As2O3对耐药的白血病细胞株UF-1和K562/D细胞增殖的影响

目的:探讨三氧化二砷(As2O3)对耐药的白血病细胞株UF-1和K562/D的作用.方法:采用台盼蓝拒染法计数活细胞数,并计算细胞生长率;细胞涂片经Wright-Giemsa染色,光镜下观察细胞的形态;流式细胞仪解析细胞周期.结果:As2O3对耐药的白血病细胞株UF-1和K562/D的增殖均具有明显的抑制作用,与敏感细胞株NB4和K562细胞相比均无显著性差异.2 μmol/L的As2O3能够使UF-1细胞株的凋亡细胞占48.5%,亚G1期细胞明显增多,4 μmol/L的As2O3使K862/D细胞株的分裂期细胞占40.6%,G2/M期细胞增多.结论:耐药白血病细胞株UF-1和K562/D分别与敏感株NB4和K562相比,对As2O3的敏感性相同.As2O3诱导UF-1细胞凋亡,使K562/D细胞发生G2/M期阻滞.     

三氧化二砷抑制活化Ｔ细胞白介素－１３基因的表达

目的:研究T细胞在CD3/CD28双信号通路刺激后白介素-13(IL-13)的基因表达以及三氧化二砷对该基因表达的影响.方法:用CD3/CD28单克隆抗体(浓度分别为10ug/na和5ug/ml双信号通路对Hut-78细胞进行共刺激,研究Hut-78细胞IL-13基因的表达.结果:CD3/CD28双信号通路共刺激后,Hut-78细胞的IL-13 mRNA表达增加,砷剂能够明显抑制该基因的表达(P<0.05).结论:砷剂抑制了T细胞活化过程中IL-13基因的表达.     

Arsenic trioxide in treatment of de novo acute basophilic leukemia

Acute basophilic leukemia (ABL) is a rare subtype of acute myeloid leukemia (AML),accounting for 4％-5％ of AML and less than 2％ of all hematopoietic malignancies.It is usually characterized by a very rapid clinical course,symptoms of hyperhistaminemia,peptic ulceration,gastrointestinal cerebrovascular bleeding and resistance to therapy.1 However,the clinical outcome of ABL remains disappointing.Most patients died within 1 year after diagnosis.We reported a de novo ABL case in a 70-year-old patient treated with single-agent arsenic trioxide (ATO).And prolonged survival was observed.     

Arsenic trioxide downregulates the expression of annexin II in bone marrow cells from patients with acute myelogenous leukemia

Background Most patients with acute myelogenous leukemia （AML） suffer from disordered hemostasis. We have previously shown that annexin II （Ann II）, a high-affinity co-receptor for plasminogen/tissue plasminogen activator, plays a central role in primary hyperfibrinolysis in patients with acute promyelocytic leukemia （APL）. The expression of Ann II in cells from patients with major subtypes of AML and the effect of arsenic trioxide （As203） on Ann II expression in AML cells were investigated to determine whether As203-mediated downregulation of Ann II could restore hemostatic stability. Methods A total of 103 patients （48 females and 55 males; age, 19-58 years） were included. Plasma samples were collected before and after treatment as well as after complete remission. Ann II and plasminogen activation were measured in leukemic cells during treatment with 1 pmol/L As203. Results Before AS203 treatment, Ann II mRNA expression （real-time PCR） was the highest in M3 cells （P 〈0.05）, higher in M5 cells than that in M1, M2, M4, and M6 cells （P〈0.001）, and positively correlated with Ann II protein expression （flow cytometry） （r=0.752, P 〈0.01）. Exposure for up to 120 hours to As203 （1 μmol/L） had no significant effect on Ann II protein in M1 and M2 leukemic cells, but decreased Ann II protein expression twofold within 48 hours of exposure in M3 cells （P 〈0.05） and twofold within 96 hours in M5 cells （P 〈0.05）. The rate of plasmin generation was higher in APL, M5, and M4 cells than in M1, M2, and M6 cells. Conclusions As203 may reduce hyperfibrinolysis in AML by downregulation of Ann 11. Furthermore, As2O3 affects more than one form of AML （APL, M4 and M5）, suggesting its potential role in their management.     

三氧化二砷诱导慢性髓细胞性白血病K562细胞株凋亡与c-myc的表达

目的：观察三氧化二砷(As2O3)诱导慢性髓细胞性白血病K562细胞株凋亡和c-myc mRNA表达的作用，并探讨其作用机制。方法：应用MTT法、苔盼蓝拒染法、DNA凝胶电泳和细胞周期凋亡检测，观察0μmol／L、0．5μmol／L、lμmol／L、2μmol／L、4μmol／L、8μmol／LAs2O3分别作用24h、48h、72h后，对K562细胞增殖及活力的影响。应用RT-PCR和免疫组织化学法检测As2O3处理后K562细胞c-myc mRNA和蛋白表达的变化。结果：As2O3诱导后K562细胞核DNA凝缩，核片段化，最后形成凋亡小体。在一定范围内，随着As2O3浓度的增加和As2O3处理时间的延长，细胞存活率明显下降；流式细胞仪检测可见As2O3诱导K562细胞凋亡，影响细胞周期，细胞阻滞于G2／M期；As2O3处理后c-myc mRNA和c-myc蛋白表达均有先上调后回落的趋势。结论：As2O3可以抑制K562细胞增殖并诱导凋亡，其作用机制可能是使细胞受阻于G2／M期而进入凋亡程序，c-myc基因参与了As2O3诱导细胞凋亡的基因调控。     

Arsenic trioxide up-regulates Fas expression in human osteosarcoma cells

Background Osteosarcoma is a common primary malignant tumor of bone with a poor prognosis due to its propensity for metastasis. The prognosis of patients is highly dependent on the presence or absence of lung metastasis and on the effectiveness of treatment against it. It has been reported that low level expression of Fas protein in human osteosarcoma cell is closely associated with lung metastasis. A large number of studies have shown that arsenic trioxide （ATO） can inhibit proliferation and induce apoptosis of many cancer cell lines; however, its effects on human osteosarcoma cells （Saos-2 cell line） remains unknown. The aim of this study was to investigate the effects of ATO on Saos-2 cells and to characterize its mechanism of Fas-expressing. Methods A group of Saos-2 cells was treated with or without 0.5, 1, 2, 4 and 8 pmol/L ATO for three successive days, and the cytotoxicity of ATO was determined by an 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide （MTT） assay. Morphological changes in cells were studied by acridine orange/ethidium bromide （AO/EB） double staining. Flow cytometry （FCM） was used to assay cell DNA distribution. Another group of cells was pretreated with 10 nmol/L matrix metalloproteinase 7 （MMP-7） for 3 hours. They were then incubated with or without 2 pmol/L ATO for 24, 48 and 72 hours. Cytotoxicity, Fas protein and mRNA levels were systematically studied using MTT, Western blotting and real-time PCR, respectively. Cell proliferation, cell cycle progression and apoptosis were examined in this study. Results Proliferation of Saos-2 cells was inhibited by ATO in both a dose- and time-dependent manner. The IC50 values at 24, 48 and 72 hours were 9.30, 5.54 and 3.49 pmol/L, respectively. The survival rate of Saos-2 cells in the MMP-7 and ATO co-treated group was significantly higher than the ATO group, but it was lower than the control group. ATO induced G1 phase arrest of the cell cycle and very efficiently stimulated apoptosis in Saos-2 cells, as evidenced by flow cytometric detection of sub-G1 DNA content and AO/EB staining. Western blotting results indicated that Fas （FasL） protein expression in osteosarcoma cultures markedly increases in a time dependent manner after exposure to ATO. Compared with control, treatment with ATO 2 IJmol/L and 4 pmol/L for 48 hours, resulted in increase of Fas gene expression to 28.31% and 56.74%, respectively. Our results indicated that ATO induced-apoptosis of Saos-2 cells may be mediated through the Fas pathway. Conclusions ATO suppressed cell proliferation of Saos-2 cell in a dose- and time-dependent manner and increased Fas protein expression. However, Fas-mediated apoptosis was incompletely interrupted by MMP-7, which suggested that other molecular mechanisms may mediate this process.     

Effect of arsenic trioxide on cytokine expression by acute promyelocytic leukemia cells

Objective To detect the expression of cytokines by acute promyelocytic leukemia (APL) cells before and after exposure to arsenic trioxide. Methods Diagnoses were performed according to the FAB cytological classification criteria and cytogenetic criteria. Bone marrow or blood samples from APL patients were collected in heparinized tubes,then primary APL cells were separated by traditional Ficoll-Hypaque density centrifugation and purified after adherence to plastic surfaces. IL-1β, IL-6, IL-8, TNFα and G-CSF levels in the leukemia cell culture supernatants were detected by ELISA. At the same time, nitro blue tetrazolium (NBT) reduction test was used to detect the differentiation of APL cells. Results After 96 hours exposure to arsenic trioxide, 10(-6) mol/L in vitro or 10 mg/d in vivo, APL cells showed a significant increase of IL-1β(P&lt;0.05) and G-CSF(P&lt;0.05) production, and a significant decrease of IL-6 (P&lt;0.05) and IL-8 (P&lt;0.05). However, there was no obvious variation of TNFα when compared with APL cells without exposure to arsenic trioxide. On the other hand, the proliferation ratio of APL cells in vitro was statistically correlated to the IL-1β secretion ratio or G-CSF secretion ratio. The cell number ratio in patients with detectable IL-1β or G-CSF was higher than that without detectable IL-1β or G-CSF.Conclusion IL-1β and G-CSF secretion may play an important role in the proliferation of APL cells after exposure to arsenic trioxide.     

三氧化二砷对人肺腺癌细胞A549/DDP裸鼠体内的多药耐药逆转作用

目的研究三氧化二砷（As_2O_3）对人肺腺癌耐顺铂细胞A549/顺铂（DDP）裸鼠移植瘤的耐药逆转作用。方法建立人肺腺癌裸鼠移植瘤模型,观察As_2O_3、DDP及联合用药对体内移植瘤生长状况的影响;采用流式细胞术（FCM）测定不同用药对肿瘤细胞凋亡率变化和耐药细胞A549/DDP P-糖蛋白（P-gp）表达;采用RT-PCR检测不同用药对A549/DDP移植瘤组织MRP1-mRNA和LRP-mRNA表达的变化。结果体内裸鼠抑瘤实验显示As_2O_3有一定抑瘤作用,联合应用DDP可显著抑制肿瘤生长。FCM结果显示应用As_2O_3后肿瘤细胞平均凋亡率,明显高于对照组（P〈0.05）[（17.204±3.091）%vs（3.436±0.537）%],低浓度As_2O_3联合DDP后肿瘤细胞的凋亡率,明显高于DDP组（P〈0.05）[（14.472±3.891）%vs（5.612±1.167）%]。FCM对P-gp表达检测提示As_2O_3对移植瘤Pgp水平无影响。RT-PCR检测结果示含As_2O_3组MRP1表达明显低于不含As_2O_3组（P〈0.05）,肺癌耐药相关蛋白（LRP）在转录水平呈现相对低表达,含As_2O_3组同不含As_2O_3组间比较差异无统计学意义（P〉0.05）。结论 As_2O_3能在体内逆转A549/DDP细胞的耐药性,其机制可能是As_2O_3可通过下调MRP1基因表达,提高A549/DDP细胞对DDP敏感性逆转其耐药,并可能通过诱导肿瘤细胞凋亡来起作用。     

砷剂诱导人胃癌细胞株凋亡及对C-myc基因作用的研究

目的研究砷剂（As2O3）对人胃癌细胞的诱导凋亡作用及对C-myc基因表达的影响。方法选用人胃癌BGC-823细胞株,运用体外细胞培养法、MTT法、流式细胞术检测As2O3对人胃癌的诱导凋亡作用;用逆转录-聚合酶链反应（RT-PCR）方法检测C-mycmRNA的表达。结果As2O3对人胃癌BGC-823细胞具有抑制作用,其抑制率呈时间-剂量依赖关系。不同浓度的As2O3均可诱导凋亡。1．0μmol／L、3．0μmol／L的As2O3可下调C-myc的表达。结论As203具有抗肿瘤作用,主要是通过诱导细胞凋亡实现。其机制与下调C-myc表达有密切关系。     

急性白血病患者多药耐药基因MDR1的表达及临床意义的研究

目的探讨急性白血病(AL)患者多药耐药基因MDR1的表达和化疗敏感性的关系.方法应用实时荧光定量RT-PCR技术测定45例初治AL患者MDR1水平的表达. 结果耐药组MDR1阳性表达(56.52%)明显高于敏感组(13.64%),P＜0.01,两组差异显著,有统计学意义.结论 MDR1基因表达是AL临床耐药的因素之一.     

三氧化二砷诱导肝癌细胞HepG2凋亡作用

目的 探讨三氧化二胂（As2O3)诱导肝癌细胞HepG2凋亡作用。方法 应用普通光学显微镜、荧光显微镜和流式细胞仪观察As2O3对HepG2细胞株的形态学改变和诱导凋亡率。结果 As2O3作用于细胞后,可看到较典型的细胞凋亡形态学改变,细胞体积缩小、染色质固缩成斑块状、呈半月型紧贴于核膜周边、核碎裂、凋亡小体形成等。AO／EB荧光染色法显示,细胞凋亡率为3．1％－9．1％。As2O3诱导HepG2细胞凋亡作用呈时间依赖性,最佳浓度为2μmol／L。流式细胞仪DNA直方图上呈现典型的亚二倍体凋亡峰。As2O3主要作用于细胞周期的G2／M期。结论 As2O3具有诱导HepG2细胞凋亡作用,具有治疗肝癌的潜在价值。     

bcl-xL基因介导白血病细胞多药耐药的形成

观察ｂｃｌ－ｘＬ基因可否介导白血病细胞的多药耐药,并探讨其机制。方法采用脂质体法将ｂｃｌ－ｘＬｃＤＮＡ转导入ＨＬ－６０细胞,免疫印迹法检测Ｂｃｌ－ｘＬ及抗凋亡蛋白Ｂａｘ的表达;ＭＴＴ法测定呈足乙甙、柔红霉素、阿霉素对转染细胞的细胞毒性;流式细胞仪定量检测凋亡细胞及细胞内药物浓度。     

Arsenic Trioxide Inhibits Proliferation in K562 Cells by Changing Cell Cycle and Survivin Expression

To study the mechanisms involved in the inhibition of chronic myeloid leukemic cells (K562) proliferation induced by arsenic trioxide (As2O3) and to explore the potential role of Survivin, an inhibitor of apoptosis protein, in the regulation of As203 induced cell apoptosis, K562 cells were cultured with As203 of different concentrations. Cells were collected for proliferation analysis by MTT assay. Cell cycle distribution and cell apoptosis were analyzed by flow cytometry. Expression of Survivin protein and mRNA were detected by flow cytometry and RT-PCR, respectively. Our results showed that As2O3 (2-10/μmol/L) inhibited K562 cells growth effectively, but it did not induce cells apoptosis significantly. The percentage of K562 cells at G2/M phase increased in proportion to As2O3 concentrations, and the expression of Survivin mRNA and content of Survivin protein was up-regulated accordingly. It is concluded that As2O3 inhibited K562 cells growth by inducing cell cycle arrest mainly at G2/M phase. Over-expression of Survivin gene and protein might be one of the possible mechanisms contributing to K562 cells‘ resistance to As2O3-induced apoptosis.     

三氧化二砷联合偏钒酸钠对HL-60细胞增殖及凋亡的影响

目的 探讨三氧化二砷(As2O3)联合偏钒酸钠(NaVO3)对人白血病细胞HL-60增殖及凋亡的影响.方法 采用MTT法检测不同浓度的As2O3、NaVO3单药或联合(1×10-8 mol/L NaVO3联合5×10-3 mol/LAs2O3)对HL-60细胞的生长抑制作用;琼脂糖电泳检测DNA条带;Hoechst 33258染色后荧光显微镜观察不同处理组中细胞核的变化;以AnnexinV/PI双染色流式细胞术检测5×10-3mol/L As2O3、1×10-8 mol/L NaVO3单药或联合对HL-60细胞凋亡的影响.结果 MTT结果显示As2O3能抑制HL-60细胞的增殖,并呈剂量和时间效应;低浓度的NaVO3促进细胞增殖,高浓度(≥1×10-8 mol/L)的NaVO3抑制细胞的生长;两药联合抑制作用强于对应浓度单药抑制作用(P＜0.05).HL-60细胞经As2 O3和较高浓度(≥1×10-8 mol/L)的NaVO3处理24 h后均可见到DNA梯形条带.Hoechst 33258染色结果发现HL-60细胞经As2O3和较高浓度(1×10-9 mol/L NaVO3)的NaVO3处理24 h后可见细胞核呈现核浓缩现象.流式细胞术结果显示5×10-3 mol/L As2O3和1×10-8 mol/LNaVO3联合作用于HL-60细胞所诱导的早期凋亡细胞显著多于单独用药(P＜0.05).结论 As2O3及浓度大于1×10-8 mol/L NaVO3均可有效地抑制体外白血病细胞HL-60的增殖并诱导细胞凋亡,两药联合对于抑制细胞增殖及诱导细胞凋亡具有加强作用.     

急性白血病患者MRP、p170与多药耐药关系的分析

目的：评价ｐ糖蛋白（ｐ１７０）和多药耐药相关蛋白（ｍｕｌｔｉｄｒｕｇ ｒｓｓｉｔａｎｃｅ－ａｓｓｏｃｉａｔｅｄ ｐｒｏｔｅｉｎ,ＭＲＰ）表达与急性白血病患者多药耐药的关系。方法：将急性白血病患者按治疗效果分为初治敏感组、完全缓解组和复发难治组三组,用免疫细胞化学结合流式细胞仪测定ｐ１７０和ＭＲＰ。结果：ｐ１７０在各型白血病中完全缓解组均低于初治和复发难治组,ＭＲＰ在ＡＭＬ中复发难治组明显高于完全缓     

急性白血病多药耐药基因表达及临床意义

目的研究多药耐药基因(MDR1)在急性白血病(AL)中的表达及与预后的关系.方法采用链亲和素-胶体金原位杂交(ISH-SAG)方法对59例不同病期的AL患者进行MDR1检测.结果(1)ANLLMDR1阳性表达率(50.0%)虽高于ALL阳性表达率(37.5%),但差异无显著意义(P＞0.05).(2)MDR1在复发难治组的阳性表达率明显高于缓解组(P＜0.05).(3)MDR1阳性表达与临床缓解密切相关,MDR1阳性表达者的完全缓解(CR)率(22.2%)明显低于MDR1阴性者的CR率(80.0%)(P＜0.05).(4)MDR1阳性表达作为耐药标准的评价,其敏感率、特异率、准确率分别为77.8%、80.0%、79.0%.结论MDR1阳性表达与临床耐药相关,是影响AL患者预后的一个重要的因素.且其敏感性、特异性均较高.     

三氧化二砷对前列腺癌细胞PC-3凋亡抑制蛋白XIAP表达的影响

[目的]探讨三氧化二砷(As2O3)对前列腺癌细胞株PC-3细胞增殖、细胞凋亡及X染色体连锁凋亡抑制蛋白(XIAP)表达的影响.[方法]取对数生长期PC-3细胞,分别经0.5,1.0,2.0μmol/L As2O3处理,采用四甲基偶氮唑蓝比色法检测细胞生长抑制作用;流式细胞仪检测细胞凋亡率;蛋白质印迹法及实时荧光定量PCR检测XIAP蛋白表达及XIAP mRNA表达的变化.[结果]0.5,1.0,2.0μmol/LAs2O3均可抑制PC-3细胞增殖,在处理24,48,72h后,细胞生长抑制率间差异具有统计学意义(P<0.01).检测0.5,1.0,2.0μmol/L As2O3处理48h的PC-3细胞株细胞凋亡率分别为11.47%±1.81%,38.47%±1.60%,58.93%±3.35%,相比较差异具有统计学意义(P<0.01).As2O3处理48h时0.5,1.0,2.0μmol/L As2O3组的XIAP mRNA表达水平分别为0.67±0.12,0.25±0.15,0.03±0.01,各组间差异均具有统计学意义(P<0.05).[结论]As2O3可抑制PC-3细胞增殖,诱导细胞凋亡,此作用可能与As2O3抑制PC-3细胞XIAP基因的表达有关联.     

Arsenic trioxide up-regulates Fas expression in human osteosarcoma cells

Background Osteosarcoma is a common primary malignant tumor of bone with a poor prognosis due to its propensity for metastasis. The prognosis of patients is highly dependent on the presence or absence of lung metastasis and on the effectiveness of treatment against it. It has been reported that low level expression of Fas protein in human osteosarcoma cell is closely associated with lung metastasis. A large number of studies have shown that arsenic trioxide (ATO) can inhibit proliferation and induce apoptosis of many cancer cell lines; however, its effects on human osteosarcoma cells (Saos-2 cell line) remains unknown. The aim of this study was to investigate the effects of ATO on Saos-2 cells and to characterize its mechanism of Fas-expressing.Methods A group of Saos-2 cells was treated with or without 0.5,1,2,4 and 8 urnol/L ATO for three successive days, and the cytotoxicity of ATO was determined by an 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Morphological changes in cells were studied by acridine orange/ethidium bromide (AO/EB) double staining. Flow cytometry (FCM) was used to assay cell DNA distribution. Another group of cells was pretreated with 10 nmol/L matrix metalloproteinase 7 (MMP-7) for 3 hours. They were then incubated with or without 2 umol/L ATO for 24, 48 and 72 hours. Cytotoxicity, Fas protein and mRNA levels were systematically studied using MTT, Western blotting and real-time PCR, respectively. Cell proliferation, cell cycle progression and apoptosis were examined in this study. Results Proliferation of Saos-2 cells was inhibited by ATO in both a dose- and time-dependent manner. The IC50 values at 24, 48 and 72 hours were 9.30, 5.54 and 3.49 μmol/L, respectively. The survival rate of Saos-2 cells in the MMP-7 and ATO co-treated group was significantly higher than the ATO group, but it was lower than the control group. ATO induced G1 phase arrest of the cell cycle and very efficiently stimulated apoptosis in Saos-2 cells, as evidenced by flow cytometric detection of sub-G1 DNA content and AO/EB staining. Western blotting results indicated that Fas (FasL) protein expression in osteosarcoma cultures markedly increases in a time dependent manner after exposure to ATO. Compared with control, treatment with ATO 2 μmol/L and 4 μmol/L for 48 hours, resulted in increase of Fas gene expression to 28.31% and 56.74%, respectively. Our results indicated that ATO induced-apoptosis of Saos-2 cells may be mediated through the Fas pathway.Conclusions ATO suppressed cell proliferation of Saos-2 cell in a dose- and time-dependent manner and increased Fas protein expression. However, Fas-mediated apoptosis was incompletely interrupted by MMP-7, which suggested that other molecular mechanisms may mediate this process.     

Arsenic trioxide up-regulates Fas expression in human osteosarcoma cells

Background Osteosarcoma is a common primary malignant tumor of bone with a poor prognosis due to its propensity for metastasis. The prognosis of patients is highly dependent on the presence or absence of lung metastasis and on the effectiveness of treatment against it. It has been reported that low level expression of Fas protein in human osteosarcoma cell is closely associated with lung metastasis. A large number of studies have shown that arsenic trioxide (ATO) can inhibit proliferation and induce apoptosis of many cancer cell lines; however, its effects on human osteosarcoma cells (Saos-2 cell line) remains unknown. The aim of this study was to investigate the effects of ATO on Saos-2 cells and to characterize its mechanism of Fas-expressing.Methods A group of Saos-2 cells was treated with or without 0.5,1,2,4 and 8 urnol/L ATO for three successive days, and the cytotoxicity of ATO was determined by an 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Morphological changes in cells were studied by acridine orange/ethidium bromide (AO/EB) double staining. Flow cytometry (FCM) was used to assay cell DNA distribution. Another group of cells was pretreated with 10 nmol/L matrix metalloproteinase 7 (MMP-7) for 3 hours. They were then incubated with or without 2 umol/L ATO for 24, 48 and 72 hours. Cytotoxicity, Fas protein and mRNA levels were systematically studied using MTT, Western blotting and real-time PCR, respectively. Cell proliferation, cell cycle progression and apoptosis were examined in this study. Results Proliferation of Saos-2 cells was inhibited by ATO in both a dose- and time-dependent manner. The IC50 values at 24, 48 and 72 hours were 9.30, 5.54 and 3.49 μmol/L, respectively. The survival rate of Saos-2 cells in the MMP-7 and ATO co-treated group was significantly higher than the ATO group, but it was lower than the control group. ATO induced G1 phase arrest of the cell cycle and very efficiently stimulated apoptosis in Saos-2 cells, as evidenced by flow cytometric detection of sub-G1 DNA content and AO/EB staining. Western blotting results indicated that Fas (FasL) protein expression in osteosarcoma cultures markedly increases in a time dependent manner after exposure to ATO. Compared with control, treatment with ATO 2 μmol/L and 4 μmol/L for 48 hours, resulted in increase of Fas gene expression to 28.31% and 56.74%, respectively. Our results indicated that ATO induced-apoptosis of Saos-2 cells may be mediated through the Fas pathway.Conclusions ATO suppressed cell proliferation of Saos-2 cell in a dose- and time-dependent manner and increased Fas protein expression. However, Fas-mediated apoptosis was incompletely interrupted by MMP-7, which suggested that other molecular mechanisms may mediate this process.     

三氧化二砷诱导人肿瘤细胞凋亡和G2＋M期阻滞但引起人永 …

目的　研究 As2 O3引起肿瘤细胞凋亡和对细胞周期的影响。方法　采用 DNA凝胶电泳 ,流式细胞仪分析、RT- PCR和 Western免疫印迹等技术检测细胞凋亡的发生。结果　由 As2 O3诱导的人肺腺癌 GL C- 82、胃腺癌 MGC- 80 3和 SGC- 790 1、食管癌 Ec10 9、宫颈癌 He L a细胞凋亡前 ,细胞阻滞在 G2 M期 ,上述细胞均表现为对c- myc基因的下行调节 ;但在导致永生化人宫颈上皮 HCE16 /3细胞凋亡之前 ,细胞却被阻滞在 G1期 ,对 c- m yc基因表达无影响。结论　 As2 O3引起细胞凋亡与细胞周期阻滞有关 ,在肿瘤细胞和前恶变的 HCE16 /3细胞中阻滞的时期不同 ,这可能与 c- myc基因表达的改变与否有关