土贝母苷甲对人HL-60髓性白血病细胞周期与凋亡的影响

目的:研究土贝母苷甲(下称苷甲)对人髓性白血病细胞HL-60的细胞周期及凋亡的影响。方法:采用MTT(四甲基偶氮唑蓝)法检测苷甲对HL-60细胞生长的影响;形态学方法(荧光显微镜和透射电镜)、流式细胞仪和DNA琼脂糖凝胶电泳观察和分析在苷甲作用下HL-60细胞形态、DNA含量的变化和DNA断裂的情况;蛋白印迹免疫法检测细胞凋亡及周期相关基因bcl-2、cyclinB1表达的变化。结果:苷甲显著抑制HL-60细胞的生长,其抑制效果与浓度及时间呈依赖关系。15μmol·L-1苷甲作用24小时可将HL-60细胞阻滞于G2/M期,进而诱导其凋亡,凋亡细胞具有典型的凋亡形态特征,琼脂糖凝胶电泳可见明显的梯状区带。bcl-2表达无明显变化,cyclinB1表达降低。结论:苷甲对细胞周期起阻滞作用,并诱导其凋亡,其作用机制可能与cyclinB1表达降低有关。     

Avemar, a nontoxic fermented wheat germ extract, induces apoptosis and inhibits ribonucleotide reductase in human HL-60 promyelocytic leukemia cells

Avemar (MSC) is a nontoxic fermented wheat germ extract demonstrated to significantly improve the survival rate in patients suffering from various malignancies. We investigated its effects in human HL-60 promyelocytic leukemia cells. After 24, 48, and 72 h of incubation, Avemar inhibited the growth of HL-60 cells with IC₅₀ values of 400, 190, and 160 μg/ml, respectively. Incubation with MSC caused dose-dependent induction of apoptosis in up to 85% of tumor cells. In addition, Avemar attenuated the progression from G2–M to G0–G1 phase of the cell cycle and was also found to significantly reduce the in situ activity of ribonucleotide reductase, the key enzyme of de novo DNA synthesis. We conclude that Avemar exerts a number of beneficial effects which could support conventional chemotherapy of human malignancies.     

Gallic acid inhibits ribonucleotide reductase and cyclooxygenases in human HL-60 promyelocytic leukemia cells

Gallic acid (GA) is a naturally occurring polyhydroxyphenolic compound and an excellent free radical scavenger. In this study, we examined its cytotoxic and biochemical effects on the human HL-60 promyelocytic leukemia cell line. GA caused a significant imbalance of deoxynucleosidetriphosphate (dNTP) pool sizes, indicating ribonucleotide reductase inhibition. Moreover, GA induced dose-dependent apoptosis in HL-60 cells (80microM GA led to the induction of apoptosis in 39% of cells) and attenuated progression from G0/G1 to the S phase of the cell cycle (60microM GA doubled the number of cells in G0/G1 phase from 22 to 44% when compared to untreated controls). We further determined IC(50) values of 3.5 and 4.4nM for the inhibition of cyclooxygenases I and II, respectively. When cells were simultaneously treated with GA and trimidox, another inhibitor of RR, highly synergistic growth inhibitory effects could be observed. Taken together, we identified novel biochemical effects of GA which could be the basis for further preclinical and in vivo studies.     

蛋白酶体抑制剂MG132诱导HL-60细胞凋亡前G2/M期阻滞及机制

背景和目的:蛋白酶体(proteasome)抑制剂能够诱导多种肿瘤细胞凋亡,是一种潜在的有应用前景的抗肿瘤剂.本研究旨在探讨蛋白酶体抑制剂MGl32(Z-Leu-Leu-Leu-CHO)诱导白血病细胞HL-60凋亡和C2/M期阻滞的机制.方法:采用荧光显微镜观察、流式细胞术和免疫印迹研究测定MG132诱导HL-60细胞凋亡和周期阻滞及机制.结果:2μmol/L的MG132能够有效地诱导HL-60细胞凋亡,用药后24 h就显现有细胞凋亡;在MG132诱导HL-60细胞凋亡出现之前有一个明显的G2/M期阻滞,加MG132后12 h时G2/M期时相百分比为63.42±2.02;24 h时加MG132组细胞凋亡为16.67±1.48,与对照组G2/M期时相百分比为7.29±3.01及细胞凋亡为0相比,两者之间有显著性差别(P＜0.01);咖啡因CAF能够减少MG132诱导HL-60细胞出现的G2/M期阻滞,同时也减少凋亡细胞的比例;细胞周期检查点的负调控因子p21waf/cip1蛋白在加MG132处理后3 h有明显的表达,但并未能检测到p53和p27蛋白.结论:MG132诱导HL-60细胞凋亡之前有一个明显的G2/M期阻滞,p21蛋白表达明显上调提示:是p21waf/cip1而不是p53或其同源蛋白参与了其中的调控.     

亚硒酸钠对人早幼粒白血病细胞的RB蛋白磷酸化的影响

 以人早幼粒白血病细胞(HL－60)为实验对象,利用Western－blotting方法和流式细胞仪分析,研究亚硒酸钠对HL－60细胞的RB蛋白产物磷酸化的影响和探讨其抗癌机制。Western－blotting结果显示:与对照组相比,在第四天5.8μmol/LNa2SeO3可使磷酸化Rll蛋白减少49％,去磷酸化RB蛋白仅轻度增加,但在加硒组中去磷酸化RB蛋白占RB蛋白总量的71.1％。与此同时,细胞周期的结果表明:亚硒酸钠对HL－60细胞的G2＋M和S期有一定的阻滞。该实验在蛋白分子水平上研究了亚硒酸钠抑制HL－60细胞增殖的作用机制。     

土贝母皂苷对HL-60细胞周期作用的研究

目的:应用土贝母皂苷(下称皂苷)作用于人早幼粒白血病细胞(HL -60),研究皂苷抗肿瘤作用的分子机制。方法:采用流式细胞术等方法分析细胞周期及凋亡;蛋白印迹免疫法检测细胞凋亡及周期相关基因 bcl- 2、cdc2 和 cy clinB1表达的变化。结果:15μmol/L皂苷作用 24 h 可将 HL -60 细胞阻滞于G2/M期,进而诱导凋亡,流式细胞仪检测肿瘤细胞出现典型的亚二倍体“凋亡小峰”。凋亡抑制基因bcl 2表达无明显变化,周期蛋白 cyclinB1 表达降低,而cdc2表达无明显改变。结论:皂苷导致HL- 60细胞 G2/M期阻滞,进而诱导凋亡;周期阻滞的分子机制与降低 cy clinB1蛋白水平有关,而凋亡的诱导与bcl- 2表达无关。     

Arsenic trioxide induces oxidative stress,DNA damage,and mitochondrial pathway of apoptosis in human leukemia (HL-60) cells

Background

Acute promyelocytic leukemia (APL) is a subtype of acute myeloid leukemia (AML), which accounts for approximately 10% of all acute myloid leukemia cases. It is a blood cancer that is formed by chromosomal mutation. Each year in the United States, APL affects about 1,500 patients of all age groups and causes approximately 1.2% of cancer deaths. Arsenic trioxide (ATO) has been used successfully for treatment of APL patients, and both induction and consolidated therapy have resulted in complete remission. Recently published studies from our laboratory have demonstrated that ATO pharmacology as an anti-leukemic drug is associated with cytotoxic and genotoxic effects in leukemia cells.

Methods

In the present study, we further investigated the detailed molecular mechanism of ATO-mediated intrinsic pathway of apoptosis; using HL-60 cells as a test model. Oxidative stress was assessed by spectrophotometric measurements of MDA and GSH levels while genotoxicity was determined by single cell gel electrophoresis (Comet assay). Apoptosis pathway was analyzed by Western blot analysis of Bax, Bcl2 and caspase 3 expression, as well as immunocytochemistry and confocal imaging of Bax and Cyt c translocation and mitochondrial membrane potential depolarization.

Results

ATO significantly (p < 0.05) induces oxidative stress, DNA damage, and caspase 3 activityin HL-60 cells in a dose-dependent manner. It also activated the intrinsic pathway of apoptosis by significantly modulating (p < 0.05) the expression and translocation of apoptotic molecules and decreasing the mitochondrial membrane potential in leukemia cells.

Conclusion

Taken together, our research demonstrated that ATO induces mitochondrial pathway of apoptosis in HL-60 cells. This apoptotic signaling is modulated via oxidative stress, DNA damage, and change in mitochondrial membrane potential, translocation and upregulation of apoptotic proteins leading programmed cell death.     

Z-ajoene引起HL-60细胞G2/M期阻滞及端粒酶表达活性的降低

目的 探讨Z-ajoene诱导细胞周期阻断于G2／M期的分子机制以及对端粒酶活性的抑制作用。方法 采用MTT法测定Z-ajoene对HL-60细胞的增殖抑制率;以流式细胞仪测定Z-ajoene对HL-60细胞的周期阻断作用,并采用Western blot法测定相关蛋白p34^cdc2、cyclinB1、cyclinA的表达水平;TRAP-银染法测定端粒酶活性的变化,同时采用RT-PCR方法检测端粒酶hTRT和TP1mRNA的表达。结果 10μmol／L Z-ajoene作用后能明显将HL-60细胞阻滞于G2／M期。在药物作用10h后,G2／M期细胞的比例达到顶峰,与对照组比较增加了1．95倍。另外,10μmol／L Z-ajoene作用后出现cyclinB1蛋白的聚集及p34^cdc2蛋白表达的降低,但cyclinA蛋白的水平并无显著性变化。经Z-ajoene作用24h后,HL-60细胞端粒酶活性显著降低。而不同浓度的药物作用12h,其端粒酶活性均无显著性变化。在10μmol／L Z-ajoene作用24h后,能够降低端粒酶hTRT和TP1 mRNA的水平。结论 Z-ajoene能够在作用较短时问内明显将细胞周期阻断于G2／M期,同时伴有cyclinB1聚集及p34^cdc2的抑制;而HL-60细胞的端粒酶活性仅在药物作用较长时间后才有一定降低,并且端粒酶hTRT和TP1mRNA的表达也同时降低。结果表明,Z-ajoene的细胞周期阻断作用可能是造成端粒酶缺失及HL-60细胞生长抑制的重要原因。     

细胞色素C诱导HL-60细胞凋亡及其周期特异性分析

目的分析细胞色素C诱导HL-60细胞凋亡的时间效应及其细胞周期的特异性.方法 (1)利用透射电镜观察细胞色素C诱导HL-60细胞凋亡时凋亡小体的形成;(2)应用流式细胞仪技术检测细胞色素C诱导HL-60细胞的凋亡率并分析其凋亡的时-效关系以及凋亡与细胞周期的关系.结果 (1)细胞色素C作用HL-60细胞24小时发生凋亡,形成凋亡小体;(2)细胞色素C诱导HL-60细胞凋亡的作用体现一定的时间效应,作用时间不同,诱导凋亡率亦不相同,其中作用24小时凋亡率最高;(3)细胞色素C诱导HL-60凋亡的作用具有细胞周期特异性,随凋亡率升高,S期和G2期细胞比例随之下降,且S期细胞比例与凋亡率二者呈显著负性关系(r=0.718,P＜0.01).结论细胞色素C诱导HL-60细胞凋亡与细胞周期密切相关,其周期特异性具有一定的实际意义.     

Resveratrol, an antioxidant present in red wine, induces apoptosis in human promyelocytic leukemia (HL-60) cells

Resveratrol, a triphenolic stilbene present in grapes and other plants, has striking antioxidant and anti-inflammatory activities which have been considered to be responsible for the beneficial effects of red wine consumption on coronary heart disease. Recent studies reveal that resveratrol can inhibit each step of multistage carcinogenesis. However, the molecular mechanisms underlying anti-tumorigenic or chemopreventive activities of this phytochemical remain largely unknown. In the present work, we have found that resveratrol reduces viability and DNA synthesis capability of cultured human promyelocytic leukemia (HL-60) cells. The growth inhibitory and antiproliferative properties of resveratrol appear to be attributable to its induction of apoptotic cell death as determined by morphological and ultrastructural changes, internucleosomal DNA fragmentation, and increased proportion of the subdiploid cell population. Resveratrol treatment resulted in a gradual decrease in the expression of anti-apoptotic Bcl-2. These results, together with previous findings, suggest the cancer therapeutic as well as chemopreventive potential of resveratrol.     

亚硒酸钠和维甲酸联合对HL－60细胞生长、分化的影响

 以人早幼粒白血病细胞（HL－60）为实验对象，观察了亚硒酸钠和维甲酸联合作用对其生长、分化的影响。结果表明：5.8μmol/L亚硒酸钠和0.1μmol/L维甲酸联合可显著抑制细胞生长，且细胞毒性并无增加，强于两者的单独作用。而且可明显诱导细胞向粒系细胞分化，在处理5天后有72%的细胞进行分化。单用0.1μmol/L维甲酸只有39%的细胞分化成熟。NBT还原实验表现出类似结果。     

亚硒酸钠和维甲酸联合对HL－60细胞生长、分化的影响

以人早幼粒白血病细胞（ＨＬ－６０）为实验对象，观察了亚硒酸钠和维甲酸联合作用对其生长、分化的影响。结果表明：５．８μｍｏｌ／Ｌ亚硒酸钠和０．１μｍｏｌ／Ｌ维甲酸联合可显著抑制细胞生长，且细胞毒性并无增加，强于两者的单独作用。而且可明显诱导细胞向粒系细胞分化，在处理５天后有７２％的细胞进行分化。单用０．１μｍｏｌ／Ｌ维甲酸只有３９％的细胞分化成熟。ＮＢＴ还原实验表现出类似结果。     

G2/M cell cycle arrest and apoptosis induced by COH-203 in human promyelocytic leukemia HL-60 cells

The combretastatin A-4/oltipraz hybrid (COH), 5-(3-amino-4-methoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-3H−1,2-dithiole-3-one (COH-203) is one of the COH compounds synthesized by our previous study, which has been reported to affect a number of cancer cell lines, such as SGC-7901, KB, HT-1080, HepG2, SMMC-7721 and BEL-7402. The sensitivity of human acute leukemia cell lines to COH-203, and the mechanism underlying its anti-proliferative effects remain unknown, which was investigated in the present study. In the present study, it was demonstrated that COH-203 had notable time- and dose-dependent antiproliferative effects on the human acute promyelocytic leukemia HL-60 cell line. Furthermore, COH-203 treatment resulted in cell cycle arrest at G₂/M phase in a dose-dependent manner, and subsequently induced apoptosis. Western blot analysis revealed that upregulation of cyclin B was associated with G₂/M arrest. In addition, treatment with COH-203 resulted in downregulated expression of Bcl-2. This result revealed that COH-203-induced apoptosis in HL-60 cells may occur via the mitochondrial pathway in a caspase-dependent manner.     

Baicalin induces apoptosis in leukemia HL-60/ADR cells via possible down-regulation of the PI3K/Akt signaling pathway

Background: The effect and possible mechanism of traditional Chinese medicine, baicalin, on the PI3K/Akt signaling pathway in drug-resistant human myeloid leukemia HL-60/ADR cells have been investigated inthis current study. Methods: HL-60/ADR cells were treated by 20, 40, 80 μmol/L baicalin followed by cell cycleanalysis at 24h. The mRNA expression level of the apoptosis related gene, Bcl-2 and bad, were measured byRT-PCR on cells treated with 80 μmol/L baicalin at 12, 24 and 48hr. Western blot was performed to detect thechanges in the expression of the proteins related to HL-60/ADR cell apoptosis and the signaling pathway beforeand after baicalin treatment, including Bcl-2, PARP, Bad, Caspase 3, Akt, p-Akt, NF-κB, p-NF-κB, mTOR andp-mTOR. Results: Sub-G1 peak of HL-60/ADR cells appeared 24 h after 20 μmol/L baicalin treatment, andthe ratio increased as baicalin concentration increased. Cell cycle analysis showed 44.9% G0/G1 phase cells24 h after baicalin treatment compared to 39.6% in the control group. Cells treated with 80 μmol/L baicalindisplayed a trend in decreasing of Bcl-2 mRNA expression over time. Expression level of the Bcl-2 and PARPproteins decreased significantly while that of the PARP, Caspase-3, and Bad proteins gradually increased. Nosignificant difference in Akt expression was observed between treated and the control groups. However, theexpression levels of p-Akt, NF-κB, p-NF-κB, mTOR and p-mTOR decreased significantly in a time-dependentmanner. Conclusions: We conclude that baicalin may induce HL-60/ADR cell apoptosis through the PI3K/AKTsignaling pathway.     

5'-nitro-indirubinoxime induces G2/M cell cycle arrest and apoptosis in human KB oral carcinoma cells

Our previous study demonstrated that the novel indirubin derivative, 5'-nitro-indirubinoxime (5'-NIO), effectively arrested the tumor growth through the inhibition of cell proliferation and the induction of apoptosis. However, the precise molecular mechanisms underlying 5'-NIO-induced antitumor activity remain unclear. Here, we report that 5'-NIO inhibits the proliferation of human KB oral carcinoma cells via the cell cycle arrest in G2/M phase. 5'-NIO reduced the activity of Cdc2/cyclin B complex through the inhibition of the PLK1 expression. Partially, 5'-NIO also arrested cell cycle in G1/S phase via the reduction of CDK4 and cyclin D1/D3 levels by p16 and induction of the level of p21waf1. Using flow cytometry analysis, we showed that 5'-NIO-induced cell cycle arrest is followed by apoptosis. We determined further that 5'-NIO-induced apoptosis is accomplished by the mitochondria-dependent activation of the caspase cascade. Overall, these observations suggest the potential value of 5'-NIO as a candidate for a therapeutic modality for the treatment of oral cancer.     

~(131)I-GMCSF诱导HL-60细胞凋亡与细胞周期阻滞的研究

目的　观察和探讨1 31 I-GMCSF诱导HL - 6 0细胞凋亡及其与细胞周期的关系。方法　采用体外放射免疫治疗模型,通过MTT比色法、TUNEL来研究1 31 I -GMCSF辐射后HL - 6 0细胞的存活率、凋亡率的改变;用流式细胞术及免疫细胞化学方法细胞周期的改变。结果　放射性浓度≥18.5×10 8Bq/L时HL - 6 0细胞存活率显著下降。1 31 I -GMCSF能致HL - 6 0细胞凋亡、细胞发生G2 /M期阻滞。结论　GMCSF作为载体携带1 31 I能诱导HL - 6 0细胞凋亡,凋亡与细胞发生G2 /M期阻滞有关。     

Epigallocatechin-3-gallate induces apoptosis and cell cycle arrest in HTLV-1-positive and -negative leukemia cells

The objective of this study is to evaluate the efficacy of epigallocatechin gallate against ATL cells. The anti-proliferative and pro-apoptotic effects of EGCG were evaluated in HTLV-1-positive and -negative cells. EGCG exhibited a marked decrease in proliferation of ATL cells at 96 h of treatment. The results indicated that TGF-α was down-regulated whereas levels of TGF-β2 increased. Cell cycle distribution analysis revealed an increase in cells in the pre-G₁ phase which was confirmed by ELISA. The results on proteins showed an up-regulation of p53, Bax and p21 protein levels while the levels of Bcl-2α were down-regulated.     

HL-60和SiHA细胞株ATM表达量与60Co照射后细胞周期阻滞之间的关系

背景与目的:毛细血管扩张性共济失调综合征( ataxia telangiectasia,AT)是由 ATM( ataxia telangiectasia mutant)基因所致,其突出特点是对放射线非常敏感,因此, ATM表达与放射敏感性应存在相关性.本研究旨在探讨两种肿瘤细胞株 ATM表达量与 60Co照射后细胞周期阻滞功能之间的关系.方法:使用半定量 RT-PCR和流式细胞仪技术检测 HL-60细胞和 SiHA细胞中 ATM mRNA和 ATM蛋白表达量,同时以 6、 10和 15 Gy 60Co照射 SiHA细胞, HL 60细胞仅以 6、 10 Gy照射,于照射后 6、 12、 24、 48及 60 h观察细胞周期阻滞现象和细胞凋亡率的变化.结果: HL 60细胞 ATM平均蛋白荧光强度为 14.11±2.38, SiHA细胞为 27.74± 1.16,约为 HL-60细胞的 2倍; HL-60细胞 ATM mRNA相对表达量为 0 .09, SiHA细胞为 0.80,约为 HL-60细胞的9倍.照射后 HL-60细胞和 SiHA细胞均表现 G2/M期阻滞.射线对 HL-60细胞周期阻滞功能明显较 SiHA细胞弱.结论:放射线对 HL-60细胞和 SiHA细胞的周期阻滞功能与 ATM表达量相符,即 ATM表达量低,细胞周期阻滞功能差.     

Molecular mechanisms of G0/G1 cell-cycle arrest and apoptosis induced by terfenadine in human cancer cells

Terfenadine (TF), a highly potent histamine H1 receptor antagonist, has been shown to exert no significant central nervous system side effects in clinically effective doses. In this study, we demonstrated that TF induced significant growth inhibition of human cancer cells, including Hep G2, HT 29, and COLO 205 cells, through induction of G(0)/G(1) phase cell-cycle arrest. The minimal dose of TF induced significant G(0)/G(1) arrest in these cells was 1-3 microM. The protein levels of p53, p21/Cip1, and p27/Kip1 were significantly elevated, whereas the kinase activities of cyclin-dependent kinase 2 (CDK2) and CDK4 were inhibited simultaneously in the TF-treated cells. On the other hand, significant apoptosis, but not G(0)/G(1) arrest, was induced in the HL 60 (p53-null) or Hep 3B (with deleted p53) cells when treated with TF (3-5 microM). To clarify the roles of p21/Cip1 and p27/Kip1 protein expression, which was involved in G(0)/G(1) arrest and apoptosis induced by TF in human cancer cells, antisense oligodeoxynucleotides (ODNs) specific to p21/Cip1 and p27/Kip1 were used, and the expression of the p21/Cip1 and p27/Kip1 were monitored by immunoblotting analysis. Our data demonstrated that the percentage of the apoptotic cells detected by annexin V/PI analysis in the TF-treated group was clearly attenuated by pretreatment with p27/Kip1-specific ODNs. These results indicated that p27/Kip1 (but not p21/Cip1) protein indeed played a critical role in the TF-induced apoptosis. We also demonstrated that the TF-induced G(0)/G(1) cell-cycle arrest effect was not reversed by TF removal, and this growth inhibition lasted for at least 7 d. Importantly, the occurrence of apoptosis and cell growth arrest was not observed in the TF-treated normal human fibroblast, even at a dose as high as 25 microM. Our study showed the molecular mechanisms for TF-induced cell growth inhibition and the occurrence of apoptosis in human cancer cells.