氧化砷诱导胃癌细胞凋亡的实验研究

目的 研究三氧二化砷（氧化砷）对胃癌细胞的诱导凋亡作用。方法 应用ＴＵＮＥＬ染色、流式细胞仪技术研究氧化砷对胃癌细胞ＭＫＮ－４５、ＭＫＮ－２８的诱导凋亡作用。结果 氧化砷作用于不同分化程度的胃癌细胞后,可看到较为典型的细胞凋亡的形态学变化：细胞核固缩,染色质凝集,呈新月型紧贴于核膜周边,核碎裂,染色质片断化,凋 亡小体形成等。流式细胞仪ＤＮＡ直方图上出现典型的亚二倍体的“凋亡峰”。ＴＵＮＥＬ染色法     

氧化砷诱导食管癌细胞系细胞凋亡的形态学研究

目的在氧化砷（As2O3）作用于食管癌细胞株EC8712过程中，用光镜和电镜观察培养细胞凋亡的形态改变方法ECh712于199培养基常规培养，以3μmolAs2O3作用于细胞，72h收获细胞，作光镜（HE染色，TUNEL标记）、透射电镜和流式细胞仪检查.结果3μmolAs2O3作用72h，出现许多凋亡细胞，培养细胞部分变圆，脱落.在光镜下HE染色观察2种凋亡细胞.一种核小；圆形，致密呈固缩核、和核碎,另一种胞质红染，染色质凝集，二者TUNEL标记阳性．流式细胞仪检测有凋亡峰出现（亚G1／G0峰）．电镜检查有二种凋亡类型.一呈典型凋亡细胞核改变；在早期染色质凝集成块状，细胞器保存完好.第二期，随着染色质改变，细胞核变圆，饱满，核膜完整，染色质靠边，大块染色质，构成车轮状或半月状.核膜变性解体，使染色质逸出．最后细胞变性坏死.凋亡小体易见，小块状球状，膜包或裸露.另一种固缩细胞，细胞皱缩，胞质致密，核电子密度高.结论光镜和电镜检查结果证实As2O3可以诱导食管癌细胞系ECh712细胞凋亡，因此As2O3可作为食管癌辅助治疗药物．     

三氧化二砷对肺成纤维细胞株NIH3T3增殖和凋亡的影响

目的 探讨三氧化二砷（As2O3）的抗肺纤维化（PF）作用及其机制。方法将对数生长期成纤维细胞株NIH3T3随机分为对照组及观察1组、观察2组,分别用含0、2、4μmol／LAs2O3的DMEM培养液处理24h和48h,采用四甲基偶氮唑蓝（MTF）法检测细胞增殖抑制率（IR）,流式细胞术检测细胞周期分布,透射电镜和Hoechst染色方法观察细胞超微结构及细胞核形态变化。结果 观察1组和观察2组细胞增殖IR均显著高于对照组,尤以作用48h时和观察2组为著（P均〈0.01）;观察1组和观察2组G0／G1,期细胞显著多于对照组,而G2／M期细胞显著少于对照组,尤以观察2组为著（P均〈0.01）;观察1组和观察2组细胞具有早、中期凋亡形态学特征（细胞膜结构完整、细胞质浓缩、染色质边集、固缩）。结论As2O3可抑制肺成纤维细胞株NIH3T3增殖并促进其凋亡,此为临床PF治疗提供了新思路。     

Dual effects of arsenic trioxide (As2O3) on non-acute promyelocytic leukaemia myeloid cell lines: induction of apoptosis and inhibition of proliferation

Clinical efficacy of As2O3 has been shown in patients with relapsed acute promyelocytic leukaemia (APL). There is evidence that the effects of As2O3 are not restricted to events specific for APL. As2O3 might target mechanisms involved in the pathogenesis of other malignancies. We assessed susceptibility to induction of apoptosis by As2O3 and cytostatics in 22 myeloid and non-myeloid malignant cell lines. As2O3 was used in concentrations of 0.01-10 micromol/l. Cell lines displayed different kinetics of response and different sensitivity to As2O3. The minimum concentration of As2O3 for induction of apoptosis was 0.1 micromol/l. High concentrations of As2O3 (5 micromol/l) induced apoptosis in a large proportion of cells in all cell lines tested. Low (1 micromol/l As2O3) concentrations induced apoptosis in NB-4, HL-60, U-937, CEM, HL-60, KG-1a, PBL-985, ML-2 and MV-4-11, but not in HEL, K-562, KG-1 and Jurkat up to 35 d of incubation. However, the non-apoptotic population of 1 micromol/l As2O3-treated HEL, K-562, K-562 (0.02), K-562(0.1) and Jurkat showed reduced proliferation. CEM as well as its' multidrug-resistant derivatives were sensitive to 1 micromol/l As2O3. In summary, these data demonstrate that As2O3-induced apoptosis is not restricted to cell lines with t(15;17). Apoptosis was induced in vitro by As2O3 concentrations that are achievable in vivo after infusion of well-tolerated As2O3 doses. Thus, As2O3 might be a suitable therapeutic agent for malignancies other than APL provided the adequate dose and duration of As2O3 treatment are used.     

As2O3对肾癌细胞增殖、凋亡的影响及意义

目的观察As2O3对肾癌细胞株786-0增殖、凋亡及细胞内X染色体连锁凋亡抑制蛋白（XIAP）表达的影响,探讨其意义。方法取对数生长期786-0,分别经0．5、1．0、2．0μmol／L的As2O3处理后,采用MTT比色法检测细胞生长情况,流式细胞仪测算细胞凋亡率,蛋白质印迹法及RT—PCR法检测细胞中的XIAP及其mRNA。结果0．5、1．0、2．0μmol／LAs2O3均可抑制786-0增殖。随着作用时间的延长,细胞生长抑制率升高（P均〈0．01）;随着As2O3浓度的增加,细胞凋亡率升高（P均〈0．01）、细胞内XIAP及其mRNA表达明显下调（P均〈0．05）。结论As2O3可抑制786-0增殖,并诱导其凋亡。这一作用与As2O3抑制786-0中XIAP及其mRNA表达有关。     

Effect of arsenic trioxide on human hepatoma cell line BEL-7402 cultured in vitro

AIM:To study the effect of a varying concentrations of arsenic trioxide on human hepatoma cell line BEL-7402 cultured in vitro and its mechanism of action.METHODS:The BEL-7402 cells were treated with arsenic trioxide (at the concentrations of 0.5 1 2&mgr;mol/L, respectively) for 4 successive days. The cell growth and proliferation were observed by cell counting and cell-growth curve. Morphologic changes were studied with electronmicroscopy. Flow cytometry was used to assay cell-DNA distribution and the protein expression of Bcl-2 and Bax detected by immunocytochemical method.RESULTS:The cell growth was significantly inhibited by varying concentrations of arsenic trioxide as revealed by cell counting and cell-growth curve, which was dose- and time-dependent. Arsenic trioxide treatment at 0.5, 1 and 2&mgr;mol/L resulted in a sub-G1 cell peak, the apoptosis rate of the control group was 9.31% and that of 0.5&mgr;mol/L arsenic trioxide 15.53%, no significant difference was seen between the two.The apoptosis rates of 1,2&mgr;mol/L arsenic trioxide were 19.10% and 21.87% respectively, which were much higher (both P < 0.05). Decrease of G(0)/G(1) phase cells and increase of S phase cells were observed by flow cytometry, suggesting the inhibition effect of 0.5, 1, 2&mgr;mol/L arsenic trioxide on BEL-7402 cell lay in the G(0)/G(1) phase. Morphologic changes such as intact cell membrane, nucleic condensation, apoptotic body formation were seen under transmission electronmicrescopy, whereas the 0.5mol/L arsenic trioxide-treated BEL-7402 cells showed decrease of nucleocytoplasmic ratio, round nucleus, well-differentiated organelles in the cytoplasm. The processes and microvilli on the cell surface of the experimental groups under scanning electron microscopy were significantly decreased. High expressions of Bcl-2 and Bax were detected in 1 and 2&mgr;mol/L arsenic trioxide-treated cells, these were 46%, 87.33% and 83.08%, 95.83% respectively, among which that of Bax was more significant. Arsenic trioxide treatment at 0.5&mgr;mol/L resulted in a higher expression level of Bcl-2 and lower expression level of Bax,which were 8.81% and 3.83% respectively, as compared with that of the control group (15.33%) (P(1)<0.01, P(2)<0.01).CONCLUSION:Arsenic trioxide not only inhibited proliferation but also induced apoptosis of human hepatoma cell line BEL-7402. The induced-apoptosis effect of 1,2&mgr;mol/L arsenic trioxide was related to the expression level of Bcl-2 and Bax.     

microRNA expression alteration after arsenic trioxide treatment in HepG-2 cells

Background and Aim: More and more microRNA (miRNA) are found to be involved in tumor genesis and progress. Arsenic trioxide has been an effective chemotherapeutic drug in cancer therapy for many years. In this study, we aimed to find the miRNA involved in the mechanisms of arsenic trioxide treatment in cancer therapy. Methods: We detected the expression profile of miRNA by miRNA microarray and quantitative real‐time polymerase chain reaction. Cell viability assay, flow cytometry analysis, prediction of miRNA targets, Western blot analysis and luciferase reporter assay were carried out to determine the role of one selected miRNA, namely mir‐29a, in affecting the biological behaviors of HepG‐2 cells. Results: Among the 677 human miRNA in the microarray, five miRNA were upregulated and four were downregulated in HepG‐2 cells treated with arsenic trioxide compared to their controls. If only changes above two folds were considered, four miRNA were identified, namely miR‐24, miR‐29a, miR‐30a and miR‐210, which were all upregulated. Among them, miR‐29a showed a positive therapeutic effect in liver cancer cells by inhibiting cell growth and inducing cell apoptosis, and PPM1D was confirmed to be the target gene of miR‐29a. Furthermore, a synergy effect was detected between miR‐29a and arsenic trioxide. Conclusions: Arsenic trioxide altered miRNA expression profile in HepG‐2 cells. Among the altered miRNA, miR‐29a seemed to take a role in the mechanism of arsenic trioxide in liver cancer therapy. The synergy effect between miR‐29a and arsenic trioxide may offer this drug a new chance in cancer therapy by decreasing its dose and toxic side‐effects.     

三氧化二砷对裸鼠膀胱癌细胞凋亡的影响

目的探讨三氧化二砷(As2O3)抑制膀胱癌细胞生长的作用。方法体外培养膀胱癌T24细胞,取指数生长期T24细胞裸鼠皮下接种,成瘤后连续7 d尾静脉分别注射As2O3(5、10 mg·kg-1·d-1)、丝裂霉素(MMC)及生理盐水。应用电镜、流式细胞术和免疫组化等方法检测了癌细胞的超微结构变化、细胞的凋亡和Caspase3蛋白的表达。结果电镜下As2O3组可见典型癌细胞凋亡的形态学改变;流式细胞分析,As2O3组可见癌细胞凋亡峰,凋亡率分别为10．67％和23．42％,明显高于对照组(0．83％);免疫组化检测As2O2组Caspase 3蛋白表达(33．54％和56．22％)也明显高于对照组(6．25％)。结论As2O3可以通过诱导膀胱癌细胞凋亡,抑制膀胱癌细胞生长。     

Anion exchanger 2 mediates the action of arsenic trioxide

Anion exchanger 2 (AE2) mediates the exchange of C1-/HCO3- across the plasma membrane and plays a role in the regulation of intracellular pH. The present study showed that AE2 protein expression was upregulated immediately after exposure to either low (0.5 micromol/l) or high (1 and 2 micromol/l) concentrations of arsenic trioxide. This suggests that arsenic trioxide may act via regulation of intracellular pH. Changing the culture pH in NB4 cells modulated the degradation of promyelocytic leukaemia-retinoic acid receptor-alpha (PML-RARalpha), PML and RARalpha, which supported this hypothesis. DIDS (4,4'-diisothiocyanodihydrostilbene-2,2'-disulphonic acid) inhibited AE2 function, preventing the arsenic trioxide-induced degradation of RARalpha and low concentration showed synergistic effects on the expression of CD11c, which is related with cell differentiation. In addition, DIDS rescued the cells from 1 micromol/l arsenic trioxide-induced apoptosis. In conclusion, AE2 mediated the action of arsenic trioxide via regulation of intracellular pH and a novel pathway for the mechanism of action of arsenic trioxide is reported.     

Significance of intracellular arsenic trioxide for therapeutic response in acute promyelocytic leukemia

Arsenic trioxide (As2O3) is an effective drug for treatment of acute promyelocytic leukemia (APL) and malignant tumors. However, it is not commonly known to researchers that sensitivity has been associated with As2O3 concentration in target cells. Cell lines and cell strains of leukemia and solid cancer cells were treated with different concentrations of As2O3, and the concentrations were compared to apoptosis detected by FITC-annexin V and propidium iodide (PI) double staining. Results showed that intracellular and intercellular concentrations of arsenic in different cell lines differed. Our study noted that the cell lines had concentrations of arsenic trioxide in decreasing order, as follows: APL primary cell > K562 > CML primary cell > HL-60 > AML-M2 primary cell > HeLa > H-22. Higher intracellular As2O3 concentrations in cell lines APL, NB4, and K562 can be obtained by treating in culture medium with lower As2O3 concentration for longer times than the transient higher concentration. These results indicate that different leukemia and solid carcinoma cell lines have different intracellular arsenic concentrations, which correlate with different sensitivities to As2O3 in clinical treatment. The intracellular As2O3 concentration is higher; in addition, we note apoptosis, a very important observation in our study. As2O3 inhibited the growth of these cell lines significantly. Novel techniques by maintaining continuous low but effective arsenic levels inside the target leukemic cells in APL may improve the complete remission rate and overall survival with minimum cost and drug toxicity.     

三氧化二砷对人体胃肠癌细胞凋亡及p53、survivin表达的影响

目的研究三氧化二砷（arsenic trioxide,As2O3）在人体内诱导胃肠癌细胞凋亡作用及对凋亡相关基因p53、survivin表达的影响,探讨其抗肿瘤作用及发生机制。方法采用原位末端转移酶标记技术（TUNEL）和免疫组化法分别检测As2O3用药前后胃肠癌细胞凋亡指数和凋亡相关基因蛋白P53、Survivin的表达变化情况。结果 As2O3用药后胃肠癌细胞凋亡指数为（17.04±3.67）%,与用药前（6.07±2.21）%相比差异有统计学意义（P〈0.01）;用药后胃肠癌细胞P53蛋白阳性表达率为（35.05±19.64）%,与用药前（34.80±16.48）%相比差异无统计学意义（P〉0.05）;用药后胃肠癌细胞Survivin蛋白阳性表达率为（15.59±3.94）%,与用药前（36.74±20.5）%相比明显下调,差异有统计学意义（P〈0.01）;As2O3作用后胃肠癌细胞Survivin蛋白表达下调时凋亡率升高,二者之间具有相关性（r=-0.47,P=0.04）。结论 As2O3在人体内可诱导胃肠癌细胞凋亡而发挥抗肿瘤作用,其机制可能与下调survivin基因的表达有关。     

三氧化二砷联合沙利度胺治疗骨髓增生异常综合征

目的:探讨沙利度胺联合三氧化二砷治疗骨髓增生异常综合征的有效性和安全性。方法:42例骨髓增生异常综合征患者分为2组,治疗组使用沙利度胺和三氧化二砷,对照组接受促红细胞生成素及输血为主的对症支持治疗。比较2组的疗效,观察药物的不良反应。结果:治疗组20例完全缓解1例,部分缓解3例,血液学改善11例,总有效率75%,未发现严重不良反应;对照组22例无完全缓解,部分缓解1例,血液学改善8例,总有效率40.91%,与治疗组比较,差异有统计学意义(P<0.05)。结论:沙利度胺联合三氧化二砷治疗骨髓增生异常综合征有效率高,不良反应轻微,耐受性好。     

Selective apoptosis of multiple myeloma cells in primary samples induced by arsenic trioxide

Objectives

Currently, multiple myeloma (MM) is an incurable disease. Despite the fact that arsenic trioxide (ATO) shows promising results in vitro, data from treatment of patients with MM are disappointing. Due to these discrepancies, we compared the efficacy and selectivity of ATO at two different concentrations in samples from MM patients.

Methods

The extent of apoptosis induced by 2 and 5 µM ATO was evaluated by flow cytometry using annexin V. 34 diagnostic bone marrow samples obtained from MM patients were analysed.

Results

5 µM ATO efficiently induced apoptosis in primary samples. Besides efficacy, also selectivity of action on MM cells in comparison to remaining haematopoietic cells was demonstrated for 5 µM ATO but not for 2 µM ATO.

Discussion

Our study on primary samples confirmed that ATO has a potential role in therapeutic management of MM. Further controlled studies on MM patients are needed.     

YB-1抑制三氧化二砷诱导的胃癌细胞自噬机制

目的研究YB-1抑制三氧化二砷(As2O3)诱导人胃癌BGC-823细胞自噬的机制。方法采用脂质体转染siRNA干扰YB-1和腺病毒转染pAd1Easy/YB-1过表达YB-1;实时荧光定量PCR检测Bcl-2和Beclin1基因转录;Western blot检测YB-1、Bcl-2、Beclin1、P62和LC3Ⅱ蛋白的表达;MDC染色、荧光显微镜观察自噬泡。结果与空病毒(AdGFP)组相比,pAd1Easy/YB-1(AdYB-1)组Bcl-2基因表达增高,而干扰质粒(siYB-1)组Bcl-2基因表达水平较空质粒(HK)组降低(P均<0.05),各组Beclin1基因表达比较无统计学差异。与AdGFP和HK组相比,AdYB-1组Beclin1和LC3Ⅱ蛋白减少,Bcl-2和P62蛋白增加(P均<0.01),siYB-1组Beclin1和LC3Ⅱ蛋白增加,Bcl-2和P62蛋白减少(P均<0.01)。与AdGFP组相比,AdYB-1组自噬泡聚集减少,加入Bcl-2抑制剂HA14-1后自噬泡重新聚集,Beclin1蛋白恢复表达,P62降解增加,LC3Ⅱ升高。结论 YB-1可能通过上调Bcl-2、抑制Bec-lin1,实现对As2O3诱导的BGC-823细胞自噬的抑制。     

亚砷酸治疗老年恶性血液病的初步观察

目的探讨亚砷酸治疗老年恶性血液病的临床疗效及不良反应。方法对40例≥60岁的恶性血液病患者,应用亚砷酸治疗(10mg/d,静脉滴注,28d为1疗程,如不良反应明显则改为14d短疗程,间隔14d后再用14d,2次为1疗程)。观察其临床疗效及不良反应。结果急性早幼粒细胞白血病(APL)完全缓解(CR)8例,其他急性非淋巴细胞白血病(ANLL)CR1例,部分缓解(PR)1例,未缓解(NR)6例;慢性粒细胞白血病(CML)PR4例,NR2例;慢性淋巴细胞白血病(CLL)CR1例,PR1例;B细胞非霍奇金淋巴瘤(NHL)CR1例,PR2例,进步1例,无效1例;骨髓增生异常综合征(MDS)PR2例,进步2例,无效1例;慢性粒单细胞白血病(CMML)CR2例,PR2例;多发性骨髓瘤(MM)PR1例,进步1例。所有病例总有效率为75%。仅2例因严重肝损害、骨髓抑制而停药,无用亚砷酸相关死亡病例。结论对不能耐受强化疗的老年难治、复发的血液肿瘤患者,亚砷酸具有一定的治疗效果,且不良反应相对较低。     

Effects of arsenic trioxide (As2O3) on leukemic cells from patients with non-M3 acute myelogenous leukemia: studies of cytotoxicity, apoptosis and the pattern of resistance

Arsenic oxide (As2O3) has recently been reported to induce remission in a high percentage of patients with acute promyelocytic leukemia (APL). The aim of this study was to investigate the effects of As2O3 at therapeutic concentrations on cell viability and apoptosis on leukemic cells from patients with non-M3 acute myelogenous leukemia (AML) and to study the resistance profile compared to conventional AML drugs. Cells from 20 patients were exposed to therapeutic concentrations of As2O3 continuously for 96 h. As2O3 reduced the viability in blast cells from all the 20 tested patients compared to unexposed controls (p-value: 0.02 at 0.05 microM; <0.005 at 1.0 microM and higher concentrations). An increase in the apoptotic rate was also seen after incubation with As2O3. Parallel to the incubation with arsenic the in vitro sensitivity to a number of chemotherapeutic agents commonly used in AML was studied. Correlation coefficients for the in vitro sensitivity were highly significant between the conventional AML drugs except for Ara-C. For As2O3, all the correlation coefficients were negative and ranged between -0.05 and -0.51. Furthermore, increased P-gp expression in a multidrug resistant HL-60 cell line did not decrease the sensitivity to As2O3 as compared to the parental cell line. Neither did a P-gp-transfected variant of the K562 cell line show decreased sensitivity to As2O3. We conclude that As2O3 at therapeutic concentrations induces apoptosis and cytotoxic effects in blast cells from patients with non-M3 AML, and that As2O3 differs from conventional AML drugs with respect to the mechanisms that confer resistance to the drugs.     

The effect of arsenic trioxide on human hepatoma cell line BEL-7402 culturedin vitro

AIM To study the effect of a wide range of concentration of arsenic trioxide on human hepatoma cell lineBEL-7402 and its mechanism.METHODS The BEL-7402 cells were treated with arsenic trioxide (a final concentration of 0.5, 1 and2 μmol/L, respectively) in various durations or for 4 successive days. The cell growth and proliferation wereobserved by cell counting and cell-growth curve. Morphologic changes were studied under electronmicroscopy. Flow cytometry was used to assay cell-DNA distribution and the protein expression of Bcl-2 andBax was detected by immunocytochemical method.RESULTS The cell growth was significantly inhibited by the different concentrations of arsenic trioxide asrevealed by cell counting and cell-growth curve. Arsenic trioxide treatment at 0.5, 1 and 2 μmol/L, resultedin a sub-G1 cell peak. The decreased G0/G1 phase cell and the increased percentage of S phase cell were observed by flow cytometer, suggesting that the inhibiting effect of arsernic trioxide on BEL-7402 cell lay inG0/G1 phase cell. Apoptotis-related morphology, such as intact cell membrane, nucleic condensation,apoptotic body formation, can be seen under the electron microscopy. High protein expression level of Bcl-2and Bax was detected in 1 and 2 μmol/L arsenic trioxide-treated cells, but that of Bax was more significant.Arsenic trioxide treatment at 0.5 μmol/L resulted in higher expression level of Bcl-2 and lower expressionlevel of Bax compared with control (P1<0.01, P2<0.01).CONCLUSION Arsenic trioxide not only inhibited the proliferation but also induced apoptosis of humanhepatoma cell line BEL-7402. The induced-apoptosis effect of 1 and 2 μmol/L arsenic trioxide was relative tothe expression level of Bcl-2 and Bax.     

氧化砷诱导胃癌细胞凋亡的信号传导途径研究

目的 检测氧化砷(As2O3)诱导胃癌细胞株(SGC-7901和MKN-45)凋亡过程中cAMP、蛋白激酶C(PKC)和酪氨酸蛋白激酶(PTK)活性变化，以探讨其诱导胃癌细胞凋亡过程中可能存在的信号传导途径。方法 应用钙离子拮抗剂、PKC和PTK抑制剂研究其对AS2O3诱导胃癌细胞凋亡过程的影响，以TUNEL法检测细胞凋亡率。以放射免疫法测定As2O3作用前后细胞内cAMP水平的变化。抽提PKC和PTK蛋白，以Lowry法测定As2O3作用前后各自蛋白表达水平的变化。结果 钙离子拮抗剂对As2O3诱导胃癌细胞凋亡过程没有影响，PKC和PTK抑制剂不仅本身能诱导胃癌细胞凋亡，且对As2O3诱导胃癌细胞凋亡具有协同作用。在As2O3诱导胃癌细胞凋亡过程中存在cAMP浓度增高和PKC、PTK活性显著降低，提示cAMP、PKC和PTK可能参与As2O3诱导胃癌细胞凋亡的作用。结论 PKC和PTK抑制剂可以通过影响信号传导系统诱导胃癌细胞凋亡，并能促进As2O3诱导胃癌细胞凋亡。