全反式维甲酸对食管癌细胞系EC109作用的研究

目的 探讨不同浓度全反式维甲酸(ATRA)对食管癌细胞系EC109的生长抑制作用及其机理.方法 不同浓度ATRA作用于细胞EC109,采用MTT法检测细胞生长;通过流式细胞仪检测和DNA梯状电泳证实凋亡存在;用RT-PCR方法检测凋亡诱导过程中p53、bcl-2和bax基因表达变化.结果 ATRA呈剂量及时间依赖性抑制细胞生长;琼脂糖电泳呈现凋亡DNA梯状条带;流式细胞仪分析存在明显的凋亡峰;ATRA处理组bax和p53基因表达上调,但bcl-2基因表达下调.结论 ATRA具有抑制食管癌细胞株EC109生长作用,其机理可能是诱导细胞凋亡,其分子机制可能与bcl-2/bax和p53的表达相关.     

放射诱导胃癌细胞的凋亡及其相关基因的研究

目的观察放射诱导人胃癌细胞株SGC-7901凋亡的作用，并进一步研究bcl-2基因及家族、bax基因、p53基因在此过程中的作用。方法用不同剂量的9 MeV β线照射SGC-7901细胞，观察细胞在受照后的不同时间生长情况。电子透射电镜下观察细胞形态变化。琼脂糖凝胶电泳检测DNA条带变化。流式细胞仪检测受照前后细胞周期及凋亡率的变化。免疫细胞化学法检测受照前后bcl-2、bax、p53基因的表达水平。结果单次剂量照射后，SGC-7901细胞凋亡率与时间、剂量有相关性。在放射诱导SGC-7901细胞凋亡的过程中，bcl-2基因表达水平下降，bax基因表达水平升高，而p53基因表达水平无变化。结论放射能够诱导胃癌细胞株SGC-7901凋亡，凋亡率在72h达高峰。bcl-2及bax基因参与了放射诱导凋亡的调控。细胞凋亡主要是通过p53基因非依赖途径。     

细胞周期蛋白激酶抑制剂诱导尤文肉瘤细胞凋亡作用的机制

目的探讨小分子细胞周期蛋白激酶抑制剂flavopiridol（FP）尤文肉瘤细胞株RD-ES凋亡诱导作用及其调控机制。方法FP作用RD-ES细胞后，光学显微镜观察其形态变化，MTT法测定FP对细胞增殖的抑制率；流式细胞仪检测细胞凋亡；Western blot检测bcl-2，bax，mcl-l和caspase-8的蛋白表达变化。结果MTT实验显示FP对尤文肉瘤RD-ES细胞增殖有抑制作用，其抑制效应具有时间及浓度依赖的特点，流式细胞计数分析表明FP可诱导细胞凋亡，免疫印迹检测显示FP对bcl-2及bax的表达无影响，但细胞凋亡抑制基因mcl-1活性型caspase-8的表达被上调。结论FP可诱导尤文肉瘤细胞株凋亡，其作用不依赖于bcl-2基因的变化，mcl-1基因表达的抑制及caspase-8路径的激活可能为其机制之一。     

宫颈癌放疗前后肿瘤细胞凋亡及其相关基因的变化

目的:探讨宫颈癌组织放疗前后肿瘤细胞凋亡及凋亡调节基因p53、bcl-2和bax蛋白表达的变化及意义.方法:选择未经治疗的宫颈癌患者20例为试验对象,采集放疗前和放疗10Gy后宫颈癌组织标本,用原位DNA切口末端标记(TUNEL)法检测凋亡细胞;单克隆抗体免疫组化SABC法检测细胞凋亡相关基因p53、bcl-2和bax的蛋白表达水平.结果:1)在宫颈癌放疗前后,肿瘤细胞凋亡阳性率和平均凋亡指数分别为25.00%和0.11%、75.00%和3.40%,放疗前后有显著性差异(P＜0.01);2)放疗前肿瘤细胞凋亡相关基因p53、bax和bcl-2蛋白表达阳性率分别为55%、10%和20%,而放疗后分别为25%、60%和25%,放疗后p53蛋白表达减少,bax蛋白明显增加,bcl-2蛋白无明显变化.结论:放射治疗诱导宫颈癌肿瘤细胞凋亡,可能与凋亡调节基因bax基因表达的诱导密切相关.     

白藜芦醇对胃癌细胞系SGC-7901细胞增殖和凋亡作用的实验研究

目的:研究白藜芦醇(resveratrol, Res)影响人胃癌细胞SGC-7901增殖及凋亡的机制.方法:使用不同浓度Res处理SGC-7901细胞不同时间后,采用MTT法测定肿瘤细胞生长抑制率;FCM和TUNEL法检测分析细胞周期和细胞凋亡率;免疫细胞化学法检测细胞中bcl-2、bax、caspase-3和Fas蛋白的表达;RT-PCR检测Fas、bcl-2、bax、caspase-3 mRNA的表达.结果:Res对胃癌SGC-7901细胞的生长抑制作用随着Res作用时间的延长和浓度的增加而明显增强(P<0.01,P<0.05),同时能诱导其发生凋亡(P<0.01);Res(150 μmol/L)能明显上调SGC-7901细胞中bax、caspase-3、Fas mRNA及其蛋白的表达,下调bcl-2 mRNA及其蛋白的表达.结论:Res抑制SGC-7901细胞的增殖、诱导细胞凋亡呈浓度、时间依赖性;这可能与Res上调肿瘤细胞Fas、bax和caspase-3的表达及下调bcl-2的表达有关.     

bcl-2、bax和p53在鼻咽鳞癌中的表达及其与瘤细胞凋亡的关系

目的探讨bcl-2、bax和p53在鼻咽鳞癌中的表达及其与瘤细胞凋亡指数的关系。方法用免疫组织化学SP法检测48例鼻咽鳞癌中bcl-2、bax和p53的表达,用TUNEL法检测鼻咽鳞癌细胞的凋亡指数。结果48例鼻咽鳞癌中bcl-2、bax和p53阳性率分别为85.00%(41/48)、68.00%(33/48)和77.00%(37/48)。48例鼻咽鳞癌细胞的平均凋亡指数为25.62±25.78/HPF,凋亡指数与bcl-2、bax和p53的表达无相关性。结论鼻咽鳞癌中bcl-2和bax均呈高表达且已达到相对平衡,推测它们可能并不起到介导瘤细胞凋亡的主导作用。鼻咽鳞癌中p53的过表达可能已经失去了对bcl-2和bax表达的调节进而影响细胞凋亡的功能。     

腺病毒介导的IL-24对人大细胞肺癌NCI-H460细胞的体外抑制效应

目的研究腺病毒介导的IL-24基因表达对NCI-H460肺癌细胞抑癌增效作用及分子机制。方法将Ad-IL-24重组腺病毒感染NCI-H460细胞。以Western blot法鉴定IL-24基因在NCI-H460细胞中的表达;MTT法检测重组腺病毒对NCI-H460细胞的生长抑制作用;经Annexin-V-PE/7-AAD染色后流式细胞术（FCM）检测细胞凋亡率变化;RT-PCR检测NCI-H460细胞中bax、caspase-3、bcl-2、survivin等因子的表达。结果腺病毒介导的IL-24基因在NCI-H460细胞中能够有效表达;Ad-IL-24组对NCI-H460细胞的生长具有明显的抑制作用, Ad-IL-24能够上调bax、caspase-3等因子的表达,下调bcl-2、survivin等因子的表达,诱导细胞凋亡。结论腺病毒介导的IL-24 基因在体外可明显抑制人肺癌细胞NCI-H460的生长,诱导其凋亡,其分子机制可能与上调bax、caspase-3等促凋亡因子的表达,下调bcl-2、survivin等凋亡抑制因子的表达有关。     

p53基因诱导胱癌细胞HTB9凋亡及相关基因的表达

目的 研究野生型p53基因诱导膀胱癌细胞凋亡的作用,及其对凋亡相关基因bcl-2、bax和ICE表达的调控。方法 将野生型p53基因重组腺病毒载体转染人膀胱癌细胞HTB9,应用RT－PCR检测bax的mRNA表达水平,应用免疫组化法检测bcl-2、bax和ICE蛋白表达水平,以DNA琼脂糖凝胶电泳、脱氧核苷酸转移酶介导的dUTP切口末端标记技术（TUNEL）和流式细胞仪检测细胞凋亡。结果 野生型p53基因导入可诱导HTB9细胞凋亡,凋亡细胞百分率可达50．4％;bax mRNA和蛋白水平增高,ICE和Bcl-2蛋白水平分别增高和下降。结论 野生型p53基因很可能是通过调控凋亡相关基因ICE、Bax和Bcl-2的表达来诱导细胞凋亡。     

顺铂对宫颈癌HeLa细胞端粒酶活性和凋亡及p53和bcl-2 表达的影响

目的观察顺铂对 HeLa 细胞端粒酶活性、凋亡及其 p53、bcl-2 表达的影响,以揭示顺铂抗宫颈癌的机理.方法运用体外细胞培养技术,以不同浓度的顺铂作用于培养的 HeLa 细胞 72 h,通过端粒酶重复序列扩增-酶联免疫吸附法(TRAP-ELISA)检测细胞端粒酶活性,以及流式细胞术观察细胞凋亡及 p53、bcl-2 的表达.结果顺铂能以浓度依赖方式下调端粒酶活性并诱导细胞凋亡,使其 bcl-2 基因的表达显著降低,而 p53 基因的表达则增强.端粒酶活性下调与细胞凋亡及其 p53、bcl-2 基因表达紧密相关,P＜0.01.结论顺铂能下调端粒酶活性,诱导细胞凋亡,使 bcl-2 表达降低和 p53 表达增强,这可能是顺铂抗癌作用的重要机制之一.     

VES诱导的人口腔鳞癌Tca 8113细胞凋亡作用机制的初步研究

目的：明确维生素E琥珀酸酯（vitamin E succinate，VES）诱导的人口腔鳞癌Tea8113细胞的凋亡作用，初步探讨其凋亡机制。方法：PI单染色和Annexin V-PI双染色后，流式细胞术检测VES对细胞周期的影响及细胞凋亡率；RT-PCR、western blot法检测促凋亡基因bax在mRNA水平和蛋白水平上的表达。结果：VES能显著抑制Tea8113细胞的生长，诱导出现典型的凋亡峰，bax基因及蛋白表达上调。结论：VES能诱导口腔鳞癌细胞Tca8113的凋亡，该作用可能与bax基因表达上调有关。     

靶向survivin利用RNA干扰技术影响云南个旧肺鳞癌细胞株YTMLC凋亡的初步研究

 目的检测云南个旧肺鳞癌细胞株YTMLC细胞内源凋亡抑制因子survivin基因的表达以及促进YTMLC细胞凋亡的情况。方法构建和转染重组质粒pshRNA-survivin-1和pshRNA-survivin-2至YTMLC细胞株,通过免疫荧光和半定量RT-PCR检测survivin蛋白表达及mRNA转录水平的变化,并通过流式细胞仪使用PI-AnnexinV双染法检测YTMLC细胞株的凋亡。结果构建的2种重组质粒pshRNA-survivin-1和pshRNA-survivin-2均能明显抑制survivin基因的表达;应用免疫荧光检测survivin基因的表达,转染重组质粒pshRNA-survivin-1和pshRNA-survivin-2的实验组survivin荧光强度明显低于转染空载体pGE-1和pshRNA-negative非特异对照质粒;通过半定量RT-PCR检测到sur-vivin基因mRNA转录明显减少,抑制率为80.60%和70.09%;通过PI-AnnexinV双染法检测YTMLC细胞的凋亡分别达(33.42±2.42)%(P<0.01)和(20.09±1.32)%(P<0.01)。结论重组...     

Recombinant adenoviruses expressing TRAIL demonstrate antitumor effects on non-small cell lung cancer (NSCLC)

INTRODUCTION: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in a variety of malignant cells, but not in normal cells. This preferential toxicity to the abnormal cells renders TRAIL potentially a very powerful therapeutic weapon against cancer. However, a requirement for large quantities of TRAIL to suppress tumor growth in vivo is one of the major factors that has hindered it from being widely applied clinically. To overcome this, we constructed a replication-deficient adenovirus that carries a human full-length TRAIL gene (Ad-TRAIL) and tested its efficacy against a lung cancer model system in comparison to that of the recombinant soluble TRAIL protein. METHODS: To investigate the antitumor activity and therapeutic value of the Ad-TRAIL on the non-small cell lung cancer (NSCLC), four NSCLC cell lines, namely, YTMLC, GLC, A549, and H460 cells, were used. TRAIL protein expression was determined by Western blotting and flow cytometry. Cell viability was analyzed by proliferation assay, and DNA ladder and cell-cycle analysis were used to identify apoptosis. To further evaluate the effect of Ad-TRAIL in vivo, YTMLC cells were inoculated to the subcutis of nude mice. The Ad-TRAIL was subsequently administered into the established tumors. Tumor growth and the TRAIL toxicity were evaluated after treatment. RESULTS: YTMLC cells infected with Ad-TRAIL showed decreased cell viability and a higher percentage of apoptosis. Similar, Ad-TRAIL treatment also significantly suppressed tumor growth in vivo. CONCLUSIONS: TRAIL gene therapy provides a promising therapy for the treatment of NSCLC.     

Flavone inhibition of tumor growth via apoptosis in vitro and in vivo

Colorectal carcinoma is a human malignant tumor, which is very resistant to currently available methods of treatment. Therefore, developing an effective agent with anti-colorectal carcinoma activity is important. In the present study, 8 structurally related flavones including flavone, 3-OH flavone, 5-OH flavone, 7-OH flavone, quercetin, kaempferol, quercetin, and morin were used to study their effects on colorectal carcinoma cells (HT29, COLO205, COLO320-HSR). Results of MTT assay indicated that flavone shows the most potent cytoxic effect among them on these three cell types. The cytotoxicity induced by flavone is mediated by inducing the occurrence of apoptosis characterized by the appearance of DNA ladders, apoptotic bodies and hypodiploid cells. Activation of caspase 3 protein procession and enzyme activity with inducing cleavage of caspase 3 substrates PARP was identified in flavone-treated cells, and an inhibitory peptide Ac-DEVD-FMK for caspase 3, but not Ac-YVAD-FMK for caspase 1, attenuates the cytotoxic effect of flavone in COLO205 and HT29 cells. Elevation of p21 but no p53 protein was observed in flavone-treated cells. Increasing intracellular peroxide level was detected in flavone-treated cells by DCHF-DA assay, and antioxidants such as tiron, catalase, SOD, PDTC, but not DPI, suppress flavone-induced cytotoxic effect. In vivo anti-tumor study indicates that flavone exhibits ability to inhibit tumor formation elicited by s.c. injection of COLO205 cells in nude mice, and apoptotic cells and an increase in p21, but not p53, protein were observed in tumor tissues derived from flavone-treated group. Additionally, flavone induced apoptosis in primary colon carcinoma cells COLO205-X with appearance of DNA ladders, caspase 3 protein procession, PARP protein cleavage, and an increase in p21 (not p53) protein. These data provide evidence to suggest that flavone is an effective agent to induce apoptosis in colorectal carcinoma cells in vitro and in vivo; activation of caspase 3, ROS production, and increasing p21 protein are involved.     

黄芩提取物抗卵巢癌的体外活性研究

目的：研究从黄芩中提取获得的化合物黄芩黄酮Ａ抑制卵巢癌Ａ２７８０细胞生长及对常用抗肿瘤药的体外增效作用。方法：ＭＴＴ法测定黄芩黄酮Ａ的细胞毒作用及与多种抗癌药物作用后对卵巢癌Ａ２７８０细胞的抑制作用,集落形成实验观察药物的锈导分化作用,ＰＣＲ－ＥＬＩＳＡ试剂盒测定细胞端粒酶活性。     

3-OH flavone inhibition of epidermal growth factor-induced proliferaton through blocking prostaglandin E2 production

Epidermal growth factor (EGF) has been shown to induce proliferation in cells, however, the role of prostaglandin E(2) (PGE(2)) plays in EGF-induced proliferation in still unclear. EGF and PGE(2) showed proliferation responses in epidermoid carcinoma cell A431 by MTT and [(3)H] thymidine incorporation assay. Activation of the EGF receptor and extracellular signal-regulated protein kinases (ERK1/2), but not p38 and JNK, appeared 10 min after EGF treatment, whereas total amounts of ERK1/2, p38 and JNK remained unchanged in A431 cells, accompanied by induction of COX-2 and PGE(2) production. PD98059, a specific ERK1/2 inhibitor, inhibited EGF-induced proliferation with concomitant decreases in ERK1/2 phosphorylation and COX-2/PGE(2) induction. Non-steroid anti-inflammatory drugs (NSAIDs) such as aspirin and diclofenac, a COX activity inhibitor, inhibited EGF-induced proliferation by blocking PGE(2) production. The addition of PGE(2) reversed the inhibitory effects of PD98059, aspirin, and diclofenac on EGF-induced proliferation. This suggests that COX-2/PGE(2) activation involves in EGF-induced proliferation and locates at the downstream of ERK1/2 activation. Furthermore, the natural product, 3-OH flavone, showed the most-potent inhibitory activity on EGF-induced proliferation among 9 structurally-related compounds, and suppression of EGF receptor phosphorylation, ERK1/2 phosphorylation, and COX-2/PGE(2) production by 3-OH flavone was identified. PGE(2) addition attenuates the inhibitory activity of 3-OH flavone on EGF-induced proliferation by MTT assay and colony formation by soft agar assay. Additionally, 3-OH flavone also showed more-specific inhibition on EGF- than on fetal bovine serum (FBS)-induced proliferation in A431 cells. Results of our present study provide evidence to demonstrate that PGE(2) is an important downstream molecule in EGF-induced proliferation, and 3-OH flavone, which inhibits PGE(2) production by blocking MAPK cascade, might reserve potential for development as an anti-cancer drug.     

Enhancement of natural killer activity in human peripheral blood by flavone acetic acid

Natural killer cell activity and interferon (IFN) production were measured in 6 patients receiving flavone acetic acid for treatment of cancer. Natural killer cell activity was significantly increased in 3 of 6 patients receiving 6.4 g of flavone acetic acid/m2 by 3-hour iv infusion. Analysis of cell surface markers failed to reveal significant changes in any cell population. There was no evidence of induction of IFN-gamma, but 3 of 4 patients tested had evidence of induction of type I IFN, as measured in a virus neutralization assay.     

全反式维甲酸对甲状腺癌细胞NIS基因表达及吸碘能力影响的实验研究

目的：探讨全反式维甲酸（ATRA）对甲状腺癌细胞株钠/碘同向转运体（NIS）基因表达、吸碘能力的影响,为ATRA用于放射性碘治疗甲状腺癌提供理论依据。方法：分别以不同浓度（10^-7mol/L、10^-6mol/L、10^-5mol/L、10^-4mol/L）的ATRA处理体外培养的甲状腺癌细胞株（FTC-133）,48h后利用半定量RT-PCR检测细胞NISmRNA表达,γ-计数仪检测细胞吸碘能力。结果：ARTA浓度在（0～10%-5）mol/L范围内,细胞NIS基因表达及吸碘能力随ARTA剂量的增加而增加（P〈0.05）。当ARTA浓度达10%-4mol/L时,增加与前一浓度相比无统计学意义（P〉0.05）。结论：ATRA可上调甲状腺癌FTC-133细胞NIS基因表达,增强其吸碘能力,而且这种作用在一定浓度范围内具有剂量依赖性。