三氧化二砷对恶性淋巴瘤细胞株凋亡的研究

目的 研究不同浓度的三氧化二砷对恶性淋巴瘤细胞株的影响。方法 采用细胞染色方法观察细胞凋亡的形态,原位末端标记法（TUNEL)检测凋亡细胞,流式细胞仪检测细胞的DNA含量的形态,原位末端标记法（TUNEL）检测凋亡细胞,流式细胞仪检测细胞的DNA含量和bcl－2蛋白的表达。结果 0．5μmol/L-2.0μmol/L三氧化二砷抑制B淋巴瘤细胞株Raji细胞生长,出现细胞凋亡的形态学改变,流式细胞仪检测Raji细胞亚C1期细胞明显增多,bcl－2蛋白的表达明显降低,呈现剂量时间依赖效应。0．5μmol／L－4．0μmol／L三氧化二砷对T淋巴瘤细胞株Jurkat细胞无明显作用。结论 三氧化二砷抑制恶性B淋巴瘤细胞生长和促进细胞凋亡的作用。     

三氧化二砷诱导卵巢癌OVCAR-3细胞周期阻滞及凋亡

目的探讨As2O3对卵巢癌细胞增殖的抑制作用及对细胞周期和凋亡的影响.方法采用MTT法及集落形成实验测定细胞的增殖活力,通过细胞形态学观察细胞分裂及凋亡,应用流式细胞仪进行细胞周期解析、凋亡及bcl-2蛋白表达的检测.结果As2O3呈剂量依赖性抑制OVCAR-3细胞增殖,抑制50%细胞生长的药物浓度(IC50)为2μmol/L.0.5～5μmol/L的As2O3作用7天,集落抑制率均在40%以上(P＜0.01).2μmol/L与5μmol/L的As2O3作用12 h后,细胞周期出现了G2/M期阻滞及亚二倍体凋亡峰,随着作用时间的延长,凋亡细胞随G2/M期细胞减少而逐渐增多.细胞形态学观察可见分裂期细胞及凋亡细胞明显增加.0.5～5μmol/L的As2O3均能下调bcl-2蛋白的表达.结论As2O3能够抑制卵巢癌OVCAR-3细胞的增殖,诱导M期阻滞及细胞凋亡.     

三氧化二砷抑制人膀胱癌 EJ细胞增殖及其作用机制探讨

背景与目的:观察三氧化二砷(Arsenictrioxide,As2O3)对人膀胱癌EJ细胞生长抑制作用,并探讨其作用机理。材料与方法:四甲基偶氮唑蓝(3_[4,5_dimethylthiazol_2_yl]_2,5diphenyltetrazoliumbromid,MTT)法检测EJ细胞增殖活力;荧光染色观察凋亡细胞的形态学变化;流式细胞术分析细胞周期及细胞凋亡;免疫细胞化学染色观察caspase_3蛋白的表达。结果:As2O3 与EJ细胞生长抑制率之间有显著的浓度依赖关系,IC50 为22.51μmol/L;荧光显微镜下观察到经As2O3 作用后,EJ细胞出现凋亡现象;流式细胞术结果表明20μmol/L的As2O3 处理EJ细胞48h后,细胞周期变化无显著性差异,细胞凋亡率从对照组的3.37 %上升到19.07 %;免疫细胞化学染色结果显示,20μmol/L的As2O3 处理EJ细胞48h后,能够诱导caspase_3蛋白的表达。结论:As2O3 能显著抑制EJ细胞增殖,诱导caspase_3蛋白表达,并进一步诱导细胞凋亡。     

bcl-2基因的反义寡核苷酸与三氧化二砷联合对恶性淋巴瘤细胞系凋亡的影响

目的：研究bcl-2基因的反义寡核苷酸与三氧化二砷（As2O3）联合对恶性淋巴瘤细胞系凋亡的影响。方法：采用细胞染色方法观察细胞凋亡的形态，原位末端标记法（TUNEL）检测凋亡细胞，流式细胞仪检测细胞的DNA含量和bcl-2蛋白的表达。结果：10－40μmol/l bcl-2基因的反义寡核苷酸和0．5－2．0μmol/L三氧化二砷均能抑制恶性B淋巴瘤细胞系Raji细胞生长，诱导细胞凋亡，流式细胞仪检测Raji细胞，发现亚G1期细胞明显增多，bcl-2蛋白的表达明显降低，呈现时间剂量依赖效应，两者联合应用比单独应用抑制作用显著。结论：bcl-2基因的反义寡核苷酸与三氧化二砷联合应用，明显抑制恶性B淋巴瘤细胞系生长，促进细胞凋亡。     

三氧化二砷联合抗坏血酸抑制人肾癌 786 -0 细胞增殖及相关蛋白表达的研究

目的：观察三氧化二砷（As2O3）联合抗坏血酸（AA）对786-0人肾透明细胞癌细胞增殖的影响,并通过其对bcl-2和bax蛋白表达的影响探讨相关机制.方法：将体外培养的786-0人肾透明细胞癌细胞分为对照组（N）和实验组,实验组分为AA组、As2O3组、As2O3与AA联合组.用CCK-8细胞增殖-毒性检测试剂盒检测药物对细胞增殖的影响,TUNEL试剂盒检测细胞凋亡,Western blot方法测定bcl-2基因和bax基因的蛋白表达.结果：以0μmol/L或50μmol/L AA分别联合0、1、2、4、8、16μmol/L As2O3作用786-0细胞24h,与As2O3单独应用相比,AA与不同浓度As2O3联合应用都可显著提高As2O3对786-0细胞的抑制率,其作用具有剂量依赖性（P＜0.05）.0μmol/L或8μmol/L As2O3分别联合0μmol/L、50μmol/L、100μmol/L AA作用786-0细胞24h,与As2O3单独应用相比,AA与As2O3联合应用能够显著下调bcl-2表达,上调bax表达,联合组与其他组比较有明显差异,并具有剂量依赖性.结论：抗坏血酸（AA）联合三氧化二砷（As2O3）可以明显协同抑制786-0人肾透明细胞癌细胞的增殖,且具有剂量依赖性,其机制可能与下调bcl-2基因表达,上调bax蛋白表达从而诱导肾癌细胞的凋亡有关.     

As2S2诱导K562细胞凋亡的分子机制初步研究

目的　探索As2 S2 对K5 6 2细胞的诱导凋亡作用及其机制。方法　细胞凋亡的检测用流式细胞分析、基因组DNA电泳、细胞形态学观察等方法 ,Westernblot方法用于蛋白表达的检测 ,基因表达的变化用半定量RT PCR方法。结果　 3～ 5 μmol L的As2 S2 作用 4 8～ 72h即可诱导K5 6 2细胞凋亡。 3μmol LAs2 S2 作用 72h时 ,细胞凋亡率达 (34.4± 3.3) % ;5 μmol LAs2 S2 作用 4 8,72h时 ,细胞凋亡率分别为 (2 1.8± 3.6 ) %和 (4 6 .0± 5 .2 ) %。 5 μmol LAs2 S2 作用下 ,As2 S2 可降低Bcr Abl和JAK2的蛋白含量。As2 S2 从基因水平上调bax表达 ,下调c myc表达。As2 S2 作用后 ,Caspase 3被激活。As2 S2 也能诱导慢性粒细胞性白血病 (CML)患者单个核细胞凋亡。结论　As2 S2 可诱导CML细胞凋亡 ,Bcr Abl含量的降低可能起了很重要的作用。bax表达的增加、c myc表达的减少、JAK2蛋白含量的降低以及Caspase 3激活也可能参与了该细胞凋亡机制。     

三氧化二砷诱导鼻咽癌CNE-2Z细胞凋亡及其作用机制的初步研究

目的:研究三氧化二砷(As2O3)对人鼻咽癌CNE2Z细胞的生物学效应及其作用机制。方法:台盼蓝计数法计算As2O3的IC50;CNE-2Z细胞经As2O3处理后,通过流式细胞仪、荧光染色及DNA电泳检测细胞凋亡;流式细胞仪测定bcl2和bax阳性细胞百分率;罗丹明123染色后进行线粒体膜电位分析。结果:As2O3在一定浓度范围内以浓度依赖的方式抑制CNE2Z细胞生长,其IC50为(1.35±0.30)μmol/L;0.5～2.0μmol/LAs2O3处理CNE2Z细胞后,流式细胞仪检测出凋亡峰,荧光显微镜下可见明显的细胞凋亡形态特征,琼脂糖凝胶电泳出现DNA梯形条带;As2O3对bcl2的表达没有影响(P>0.05),但能显著增加bax的表达(P<0.01)及降低线粒体膜电位(P<0.01)。结论:As2O3在体外可诱导鼻咽癌CNE2Z细胞凋亡,其机制可能与上调bax表达和降低线粒体膜电位有关。     

IWP-2对人肝癌Hep3B细胞增殖和凋亡的影响及其机制探讨

目的:研究Wnt/β-catenin抑制剂IWP-2对体外培养的人肝癌细胞Hep3B细胞增殖和凋亡的影响,并探讨其可能的作用机制。方法:用终浓度分别为0、20、40、80、160、320μmol/L的IWP-2作用于人肝癌Hep3B细胞,采用CCK-8法检测细胞的增殖抑制率,FCM法检测细胞周期分布与细胞凋亡率,Western blot法检测细胞凋亡蛋白的表达,Western blot法检测细胞中Cyclin D1和survivin蛋白表达的变化,实时定量RT-PCR法检测Cyclin D1和survivin mRNA表达的变化。结果:20~320μmol/L的IWP-2对细胞的增殖均有抑制作用,其抑制作用随IWP-2浓度的升高和作用时间的增长而增强,各组与对照组相比差异有统计学意义（P＜0.01）。FCM检测结果显示,IWP-2(20~320μmol/L)能够导致G0/G1期细胞比例上升,S期细胞比例下降;同时诱导细胞凋亡,凋亡率随IWP-2浓度的升高而上升,与对照组相比差异有统计学意义（P＜0.01）。IWP-2可引起caspase-3和caspase-7蛋白表达水平的升高,并且可下调肝癌细胞中Cyclin D1和survivin基因和蛋白的表达水平,呈明显的剂量依赖性。结论:IWP-2可抑制Hep3B细胞的增殖并诱导其凋亡,其机制可能与抑制Cyclin D1和survivin的表达有关。     

三氧化二砷诱导雌激素受体阴性乳腺癌细胞株MDA-MB-435s凋亡和bcl-2、bax表达关系的研究

目的 观察不同浓度三氧化二砷(As2O3)诱导人乳腺癌细胞系MDA-MB-435s凋亡的情况及对bcl-2和bax表达的影响,初步探讨了其诱导凋亡的途径.方法 不同浓度As2O3体外作用于MDA-MB-435s细胞24h后,采用TUNEL染色法和DNA梯状电泳法检测细胞凋亡情况,应用免疫组化法检测细胞中bcl-2和bax蛋白表达情况.结果 As2O3作用后,DNA琼脂糖凝胶电泳法呈现凋亡DNA梯状条带;As2O3作用组的凋亡指数明显高于阴性对照组(P＜0.05);bcl-2表达下调,bax表达上调.结论 As2O3能诱导MDA-MB-435s细胞凋亡,上调bcl-2蛋白表达、下调bax蛋白表达是其诱导凋亡的途径之一.     

Studies on arsenic trioxide induced human pulmonary adenocarcinoma GLC-82 cell apoptosis and its molecular mechanisms

】 ObjectiveTo study the biological effect of As₂O₃ on human pulmonary adenocarcinoma GLC-82 cells and its mechanisms. MethodsMTT reduction assay,morphology investigation,flowcytometric analysis,DNA gel electrophoresis and TUNEL,RT-PCR,Northern blot, Western blot methods were perfomed. ResultsAs₂O₃ inhibited the growth of GLC-82 cell line. The cells treated with As₂O₃ showed a typical apoptotic morphology and hypodiploid peak before G1 phase. DNA of treated GLC-82 cells appeared a ladder pattern characteristic of apoptosis. In situ cell death detection analysis also revealed the DNA fragmentation. Besides,As₂O₃ inhibited c-myc gene expression and increased p53 and p16 gene expression. ConclusionAs₂O₃ can induce GLC-82 cell apoptosis mainly with regulation of c-myc,p53 and p16 gene expression.     

Parthenolide-Induced Apoptosis,Autophagy and Suppression of Proliferation in HepG2 Cells

Purpose: To investigate the anticancer effects and underlying mechanisms of parthenolide on HepG2 human hepatocellular carcinoma cells. Materials and Methods: Cell viability was assessed by MTT assay and cell apoptosis through DAPI, TUNEL staining and Western blotting. Monodansylcadaverin(MDC) and AO staining were used to detect cell autophagy. Cell proliferation was assessed by Ki67 immunofluorescence staining. Results: Parthenolide induced growth inhibition in HepG2 cells. DAPI and TUNEL staining showed that parthenolidecould increase the number of apoptotic nuclei, while reducing the expression of the anti-apoptotic protein Bcl-2 and elevating the expression of related proteins, like p53, Bax, cleaved caspase9 and cleaved caspase3. Parthenolide could induce autophagy in HepG2 cells and inhibited the expression of proliferation-related gene, Ki-67. Conclusions: Parthenolide can exert anti-cancer effects by inducing cell apoptosis, activating autophagy and inhibiting cell proliferation.     

氧化砷诱导结肠癌细胞凋亡及其分子机制

 目的　观察不同浓度As2O3对结肠癌Lovo、LS-174T细胞株生长的影响。方法　0.125～2μ mo1/L的As2O3与结肠癌细胞株Lovo、LS-174T共同孵育,观察不同浓度As2O3作用不同时间对结肠癌细胞的生长抑制作用、细胞形态学改变、DNA的变化。结果　1～2μ mol/L As2O3作用的结肠癌细胞呈凋亡特征性改变：细胞膜不发生破裂,细胞核出现核浓缩、核碎裂和凋亡小体形成;流式细胞仪检测在G1期前出现亚二倍体凋亡峰;细胞DNA抽提琼脂糖凝胶电泳呈凋亡特征性条带。结论　1～2μ mol/L As2O3可诱导结肠癌细胞凋亡,肿瘤细胞凋亡与Fas、Fas-L表达有关。     

Glutathione depletion overcomes resistance to arsenic trioxide in arsenic-resistant cell lines.

Arsenic trioxide (As(2)O(3)) is an effective treatment for acute promyelocytic leukemia (APL), but is less effective against other leukemias. Although the response of APL cells to As(2)O(3) has been linked to degradation of the PML/RARalpha fusion oncoprotein, there is evidence that PML/RARalpha expression is not the only mediator of arsenic sensitivity. Indeed, we found that exogenous expression of PML/RARalpha did not sensitize a non-APL leukemic line to As(2)O(3). To evaluate possible other determinants of sensitivity of leukemic cells to As(2)O(3), we derived two arsenic-resistant NB4 subclones. Despite being approximately 10-fold more resistant to arsenic than their parental cell line, PML/RARalpha protein was still degraded by As(2)O(3) in these cells, providing further evidence that loss of expression of the oncoprotein does not confer arsenic sensitivity. Both arsenic-resistant clones contained high glutathione (GSH) levels, however, and we found that GSH depletion coupled with As(2)O(3) treatment dramatically inhibited their growth. Annexin V-staining and TUNEL analysis confirmed a synergistic induction of apoptosis. In addition, these cells failed to accumulate ROS in response to arsenic treatment, in contrast to their arsenic-sensitive parental cells, unless cotreated with buthionine sulfoximine. While other malignant cells did not show a good correlation between arsenic sensitivity and GSH content, GSH depletion nevertheless sensitized all cell lines examined, regardless of their initial response to arsenic alone. These findings suggest that PML/RARalpha expression is not a determinant of arsenic sensitivity, and further support the coupling of GSH depletion and arsenic treatment as a novel treatment for human malignancies that are unresponsive to arsenic alone.     

Apoptosis and growth inhibition in malignant lymphocytes after treatment with arsenic trioxide at clinically achievable concentrations.

BACKGROUND: Arsenic trioxide (As2O3) can induce clinical remission in patients with acute promyelocytic leukemia via induction of differentiation and programmed cell death (apoptosis). We investigated the effects of As2O3 on a panel of malignant lymphocytes to determine whether growth-inhibitory and apoptotic effects of As2O3 can be observed in these cells at clinically achievable concentrations. METHODS: Eight malignant lymphocytic cell lines and primary cultures of lymphocytic leukemia and lymphoma cells were treated with As2O3, with or without dithiothreitol (DTT) or buthionine sulfoximine (BSO) (an inhibitor of glutathione synthesis). Apoptosis was assessed by cell morphology, flow cytometry, annexin V protein level, and terminal deoxynucleotidyl transferase labeling of DNA fragments. Cellular proliferation was determined by 5-bromo-2'-deoxyuridine incorporation into DNA and flow cytometry and by use of a mitotic arrest assay. Mitochondrial transmembrane potential (delta psi(m)) was measured by means of rhodamine 123 staining and flow cytometry. Protein expression was assessed by western blot analysis or immunofluorescence. RESULTS: Therapeutic concentrations of As2O3 (1-2 microM) had dual effects on malignant lymphocytes: 1) inhibition of growth through adenosine triphosphate (ATP) depletion and prolongation of cell cycle time and 2) induction of apoptosis. As2O3-induced apoptosis was preceded by delta psi(m) collapse. DTT antagonized and BSO enhanced As2O3-induced ATP depletion, delta psi(m) collapse, and apoptosis. Caspase-3 activation, usually resulting from delta psi(m) collapse, was not always associated with As2O3-induced apoptosis. As2O3 induced PML (promyelocytic leukemia) protein degradation but did not modulate expression of cell cycle-related proteins, including c-myc, retinoblastoma protein, cyclin-dependent kinase 4, cyclin D1, and p53, or expression of differentiation-related antigens. CONCLUSIONS: Substantial growth inhibition and apoptosis without evidence of differentiation were induced in most malignant lymphocytic cells treated with 1-2 microM As2O3. As2O3 may prove useful in the treatment of malignant lymphoproliferative disorders.     

Leukemia-associated translocation products able to activate RAS modify PML and render cells sensitive to arsenic-induced apoptosis

Since the 19th century, arsenic (As2O3) has been used in the treatment of chronic myelogenous leukemia (CML) characterized by the t(9;22) translocation. As2O3 induces complete remissions in patients with acute promyelocytic leukemia. The response to As2O3 is genetically determined by the t(15;17)-or the t(9;22)-specific fusion proteins PML/RARalpha or BCR/ABL. The PML portion of PML/RARalpha is crucial for the sensitivity to As2O3. PML is nearly entirely contained in PML/RARalpha. PML is upregulated by oncogenic RAS in primary fibroblasts. The aberrant kinase activity of BCR/ABL leads to constitutive activation of RAS. Therefore, we hypothesized that BCR/ABL could increase sensitivity to As2O2-induced apoptosis by modifying PML expression. To disclose the mechanism of As2O3-induced apoptosis in PML/RARalpha- and BCR/ABL-expressing cells, we focused on the role of PML for As2O3-induced cell death. Here we report that (i) sensitivity to As2O3-induced apoptosis of U937 cells can be increased either by overexpression of PML, or by conditional expression of activated RAS; (ii) also the expression of the t(8;21)-related AML-1/ETO increased sensitivity to As2O3-induced apoptosis; (iii) both BCR/ABL and AML-1/ETO activated RAS and modified the PML expression pattern; (iv) the expression of either BCR/ABL or AML-1/ETO rendered U937 cells sensitive to interferon alpha-induced apoptosis. In summary, these data suggest a crucial role of factors able to upregulate PML for As2O2-induced cell death.     

三氧化二砷对膀胱癌T24细胞Apaf-1基因表达的影响

目的：观察三氧化二砷 (arsenic trioxide,As2O3)对人膀胱癌T24细胞增殖及凋亡蛋白酶活化因子-1 (apoptotic protease activating factor-1,Apaf-1)基因表达的影响。方法：取处于对数生长期的T24细胞,用0.25%胰酶消化成细胞密度为1×105/mL的单细胞悬液,再用含有不同浓度 (0、1、2、4、8 μmol/L)As2O3的培养基作为药物组,并设置空白对照组,置于培养箱中分别培养24、48和72 h后,用二甲基四氮唑蓝 (MTT)法检测As2O3对T24细胞的增殖抑制率;取T24细胞在不同浓度 (0、1、2、4、8 μmol/L)的As2O3培养液中培养72 h后用脱氧核糖核酸原位末端转移酶标记技术 (TUNEL)法检测细胞凋亡,用RT-PCR及Western blotting检测As2O3 对Apaf-1 mRNA和蛋白表达的影响。结果：与对照组相比,2、4、8 μmol/L As2O3剂量组能有效抑制T24细胞增殖,且具有剂量-反应关系 (24 h时r=-0.962,P=0.038;48 h时r =-0.959,P=0.041;72 h时r=-0.973,P=0.027)。As2O3于1～8 μmol/L作用72 h时细胞出现典型的凋亡变化,具有剂量-反应关系 (r=0.993,P =0.007);同时Apaf-1 mRNA和蛋白的表达均明显增强,且具有剂量-反应关系 (mRNA：r=0.986,P=0.014;蛋白：r=0.989,P=0.000)。结论：As2O3能够有效抑制膀胱癌T24细胞生长、增殖并诱导其凋亡,机制可能与其上调Apaf-1基因的表达有关。     

三氧化二砷对肝癌HepG2细胞侵袭转移及USP22蛋白表达的影响

目的:探究不同浓度三氧化二砷(As2O3)对肝癌HepG2细胞侵袭转移能力的影响以及对HepG2细胞中USP22蛋白表达的影响,进一步完善其分子机制。方法:CCK8细胞增殖实验检测不同浓度As2O3在不同时间点对HepG2细胞增殖的影响;细胞划痕和Transwell方法检测HepG2细胞在不同浓度As2O3作用下侵袭转移能力的变化;Western blot检测As2O3作用下HepG2细胞中USP22蛋白的表达水平。结果:随着As2O3浓度和作用时间的增加,HepG2细胞增殖明显受到抑制。与对照组相比,24 h时分别用2、4、8 μmol/L的As2O3处理的HepG2细胞侵袭转移能力降低,细胞中USP22蛋白表达水平明显下降。结论:As2O3可抑制人肝癌HepG2细胞侵袭转移能力,其分子机制可能与下调的USP22蛋白水平相关。