N-4-(二氯乙基)丁胺-1,8-萘酰亚胺对人肝癌HepG2细胞的抑制作用及其机制研究北大核心CSCD

目的体外评价N-4-(二氯乙基)丁胺-1,8-萘酰亚胺(XHH)对Hep G2细胞的抑制作用及其作用机制。方法采用MTT法检测细胞增殖,高内涵筛选分析仪结合Annexin V-FITC/Hoechst33342,PI/Hoechst33342和Rh123/Hoechst33342双染色法检测细胞形态及膜电位;免疫荧光法检测caspase-3,caspase-9,Bcl-2,Bax的表达水平。结果 XHH能抑制Hep G2细胞增殖,诱导细胞凋亡,降低线粒体膜电位,提高Bax/Bcl-2,使caspase-3,caspase-9表达增加。结论 XHH具有较好的抗Hep G2肿瘤细胞作用,可通过线粒体途径诱导细胞凋亡。     

辛伐他汀通过线粒体途径诱导K562细胞凋亡

目的观察辛伐他汀诱导K562细胞凋亡不同时间的膜电位(Δψm),caspase-3、9和细胞色素C的改变,以推测其凋亡通路。方法采用浓度为20μmol.L-1的辛伐他汀处理K562细胞24、48、72 h,采用流式细胞技术检测细胞凋亡率和线粒体膜电位,分光光度法检测caspase-3、9蛋白活性,免疫组织化学法检测细胞色素C蛋白。结果浓度为20μmol.L-1辛伐他汀作用K562细胞24、48、72 h后,凋亡率分别为(6.1±0.35)%、(14.15±0.42)%(、30.70±0.65)%,随着凋亡率增加线粒体膜电位降低分别为(39.6±4.80)%,(24.4±2.45)%,(6.0±1.62)%;caspase-3、9蛋白活性与对照组相比上调,细胞浆内细胞色素C升高。结论辛伐他汀诱导K562细胞凋亡时线粒体膜电位下降,caspase-3、9活性增高和细胞色素C释放,推测辛伐他汀诱导K562细胞的凋亡可能经过线粒体凋亡途径。     

α-维尼非林经线粒体凋亡途径诱导K562细胞凋亡

目的旨在研究α-维尼非林(α-viniferin)对人慢性髓系白血病细胞K562的作用与相关机制。方法 MTT法评价α-viniferin对K562细胞的细胞毒活性。采用细胞形态学和生物化学方法检测细胞凋亡。通过化学荧光法对细胞内线粒体膜电位、caspase-9、caspase-3活性分析。通过半定量RT-PCR表达分析来确定Bcl-2家族相关基因在α-viniferin诱导K562细胞凋亡中的作用。结果α-viniferin能抑制K562细胞增殖,呈剂量和时间依赖性,IC50为13.61 mg·L-1。α-viniferin引起K562细胞出现死亡并伴随有染色质聚集、核破碎、凋亡小体等典型的凋亡形态学特征;此外还伴随有线粒体膜电位显著降低,caspase-9、caspase-3活性升高等现象;α-viniferin(2~32 mg·L-1)引起K562细胞caspase-3 mRNA表达持续升高,Bax、Bad、Bim、Bid促凋亡基因mRNA表达增加,而Bcl-2、Bcl-xL抗凋亡基因mRNA表达持续下降。结论α-viniferin通过线粒体途径诱导K562细胞凋亡。     

新型多胺缀合物NNAMB诱导B16细胞凋亡及分化作用

目的评价新型多胺缀合物NNAMB对B16黑色素瘤细胞诱导凋亡及分化作用。方法以MTT法、台盼蓝拒染法检测细胞活力;Hoechst33258染色观察细胞形态变化;流式细胞仪检测细胞周期变化、凋亡率及线粒体膜电位的变化;酶标仪检测caspase-3、-8、-9的活性及B16细胞内黑色素含量、酪氨酸酶活性等的变化。结果NNAMB在高剂量(>0.1μmol·L-1)下呈现剂量及时间依赖性的抑制B16黑色素瘤细胞的生长、诱导凋亡、降低线粒体膜电位、促进Caspase-3及-9的活化,但caspase-8活性与对照组细胞相比变化差异无显著性;NNAMB在低剂量(<0.1μmol·L-1)下通过增强酪氨酸酶活性,增加黑色素生成等诱导B16细胞分化。结论NNAMB在高剂量下通过线粒体/caspase-9/caspase-3途径诱导B16细胞凋亡;低剂量诱导细胞分化。     

双氢青蒿素诱导人肿瘤细胞凋亡及其分子机制的研究

目的:研究双氢青蒿素诱导人白血病细胞凋亡作用及其机制。方法:用双氢青蒿素处理K562细胞,通过MTT比色法检测细胞增殖抑制的效果;荧光显微镜观察细胞的凋亡;逆转录-聚合酶链反应(RT-PCR)检测半胱氨酰-天冬氨酸蛋白酶-3(caspase-3)的表达,蛋白印迹技术(Western blot)检测线粒体、胞浆细胞色素C的表达。结果:双氢青蒿素处理K562细胞48h后MTT检测,570nm波长处测定半数细胞抑制浓度为8×10-5mol.L-1;Hoechst33342/PI双荧光染色可观察到明显核固缩、凝集等细胞增殖抑制表现;RT-PCR检测到caspase-3的表达,Western-blot检测线粒体细胞色素C表达下调,胞浆中细胞色素C表达阳性。结论:双氢青蒿素能够在体外抑制人白血病细胞增殖并诱导其凋亡,而促进细胞色素C的释放,激活caspase-3可能是其作用机制之一。     

辛伐他汀诱导人红白血病K562细胞凋亡的实验研究

目的:探讨辛伐他汀诱导K562细胞凋亡及其机制。方法:取浓度为0(阴性对照组)、10、20、30μmol·L-1的辛伐他汀作用K562细胞72h后,双染色法检测细胞凋亡率;DNALadder实验检测细胞凋亡条带;用线粒体分离试剂分离出胞浆蛋白、微粒体蛋白、线粒体蛋白;逆转录-聚合酶链反应法检测GRP78、caspase-9、caspase-3、GADD153mRNA表达;Western blot法检测GRP78、caspase-12、caspase-9、caspase-3、GADD153、细胞色素C蛋白水平。结果:与阴性对照组比较,10、20、30μmol·L-1辛伐他汀作用K562细胞72h后出现典型的凋亡条带,凋亡率分别为12.41%、19.08%、23.41%(P<0.01),GRP78、caspase-9、caspase-3和GADD153 mRNA表达上调(P<0.05),caspase-12、caspase-9、caspase-3蛋白水平下降,caspase-12定位于内质网,细胞色素C从线粒体释放,GRP78、GADD153蛋白表达上调。结论:辛伐他汀可通过内质网和线粒体途径诱导K562细胞凋亡。     

葛根素保护双氧水诱导的SH-SY5Y细胞凋亡

目的探讨葛根素对双氧水(H_2O_2)诱导的SH-SY5Y细胞凋亡的保护作用及其机制。方法建立体外神经元损伤模型,MTT法观察细胞存活率;Hoechst 33342染色观察细胞核改变;JC-1染色检测细胞线粒体膜电位的改变;酶活性检测线粒体caspase-3和caspase-9的变化;Western blot检测细胞中Bcl-2、Bax、p-Akt、Akt蛋白的表达。结果与H_2O_2模型组相比,葛根素预处理能明显改善H_2O_2诱导的SHSY5Y细胞存活率下降(P<0.05),缓解H_2O_2引起的线粒体膜电位的下降(P<0.01),抑制caspase-3和caspase-9的酶活性(P<0.01),减少H_2O_2诱导的细胞凋亡。此外,葛根素还促进细胞内p-Akt、Bcl-2蛋白表达,抑制Bax蛋白表达,而这种作用能被PI3K/Akt的抑制剂LY294002所抑制。结论葛根素可保护H_2O_2诱导的SH-SY5Y细胞凋亡,这种保护作用可能是通过激活PI3K/Akt信号通路实现的。     

丙戊酸钠诱导K562细胞凋亡的机制探讨

目的 探讨丙戊酸钠(VPA)诱导K562细胞凋亡的可能机制.方法 将K562细胞分为经VPA 2.0mmol/L处理的实验组(A组)和正常对照组(B组),分别培养24、48、72 h.流式细胞术检测细胞凋亡率和线粒体膜电位改变,分光光度法检测半胱氨酸天门冬氨酸蛋白酶(Caspase)8、Caspase-9蛋白活性.结果 A组细胞凋亡率、细胞线粒体跨膜电位破坏率呈时问依赖性地增加,且明显高于B组(P<0.05);与B组相比,A组不同时间的Caspase-8、Caspase-9活性均上调(P<0.05).结论 VPA诱导K562细胞凋亡的机制可能与线粒体跨膜电位崩溃或死亡途径有关.     

木犀草素对K562细胞caspase-3活化的影响

目的:探讨木犀草素对K562细胞增殖和凋亡的影响.方法:采用MTT法检测K562细胞的增殖,流式细胞术和Hoechst33258/PI荧光染色分析K562细胞的凋亡,比色法测定caspase-3的相对活性,半定量RT-PCR检测caspase-3 mRNA水平的改变,Western-blot分析caspase-3酶原的变化.结果:木犀草素处理细胞24 h后的IC50值为(104.6±13.5)μmol·L-1.浓度为10,20,40μmol·L-1木犀草素处理细胞24 h后均可诱导K562细胞发生凋亡,各处理组的细胞凋亡率均明显高于对照组(P＜0.01).随着浓度及时间的增加,各个木犀草素处理组K562细胞的caspase-3活性升高(P＜0.01),其作用具浓度及时间依赖性.而随着木犀草素浓度的增加,K562细胞中caspase-3的mRNA水平逐渐增加,caspase-3酶原的蛋白水平逐渐减少.结论:木犀草素可通过诱导K562细胞凋亡而抑制其增殖,其诱导K562细胞凋亡可能与激活caspase-3有关.     

新型蒽醌类衍生物HG251诱导人白血病K562/DOX细胞凋亡的机制

目的探讨新型蒽醌类衍生物HG251诱导K562/DOX细胞凋亡的机制。方法以MTT法检测细胞活力,流式细胞仪检测细胞周期变化、凋亡率、线粒体膜电位的变化,Western blot检测P-gp及凋亡相关蛋白如半胱天冬蛋白酶-3、-8、-9、p53、Bcl-xL、cytochrome C的表达。结果HG251剂量依赖性的抑制K562/DOX细胞的生长、降低线粒体膜电位并诱导其凋亡;上调p53并下调Bcl-xL;诱导半胱天冬蛋白酶-3、-8、-9的活化及cytochrome C的释放,但对P-gp的表达无影响。结论HG251通过干扰p53及Bcl-xL的表达而克服K562/DOX细胞的多药耐药,并通过细胞膜死亡受体途径及线粒体途径诱导其细胞凋亡。     

一种海洋来源的ETP类化合物HDN-1诱导K562细胞凋亡作用及机制初探

目的 探讨南极土壤来源真菌的次级代谢产物HDN-1对人慢性粒细胞白血病K562细胞的增殖抑制,诱导凋亡作用及其机制。方法 采用MTT法检测HDN-1对K562细胞的增殖抑制作用;DNA结合染料Hoechst 33342染色,Western Blotting以及DNA琼脂糖凝胶电泳检测细胞凋亡以及凋亡相关蛋白的变化。结果 HDN-1能显著抑制K562细胞的增殖,并呈剂量-时间依赖性;HDN-1作用后,细胞核形态发生明显变化并且出现了基因组DNA的梯状剪切条带;Caspase-9、8、3逐渐被激活,Caspase3的作用底物PARP被活化裂解出现89KD的剪切条带,并且Caspase蛋白的激活可被特异性抑制剂所阻断;抑凋亡蛋白Bcl-2,Mcl-1的表达降低,促凋亡蛋白Bax的表达量增高。另外,融合蛋白Bcr-Abl的表达被HDN-1抑制并呈剂量依赖性。结论 来源于南极土壤来源真菌的次级代谢产物HDN-1可能是通过抑制Bcr-Abl融合蛋白的表达进而诱导K562细胞凋亡,并且凋亡是通过Caspase依赖的线粒体途径和死亡受体途径共同介导发生的。     

Induction of apoptosis in human leukaemia HL-60 cells by furanone-coumarins from Murraya siamensis

To identify potential anti-tumour agents, we screened five furanone-coumarins isolated from Murraya siamensis Craib (Rutaceae) for their ability to inhibit the growth of human leukaemia HL-60 cells. Among the furanone-coumarins tested, murrayacoumarin B (compound 2) showed significant cytotoxicity against HL-60 cells. Fluorescence microscopy with Hoechst 33342 staining revealed that the percentage of apoptotic cells with fragmented nuclei and condensed chromatin increased in a time-dependent manner after treatment with murrayacoumarin B. Interestingly, this furanone-coumarin induced the loss of the mitochondrial membrane potential. In addition, treatment with murrayacoumarin B stimulated the activities of caspase-9 and caspase-3, and caspase-9 and caspase-3 inhibitors suppressed the apoptosis induced by murrayacoumarin B. These results suggest that murrayacoumarin B induced apoptosis in HL-60 cells through activation of the caspase9/caspase-3 pathway triggered by mitochondrial dysfunction.     

灯盏花素促进阿霉素诱导的K562细胞凋亡

目的观察灯盏花素对淋巴细胞增殖和阿霉素致肿瘤细胞死亡的影响。方法MTT法检测细胞增殖,Western blot检测p53/bcl-2表达,Histone/DNA ELISA和流式细胞仪检测细胞凋亡,ELISA检测细胞色素C释放,分光光度法检测caspase-8和caspase-3激活。结果灯盏花素能增强小鼠淋巴细胞对阿霉素的抵抗,但促进阿霉素引起的K562细胞生长抑制、细胞色素C释放、caspase-8和caspase-3激活,上调其p53/bcl-2表达比率,增加细胞凋亡。结论灯盏花素有增强阿霉素抗肿瘤作用,激活肿瘤细胞凋亡通路可能是其化疗增敏的主要机制。     

A novel homospermidine conjugate inhibits growth and induces apoptosis in human hepatoma cells

Aim： To elucidate the mechanism responsible for the antiproliferative effects of a novel homospermidine conjugate, anthracenylmethyl homospermidine （ANTMHspd）, in the human hepatoma BEL-7402 cell line. Methods： The viability of the cells was assessed by MTT assay and the trypan blue dye exclusion method. Morphological changes were observed by fluorescence microscopy with Hoechst 33258 staining. Cell cycle distribution, apoptosis, and mitochondrial membrane potential were measured by flow cytometry. Protein expression was detected by Western blot analysis. Results： ANTMHspd strongly decreased BEL-7402 cell proliferation in a dose- and time-dependent manner. Hoechst 33258 staining and the flow cytometry assay showed that ANTMHspd induced cell apoptosis and cell cycle perturbation. Furthermore, ANTMHspd could induce mitochondrial membrane potential loss and cytochrome c release and enhance cleaved caspase-3, cleaved caspase-9, and Bax protein expression without caspase-8 activation. ANTMHspd could also decrease the expression of Bcl-2 and cytochrome c in mitochondria. In addition, the specific inhibitors of caspase-9 and caspase-3 almost abolished the ANTMHspd-induced caspase-9 and caspase-3 activation, respectively. Conclusion： ANTMHspd could induce BEL-7402 cell apoptosis via the mitochondrial/caspase-dependent pathway and the Bcl-2 family was involved in the control of apoptosis.     

Apoptosis inducing activity of 4-substituted coumarins from Calophyllum brasiliense in human leukaemia HL-60 cells

With the objective of identifying anti-tumour-promoting agents, we carried out a primary screening of ten 4-substituted coumarins isolated from Calophyllum brasiliense Camb. (Guttiferae), to determine the ability of these compounds to inhibit proliferation of the human leukaemia cell line HL-60. Among the 4-substituted coumarins isolated, calophyllolide (2) and mammea B/BB (3) showed significant cytotoxicity against HL-60 cells. Fluorescence microscopy with Hoechst 33342 staining revealed that the percentage of apoptotic cells with fragmented nuclei and condensed chromatin increased in a time-dependent manner after treatment with calophyllolide (2) or mammea B/BB (3). In addition, the activity of caspase-9 and caspase-3 was also enhanced in a time-dependent manner upon treatment with the 4-substituted coumarins 2 and 3. Caspase-9 and caspase-3 inhibitors suppressed apoptosis induced by 4-substituted coumarins 2 and 3. These results suggest that calophyllolide (2) and mammea B/ BB (3) induced apoptosis in HL-60 cells through activation of the caspase-9/caspase-3 pathway, which is triggered by mitochondrial dysfunction.     

Apoptotic effects of mahanine on human leukemic cells are mediated through crosstalk between Apo-1/Fas signaling and the Bid protein and via mitochondrial pathways

Apo-1 (Fas/CD95), a cell surface receptor, triggers apoptosis after binding to its physiological ligand, Apo-1L (FasL/CD95L). This study reports that mahanine, purified from the leaves of Murraya koenigii, has a dose- and time-dependent anti-proliferative activity in acute lymphoid (MOLT-3) and chronic myeloid (K562) leukemic cell lines and in the primary cells of leukemic and myeloid patients, with minimal effect on normal immune cells including CD34⁺ cells. Leukemic cells underwent phosphatidylserine externalization and DNA fragmentation, indicating mahanine-induced apoptosis. An increase in reactive oxygen species suggests that the mahanine-induced apoptosis was mediated by oxidative stress. A significant drop in the Bcl2/Bax ratio, the loss of mitochondrial transmembrane potential as well as cytochrome c release from the mitochondria to the cytosol suggested involvement of the mitochondrial pathway of apoptosis. Cytochrome c release was followed by the activation of caspase-9, caspase-3 and caspase-7, and cleavage of PARP in both MOLT-3 and K562 cells. In MOLT-3 cells, formation of the Fas-FasL-FADD-caspase-8 heterotetramer occurred, leading to the cleavage of Bid to its truncated form, which consequently resulted in formation of the mitochondrial transmembrane pore. The incubation of MOLT-3 cells with mahanine in the presence of caspase-8 inhibitor or FasL-neutralizing NOK-2 antibody resulted in the decrease of mahanine-induced cell death. Mahanine was also a potent inhibitor of K562 xenograft growth, which was evident in an athymic nude mice model. In summary, these results provide evidence for involvement of the death receptor-mediated extrinsic pathway of apoptosis in the mahanine-induced anticancer activity in MOLT-3 cells, but not in K562 cells, which are deficient in Fas/FasL.     

Colchicine-induced apoptosis in human normal liver L-02 cells by mitochondrial mediated pathways

Colchicine is an alkaloid that has been widely used to treat gout. It also has a curative effect on cancer. Although many studies have shown that its effect on cell apoptosis was mediated by the activation of caspase-3, the pathways involved in the process remained obscure. Here we show some evidence regarding the missing information using human normal liver cells L-02 in our study. The effect of colchicine on apoptosis in L-02 cells and the apoptosis-associated signaling pathways were determined using different tests including cell viability assay, Annexin V and propidium idodide binding, PI staining, Hoechst 33342 staining, mitochondrial membrane potential assay, caspase activity assay and Western blot analysis. We found that colchicine-induced a dose-dependent drop of cell viability in L-02 cells; early apoptosis happened when cells were treated with 0.1 μM of colchicine. The colchicine-induced loss of mitochondrial membrane potential, activation of caspase-3 and 9, up-regulation of Bax and down-regulation of Bcl-2 showed an evidence for the colchicine activity on apoptosis, at least, by acting via the intrinsic apoptotic pathway.