金属硫蛋白对人宫颈癌细胞增殖和凋亡的影响

 目的 探讨金属硫蛋白（metallothionein，MT）对人宫颈癌细胞HeLa增殖和凋亡的影响并初步分析其机制。方法 以不同浓度的MT（0．001、0．01、0．1和1ng／m1）干预HeLa细胞，MTT法测定其对细胞 增殖的促进作用，流式细胞仪分析凋亡率，免疫细胞化学法和RT-PIER法测定p53和PCNA的表达。结果 （1）MT对HeLa细胞增殖表现出浓度依赖性的促进作用，以1ng／ml时作用最明显（P〈0．05）。（2）MT可抑制细胞凋亡，其浓度为0、0．01和1ng／ml时，凋亡指数（AJ）分别为（6．35±1．08）％、（4．45±0．95）％和（2．15±0．77）％。（3）MT作用后细胞p53表达显著减弱，PCNA表达显著增强，两者均呈浓度依赖性。结论 MT对人宫颈癌HeLa细胞具有显著地促进增殖和抑制凋亡作用，其机制可能与抑制p53基因表达有关。     

RNAi沉默GTPBP4基因对结肠癌RKO细胞增殖及凋亡的影响

 目的 探讨GTPBP4基因沉默后,RKO细胞增殖和凋亡等生物学行为的改变。方法 将慢病毒GTPBP4-siRNA及CON053阴性病毒转染结肠癌RKO细胞株,以Real-time PCR 和Western blot检测敲减效率。Cellomics细胞计数检测细胞生长,MTT法检测细胞增殖,FACS法进行细胞周期检测,并进行细胞克隆形成实验,AnnexinⅤ-APC单染法流式细胞仪检测细胞凋亡。 结果 慢病毒成功感染RKO细胞,mRNA和蛋白检测均显示GTPBP4基因敲减成功。GTPBP4基因敲减后,RKO细胞增殖速率受到显著抑制,MTT值比值（即增殖倍数）减小,G_0/1、G₂/M期细胞显著增多,S期明显减少,细胞克隆集落数目减少,凋亡峰值明显高于对照组,且峰值出现时间早于对照组。 结论 GTPBP4基因可能通过促进肿瘤细胞增殖、抑制凋亡而影响结肠癌的发生发展。     

Early Alterations of Apoptosis and Cell Proliferation in Azoxymethane-initiated Rat Colonic Epithelium

Alterations of apoptosis and cell proliferation in the colonic epithelium of rats after exposure to azoxymethane (AOM) were estimated by means of the terminal deoxynucleotidyl transferasemediated dUTP-biotin nick end labeling (TUNEL) method, measurement of 5-bromo-2'-deoxyuridine (BrdU) incorporation, immunohistochemical staining for proliferating cell nuclear antigen (PCNA), and counting of raitotic cells. F344 male rats were given a single s.c. injection of AOM (15 mg/kg body weight) at 6 week of age, and killed 4 h, 8 h, 3 days, and 7 days after the AOM treatment. At 4 h after the treatment, many damaged cells were already observed in the colonic epithelium, and they were positive by TUNEL staining. At 8 h, the number of TUNEL-positive cells was largest. The reduction of DNA synthesis in the colonic epithelium, confirmed by BrdU incorporation, was not distinct in comparison with the mitotic inhibition. There was no remarkable change in PCNA labeling index, except that strong expression of PCNA was detected in many damaged cells. On the 3rd day, the appearance of cell death became infrequent and an increase of cell proliferation occurred. On the 7th day, the expression of TUNEL and the cell proliferation biomarkers were at almost normal levels. These findings suggest that AOM induces apoptosis, which is associated with synchronous inhibition of mitosis. The data also indicate that PCNA immunostaining does not reflect the true proliferation state in the early phase after AOM exposure, probably due to the occurrence of cell cycle arrest or DNA repair.     

Antioxidative and Modifying Effects of a Tropical Plant Azadirachta indica (Neem) on Azoxymethane-induced Preneoplastic Lesions in the Rat Colon

The purpose of the present study was to examine whether Neem leaf (Azadirachta indica) has short-termchemopreventive effects on endpoint preneoplastic lesions involved in rat colon carcinogenesis and might also exertantioxidative activity. Forty- two male F344 rats were randomly divided into 6 experimental groups. Groups 1 to 4were given a subcutaneous injection of azoxymethane (AOM, 20 mg/kg body weight) once a week for 2 weeks.Starting one week before the first injection of AOM, rats in groups 2 to 4 received an aqueous extract of Neem leaf(20, 100, and 250 mg/kg, respectively) by gavage 3 times per week, for 5 weeks. Rats in group 5 also were given theNeem extract by gavage feeding 3 times per week for 5 weeks, while group 6 served as untreated controls. Theexperiment was terminated 5 weeks after the start. Dietary feeding of the Neem extract at all dose levels significantlyinhibited the induction of aberrant crypt foci (ACF) (P<0.0002), when compared to the AOM-treated group (group1). In groups 2 to 4, treatment of rats with the Neem extract also significantly decreased the proliferating cell nuclearantigen (PCNA) labeling indices (P<0.0006) of colon epithelium and ACF. Moreover, the Neem extract also showedantioxidative activity. The finding that dietary Neem has possible chemopreventive effects in the present short-termcolon carcinogenesis bioassay suggests that longer-term exposure may cause suppression of tumor development.     

TRAIL和ACNU对实验性大鼠脑胶质瘤的治疗作用

背景与目的：有研究证明体外条件下肿瘤坏死因子相关的凋亡诱导配体（tumor necrosis factor-related apoptosis inducing ligand,TRAIL）与化疗药物联合应用促进肿瘤细胞的凋亡,但体内的研究却较少报道。本研究观察TRAIL和嘧啶亚硝脲（ACNUl对实验性大鼠脑胶质瘤的治疗作用．并进一步研究TRAIL和ACNU在其联合作用诱导细胞凋亡中影响作用的机制。方法：制备wistar大鼠C6细胞胶质瘤动物模型,10天后将动物随机分成4组：TRAIL＋ACNU治疗组（A组）、ACNU治疗组（B组）、TRAIL治疗组（C组）、生理盐水对照组（D组）：各组经治疗10天后．观察动物的生存状况．动物处死后行肿瘤大体观察、测量肿瘤的体积、计算肿瘤的抑制率;TRAILR2／DR5免疫组织化学表达变化情况：电镜观察肿瘤细胞变化;流式细胞仪检测肿瘤细胞凋亡情况。结果：A组与B组的生存状态较好．而C组与D组的生存状态差。肿瘤体积分别为A组（19．00±2．59）mm3 B组（68．76±5．56）mm3、C组（230．31±13．94）mm3、D组（238．84±10．64）mm3：A、B组与C、D组比较差异有显著性意义（P〈0．01）。A组与B组相比差异有统计学意义（P〈0．05）,C组与D组相比差异无统计学意义;电子显微镜观察,A组和B组可见明显凋亡小体．C组与D组少见一肿瘤细胞凋亡率A组（20.38±1．62）％大于B组（14．85±2．41）％,差异有统计学意义（P〈0．05）;C组（0．44±0．21）％与D组（0．35±0．24）％相比较差异尢统计学意义（P〉0．05）;A、B组与C、D组相比较差异有统计学意义（P〈0．01）。结论：ACNU引起肿瘤细胞凋亡,并可诱导大鼠脑胶质瘤细胞表达DR5．使其对TRAIL诱导的凋亡敏感,二者体内联合应用具有协同作用。     

Tspan8基因敲除联合安罗替尼对结肠癌SW480细胞增殖、迁移、侵袭和凋亡的影响

目的 探讨Tspan8基因敲除联合安罗替尼对结肠癌SW480细胞增殖、迁移、侵袭和凋亡的影响。方法 采用CRISPR/Cas9技术构建质粒并敲除SW480细胞的Tspan8基因,Western blot法检测敲除效果。采用MTT法计算安罗替尼的半数抑制浓度（IC₅₀）。实验分为对照组、安罗替尼组、Tspan8敲除组和联合组。采用细胞增殖实验、克隆形成实验、划痕实验、Transwell小室法和流式细胞术检测各组细胞的增殖、迁移、侵袭和凋亡情况;Western blot法检测安罗替尼对SW480细胞中Tspan8表达水平的影响。结果 在Tspan8敲除组中,SW480-KO-Ⅲ细胞的敲除效率最高,用于后续实验。不同浓度的安罗替尼在不同作用时间均能抑制SW480细胞的增殖（P<0.01）,且呈浓度依赖性和时间依赖性（P<0.01）,根据IC50选择14 μmol/L为后续实验浓度。与对照组相比,安罗替尼组、Tspan8敲除组和联合组的细胞增殖、迁移及侵袭能力显著降低,细胞凋亡水平明显提高（P<0.05）,且联合组的上述变化较安罗替尼组或Tspan8敲除组更为显著（P<0.05）。与对照组相比,安罗替尼组SW480细胞的Tspan8表达水平明显下降（P<0.01）。结论 Tspan8基因敲除联合安罗替尼能协同抑制SW480细胞增殖、迁移、侵袭,并促进其凋亡。     

番茄红素对人肝癌细胞增殖和凋亡的影响及其机制

目的 研究番茄红素对人肝癌HepG2细胞增殖和凋亡的影响及其机制.方法 取对数生长期人肝癌HepG2细胞,分别给予不同浓度番茄红素(5、10、20 μg/ml)和顺铂(40 μg/ml)进行干预,48 h后通过四甲基偶氮唑蓝(MTT)比色法测定细胞增殖抑制率,通过流式细胞术检测细胞周期和细胞凋亡状况,采用Western blotting技术检测Bax、Bcl-2、激活型Caspase-3蛋白表达.结果 干预48 h后,空白对照组人肝癌HepG2细胞增殖抑制率为0,番茄红素(5、10、20 μg/ml)组和顺铂组分别为(21.3±4.2)％、(40.5±7.6)％、(63.8±9.1)％和(37.8±5.9)％,差异有统计学意义(F=37.905,P=0.000);它们分别与空白对照组比较,差异均具有统计学意义(t=208.124,P=0.000;t=394.637,P=0.000;t=628.592,P=0.000;t =257.168,P=0.000).番茄红素(10、20μg/ml)组细胞周期G0-G1期比例分别为(54.0±2.9)％、(67.3±3.6)％,与空白对照组(37.9±1.5)％比较,差异有统计学意义(t =4.508,P=0.024;t=10.673,P=0.006);番茄红素(10、20 μg/ml)组G2-M期比例分别为(8.5±0.6)％、(4.7±0.5)％,与空白对照组比较(18.4±0.8)％,差异有统计学意义(t=9.975,P=0.008;t=13.864,P=0.003).番茄红素组(5、10、20 μg/ml)和顺铂组细胞凋亡指数分别为(19.5±4.8)％、(43.0±9.2)％、(67.6±10.1)％和(36.9±6.8)％,与空白对照组[(3.6±1.7)％]比较均显著升高,差异有统计学意义(t=18.617,P=0.001;t=34.295,P=0.000;t=51.437,P=0.000;t =29.804,P=0.000).番茄红素(10、20 μg/ml)组和顺铂组Bel-2、Bax表达及Bax/Bcl-2比值分别为0.42±0.09、0.43 ±0.14、1.02±0.39,0.27±0.08、0.76 ±0.19、2.81 ±0.85和0.34 ±0.11、0.31 ±0.09、0.91 ±0.40,与空白对照组(0.59 ±0.17、0.18 ±0.06、0.31 ±0.12)比较,Bcl-2表达显著下调,差异具有统计学意义(t=4.327,P=0.023;t=11.064,P=0.006;t =5.182,P=0.018),Bax表达显著上调,差异具有统计学意义(t=9.837,P =0.008;t=17.349,P=0.001;t=10.165,P=0.007),Bax/Bcl-2比值显著升高,差异均具有统计学意义(t=11.521,P=0.006;t=18.194,P=0.001;t=9.537,P=0.008).番茄红素(5、10、20 μg/ml)组和顺铂组激活型Caspase-3蛋白表达分别为0.25 ±0.07、0.34 ±0.11、0.46 ±0.18和0.17 ±0.05,与空白对照组(0.08±0.03)比较,差异具有统计学意义(t=8.307,P=0.009;t=13.067,P=0.006;t=16.218,P=0.003;t=5.202,P=0.019).结论 番茄红素能够通过抑制细胞增殖并促进其凋亡而对人肝癌HepG2细胞生长起到一定的抑制作用,其机制可能与番茄红素能够影响细胞周期进程并调节凋亡相关基因蛋白表达有关.     

Evaluation of Effects of Metformin in Primary Ovarian Cancer Cells

Background: Ovarian cancer is the third most common cause of cancer in Indian women. Despite an initial70-80% response rate, most patients relapse within 1-2 years and develop chemoresistance. Hence, identificationor repositioning of drugs to resensitise ovarian cancer cells to existing chemotherapy is needed. Traditionallyimmortalized cell lines have been used in research, but these may contain genetic aberrations and chromosomalabnormalities serving as poor indicators of normal cell phenotype and progression of early-stage disease. Theuse of primary cells, maintained for only short periods of time in vitro, may serve as the best representative forstudying in vivo conditions of the tissues from which they are derived. In this study we have attempted to evaluatethe effect of metformin (an antidiabetic drug) in primary ovarian cancer cells because of its promising effectin other solid tumours. Materials and Methods: Primary cultures of epithelial ovarian cancer cells establishedfrom ascitic fluid of untreated ovarian cancer patients were used. The cells were treated with metformin at dosesstandardized by MTT assay and its ability to induce apoptosis was studied. The cells were analysed for apoptosisand apoptosis related proteins by flow cytometry and western blotting respectively. Results: Metformin inducedapoptosis in ovarian cancer cells, provoking cell cycle arrest in the G0/G1 and S phase. It induced apoptosis inovarian cancer cells by, down-regulating Bcl-2 and up-regulating Bax expression. Conclusions: Metformin wasable to induce apoptosis in primary ovarian cancer cells by modulating the expression of Bcl-2 family proteins.These data are relevant to ongoing translational research efforts exploring the chemotherapeutic potential ofmetformin.     

乳腺癌中COX-2表达及其抑制剂塞来昔布对乳腺癌细胞系增生和凋亡的影响

目的为进一步观察COX-2对乳腺癌的作用,我们检测了乳腺癌组织、乳腺癌细胞株MCF-7和B37中COX-2的表达,并观察选择性COX-2抑制剂塞来昔布对乳腺癌细胞株生长和凋亡的影响。方法应用免疫组织化学染色的方法检测132例乳腺癌组织标本中COX-2蛋白的表达;应用免疫细胞化学染色、原位杂交、逆转录多聚酶联反应（RT-PCR）的方法,分别检测COX-2蛋白和mRNA在乳腺癌细胞株MCF-7、B37中的表达;采用MTT法、AO/EB双荧光染色法和流式细胞术,研究塞来昔布对乳腺癌细胞增殖和凋亡的影响。结果52.3%(69/132)的乳腺癌组织标本表达COX-2蛋白;在乳腺癌细胞株MCF-7和B37中均有COX-2的表达,25μmol/L塞来昔布作用72h后,COX-2表达明显减少;25、50、100μmol/L的塞来昔布与MCF-7细胞作用72h,生长抑制率分别为36.3%、57.7%、74.5%。100μmol/L塞来昔布作用72h后,MCF-7细胞凋亡率为38.5％。结论乳腺癌组织和乳腺癌细胞株MCF-7、B37中存在COX-2的表达;塞来昔布可抑制乳腺癌细胞增殖,并促进细胞凋亡,塞来昔布可能作为新的药物治疗乳腺癌。     

PRR11在膀胱癌组织中的表达及其对膀胱癌T24细胞增殖和凋亡的影响

目的 探讨富含脯氨酸蛋白11(PRR11)在膀胱癌组织中的表达及其基因沉默对膀胱癌T24细胞增殖和凋亡的影响.方法 采用免疫组织化学法检测57例膀胱尿路上皮癌组织及其癌旁组织中PRR11蛋白的表达,并分析PRR11蛋白表达水平与患者临床病理特征的关系.qRT-PCR和Western blot检测人永生化膀胱上皮细胞株S...     

Changes of Proliferative Activity and Phenotypes in Spontaneous Differentiation of a Colon Cancer Cell Line

We examined the alterations of proliferative activity and c-myc expression of a colon cancer cell line (Caco-2) during its spontaneous differentiation. Caco-2 cells were cultured in various types of media and the degree of differentiation was monitored in terms of dome formation in cell monolayers and expression of alkaline phosphatase (ALP) activity. In Caco-2 cells cultured with Eagle's minimum essential medium (EMEM) containing 10% fetal calf serum (FCS), dome formation was demonstrated and ALP activity was markedly increased after the cells reached confluence. Five-fold reduction of c- myc mRNA and a marked decrease in S-phase cells were observed in the differentiated cells. These changes were not induced in FCS-free EMEM. The addition of insulin and transferrin to FCS-free EMEM did not induce cell differentiation or reduction of c- myc mRNA expression. When Caco-2 cells were cultured with three different serum-free media, the induction of dome formation and the increase of ALP activity were observed to varying degrees. Expression of c- myc mRNA in the cells cultured with one serum-free medium decreased to a level similar to that in fully differentiated cells cultured with EMEM containing 10% FCS. These results suggest that a spontaneous switch from a proliferative state with high c- myc expression to differentiated phenotype occurs after cells reach confluence and depends on the culture conditions.     

神经节苷脂GM3对人宫颈癌HeLa细胞凋亡和血管内皮生长因子表达的影响

目的 研究外源性神经节苷脂GM3对人宫颈癌HeLa细胞增殖、凋亡和VEGF表达的影响.方法 不同浓度GM3干预HeLa细胞24 h后,MTT法检测细胞增殖变化,流式细胞学技术检测细胞凋亡率,RT-PCR技术检测细胞VEGF mRNA表达水平,Western blot技术检测细胞VEGF蛋白水平.结果 (1) GM3浓度分别为2、10、50和250 μmol/L时,HeLa细胞生长抑制率分别为9.8％、32.9％、50.7％和78.6％,半数抑制浓度(IC50)为49.8 μmol/L.(2) GM3浓度分别为10、50和250 μmol/L时,HeLa细胞凋亡率分别为(4.9±0.4)％、(15.1±0.3)％、(24.4±0.7)％.(3)当GM3浓度高于10 μmol/L时,HeLa细胞VEGF mRNA表达水平以及VEGF蛋白表达水平均显著下降(P＜0.05).结论 外源性神经节苷脂GM3能呈浓度依赖性抑制人宫颈癌HeLa细胞增殖,促进HeLa细胞凋亡,下调HeLa VEGF mRNA水平和蛋白水平,提示GM3可能通过调节肿瘤细胞凋亡和肿瘤血管生成而发挥双重抗肿瘤作用.     

Zeste基因增强子同源物2抑制剂GSK126体外对急性白血病和淋巴瘤细胞增殖及凋亡的影响

目的探讨Zeste基因增强子同源物2(EZH2)抑制剂GSK126体外对急性白血病和淋巴瘤细胞增殖和细胞凋亡的作用。方法采用CCK-8法测定不同浓度GSK126作用不同时间对人T淋巴细胞白血病CEM细胞、人急性单核细胞白血病U937细胞和人伯基特淋巴瘤Raji细胞增殖的影响,采用Annexin V/PI双染法测定GSK126对细胞凋亡的影响,采用实时荧光定量聚合酶链反应(qPCR)检测GSK126对EZH2、bcl-2、bcl-xL基因表达的影响。结果作用24、48、72 h后,与相应阴性对照组(0 μmol/L)比较,5、10、15、20、25 μmol/L GSK126对CEM细胞,5、10、15、20 μmol/L GSK126对U937细胞和5、10、15、20、25、30 μmol/L GSK126对Raji细胞的增殖均具有抑制作用,且呈浓度和时间依赖性(均P<0.05)。GSK126作用于CEM、U937、Raji细胞48 h的半数抑制浓度(IC50)分别为(13.46±0.83)、(11.65±1.02)、(15.00±0.19)μmol/L。与相应阴性对照组(0 μmol/L)比较,8、12、16 μmol/L GSK126均可不同程度促进CEM、U937细胞凋亡,凋亡率差异均有统计学意义(F=167.995,P<0.01;F=158.400,P<0.01);而Raji细胞,16 μmol/L GSK126较阴性对照组有更高的细胞凋亡率,差异有统计学意义(t=47.998,P<0.05)。8、12、16 μmol/L GSK126均较阴性对照组降低CEM、U937、Raji细胞EZH2 mRNA的表达水平(F=82.035,P<0.05;F=252.712,P<0.05;F=690.536,P<0.01)和凋亡相关基因bcl-2、bcl-xL mRNA的表达水平(bcl-2:F=1 900.525,P<0.01;F=431.324,P<0.01;F=216.184,P<0.01;bcl-xL:F=256.751,P<0.01;F=147.019,P<0.01;F=209.325,P<0.01)。结论 EZH2对急性白血病和淋巴瘤的发生发展有重要作用,GSK126作为EZH2高选择性小分子抑制剂之一,可为血液系统恶性肿瘤临床用药提供新的可能。     

Apatinib联合5-Fu协同抑制乳腺癌MCF-7细胞的体外研究

目的 探讨阿帕替尼(Apatinib)联合5-氟尿嘧啶(5-Fu)对乳腺癌MCF-7细胞的抑制作用.方法 采用人乳腺癌细胞株MCF-7,首先采用MTr法及应用流式细胞仪测定不同浓度apatinib作用后对其细胞增殖和周期的影响,其次将MCF-7细胞分为4组,即对照组、Apatinib单药组、5-Fu单药组、Apanitib+ 5-Fu联合组.对各组细胞给予相应药物处理,48 h后分别应用流式细胞仪检测各组药物对MCF-7细胞株凋亡的作用.结果 Apatinib单药对MCF-7细胞有增殖抑制作用,且存在时间剂量依赖关系,而对其细胞周期影响不大.与对照组相比,Apatinib联合5-Fu作用后有协同诱导凋亡作用,经流式细胞仪检测,Apatinib组诱导的细胞凋亡率为12.05％,5-Fu组为25.76％.与单药组比,Apatinib+5-Fu联合组凋亡率升高更为明显,达34.90％ (P＜ 0.05).结论 Apatinib和5-Fu的联合应用在体外协同抑制乳腺癌MCF-7细胞并诱导凋亡,使抗肿瘤活性显著增强.     

靶向survivin的siRNA抑制乳腺癌MCF-7细胞增殖并诱导其凋亡

目的 观察靶向survivin的siRNA对乳腺癌细胞增殖和凋亡的影响。方法构建靶向survivin的siRNA真核表达载体,采用Lipofectamine^TM2000转染乳腺癌细胞MCF-7,采用半定量RTPCR、免疫组化技术检测转染前后MCF-7细胞survivin基因表达的变化;采用MTT法检测对MCF-7细胞增殖的抑制作用;采用TUNEL法检测诱导MCF-7细胞凋亡的作用。结果靶向survivin的序列特异性siRNA可以高效抑制MCF-7细胞survivin基因的表达,在mRNA水平其表达抑制率为64．9％;在蛋白质水平其表达抑制率为79．7％;转染靶向survivin的siRNA真核表达载体可以显著抑制MCF-7细胞的增殖,细胞重新接种24、48h后,其增殖抑制率分别为31．6％和33．0％;转染后24h可以诱导12．9％的细胞凋亡。结论利用RNA干扰技术阻断survivin基因的表达可以显著抑制MCF-7细胞的增殖,并在一定程度上诱导其自发凋亡,靶向survivin的RNA干扰技术在乳腺癌的基因治疗中具有一定的价值。     

环氧合酶-2抑制剂对人舌鳞癌Tca8113/BLM 细胞MDR1/P-gp表达的影响

 目的 探讨环氧合酶 2抑制剂塞来昔布对人舌鳞癌耐药细胞系Tca8113/BLM细胞多药耐药基因和P-糖蛋白表达的影响。方法 采用BLM（30 μg/ml）反复24h暴露法处理人舌鳞癌细胞系Tca8113细胞,采用不同浓度的塞来昔布作用于Tca8113/BLM细胞,MTT法检测细胞增殖活性,流式细胞仪测定P-gp的表达水平,RT-PCR检测多药耐药基因mRNA的表达。结果 塞来昔布显著抑制Tca8113/BLM细胞增殖、下调Tca8113/BLM细胞MDR1基因表达,其作用呈剂量依赖关系。结论 塞来昔布以剂量依赖方式抑制人舌鳞癌耐药细胞系Tca8113/BLM细胞MD1l/P-gp表达,并抑制细胞增殖,这种作用可能与COX-2抑制剂增强抗癌药物对肿瘤细胞的杀伤作用有关。     

Expression of apoptosis and its related protein in astrocytic tumors

The relationship between malignant potential and apoptosis in astrocytic tumors has not been clearly defined, and further classification of astrocytic tumors is necessary. To elucidate the relationship between the histopathological grade of astrocytic tumors and apoptosis, we studied 25 cases of astrocytic tumors, comprising 10 cases of glioblastoma (GB), 7 cases of anaplastic astrocytoma (AA), and 8 cases of astrocytoma (AC). We detected apoptosis using the TdT-mediated dUTP-biotin nick-end labeling (TUNEL) method. We studied immunohistochemical expression of bcl-2 protein and p53 protein, which are apoptosis-related factors, and cell proliferative activity using Ki-67 antibody. No significant change was noted between apoptotic index and the histological grade of the tumors. In GB, apoptotic cell-rich foci were present at the pseudopalisading necrosis. No correlation between histopathological grades and expression of either p53 or bcl-2 was observed. In GB, however, poor distribution of bcl-2 was found in the areas of pseudopalisade formation. bcl-2 is one of the regulatory factors in the cell cycle and inhibits apoptosis. Expression of apoptosis had no correlation with histopathological grade. However, in GB, the distribution of apoptotic cells showed a correlation with bcl-2-poor foci. It was thought that apoptosis was one of the regulatory factors in the formation of pseudopalisading necrosis in GB.