阿糖胞苷诱导HL—60细胞凋亡的研究

明确化疗药物诱导急性白血病细胞凋亡的规律及在急性白血病化疗中的意义。方法应用光镜、电镜,结合ＤＮＡ电泳及流式细胞仪分析技术,观察阿糖胞苷（Ａｒａ－ｃ）诱导的急性髓系白血病细胞系ＨＬ－６０凋亡模式。结果Ａｒａ－ｃ诱导的细胞凋亡在０～３６小时过程中持续存在,逐渐增强,其诱导效率呈剂量性增强。而且,经其他６种化疗药物诱导后,ＨＬ－６０以及经ＤＡ方案化疗的１例急性髓系白血病患者外周血白细胞,均表现典型的ＤＮＡ梯形图谱。进一步分析表明,化疗诱导凋亡与其下调ｃ－ｍｙｃ、ｂｃｌ－２基因表达有关。结论化疗药物诱导的细胞凋亡是化疗的关键机制     

人T细胞白血病细胞株Jurkat的TCR基因重排

背景与目的:近年的一些体外实验研究发现,重组激活基因(recombi-nationactivatinggene)编码的RAG1与RAG2(recombinationactivatinggenes,RAGs)蛋白能够介导DNA链的转位(transposition)作用,因而,可能与淋巴系统肿瘤性疾病的发生有关,但迄今尚未有明确定论。我们在实验中发现,代表T细胞发育成熟阶段的人白血病细胞株Jurkat同时表达重组激活基因RAG1和RAG2,并且经适当诱导后有RAGs表达的变化。本研究旨在确证Jurkat细胞是否发生RAGs介导的T细胞受体(T-cellreceptor,TCR)基因重排。方法:采用巢式和半巢式PCR检测T细胞受体D!-J!之间的信号结合T细胞受体删除DNA环(signaljointT-cellreceptorexcisionDNAcircles,sjTRECs);连接介导的PCR(LM-PCR)法检测TCRβ链位点重排中间物-重组信号序列(recombinationsignalsequence,RSS)断点;RT-PCR法检测V(D)J重排第二阶段非同源末端连接(non-homologousendjoining,NHEJ)途径中的核心蛋白Ku70/Ku80及末端脱氧核苷酸转移酶(terminaldeoxynucleotidyltransferase,TdT)。结果:在Jurkat细胞DNA中检测到结合区具有多样性特征的TCRDβ2-Jβ2sjTRECs和RSS5′端和3′端断裂点,并检测到TdT、Ku70/Ku80的表达。结论:Jurkat细胞有TCR基因重排的发生。Jurkat细胞可能成为研究RAGs和TCR基因重排与T细胞淋巴瘤的一个潜在的细胞模型。     

Antiproliferative and proapoptotic effects of a pyrrole containing arylthioindole in human Jurkat leukemia cell line and multidrug-resistant Jurkat/A4 cells

Recently, a series of novel arylthioindole compounds, potent inhibitors of tubulin polymerization and cancer cell growth, were synthesized. In the present study the effects of 2-(1H-pyrrol-3-yl)-3-((3,4,5-trimethoxyphenyl)thio)-1H-indole (ATI5 compound) on cell proliferation, cell cycle progression, and induction of apoptosis in human T-cell acute leukemia Jurkat cells and their multidrug resistant Jurkat/A4 subline were investigated. Treatment of the Jurkat cells with the ATI5 compound for 48 hrs resulted in a strong G₂/M cell cycle arrest and p53-independent apoptotic cell death accompanied by the induction of the active form of caspase-3 and poly(ADP-ribose) polymerase-1 (PARP-1) cleavage. ATI5 treatment also caused non-cell death related mitotic arrest in multidrug resistant Jurkat/A4 cells after 48 hrs of treatment suggesting promising opportunities for the further design of pyrrole-containing ATI compounds as anticancer agents. Cell death resistance of Jurkat/A4 cells to ATI5 compound was associated with alterations in the expression of pro-survival and anti-apoptotic protein-coding and microRNA genes. More importantly, findings showing that ATI5 treatment induced p53-independent apoptosis are of great importance from a therapeutic point of view since p53 mutations are common genetic alterations in human neoplasms.     

Halofuginone enhances the radiation sensitivity of human tumor cell lines

Transforming growth factor beta (TGF-β) is implicated in radiation-induced fibrosis of normal tissues in patients receiving radiotherapy. Inhibiting the TGF-β signaling pathway by various means has been shown to reduce radiation-induced fibrosis in pre-clinical studies. The present study evaluated the effects of interfering with the TGF-β signaling pathway on the radiosensitivity of selected human tumor cell lines using the plant-derived alkaloid, halofuginone. Halofuginone treatment inhibited cell growth, halted cell cycle progression, decreased radiation-induced DNA damage repair, and decreased TGF-β receptor II protein levels, leading to increased cellular radiosensitization. These data further support the goal of manipulating the TGF-β pathway to achieve a positive increase in the therapeutic gain in clinical radiotherapy.     

Collateral sensitivity of a methotrexate-resistant L1210 cell line to the vinca alkaloids

Summary L1210 mouse leukaemia cell lines showing a 20,000-fold differential sensitivity to methotrexate have been shown to exhibit some collateral sensitivity to at least two of the vinca alkaloids, vinblastine and vindesine. Vinblastine is the more cytotoxic for both cell lines. The extent of the collateral sensitivity decreases in the order vindesine>vinblastine >vincristine.Total cellular uptake studies with radiolabelled methotrexate showed only a two- to three-fold greater incorporation in the sensitive line. On the other hand, a two-fold greater incorporation of labelled vincristine occurred in the resistant line. No significant difference in the uptake occurred following labelled vinblastine treatment by the two cell lines.It is unlikely that differences in uptake account for the altered drug responses observed in the two cell lines.     

Cytogenetic and molecular characterization of tumors in nude mice derived from a multidrug-resistant human leukemia cell line

We have evaluated whether selection of a human tumor leukemic line for resistance to vinblastine (Velban; VLB) alters its tumorigenicity. To address this question, CEM and CEM/VLB100 cells [which express the multiple drug-resistant (MDR) phenotype via amplification of the P-glycoprotein gene] were characterized by several techniques including chromosome banding, in situ hybridization, Southern blotting, RNA dot blotting, in vitro drug sensitivity, and tumorigenicity in nude mice. Analysis of the chromosome banding patterns of both drug-sensitive CEM cells and the MDR CEM/VLB100 cells revealed that the two lines differed primarily by the presence of a large metacentric marker chromosome associated with the acquisition of VLB resistance. In situ hybridization of a P-glycoprotein complementary DNA to metaphase chromosomes showed that the amplified P-glycoprotein genes in the CEM/VLB100 cell line were localized to this large marker. Tumorigenicity of both the CEM and CEM/VLB100 cell lines was measured after injection of 10(7) cells/nude mouse. The results showed that 4 of 4 drug-sensitive and 4 of 5 drug-resistant cell lines formed tumors in 5-10 wk. By comparison with the parental line, three of the four tumors arising from the CEM/VLB100 line retained their drug-resistance properties as measured by vinblastine resistance in vitro and elevated P-glycoprotein mRNA expression associated with P-glycoprotein gene amplification. In addition, tumors retaining the MDR phenotype also retained the large metacentric marker chromosome. One tumor arising from CEM/VLB100 reverted to the drug-sensitive phenotype, with a resultant decrease in P-glycoprotein mRNA expression and loss of P-glycoprotein gene amplification. This revertant was also missing the large metacentric marker present in all cells from the CEM/VLB100 parent. Our experiments show that the acquisition of the MDR phenotype resulting from overexpression of P-glycoprotein in the plasma membrane does not effect the tumorigenicity of human CEM cells.     

高能X线诱导人鼻咽癌细胞系移植瘤凋亡的研究

目的通过研究高能Ｘ线诱导人鼻咽癌细胞系移植瘤的凋亡来观察其特异的形态学特征，凋亡与时间、剂量之间的关系。材料与方法ＣＮＥ－２细胞系移植瘤模型经加速器给予一定的剂量，按不同的时间取出肿瘤，于光镜下观察ＨＥ染色切片，并计数凋亡细胞；通过电镜及凝胶电泳分别观察了凋亡细胞的超微结构和特殊的梯度ＤＮＡ片段。结果发现照射后鼻咽癌凋亡细胞出现典型的形态学特征及梯度ＤＮＡ片断。照射４Ｇｙ和８Ｇｙ，分别于受照后０．５小时、２小时、６小时、１２小时、２４小时切取肿瘤，其凋亡指数分别为１．３２％、１．７１％、３．７７％和１．９１％（２４小时未测）；１．８４％、４．２１％、６．６０％、４．１９％及３．０４％。然后按０，２，４，８，１２，２０Ｇｙ照射肿瘤，６小时后其凋亡指数分别为０．３５％、２．３６％、３．７７％、６．６０％、９．９３％及１３．５９％。结论ＣＮＥ－２细胞移植瘤的最大凋亡率出现于照射后６小时，随着照射剂量的增加凋亡指数也随之增加，没有出现明显的变缓。     

心肌细胞裂解液对鼻咽癌CNE-2细胞株的放射增敏作用及其机制的研究

目的 探讨心肌细胞裂解液对鼻咽癌CNE-2细胞的放射增敏作用和机制。方法 采用超滤离心法获得分子量＞10kD、＜5kD及5～10kD的乳Wistar大鼠心肌细胞裂解液超滤液（CMCLnr）、成年Wistar大鼠心肌细胞裂解液超滤液（CMCLar）、乳Wistar大鼠心肌细胞培养液超滤液（CMCMnr）和20日龄乳Wistar大鼠心肌细胞培养液超滤液（CMCM20dr）。用抑瘤活性实验检测上述滤液（0.3mg／ml）和顺铂（1.26μg／ml DDP）作用鼻咽癌CNE-2细胞株的细胞存活率。用放射增敏实验检测CMCLnr（5～10kD）和拓扑替康（TPT）的放射（RT）增敏效果,单击多靶数学模型进行曲线拟合作图。流式细胞术检测TPT、CMCLnr（5～10kD）、RT单独或联合作用CNE 2细胞后细胞周期分布及凋亡率情况。结果 分子量为5～10kD CMCLnr、CMCLar、CMCMnr和CMCM20dr均较对照组能够显著降低CNE-2细胞的存活率（P＜0.05）,且与DDP组差异无统计学意义。CNE-2细胞RT组的D0值为1.185Gy,Dq值为0.676Gy,N值为3.729,SF2为69％; CMCLnr+RT组的D0值为0.762Gy,Dq值为0.600Gy,N值为6.147,SF2为25％,放射增敏比指标SERD0为1.555,SERDq为1.127,SERSF2为2.760。CMCLnr+RT组的细胞凋亡率为（19.34±0.23）％,均高于TPT+RT组和RT组,差异有统计学意义（P＜0.05）。结论 心肌细胞裂解液可抑制鼻咽癌CNE-2细胞的增殖,并对CNE-2细胞具有较强的放射增敏作用,细胞水平的研究表明其放射增敏的机制可能与诱导S期阻滞及促进凋亡有关。     

ADVANCES IN THE STUDY ON LEUKEMIA STRAINS AND LEUKEMIA CELL LINES IN CHINA

ＡＤＶＡＮＣＥＳＩＮＴＨＥＳＴＵＤＹＯＮＬＥＵＫＥＭＩＡＳＴＲＡＩＮＳＡＮＤＬＥＵＫＥＭＩＡＣＥＬＬＬＩＮＥＳＩＮＣＨＩＮＡＣｈｅｎｇＬｉ；程立；ＹｉｎＬｉａｎｈｕａ；殷莲华（ＤｅｐａｒｔｍｅｎｔｏｆＰａｔｈｏｐｈｙｓｉｏｌｏｇｙ，ＳｈａｎｇｈａｉＭ...     

EDAG在白血病细胞系K562中的细胞内自激因子作用

目的为肿瘤细胞自律性生长的细胞内自激因子假设提供实验证据。方法将新发现的造血相关核蛋白EDAG基因转染人白血病细胞系K562,比较过表达EDAG对K562细胞的增生能力,以及对细胞的造血调控、凋亡及细胞周期相关蛋白表达的影响。结果在无血清培养条件下,过表达EDAG的K562细胞的增生能力明显高于两组对照细胞,并且有c—myb和bcl-2mRNA表达的显著上调。结论过表达的EDAG可以起细胞内自激因子作用。为核蛋白异常表达可以起细胞内自激因子作用提供了实验证据。     

地西他滨对人急性髓系白血病细胞株HL-60的调控作用及其机制研究

目的 研究地西他滨(DAC)对人急性髓系白血病细胞株HL-60体外生长及自然杀伤(NK)细胞活化性受体配体(NKG2DL)表达的调节作用,并探讨JAK-STAT3-SOCS信号通路相关的分子机制.方法 CCK-8法检测DAC对HL-60细胞增殖活性的影响,Annexin-V/PI双标法检测细胞凋亡,流式细胞术检测HL-60细胞表面NKG2DL分子MICA/B、ULBP的表达,羧基荧光素双乙酸盐(CFSE)法检测NK细胞的杀伤活性,蛋白印迹法分析细胞内JAK-STAT3通路中STAT3、STAT3上游激酶JAK1、JAK2及STAT3活性负调控因子细胞因子信号抑制物(SOCS)-1、SOCS-3的蛋白表达水平,甲基化敏感性高分辨率熔解曲线分析(MS-HRM)检测DAC处理后SOCS-1、SOCS-3基因甲基化程度.结果 DAC可抑制HL-60细胞活性:0.2、0.5和1.0 μmol/L DAC处理48 h,HL-60细胞活性较对照组分别下降(25±11)%、(39±8)%和(50±7)%(P<0.01);48 h时,细胞凋亡发生率分别为(24.77±7.50)%、(27.10±4.48)%和(30.53±3.93)%,均较对照组细胞的(3.11±0.50)%增加(P<0.01).DAC可诱导HL-60细胞表面MICA/B、ULBP-1及ULBP-3分子的表达增高,增强HL-60细胞对NK细胞的杀伤敏感性.DAC处理后HL-60细胞内STAT3、JAK1、JAK2及p-STAT3、p-JAK1、p-JAK2表达下降,SOCS-1和SOCS-3蛋白表达增高.DAC可抑制SOCS-3基因甲基化.结论 DAC抑制人急性髓系白血病细胞株HL-60增殖,上调HL-60细胞对NKG2DL的表达,增强NK细胞对其的杀伤活性,其机制可能与细胞内JAK-STAT3-SOCS信号通路的活性调控有关.     

Differentiation state and invasiveness of human breast cancer cell lines

Summary Eighteen breast cancer cell lines were examined for expression of markers of epithelial and fibroblastic differentiation: E-cadherin, desmoplakins, ZO-1, vimentin, keratin and ₁ and ₄ integrins. The cell lines were distributed along a spectrum of differentiation from epithelial to fibroblastic phenotypes. The most well-differentiated, epithelioid cell lines contained proteins characteristic of desmosomal, adherens and tight junctions, were adherent to one another on plastic and in the basement membrane matrix Matrigel and were keratin-positive and vimentin-negative. These cell lines were all weakly invasive in anin vitro chemoinvasion assay. The most poorly-differentiated, fibroblastic cell lines were E-cadherin-, desmoplakin- and ZO-1-negative and formed branching structures in Matrigel. They were vimentin-positive, contained only low levels of keratins and were highly invasive in thein vitro chemoinvasion assay. Of all of the markers analyzed, vimentin expression correlated best within vitro invasive ability and fibroblastic differentiation. In a cell line with unstable expression of vimentin, T47D_CO, the cells that were invasive were of the fibroblastic type. The differentiation markers described here may be useful for analysis of clinical specimens and could potentially provide a more precise measure of differentiation grade yielding more power for predicting prognosis.     

辛伐他汀对NB4细胞分化与凋亡的影响

 目的　探讨磁性纳米Fe3O4颗粒（Fe3O4-MNP）联合多柔比星（ADM）对Raji细胞的影响。方法　采用MTT法检测细胞的增殖,锥虫蓝染色计数细胞的活性,流式细胞术检测细胞凋亡情况,Western blot检测p53和NF-κB的表达水平。结果　ADM及Fe3O4-MNP-ADM对Raji细胞的生长抑制率与药物浓度、作用时间呈正相关（r＝0.412,P＝0.027;r＝0.523,P＝0.014）;12、24、48 h细胞凋亡率二者分别为8.76 % 比 14.85 %、35.08 %比 44.50 %、44 %比69.4 %,差异有统计学意义（P＝0.012、0.041、0.024）;Western blot检测示ADM组与Fe3O4-MNP-ADM组NF-κB蛋白的灰度条带与内参比较分别为4.22±0.32、3.31±0.28,p53蛋白的条带灰度值分别为1.042±0.114、1.270±0.091,差异具有统计学意义（t＝-54.416,P＝0.035;t＝33.963,P＝0.047）。结论　Fe3O4-MNP联合ADM能够有效抑制Raji细胞增殖并诱导其凋亡,作用机制可能与增强p53蛋白活化、抑制NF -κB通路的激活有关。     

柚皮素对人类白血病K562细胞生长的作用及其机制探讨

 目的 研究柚皮素（naringenin）对人类慢性髓系白血病K562细胞株的作用及其机制。方法 体外培养K562细胞,MTT法检测柚皮素在不同浓度、不同时间点对K562细胞生长的影响;用免疫组织化学的方法检测细胞增殖核抗原（PCNA）的表达,并计算PCNA标记指数（LI）;显微镜和透射电镜下观察细胞形态变化;流式细胞仪分析细胞周期分布和细胞凋亡率;用RT-PCR和Western blot的方法检测K562细胞中p53、p21WAF1 mRNA和蛋白表达的变化。结果 柚皮素对K562细胞增生有明显抑制作用,作用24、48和72 h后的半数抑制浓度（IC50）分别为455 μmol／L、225 μmol／L和175 μmol／L;PCNA在柚皮素实验组的表达显著低于对照组;普通光镜以及电镜观察均见实验组细胞显著的增生抑制和典型的细胞凋亡形态学改变;流式细胞仪分析证实柚皮素能使K562细胞聚积在G0／G1期、S期细胞减少,凋亡率增加;RT-PCR和Western-blot检测表明,实验组细胞表达p21 mRNA和蛋白质呈浓度和时间依赖性升高,而p53变化不明显。结论 柚皮素对K562细胞具有明显的增生抑制作用,细胞周期阻滞和诱导凋亡可能是其重要机制,而非p53依赖性的p21上调可能是其发挥作用的重要途径。     

Suppression of normal granulopoiesis in vitro by a leukemia associated inhibitor (LAI) derived from a human promyelocytic cell line [HL-60]

The continuous human promyelocytic leukemic cell-line HL-60 was shown to produce a high molecular weight substance, which in a reversible fashion reduced the fraction of normal marrow CFU-c in S-phase. This factor is called “leukemia associated inhibitor” (LAI). The production of LAI depends on an active cell metabolism and an intact cytoskeleton of the cell. Its production reaches a plateau or decreases after 4–5 hours of incubation partly due to sedimentation of the cells as continuous stirring results in a prolonged production of LAI. It behaved homogeneously on gel chromatography with an apparent molecular weight greater than 500,000 but ion exchange chromatography revealed charge heterogeneity. The findings of marked affinity for the lectin Lens culinaris, susceptibility to mild periodate treatment, only partial susceptibility to protease digestion and considerable resistance to heating suggest that LAI is a glycoprotein. Data from sucrose density gradient centrifugation of cell homogenates and extraction of LAI from subcellular organelles with 3M KCL suggests that it is a peripheral cell membrane component. HL-60 derived LAI seems to be identical with LAI recently found to be produced in cells from patients with myeloid leukemia. It may play a role to suppress granulopoiesis in leukemia.     

S-trityl-L-cysteine derivative induces caspase-independent cell death in K562 human chronic myeloid leukemia cell line

Effect of CF₃-STLC, a potent kinesin spindle protein (KSP) inhibitor, on K562 human CML cell line was investigated. Treatment with CF₃-STLC induced mitotic arrest of the cell cycle with the appearance of characteristic monoastral spindles, subsequent apoptotic cell death and cleavage of PARP-1, caspase-3, and 4E-BP1. The wide ranging caspase inhibitor z-VAD fmk prevented the cleavage of caspase-3 and 4E-BP1, but failed to attenuate PARP-1 cleavage or cell death triggered by CF₃-STLC. These results suggest that CF₃-STLC can induce apoptotic cell death in a caspase-independent manner, and may work effectively as an anti-cancer agent for hematological malignancies.     

Differential responses to radiation and hyperthermia of cloned cell lines derived from a single human melanoma xenograft

One uncloned and five cloned cell lines were derived from a single human melanoma xenograft. Cells from passages 7-12 were exposed to either radiation or hyperthermia (42.5 degrees C, pH = 7.4) under aerobic conditions and the colony forming ability of the cells was assayed in soft agar. The five cloned lines showed individual and characteristic responses to radiation as well as to hyperthermia. The variation in the response to radiation was mainly reflected in the size of the shoulders of the survival curves rather than in the D0-values. The variation in the response to hyperthermia was mainly reflected in the terminal slopes of the survival curves. The survival curve of cells from the uncloned line, both when exposed to radiation and hyperthermia, was positioned in the midst of those of the cloned lines. The response of the cloned lines to radiation did not correlate with the response to hyperthermia, indicating that tumor cell subpopulations which are resistant to radiation may respond well to hyperthermia.     

Intrinsic and extrinsic variables affecting sensitivity to radiation carcinogenesis

Mathematical models relating observed yield of cancers vs administered radiation dose have become popular in recent years, especially as means of predicting hazards associated with exposure conditions which are beyond the realm of practical experimentation. While the validity of these predictions remains a controversy, these models, especially the αD + βD² model, have more recently been used to infer the mechanism(s) underlying the carcinogenic process.Through the analysis of simple experimental systems, we demonstrate in this report that aD + bD² kinetics can result from injury to the cells which eventually develop into the cancer (target cells) or from injury to those cells which affect target cell survival. Further, these kinetics can fail to predict the consequences of dose protraction, largely due to the fact that transformation increases with dose, while survival decreases. The role of these models in helping to develop an understanding of mechanisms should be restricted, therefore, to the formulation of basic hypotheses which are subject to direct testing in the laboratory.