3种茶提取物对MCF-7细胞增殖、凋亡的影响及其与蛋白激酶B的相关性

目的 探讨红茶、绿茶及普洱茶提取物对人乳腺癌细胞MCF-7增殖、凋亡的影响及其与蛋白激酶B(Protein ki-nase B,PKB)的相关性。方法用不同浓度的3种茶提取物处理MCF-7细胞不同时间,MTT法检测其对MCF-7细胞增殖的影响;Annexin V-FITC/PI双染流式细胞术检测其对细胞凋亡的影响;实时定量PCR检测细胞PKB基因mRNA的转录水平。结果 3种茶提取物对MCF-7细胞的增殖均具有明显的抑制作用,且呈时间、剂量依赖性;3种茶提取物处理的细胞早期凋亡率均高于未处理细胞,PKB基因mRNA的表达量明显降低。结论 3种茶提取物均含有可以抑制PKB转录活性的天然成分,并可诱导MCF-7细胞凋亡;其中绿茶诱导MCF-7细胞凋亡效果最明显。     

鱼藤素诱导乳腺癌MDA-MB-231细胞凋亡的作用与途径

目的探讨鱼藤素诱导乳腺癌MDA-MB-231细胞凋亡的作用及其与线粒体凋亡途径的关系。方法用不同浓度的鱼藤素处理MDA-MB-231细胞,MTT法检测鱼藤素对MDA-MB-231细胞的增殖抑制作用;AnnexinV-FITC/PI双染流式细胞术检测细胞的凋亡率;罗丹明123单染法观察细胞线粒体膜电位的变化;Western blot法检测细胞cyt-c、caspase-3蛋白的表达水平;分光光度法检测细胞caspase-3蛋白活性。结果鱼藤素对MDA-MB-231细胞的增殖具有明显的抑制作用,且呈时效、量效依赖性;800和1200nmol/L鱼藤素处理组的细胞早期凋亡率显著高于未处理组;鱼藤素处理后,细胞线粒体膜电位降低,细胞浆内cyt-c和caspase-3蛋白的表达水平及caspase-3活性均明显升高。结论鱼藤素对乳腺癌MDA-MB-231细胞具有显著的增殖抑制、诱导凋亡作用,其作用与线粒体膜电位降低、释放细胞色素c,从而激活caspase-3依赖途径有关。     

姜黄素对HeLa细胞增殖和凋亡的影响

目的探讨姜黄素对HeLa细胞增殖和凋亡的影响及其机制。方法分别用10、20、40μmol/L姜黄素处理HeLa细胞24h后,MTT法检测细胞的增殖,光镜观察细胞形态,TUNEL技术检测细胞的凋亡,免疫细胞化学法检测Cytochrome C和Caspase-9蛋白的表达,Western blot法检测XIAP蛋白的表达。结果姜黄素对HeLa细胞的增殖有抑制作用,并呈剂量依赖性;部分细胞呈现典型的凋亡形态学改变;姜黄素作用后,Cytochrome C和Caspase-9蛋白的表达显著增强,XIAP蛋白的表达显著下降,且均呈剂量依赖性。结论姜黄素能抑制HeLa细胞增殖并诱导其凋亡,Cytochrome C和Caspase-9的表达上调及XIAP的表达下调可能参与凋亡过程。     

肿瘤坏死因子α诱导蛋白8对宫颈癌HeLa细胞的作用及其相关机制

目的通过shRNA干扰宫颈癌HeLa细胞中肿瘤坏死因子α诱导蛋白8(tumor necrosis factor alpha induced protein 8,TNFAIP8,TIPE)的表达,分析TIPE对宫颈癌生存的影响。方法转染pCDH-shRNA-TIPE质粒至HeLa细胞株(TIPE干扰组),同时设未转染质粒的空白对照组及空载体转染的阴性对照组,qPCR和Western blot法检测TIPE的表达;加入能诱导细胞凋亡的抗人死亡受体5单链抗体(aDR5ScFv)后,CCK-8法检测细胞增殖,流式细胞术检测细胞凋亡,Western blot法检测TIPE、激活型caspase-3、激活型caspase-8和激活型caspase-9蛋白表达。结果与空白对照组相比,TIPE干扰组细胞mRNA和蛋白表达均显著降低(P 0. 05);加入aDR5ScFv后,TIPE干扰组细胞增殖抑制率和凋亡率与空白对照组和阴性对照组相比显著升高(P 0. 05)。TIPE干扰组细胞激活型caspase-3、caspase-8和caspase-9蛋白的表达显著高于空白对照组和阴性对照组(P 0. 05)。结论 HeLa细胞干扰TIPE表达产生显著调节作用,TIPE的表达降低可对caspase诱导的HeLa细胞凋亡途径产生抑制,对生物治疗新药的进一步研发具有重要意义。     

醋酸甲羟孕酮诱导结肠癌SW480细胞凋亡及其差异表达蛋白的分析

目的对醋酸甲羟孕酮(Medroxyprogesterone acetate,MPA)诱导结肠癌SW480细胞凋亡时的差异表达蛋白进行分析。方法以不同浓度(25、50、75μmol/L)的MPA作用SW480细胞24、48和72h,MTT法检测细胞增殖水平。以上述浓度的MPA作用SW480细胞48h,流式细胞术分析细胞的凋亡率及细胞周期各时相比例的变化。以50μmol/L MPA作用SW480细胞48h,透射电镜观察细胞结构的变化;应用双向电泳技术分离细胞总蛋白,PDQUEST8.0软件分析凝胶图谱,选择差异表达蛋白,以Agilent1100HPLC-Chip/MS系统进行MS/MS分析,搜索UniProtKB/SWISS-PORT,Homo Sapiens(Human)数据库筛选目标蛋白质。结果透射电镜下观察经MPA作用的SW480细胞可见明显的凋亡形态学变化;不同浓度的MPA对SW480细胞均有明显的抑制增殖和诱导凋亡作用,且呈剂量依赖性,细胞凋亡率最高可达56.15%;细胞周期分析表明,MPA诱导结肠癌细胞凋亡的作用可能与细胞周期的阻滞相关,此阻滞作用具有剂量依赖性;共鉴定出泛素、只含LIM结构域蛋白质3、热休克蛋白10、有机阴离子转运蛋白4、泛素羧基末端水解酶2、核苷二磷酸激酶-A、层黏连蛋白受体1共7种SW480细胞凋亡相关蛋白。结论 MPA具有诱导SW480细胞凋亡的作用,SW480细胞凋亡相关蛋白可能作为MPA抗结肠癌的潜在生物标志物。     

LTD蛋白体外对HeLa细胞毒性的影响

目的探讨LTD蛋白在体外对HeLa细胞毒性的影响。方法将不同浓度的LTD蛋白作用于HeLa细胞,光学显微镜下观察细胞形态等变化,MTT法检测细胞增殖情况,激光共聚焦显微镜观察蛋白在细胞内的定位,HE染色和TUNNEL试剂盒检测细胞凋亡情况。结果 LTD蛋白对HeLa细胞具有毒性作用,能抑制细胞增殖,引起细胞凋亡。随着蛋白浓度的增加及作用时间的延长,HeLa细胞凋亡现象明显,生长抑制作用增强,蛋白浓度与细胞A_(490)值之间明显相关;且LTD由定位于细胞膜变为定位于胞浆和细胞核。结论 LTD蛋白促进HeLa细胞凋亡,对其增殖具有明显的抑制作用。     

人参皂苷代谢产物CK诱导卵巢癌细胞CAOV3的凋亡机制

目的探讨人参皂苷代谢产物CK对卵巢癌细胞CAOV3的增殖抑制作用,及其诱导细胞凋亡的机制。方法采用MTT比色法测定不同浓度(0、1.0、2.5、5.0、10.0、20.0、50.0μg/ml)CK对卵巢癌细胞CAOV3增殖的抑制作用。流式细胞术检测不同浓度(0、2.5、5.0μg/ml)CK诱导CAOV3细胞凋亡的情况;4′,6-二脒基-2-苯基吲哚(4′,6-diamidino-2-phenylindole,DAPI)染色观察细胞凋亡过程中形态变化;体外Caspase活力测定凋亡相关蛋白Caspase-3、Caspase-8和Caspase-9的激活情况;Western blot分析Caspase-3底物多聚(ADP-核糖)聚合酶[Poly(ADP-ribose)polymerase,PARP]的断裂情况。结果 CK可明显抑制卵巢癌细胞CAOV3的增殖,CK浓度与其对细胞的增殖抑制作用呈剂量-效应关系,IC50值为3.6μg/ml。随着CK浓度的增加,发生凋亡的细胞数增加,出现典型的凋亡形态特征的细胞逐渐增多。Caspase-3、Caspase-8和Caspase-9均被激活。随着CK浓度的增加,酶活性增加,Caspase-3底物PARP断裂的条带逐渐加深。结论 CK对卵巢癌细胞CAOV3有毒性作用,能够抑制细胞增殖,且CK浓度与这种抑制作用呈剂量-效应关系;CK抑制CAOV3细胞的增殖作用是通过促进细胞凋亡来实现的,且这种细胞凋亡涉及内源及外源型途径。     

苏尼替尼对HeLa细胞增殖及3-磷酸甘油醛脱氢酶表达和活性的影响

目的探讨苏尼替尼(Sutent)对HeLa细胞增殖及3-磷酸甘油醛脱氢酶(Glyceraldehyde-3-phosphate dehydro-genase,GAPDH)表达和活性的影响。方法用不同浓度的Sutent作用于HeLa细胞,采用MTT法检测Sutent对HeLa细胞增殖活力的影响;Western blot检测HeLa细胞中GAPDH蛋白表达的变化;GENMED细胞GAPDH活性终点比色法定量检测了GAPDH的活力。结果经Sutent处理24 h后,HeLa细胞的增殖受到明显抑制,且呈浓度依赖性,半数抑制浓度(IC50)为10.283μmol/L;Sutent可明显降低HeLa细胞中GAPDH蛋白的表达量,并能直接抑制GAPDH的活力。结论 Sutent可抑制HeLa细胞的增殖,降低GAPDH蛋白的表达量及活力,显示了其作为多靶点药物的重要研究价值。     

南蛇藤提取物诱导SGC-7901胃癌细胞凋亡及其机制

目的观察南蛇藤乙酸乙酯提取物和正丁醇提取物在体外诱导SGC-7901胃癌细胞凋亡的作用,并初步探讨其分子机制。方法制备南蛇藤乙酸乙酯和正丁醇提取物,采用MTT法检测二者对SGC-7901胃癌细胞增殖的影响;应用FITC-AnnexinⅤ及碘化丙锭(PI)双标法,通过流式细胞仪(FCM)观察SGC-7901细胞的凋亡率及P53蛋白的表达。结果不同浓度的南蛇藤乙酸乙酯和正丁醇提取物(15、30、60、120μg/ml)对SGC-7901细胞的增殖均有一定的抑制作用,且呈剂量依赖性。两种南蛇藤提取物(60、120、240、480μg/ml)可剂量依赖性地诱导肿瘤细胞凋亡,且随着浓度的升高,SGC-7901细胞P53蛋白的表达也增加,浓度为240和480μg/ml的提取物组与对照组相比,差异有统计学意义。结论南蛇藤乙酸乙酯提取物和正丁醇提取物在体外可诱导SGC-7901细胞凋亡,上调细胞中P53基因的表达可能是其抗肿瘤作用的分子机制之一。     

过表达脑红蛋白对SH-SY5Y细胞损伤的神经保护作用及其机制

目的探讨过表达脑红蛋白(neuroglobin,NGB)对水溶性β-淀粉样蛋白片段1-42(beta-amyloid1-42,Aβ1-42)诱导的神经母细胞瘤SH-SY5Y细胞损伤的神经保护作用及其机制。方法将质粒pEGFP-NGB转染经Aβ1-42诱导损伤的SH-SY5Y细胞,MTT法检测NGB对损伤细胞存活率的影响;JC-1染色法检测NGB对损伤细胞线粒体膜电位的影响;免疫细胞化学法及Western blot法分别检测损伤细胞中细胞色素C(cytochrome C,cytoC)和caspase-3、caspase-9的表达水平。结果过表达NGB可明显提高Aβ1-42诱导损伤的SH-SY5Y细胞的存活率(P<0.05),抑制损伤细胞线粒体膜电位的降低(P<0.01),使损伤细胞内cytoC和caspase-3、caspase-9蛋白的表达水平均明显降低(P<0.05)。结论 NGB可通过抑制与细胞凋亡密切相关的cytoC、caspase-3和caspase-9等蛋白的表达而发挥其神经保护作用。本实验为阿尔茨海默病(Alzheimer disease,AD)的治疗提供了实验依据。     

普洱茶水提物对巨噬细胞分泌肿瘤坏死因子-α的影响

目的探讨普洱茶水提物对巨噬细胞分泌肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)的影响。方法以佛波酯处理THP-1细胞48 h,分化得到巨噬细胞,以其为炎症细胞模型,用不同浓度的普洱茶水提物(125、250μg/ml)与终浓度为100 EU/ml的脂多糖的混合物作用于巨噬细胞,ELISA法检测细胞培养液中TNF-α的含量。结果普洱茶水提物能有效抑制巨噬细胞炎症因子TNF-α的分泌,且浓度为250μg/ml的普洱茶水提物对TNF-α分泌的抑制作用强于浓度为125μg/ml的普洱茶水提物,呈剂量依赖性。结论普洱茶水提物对巨噬细胞炎症因子TNF-α的分泌具有抑制作用。这种效果与已知的绿茶抗炎的主要成分EGCG无关。     

Inhibition of Carbonic Anhydrase IX Promotes Apoptosis through Intracellular pH Level Alterations in Cervical Cancer Cells

Carbonic anhydrase IX (CAIX) is a hypoxia-related protein that plays a role in proliferation in solid tumours. However, how CAIX increases proliferation and metastasis in solid tumours is unclear. The objective of this study was to investigate how a synthetic CAIX inhibitor triggers apoptosis in the HeLa cell line. The intracellular effects of CAIX inhibition were determined with AO/EB, AnnexinV-PI, and γ-H2AX staining; measurements of intracellular pH (pHi), reactive oxygen species (ROS), and mitochondrial membrane potential (MMP); and analyses of cell cycle, apoptotic, and autophagic modulator gene expression (Bax, Bcl-2, caspase-3, caspase-8, caspase-9, caspase-12, Beclin, and LC3), caspase protein level (pro-caspase 3 and cleaved caspase-3, -8, -9), cleaved PARP activation, and CAIX protein level. Sulphonamide CAIX inhibitor E showed the lowest IC₅₀ and the highest selectivity index in CAIX-positive HeLa cells. CAIX inhibition changed the morphology of HeLa cells and increased the ratio of apoptotic cells, dramatically disturbing the homeostasis of intracellular pHi, MMP and ROS levels. All these phenomena consequent to CA IX inhibition triggered apoptosis and autophagy in HeLa cells. Taken together, these results further endorse the previous findings that CAIX inhibitors represent an important therapeutic strategy, which is worth pursuing in different cancer types, considering that presently only one sulphonamide inhibitor, SLC-0111, has arrived in Phase Ib/II clinical trials as an antitumour/antimetastatic drug.     

Pu-erh Tea Inhibits Tumor Cell Growth by Down-Regulating Mutant p53

Pu-erh tea is a kind of fermented tea with the incorporation of microorganisms' metabolites. Unlike green tea, the chemical characteristics and bioactivities of Pu-erh tea are still not well understood. Using water extracts of Pu-erh tea, we analyzed the tumor cell growth inhibition activities on several genetically engineered mouse tumor cell lines. We found that at the concentration that did not affect wild type mouse embryo fibroblasts (MEFs) growth, Pu-erh tea extracts could inhibit tumor cell growth by down-regulated S phase and cause G1 or G2 arrest. Further study showed that Pu-erh tea extracts down-regulated the expression of mutant p53 in tumor cells at the protein level as well as mRNA level. The same concentration of Pu-erh tea solution did not cause p53 stabilization or activation of its downstream pathways in wild type cells. We also found that Pu-erh tea treatment could slightly down-regulate both HSP70 and HSP90 protein levels in tumor cells. These data revealed the action of Pu-erh tea on tumor cells and provided the possible mechanism for Pu-erh tea action, which explained its selectivity in inhibiting tumor cells without affecting wild type cells. Our data sheds light on the application of Pu-erh tea as an anti-tumor agent with low side effects.     

Proliferation-attenuating and apoptosis-inducing effects of tryptanthrin on human chronic myeloid leukemia k562 cell line in vitro

Tryptanthrin, a kind of indole quinazoline alkaloid, has been shown to exhibit anti-microbial, anti-inflammation and anti-tumor effects both in vivo and in vitro. However, its biological activity on human chronic myeloid leukemia cell line K562 is not fully understood. In the present study, we investigated the proliferation-attenuating and apoptosis-inducing effects of tryptanthrin on leukemia K562 cells in vitro and explored the underlying mechanisms. The results showed that tryptanthrin could significantly inhibit K562 cells proliferation in a time- and dose-dependent manner as evidenced by MTT assay and flow cytometry analysis. We also observed pyknosis, chromatin margination and the formation of apoptotic bodies in the presence of tryptanthrin under the electron microscope. Nuclei fragmentation and condensation by Hoechst 33258 staining were detected as well. The amount of apoptotic cells significantly increased whereas the mitochondrial membrane potential decreased dramatically after tryptanthrin exposure. K562 cells in the tryptanthrin treated group exhibited an increase in cytosol cyt-c, Bax and activated caspase-3 expression while a decrease in Bcl-2, mito cyt-c and pro-caspase-3 contents. However, the changes of pro-caspase-3 and activated caspase-3 could be abolished by a pan-caspase inhibitor ZVAD-FMK. These results suggest that tryptanthrin has proliferation-attenuating and apoptosis-inducing effects on K562 cells. The underlying mechanism is probably attributed to the reduction in mitochondria membrane potential, the release of mito cyt-c and pro-caspase-3 activation.     

三七总皂甙对大鼠肺动脉血管平滑肌细胞增殖和凋亡的影响及其机制

目的探讨三七总皂甙(Panax notoginseng saponins,PNS)对大鼠肺动脉血管平滑肌细胞(Pulmonary artery smoothmuscle cell,PASMC)增殖和凋亡的影响及其机制。方法将PASMC分为5组:对照组(不给药)、bFGF组(8 ku/L)、bFGF+低、中、高剂量PNS组(bFGF 8 ku/L+300、450、600μg/L PNS),给药24 h后,采用MTT法检测PASMC的增殖活力;流式细胞仪检测细胞周期分布和细胞凋亡率;Westernblot检测细胞中胱天蛋白酶-3(caspase-3)蛋白的表达。结果 PNS干预可抑制PASMC增殖,阻遏bFGF诱导的PASMC进入S期,提高滞留在G0/G1期细胞的比例,并使PASMC凋亡率和caspase-3蛋白表达上调,PASMC凋亡率达(18.70%±0.33%)～(28.40%±0.79%),是bFGF诱导组的10～14倍。结论 PNS能显著抑制bFGF诱导的PASMC增殖,促进其凋亡,其机制可能与其调控细胞周期转换、激活caspase-3蛋白的表达有关。     

Synthesis and Biological Evaluation of Novel Dehydroabietic Acid Derivatives Conjugated with Acyl-Thiourea Peptide Moiety as Antitumor Agents

A series of dehydroabietic acid (DHAA) acyl-thiourea derivatives were designed and synthesized as potent antitumor agents. The in vitro pharmacological screening results revealed that the target compounds exhibited potent cytotoxicity against HeLa, SK-OV-3 and MGC-803 tumor cell lines, while they showed lower cytotoxicity against HL-7702 normal human river cells. Compound 9n (IC₅₀ = 6.58 ± 1.11 μM) exhibited the best antitumor activity against the HeLa cell line and even displayed more potent inhibitory activity than commercial antitumor drug 5-FU (IC₅₀ = 36.58 ± 1.55 μM). The mechanism of representative compound 9n was then studied by acridine orange/ethidium bromide staining, Hoechst 33,258 staining, JC-1 mitochondrial membrane potential staining, TUNEL assay and flow cytometry, which illustrated that this compound could induce apoptosis in HeLa cells. Cell cycle analysis indicated that compound 9n mainly arrested HeLa cells in the S phase stage. Further investigation demonstrated that compound 9n induced apoptosis of HeLa cells through a mitochondrial pathway.     

Changes of constituents and activity to apoptosis and cell cycle during fermentation of tea

Tea is believed to be beneficial for health, and the effects of the fermentation process on its contributions to apoptosis and cell cycle arrest of gastric cancer cells have not been completely investigated. In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared. The polysaccharide and caffeine levels were substantially higher in the fermented black tea and pu-erh tea, while the polyphenol level was higher in the unfermented green tea. Hence, a treatment of tea aqueous extract and the components, which are emerging as promising anticancer agents, were pursued to determine whether this treatment could lead to enhance apoptosis and cell cycle arrest. In the human gastric cancer cell line SGC-7901, the cell viability and flow cytometry analysis for apoptotic cells indicated effects in a dose-dependent inhibition manner for the three tea treatment groups. The apoptosis rates were found to be elevated after 48 h of treatment with 31.2, 125, and 500 μg/mL of green tea extract, the higher catechins content may be involved in the mechanism. Cell cycle was arrested in S phase in the fermented black tea and pu-erh tea, and the populations were significantly decreased in G2/M phases, possibly due to the oxidation of tea polyphenols, which causes an increase of theabrownins. CCC-HEL-1 normal cells were not sensitive to tea extract. These findings suggest that the fermentation process causes changes of the compounds which might be involved in the changes of cell proliferation inhibition, apoptosis induction and cell cycle arrest.