Survivin Antisense Oligodeoxy-Nucleotid Induces Apoptosis in Leukaemia Cell Line K562

OBJECTIVE To investigate the effects of survivin antisense oligodeoxy-nucleotid (ASODN) on proliferation and apoptosis in the chronic myeloid leukemia cell line K562. METHODS Different concentrations of an antisense oligodeoxy-nucleotid and control sequence (scrambled ODN) targeting the survivin gene were transferred into K562 by a lipofectin reagent. The MTT assay was used to measure the growth inhibitory rate, IC50, and to observe the cytotoxicity of survivin ASODN in the K562 cells. The morphologic changes in the nucleus and the apoptotic rate were observed by Hoechst33342/PI staining. Caspase-3 activity was evaluated by a kinase activity assay. The changes of survivin protein expression after transfection were detected by Western blots. RESULTS Eight hours after transfection, fluorescence in the K562 cells was well distributed. Treatment of the cells for 44 h with different concentrations of survivin ASODN produced a IC50 of 800 nmol/L. The growth inhibitory rate with 200, 400, 600 and 1000 nmol/L of survivin ASODN was 15.8±1.6%, 23.8±5.9%, 37.1±5.6% and 77.3±2.5% respectively. After 36 h of of survivin ASODN treatment, distinct morphologic changes characteristic of cell apoptosis such as karyopyknosis and conglomeration were observed by Hoechst33342/PI staining. Caspase-3 activity increased significantly after treatment of the cells with different concentrations of survivin ASODN(P<0.01)and following treatment with 800 nmol/L survivin ASODN, survivin expression decreased significantly. CONCLUSION Survivin ASODN exerts an anti-cancer effect by inducing apoptosis in K562 leukaemia cells. Up-regulated expression of caspase-3 may play a role in this process.

INDEPENDENT AND SYNERGIC INHIBITION OF DIPYRIDAMOLE AND RADIATION ON K562-AND K562/ADM CELL LINES IN VITRO

It is first demonstrated that dipyridamole (DP) and radiation were capable of significantly inhibiting, independently and synerglcally, clonogenlc growth in the two kinds of K562 cell lines, adriamycin (ADM) -sensitive and ADM- resistant. DP or radiation alone Increased clonogenlc Inhibition rate (CIR) in the two kinds of cell lines in a dose- dependent fashion. DP potentiated radiosensitivity and radiation increased inhibition of DP in the two kinds of cell lines. K562/ ADM cell lines were higher sensitive to DP. radiation and combination of them than K562 cell lines (P<0. 01). There was stronger synergic inhibition of clonogenlc growth in the two kinds of cell lines when pretreated with DP than when posttreated with DP (P<0. 01).

INDEPENDENT AND SYNERGIC INHIBITION OF VERAPAMIL AND ELECTRIC BEAM RADIATION ON CLONOGENIC GROWTH IN K562 AND K562/ADM CELL LINES IN VITRO

It was first reported here that verupamil(VP) and electric beam radiation(EBR) were capable of inhibiting,independently or synergically,clonogenic growth in two kinds of K562 cell lines, adriamycin(ADM)-sensitive and ADM-resistant(K562/S and K562/ADM).Results showed that clonogenic rate(CGR) decreased by 3%-99.9% in the prasence of dependent dose-ADM(3.8μg/ml) in K562/ADM cell lines,while treated with 0.5μM-6μM of VP.VP was capable of potentiating radiosensitivity in K562/S and K562/ADM cell lines,whether before or after exposure of them to electric beam radiation,and significantly reduced CGR in these kinds of cell lines(P<0.01).

泰索帝对人甲状腺未分化癌细胞系(TA-K)增殖抑制作用

目的研究泰索帝对甲状腺未分化癌细胞系(TA-K)的增殖抑制作用。方法用MTT法检测不同浓度、不同作用时间泰索帝对人甲状腺未分化癌细胞系(TA-K)的增值情况。结果TA-K在泰索帝作用下细胞增殖受到抑制,当浓度为0.01μg/ml抑制作用最明显,随着作用时间的延长,抑制率增加。结论泰索帝对甲状腺未分化癌细胞有明显的抑制作用。

The Proteasomal Inhibitor MG132 Potentiates Apoptosis of Triptolide-Treated K562 Cells by Regulating the NF-κB Signal Pathway

OBJECTIVE To explore the anticancer mechanism of triptolide in human leukemia K562 cells,and to further determine whether the proteasomal inhibitor,MG132,can potentiate apoptosis in triptolide-treated K562 cells.METHODS Apoptosis was assessed via annexin V/PI double-labeled cytometry.The expressions of the IκBα and NF-κB/p65 proteins in K562 cells was investigated using Western blo ing.RESULTS The inhibitory rates of K562 cells treated by triptolide gradually increased in a dose-and time-dependent manner,and treatment with triptolide plus MG132 potentiated the apoptotic rate.Triptolide inhibited the degradation of the IκBα protein and the nuclear localization of NF-κB/p65 proteins induced by TNF-α,and MG132 potentiated the effect of triptolide.Triptolide plus MG132 almost completely blocked the NF-κB activation induced by TNF-α.CONCLUSION The anti-proliferative activities of triptolide and MG132 were related to the NF-κB signal pathway.

Apoptotic effect and mechanisms of AHPN on human skin malignant melanoma cell A375

Objective： To study apoptotic effects of synthetic retinoic acid 6-[3-（1-adamantyl）-4-hydroxyphenyl]-2-naphthalene carboxylic acid（AHPN） on human skin malignant melanoma A375 cells in comparison with the natural ligand all-trans-retinoic acid（ATRA） in vitro and the mechanisms related to the actions of AHPN. Methods：MTT assay was used to determine the anti-proliferative effects of AHPN and ATRA on A375 cells. Flow cytometry was performed to investigate the influence of AHPN and ATRA on cell cycle and cell apoptosis. In addition, transfection and luciferase activity assays were employed to explore the mechanisms of how AHPN executes its proapoptotic function. Results：Firstly, AHPN promoted apoptosis and GI arrest in A375 cells compared with ATRA. Secondly, the activity of NF-K B in A375 cells treated with AHPN increased 2-3 times compared with solvent DMSO treatment. Conclusion：AHPN, in comparison with ATRA, is a more effective alternative for therapy of malignant melanoma. The potentially proapoptotic function of AHPN requires activation of NF-K B.

Thymidylate synthase confers pemetrexed resistance of non-small cell lung cancer cells by EGFR/PI3K/AKT pathway

Chemotherapy drug resistance is the main cause leading to the relapse and metastasis of non-small cell lung cancer(NSCLC)patients.Our study aimed to investigate the mechanism of pemetrexed resistance in NSCLC.Firstly,the pemetrexed(PEM)-resistant PC-9 and A549 lung adenocarcinoma cell lines(PC-9/PEM and A549/PEM)were established.The expression of thymidylate synthase(TS)in PC-9/PEM,A549/PEM,A549,and PC-9 cells were analyzed by qRT-PCR and western blot.Then,cell viability,colony formation,migration,and invasion were performed on PEM-resistant cells transfected with TS siRNA.The role of EGFR in PEM resistance of PEM-resistant cells was investigated using EGFR siRNA.The effects of gefitinib and EGFR siRNA on EGFR/PI3K/AKT pathway and downstream signaling Cyclin D1 and E2F1 in PEM-resistant cells were analyzed.Results showed that the protein level of TS was significantly increased in A549/PEM and PC-9/PEM.TS knockdown inhibited the potency of proliferation,colony-forming potential,migration,and invasion in PEM-resistant cells.EGFR knockdown abrogated the resistance to PEM of PEM-resistant cells and suppressed the migration and invasion of PEM-resistant cells.Gefitinib treatment and EGFR knockdown respectively inhibited the EGFR/PI3K/AKT pathway and downregulated Cyclin D1 and E2F1 in PEM-resistant cells.Thus,TS might be a predictive marker for PEM resistance in NSCLC.Inhibition of the EGFR pathway abrogated the resistance to PEM and inhibited the EGFR/PI3K/AKT and downstream signaling of PEM-resistant NSCLC cell lines.

Study on Taxol in Inhibiting Human Leukemia Cell Proliferation andInducing Apoptosis

Objective: To explore the effects of Taxol in inhibiting human leukemia k562 cell proliferation and inducing apoptosis in vitro. Methods: Human leukemia K562 cells were treated with Taxol of different concentrations for 12-72 hrs. Cell proliferation was evaluated by MTT assay and morphological changes of apoptosis were examined by microscopy. Cell apoptosis was determined by flow cytometry (FCM) and DNA gel electrophoresis. Results: Growth of K562 cells was inhibited by Taxol with an IC50 value of 0. 84μg/ml. Typical nuclear condensation and apoptosis bodies were observed as early as 24 hrs after a 0.5μg/ml Taxol treatment; Apoptotic rate of the Taxol-treated K562 cells increased from 3.7% to 24.0% in 24 hrs. No DNA ladder was observed by DNA gel electrophoresis. Conclusion: Taxol could inhibit K562 cell growth and induce apoptosis in vitro.

Effects of Root Extracts from <i>Panax ginseng</i>C. A. Meyer (Araliaceae) of Different Ages on K562 Cells

It is well accepted in China that elder ginsengs have more bioactivity and value than younger ones. However, there is little research about the comparison of beneficial effects of ginsengs with different ages. In this study, ginseng root extracts (GRE) were extracted from ginsengs of 5, 8, 12, 14, and 16 years old, respectively, using 55% ethanol and their effects on human leukemic K562 cells within 48 hours were tested by using Cell Counting Kit-8. The results show that there are significant increases in the cell viability of all the GRE groups compared with Control group within 32 hours. Furthermore, the growth curves of GRE groups were obviously distinct from each other. The cell viability of 5-year-old and 8-year-old GRE groups kept a rapid increase while that of 16-year-old GRE group showed a strong fluctuation within 28 hours. Our results demonstrate that root extracts from ginsengs of different ages contain different bioactivity constituents and have different effects on cell.

绞股蓝总皂甙对小鼠S_(180)肉瘤及K_(562)细胞的抑制作用

目的 绞股蓝总皂甙 (GP)对小鼠S180 肉瘤及K562 细胞的抑制作用。方法 通过动物实验观察绞股蓝总皂甙对小鼠S180 肉瘤生长状况、肿瘤坏死面积 (TNA)与肿瘤总面积 (TTA)的比率、瘤周瘤内免疫活性细胞浸润状况及荷瘤小鼠脾脏的影响 ;通过细胞培养观察绞股蓝总皂甙对K562 细胞生长的抑制作用。结果 经重复实验证实 ,GP能显著抑制小鼠S180 肉瘤的生长 ,TNA与TTA的比率显著增加 ,瘤周尤其是瘤内淋巴细胞、巨噬细胞浸润数量明显增加 ,荷瘤小鼠脾重增加、脾白髓数目增多、体积增大。同时证实 ,GP对K562 细胞株具有明显的生长抑制作用。结论 GP的抑瘤作用主要是直接杀伤瘤细胞 。

莪术油诱导K-562细胞凋亡分子机制的实验研究

目的探讨莪术油(OCW)诱导慢性粒细胞白血病(CML)细胞株K-562凋亡及可能的分子机制。方法以不同浓度OCW(0,2.5,5,10和20 mg/mL)处理K-562细胞24 h后,光镜下观察形态学改变;CCK-8法检测细胞增殖抑制率;Hoechest33258荧光染色及FITC-AnnexinⅤ/PI双染法检测细胞凋亡率;半定量RT-PCR及Western blot方法检测bcr/abl、bcl-2、p53、Fas/FasL表达的变化。结果OCW明显抑制K-562细胞增殖,诱导细胞凋亡,与浓度呈正相关;各组药物干预后Fas/FasL基因在mRNA和蛋白水平呈浓度依赖性上调,而bcr/abl、bcl-2、p53基因表达无明显变化。结论不同浓度OCW能有效诱导K-562细胞凋亡,其作用可能通过Fas/FasL途径而实现的,与bcr/abl、bcl-2、p53基因无明显相关。

人突变K-ras基因修饰lewis肺癌细胞株的建立及其生物学特性

目的:探讨以K-ras基因为靶点,建立人K-ras(12位密码子点突变)基因修饰的lewis肺癌细胞株3LL-pcDNA3-K-ras/V12及其生物学特性。方法:应用脂质体法将人K-ras(12位密码子点突变)基因cDNA导入lewis肺癌细胞株3LL,应用流式细胞仪检测p21/V12蛋白的表达,同时检测3LL细胞株转基因前后生长、克隆形成率和体内成瘤的变化。结果:成功的将人K-ras(12位密码子点突变)基因cDNA导入lewis肺癌细胞株3LL,p21/V12蛋白在3LL-pcDNA3-K-ras/V12中稳定表达,转基因细胞株的生长曲线和克隆形成率与原代细胞株3LL无显著差异;但转基因细胞株在C57BL/6小鼠体内的成瘤性显著高于原代细胞株3LL。结论:成功的建立了导入K-ras(12位密码子点突变)的lewis肺癌细胞株3LL-pcDNA3-K-ras/V12。

生物反应调节剂与化疗药物对K-562白血病细胞系的体外协同作用

体外对生物反应调节剂(BRMs)单独及与化疗药物并用对阿霉(ADM)素敏感和耐药的K-562细胞系进行了研究。用RPMI-1640液体培养法培养细胞,以抑制率做为判断指标,研究结果如下:(1)10~3U/ml浓度IFN-α、-β和-γ对K-562细胞的抑制率分别为0.51、0.46、0.28;IFN-α、-β和-γ联合应用,抑制率无增加;对K-562/ADMIFN单独应用效果可疑,但IFN-α、-β与-γ联合应用,抑制作用明显增强;(2)IFN与ADM联合应用,对K-562细胞的抑制率为两种药物单独应用时抑制率之和,但对K-562/ADM的抑制率大于二者抑制率之和;3种IFN之间作用无差异;(3) G-CSF或RA与ADM合用能明显增强ADM对K-562/ADM细胞的抑制作用;(4) K-562/ADM细胞对MTX无交叉耐药性,对VP-16有部分交叉耐药性;RA与VP-16并用,能增强VP-16对K-562/ADM细胞的抑制作用。研究结果证明,某些BRMs可直接抑制K-562细胞,与化疗药物并用有协同作用。这种协同作用对K-562/ADM细胞尤其明显。BRMs与化疗药物联合应用可能有助于难治性或复发性白血病的治疗。

Klotho蛋白减轻低氧/复氧诱导的心肌细胞系H9C2损伤

目的研究Klotho蛋白对低氧-复氧诱导的心肌H9C2细胞系损伤的保护作用及其机制。方法将H9C2心肌细胞分为对照组、低氧/复氧组(1%O_2低氧6 h, 5%CO_2以及95%空气培养箱中复氧2 h)和Klotho蛋白(10μg/mL)干预组。通过酶标仪间接测定细胞内钙离子([Ca^(2+)]_i)水平;CCK8法和TUNEL法分别检测细胞活性及细胞凋亡;分光光度法检测细胞中钠ATP酶(Na^+/K^+-ATPase,NKA)和反向模式钠/钙交换体(Na^+/Ca^(2+)-exchange,NCX)的活性。结果体外培养的H9C2细胞低氧/复氧(6 h/2 h)处理后可明显降低H9C2细胞活性(P<0.05);增加细胞内Ca^(2+)水平和凋亡率(P<0.05);降低细胞中Na^+/K^+-ATPase的活性(P<0.05);增加反向模式Na^+/Ca^(2+)交换体的活性(P<0.05);10μg/mL Klotho蛋白处理可明显减轻上述损伤。结论 Klotho蛋白可减轻低氧/复氧诱导下的H9C2细胞内钙超载,最终减少该细胞系细胞的凋亡。

特异性抗人胰腺癌细胞株8988s突变型K-ras mRNA核酸代酶的设计

目的:设计特异切割人胰腺癌8988s细胞株中突变型K-ras基因mRNA的核酸代酶(ribozyme)。方法:PCR扩增人胰腺癌细胞株8988s的K-ras基因第一外显子,克隆并测序,明确有否突变、突变类型,以该基因mRNA为靶分子,进行计算机二级结构预测分析,选择核酸代酶切点,并进行基因组同源性分析,设计理论上最佳的核酸代酶。结果:人胰腺癌8988s中K-ras基因12密码子有突变,突变类型为GGT→GTT,设计筛选了三种针对人胰腺癌8988s突变型K-ras mRNA的核酸代酶分子,其中一种为特异性的。结论:人胰腺癌8988s中K-ras突变位点可成为特异性核酸代酶切割位点,切割此位点的核酸代酶对野生型K-ras mRNA功能无影响,K-ras编码序列中第199、205、217位点也为核酸代酶切割的理想位点。

超声对人红白血病细胞系K_(562)作用的研究

超声对人红白血病细胞系Ｋ５６２作用的研究齐浩１马玉英２谭声江１宋存牛２（１陕西师范大学生命科学学院，西安７１００６２；２陕西师范大学应用声学研究所，西安７１００６２；第一作者，女，４２岁，讲师）光动力学（ＰＤＴ）问世以来，实验已证实超声（ＵＳ）也可激...

Roles of Optineurin and Extracellular Vesicles in Glaucomatous Retinal Cell Loss

Objective To explore the role of extracellular vesicles(EVs)in the pathogenesis of glaucoma caused by E50K mutation.Methods A photoreceptor cell line,RGC-5,was transfected with empty plasmids and plasmids expressing wild-type(WT)optineurin(OPTN)or E50K OPTN to investigate the effects of OPTN glaucoma as well as to identify the role of EVs in glaucoma pathology.The RGC-5 cells were also stimulated with glutamate,and their viability was evaluated using flow cytometry or CCK-8 assay.EVs were extracted,labeled with PKH-26,and added into the medium for normal RGC-5 culture,and the status of the cells was observed thereafter.Results WT OPTN overexpression,E50K OPTN,and glutamate stimulation induced apoptosis of RGC-5 cells.However,when glutamate stimulation was used as an add-on treatment,the degree of apoptosis in WT OPTN-overexpressing RGC-5 cells was significantly lower than that in E50K OPTN-expressing and normal RGC-5 cells.The viability of normal RGC-5 cells was reduced when co-cultured with WT OPTN-overexpressing RGC-5 or E50K OPTN-overexpressing RGC-5.EVs released by the latter two transfected lines similarly reduced normal RGC-5 survival.Conclusion Our results indicate that WT OPTN overexpression may lead to photoreceptor apoptosis.However,overexpression also confers a degree of protection against high concentrations of extracellular glutamate.Additionally,EVs released by transfected RGC-5 cells may regulate the cell state.These findings may improve our understanding of the mechanisms of cell-cell interactions in pathological conditions,providing a basis for the use of EVs as novel targets for early diagnosis and treatment of glaucoma.

Reversal effect of bufalin on multidrug resistance in K562/VCR vincristine-resistant leukemia cell line

OBJECTIVE: To probe insights into the reversal effect of bufalin on vincristine-acquired multidrug resistance(MDR) in human leukemia cell line K562/VCR.METHODS: Proliferative inhibition rate and the reversal index(RI) of bufalin were determined by Methyl thiazolyl tetrazolium assay. The uptake of Adriamycin(ADM) in K562/VCR cells, cell cycle and apoptosis rate were determined by flow cytometry(FCM). Cell morphologic changes were observed with Wright-Giemsa staining. The expression of P-glycoprotein(P-gp), multidrug-associated protein-1(MRP1), Bcl-x L and Bax protein were measured by immunocytochemistry.RESULTS: The human leukemia multidrug resistant K562/VCR cells showed no cross-resistance to bufalin. The RIs of bufalin at concentrations of 0.0002,0.001 and 0.005 μmol/L were 4.85, 6.94 and 14.77,respectively. Preincubation of 0.001 μmol/L bufalin for 2 h could increase intracellular ADM fluorescence intensity to 28.07%(P<0.05) and down-regulate MRP1 expression simultaneously, but no remarkable effect was found on P-gp protein. Cell cycle analysis indicated increased apoptosis rate and apparent decreased G2/M phase proportion after treatment with bufalin. When exposed to 0.01μmol/L bufalin, typical morphological changes of apoptosis could be observed. Down-regulation of Bcl-x L and up-regulation of Bax expression in K562/VCR cells could be detected by immunocytochemistry.CONCLUSION: Bufalin could partly reverse the MDR of K562/VCR cells, with a possible mechanism of down-regulating MRP1 expression and activating apoptosis pathway by altering Bcl-x L/Bax ratio.

β-榄香烯诱发肿瘤细胞凋亡的研究

目的 :探讨 β -榄香烯的抗癌疗效及其作用机制。方法 :采用MTT方法、Hoechst3334 2和PI荧光染色法、电镜及流式细胞术分析法 ,发现 β-榄香烯乳剂对K562 细胞生长的影响。结果 :β -榄香烯明显抑制K562 细胞的生长 ,对K562 细胞的半数生长抑制剂量 (IC50 )为 17.14μg/ml。其抑制细胞生长能力主要是通过诱导细胞凋亡 ,并且呈浓度和时间依赖性。在影响细胞周期方面 ,主要使G1期细胞数目增多 ,S期细胞数目下降。结论 :β -榄香烯诱导细胞凋亡是其抗肿瘤作用机制的重要方面之一。