miR-139过表达降低急性髓系白血病TRAIL耐受性

目的:探讨miR-139过表达对急性髓系白血病肿瘤坏死因子相关凋亡诱导配体(TNF-related apoptosis inducing ligand,TRAIL)耐受性的影响。方法:采用浓度为100、200、300和400 ng/ml TRAIL处理人急性髓系白血病K562、HL-60细胞及相对应的多药耐药K562/A02和HL-60/ADM细胞,采用CCK8法计算IC50值,以IC50法评价急性髓系白血病细胞对TRAIL的敏感性。RT-PCR检测miR-139在 TRAIL敏感细胞和耐药细胞中的表达。采用脂质体2000将miR-139 mimics转染至TRAIL耐药细胞株,RT-PCR检测转染效果,CCK8法检测细胞活力及IC50值,流式细胞仪检测细胞凋亡率。结果:在K562、K562/A02、HL-60和HL-60/ADM细胞中,HL-60/ADM细胞对TRAIL最为敏感,而K562细胞对TRAIL的耐药性最强。与敏感细胞株HL-60/ADM相比,miR-139在耐药细胞株K562中表达显著下降。转染miR-139 mimics后,K562细胞中miR-139表达和细胞凋亡率明显升高,而细胞存活率及IC50值明显降低。结论:miR-139在TRAIL耐药细胞株K562中低表达,过表达miR-139可能通过促进TRAIL诱导的细胞凋亡降低K562细胞对TRAIL的耐受性。     

Effect of 4-hydroperoxycyclophosphamide on leukemic and normal human myeloid progenitor cells

The sensitivity of myeloid progenitor cells from normal subjects (N-CFU-GM) and from leukemic patients in complete remission (LR-CFU-GM) to 4-hydroperoxycyclophosphamide (4-HC) were compared to the sensitivity of leukemic progenitor cells (L-CFU) to this drug. The results were expressed as the dose of 4-HC needed to kill 90% (TD 90) of the progenitor cells. The mean TD 90 were respectively for N-CFU-GM : 59 (+/- 11 S.E.M.) nM ml-1 and for L-CFU 79 (+/- 6 S.E.M.) nM ml-1. Thus, L-CFU were equally sensitive to 4-HC as N-CFU-GM. Moreover, the mean TD 90 for LR-CFU-GM was 87 (+/- 5 S.E.M.) nM ml-1. Thus, the sensitivity of N-CFU-GM and LR-CFU-GM did not differ significantly from that of L-CFU. These results are not encouraging for the use of 4-HC in vitro to eliminate the residual leukemic cells from autologous bone marrow of AML patients in complete remission. The sensitivity of L-CFU was modified neither by previous cytoreductive therapy (different from cyclophosphamide) nor by the time elapsed since diagnosis of AML.     

Partial characterization of protein tyrosine kinase activity in normal and leukemic human myeloid cells

We have examined the expression of the protein tyrosine kinase (PTK) encoding oncogenes fes and abl in normal and malignant human myeloid cells in immunoblotting experiments. fes was markedly present in all cytosolic and most membrane fractions of normal and malignant cells. abl was only visible in normal cells, and occurred mostly in the cytosolic fractions. Molecular weights of identified proteins were different from the known products of fes and abl, possibly by alternative splicing at the mRNA level or by proteolysis. PTKs in myeloid cells were further purified by fast liquid protein chromatography (FPLC). PTK-activities of column fractions were assayed using a solid-phase non-radioactive dot-blot assay. Cytosolic and membrane fractions showed a FPLC pattern with a constant as well as a variable part in both normal and malignant cells, possibly indicative for PTKs with specialized functions in normal cell growth and transformation. Partial characterization of PTKs from different eluted peaks of AML-M4 blast cells demonstrated that PTKs from these peaks are kinetically distinct from each other.     

TRAIL的抗肿瘤机制及其应用

目的:总结国内外关于TRAIL的抗肿瘤机制及应用的研究进展.方法:应用MEDLINE及CNKI期刊全文数据库系统,以"TRAIL、机制和治疗"等为关键词,检索2000-2010年的相关文献.纳入标准:1)TRAIL的结构及受体;2)TRAIL的作用机制;3)TRAIL的应用及临床试验.根据纳入标准,纳入分析23篇文献.结果:TRAIL在TNF家族中最显著的特征是对肿瘤细胞和转化细胞具有选择性的凋亡诱导作用,而对正常的组织和细胞不具有明显的毒性反应,并且与其他试剂联合应用具有协同抗肿瘤作用.结论:相对于化疗药物的毒副反应,TRAIL的独特优势为其在肿瘤治疗中奠定了良好基础,可以为目前的肿瘤治疗提供更有效,更安全的新方法.     

A monoclonal antibody reactive with normal and leukemic human myeloid progenitor cells

Anti-MY9 is an IgG2b murine monoclonal antibody selected for reactivity with immature normal human myeloid cells. The MY9 antigen is expressed by blasts, promyelocytes and myelocytes in the bone marrow, and by monocytes in the peripheral blood. Erythrocytes, lymphocytes and platelets are MY9 negative. All myeloid colony-forming cells (CFU-GM), a fraction of erythroid burst-forming cells (BFU-E) and multipotent progenitors (CFU-GEMM) are MY9 positive. This antigen is further expressed by the leukemic cells of a majority of patients with AML and myeloid CML-BC. Leukemic stem cells (leukemic colony-forming cells, L-CFC) from most patients tested were also MY9 positive. In contrast, MY9 was not detected on lymphocytic leukemias. Anti-MY9 may be a valuable reagent for the purification of hematopoietic colony-forming cells and for the diagnosis of myeloid-lineage leukemias.     

Protein kinase C isoforms in normal and leukemic neutrophils: altered levels in leukemic neutrophils and changes during myeloid maturation in chronic myeloid leukemia.

Protein kinase C (PKC) is reported to play a role in maturation of the myeloid cell and functions of the mature neutrophil. The neutrophils in chronic myeloid leukemia (CML) exhibit defects in several functions. As a step towards understanding the role of PKC in the defects in function of the leukemic cells, this study investigates the expression of PKC isoforms, their subcellular distribution, levels and kinase activity in the normal and leukemic neutrophils. It also investigates changes in representative PKC isoforms during myeloid maturation. This study confirms the presence of PKC alpha, beta and delta and shows, for the first time, the presence of non conventional PKC isoform theta, atypical PKC isoform lambda/iota and PKC isoform mu in normal human neutrophils. In unstimulated cells all the detected PKC isoforms showed a predominantly cytosolic localisation in normal and CML neutrophils. Cytosol-membrane distribution of PKC alpha and delta were significantly altered in leukemic neutrophils as compared to normal cells. Cytosolic levels of all PKC isoforms were reduced in CML neutrophils with PKC alpha, beta, iota, theta, and mu showing a significant decrease. Cytosolic levels of PKC delta contrary to the trend observed for other PKC isoforms showed a slight increase in CML cells, while its membrane levels were significantly reduced in CML neutrophils. Total PKC kinase activity in CML neutrophil cytosol was significantly reduced, while specific kinase activity of two representative isoforms, PKC alpha and delta, from normal and CML neutrophils were similar, thereby increasing the significance of the altered levels of PKC isoforms in CML, and highlighting their role in the defects in function exhibited by the leukemic neutrophils. The levels of PKC delta and iota increased and decreased respectively as the leukemic myeloid cell matured from the blast to the neutrophil, while the levels of PKC alpha and beta were not altered. This suggests a role for PKC delta and iota in the maturation of the leukemic myeloid cell.     

急性髓系白血病细胞对树突状细胞分化、成熟和调节性T细胞生成的影响

Objective To investigate the effects of soluble factors secreted by acute myeloid leukemia (AML) cells on the phenotypical and functional properties of DCs derived from normal mononuclear cells. Methods Mononuclear cells were cultured with interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF), in the presence or absence of 24 h culture supernatants from fresh primary AML cells, to generate immature DCs. The maturation of DCs was induced by cytokines IL-1beta, IL-6, tumor necrosis factor-alpha (TNF-alpha), and prostaglandin-2 (PGE-2). The phenotypic alterations of DCs and DCs-primed CD4 T cells were evaluated using flow cytometry. Precursor frequency (PF) was calculated to monitor the allostimulatory effects of DCs on CD4 and CD8 T cells. ResultsAML cell supernatant-treated DCs showed significantly lower expression of co-stimulatory molecules CD80 and CD86, and reduced response to cytokines IL-1beta, IL-6, TNF-alpha,and PGE-2. The allostimulatory effects of AML cell supernatant-treated DCs on CD4 and CD8 T cells were significantly lower than those of normal mature DCs [PF (1.8±0.5)% vs. (5.2±1.6)% for CD4 T cells, (2.1±0.6)% vs. (6.5±2.0)%for CD8 T cells, P＜0.01]. These AML supematant-induced DCs could also induce allogeneic CD4 T cells to differentiate into CD4 CD25high T cells, which had immunophenotyping characteristics of regulatory T cells, i.e. they expressed Foxp3 but not active maker CD69. Conclusion This study demonstrates that soluble factors secreted by AML cells can inhibit development and functions of DCs. In addition, AML supematant-induced DCs can induce the generation of CD4 CD25high T cells from CD4 T cells, which may be a mechanism of increased prevalence of CD4 CD25high regulatory T cells and immune dysfunction in AML patients.     

急性髓细胞性白血病细胞培养上清对树突细胞分化、成熟、凋亡及功能的影响

背景与目的:树突细胞(dendritic cell,DC)存机体抗瘤免疫中起重要作用.研究已表明肿瘤患者和荷瘤动物体内DC功能受损并伴有DC数量的降低.最近的研究提示这种DC功能的受损可能是肿瘤细胞分泌的可溶性因子介导的免疫抑制所致.本研究拟观察急性髓系白血病(acute myeloid leukemia,AML)细胞分泌的可溶性因子对单核细胞来源DC的分化、成熟、凋亡及其功能的影响.方法:原代AML细胞培养24 h后收集上清.在含有或不含有AML细胞培养上清的培养液中,利用IL-4和GM-CSF刺激单核细胞分化成不成熟DC(immature DC,iDC),IL-1β、IL-6、TNF-α和PGE-2促进DC成熟.流式细胞仪检测DC表型和凋亡率的变化.计算前体细胞频率(precursorfrequency,PF),观察DC对异基因CD4 T细胞和CD8 T细胞的刺激功能.结果:AML细胞培养上清可显著抑制DC表面协同刺激分子CD80和CD86的表达,并可降低促成熟细胞因子对DC的促成熟作用.同时,与对照组相比,AML细胞培养上清可显著诱导DC的凋亡,凋亡率分别为(15.1±4.2)%和(29.4±9.5)%(P＜0.01).相对于正常成熟DC,AML细胞培养上清诱生的DC对异基因CD4 T细胞和CD8 T细胞的刺激功能显著降低(P＜0.01),其中CD4 T细胞的前体细胞频率分别为(5.2±1.6)%和(1.8±0.5)%,CD8 T细胞的前体细胞频率分别为(6.5±2.0)%和(2.1±0.6)%.结论:AML细胞分泌的可溶性因子可抑制DC的发育和功能.     

Mechanisms of TRAIL and gemcitabine induction of pancreatic cancer cell apoptosis

The aim of this study was to investigate induction of apoptosis by the tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and gemcitabine in the pancreatic cancer cell line SW1990. The sensitivity of SW1990 cells to TRAIL and/or gemcitabine-induced apoptosis and the rate of apoptosis were assessed by MTT assay and flow cytometry, respectively. We used Hoechst 33342 staining to observe apoptotic morphology and expression levels of proteins were analyzed by Western blottin. Growth inhibition and apoptosis rates on treatment with the combination of TRAIL and gemcitabine were significantly higher than with each drug alone (p<0.05). Pancreatic cancer cells exhibited a typical apoptosis morphology after treatment with TRAIL or gemcitabine. The levels of cellular apoptosis-associated proteins such as Smac/DIABLO, Cyto C, and the activated fragment of caspase-3 (P17) increased, but the expression of XIAP was significantly decreased after 24 h (p<0.05). SW1990 cells responded to TRAIL and/or gemcitabine-induction of apoptosis in a time and concentration-dependent manner. The mechanism of the apoptosis-sensitization effect appeared associated with significant up-regulation of Smac/DIABLO and cytochrome C, down-regulation of XIAP, and activation of caspase-3.     

Apoptosis induction in renal cell carcinoma by TRAIL and gamma-radiation is impaired by deficient caspase-9 cleavage

TNF-related apoptosis-inducing ligand (TRAIL APO-2L) is a member of the TNF family and induces apoptosis in cancer cells without affecting most non-neoplastic cells. The present investigation is focused on apoptosis induction by combined exposure to TRAIL and ionising radiation (IR) in human renal cell carcinoma (RCC) cell lines. Here, we demonstrate that all RCC cell lines coexpress TRAIL and the death-inducing receptors, TRAIL-R1 and TRAIL-R2. Exposure to TRAIL alone induced marked apoptosis in three out of eight RCC cell lines. Combined exposure to TRAIL and IR resulted in a sensitisation to TRAIL-induced apoptosis in one RCC cell line only. Enhanced apoptosis induction by TRAIL in combination with IR was paralleled by an increase in PARP cleavage and activation of executioner caspase-3, whereas caspases-6 and -7 were not involved. Moreover, exposure to TRAIL and/or IR resulted in a marked activation of initiator caspase-8, possibly augmented by the observed reduction of inhibitory c-FLIP expression. In contrast to other tumour types, activation of initiator caspase-9 was not detectable in our RCC model system after exposure to TRAIL and/or IR. This lack of caspase-9 activation might be related to an impaired 'crosstalk' with the caspase-8 pathway as suggested by the missing Bid cleavage and to the appearance of an XIAP cleavage product known to inhibit caspase-9 activation. Deficient activation of caspase-9, therefore, might contribute to the clinically known resistance of human RCC against IR and also argues against an effective combination therapy with TRAIL and IR in this tumour type.     

Survivin及肿瘤坏死因子相关凋亡诱导配体与人乳头瘤病毒在宫颈病变中表达的相关性

目的：本研究通过检测宫颈癌及癌前病变中肿瘤坏死因子相关的凋亡诱导配体（TNF related apotosis inducing ligand,TRAIL）、凋亡抑制基因Survivin及人乳头瘤病毒（human papillomavirus,HPV）16 E6/E7的表达,研究其相关性,对宫颈癌的发病机制进行更深入的探讨.方法：对15例正常宫颈组织标本、47例宫颈上皮内瘤样病变（CIN）标本及27例宫颈癌标本,采用RT-PCR方法检测HPV16 E6/E7、Survivin、TRAIL的表达.结果：HPV 16 E6/E7基因与Survivin基因的表达水平随着宫颈病变的发展呈增高趋势;TRAIL基因的表达水平呈降低趋势.HPV16E6/E7基因的表达水平在宫颈癌不同年龄、临床分期、组织学分级及组织学分型中,均无统计学差异（P＞0.05）.Survivin基因的表达水平与宫颈癌临床分期、组织学分级有关（P＜0.05）.TRAIL基因的表达水平与组织学分级有关（P＜0.05）.宫颈癌组织中HPV16 E6/E7基因与Survivin mRNA的表达水平呈正相关,与TRAIL mRNA的表达水平呈负相关,Survivin mRNA与TRAIL mRNA的表达水平呈负相关.结论：HPV16 E6/E7基因表达水平与宫颈病变的进展密切相关.HPV16 E6/E7、Strvivin、TRAIL基因可能在宫颈癌的发生发展中起协同作用,联合检测以上基因对于临床上对宫颈癌做出早期诊断,判断预后具有重要的参考价值.     

Chronic myeloid leukemic granulocytes exhibit decreased adhesion to fibronectin

Extracellular matrix components are known to regulate the process of egress of granulocytes from the bone marrow and their emigration to inflammatory sites. In this study we have compared the adhesion of normal and chronic myeloid leukemic granulocytes to fibronectin. Adhesion of granulocytes from leukemic patients to all the different concentrations of fibronecti n assessed was significantly lower than that of normal individuals. This observation suggests that the decreased adhesion of leukemic cells to fibronectin may be responsible for their early egress from the bone marrow and their delayed emigration to the sites of inflammation.     

Combination Therapy of TRAIL and Thymoquinone Induce Breast Cancer Cell Cytotoxicity-Mediated Apoptosis and Cell Cycle Arrest

Objective: Cancer is one of the leading causes of mortality in both developed and developing nations. The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is characterized by its ability to selectively trigger apoptosis in cancer cells. TRAIL-based interventions have led to the development of recombinant human (rhTRAIL) as a promising therapy for different types of human cancer. Thymoquinone (TQ) has been shown to exert anticancer effect. The aim of the current study is to investigate the anticancer effect of the combinatorial therapy of TRAIL+TQ against human breast cancer cells. Methods: To achieve this hypothesis, cytotoxicity using MTT assay, as well as apoptosis and cell cycle using flow cytometric technique were preceded against breast cancer MCF-7 and MDA-MB-231 cancerous cell lines. Results: The current study showed that TRAIL induced cell cycle arrest and apoptosis. Moreover, it inhibited proliferation of MDA-MB-231 cells more than MCF-7 cells. Adding TQ to TRAIL increased the chemo-sensitivity of MDA-MB-231, while overcame the MCF-7 resistance to TRAIL. Conclusion: In conclusion, there is a synergistic effect between TRAIL and TQ playing a therapeutic role in killing resistant breast cancer cells.     

Expression of the TRAIL receptors in blood mononuclear cells in leukemia

TRAIL receptors are differentially expressed on restricted subpopulations of normal blood cells. In the present study, we investigated the utility of individual TRAIL receptors in evaluating the presence of circulating tumor cells in blood. Patients with chronic myeloid leukemia (CML) carrying the t(9;22) translocation were compared with patients in whom no translocation was detected, with patients with multiple myeloma and with a group of healthy individuals. TRAIL receptor expression was analyzed by RT-PCR in blood mononuclear cells. Blood mononuclear cells of healthy subjects expressed the TRAIL-R1 and TRAIL-R2 death receptors and the TRAIL-R4 decoy receptor while the other decoy receptor TRAIL-R3 was not detectable. This normal expression pattern was also observed in all cases with multiple myeloma and in almost all patients without translocation (42/43; 97.7%). However, in 24/56 (42.9%) of the translocation-positive patients, the expression pattern was completely different. In this group the TRAIL-R4 receptor alone or in combination with TRAIL-R1 disappeared from blood mononuclear cells, while the TRAIL-R2 was expressed at normal level, indicating that the loss of expression is specific for the TRAIL-R4 and TRAIL-R1. This expression pattern was also confirmed by real-time PCR. The differences between the translocation-positive and -negative groups for the TRAIL-R4 and TRAIL-R1 expression were highly significant (p=0.0001 and p=0.0004, respectively). However, the differential expression pattern did not correlate with the number of leukemic cells. Our results suggest a correlation between the presence of leukemic cells in circulation and the differential expression pattern of TRAIL receptors in blood mononuclear cells.     

Decreased frequency,but normal functional integrity of mesenchymal stromal cells derived from untreated and Imatinib-treated chronic myeloid leukemia patients

In vitro, Imatinib inhibits the proliferation and stimulates the osteogenic and adipogenic differentiation of mesenchymal stromal cells (MSC). However, it is unknown whether Imatinib affects the biology of MSC in vivo. We asked whether MSC from long-term Imatinib-treated CML patients were affected by the in vivo treatment. MSC from untreated and Imatinib-treated patients displayed normal functional properties (i.e. proliferation, immunophenotype, differentiation and hematopoietic supportive capacity) – but a decreased frequency. In vitro, Imatinib lost its effect when discontinued; which suggest that it has a reversible effect on MSC. Therefore it might lose its effect on MSC after discontinuation in vivo.     

TRAIL 、NF-κB 和Caspase-3 在大肠癌中的表达及意义

 目的 研究TRAIL、NF-κB和Caspase-3在大肠癌中的表达及意义，探讨NF-κB和Caspase-3的表达对TRAIL抗癌作用的影响。方法 采用免疫组化SP法检测42例大肠癌及其癌旁5cm组织、25例正常大肠粘膜组织中TRAIL、NF-κB和Caspase-3蛋白的表达水平。结果 TRAIL和Caspase-3在大肠癌、癌旁组织及正常大肠粘膜组织中的表达呈递增趋势，而NF-κB的表达则与之相反（P〈0．05）；TRAIL和Caspase-3在中、低分化癌中的表达明显低于高分化癌中的表达，而NF-κB的表达则与之相反（P〈0．05）；TRAIL与NF-κB和Caspase-3在大肠癌中的表达均显著相关（P〈0．05）。结论 TRAIL、NF-κB和Caspase-3可能与大肠癌的发生、发展密切相关；抑制NF-κB表达及促进Caspase-3的表达，有可能提高肿瘤细胞对TRAIL的敏感性。     

Twist 1通过MPL促进髓系白血病细胞增殖和耐药

目的:检测Twist-1与骨髓增生性白血病病毒癌基因(myeloproliferative leukemia virus oncogene,MPL)在髓系白血病患者和髓系造血系统恶性肿瘤细胞系中表达的相关性,并探讨Twist-1是否通过MPL对髓系白血病细胞增殖、耐药发挥促进作用.方法:选取中国医学科学院血液病医院2005年1月至2008年12月初次诊断为急性髓系白血病(acute myeloid leu-kemia,AML)、慢性粒细胞白血病(chronic myeloid leukemia,CML)患者的骨髓标本41例(其中AML 23例、CML 18例),用Re-al-time PCR检测AML、CML患者以及髓系造血系统恶性肿瘤细胞系中Twist-1和MPL mRNA的表达情况,并分析其相关性.构建MPL过表达载体,制备慢病毒并感染髓系白血病细胞系K562、U937,通过细胞计数实验、集落形成实验以及药物敏感实验评价其对白血病细胞增殖、集落形成能力以及耐药的影响,并进一步确定Twist-1是否通过MPL发挥白血病促进作用.结果:在U937和K562细胞中过表达Twist-1明显增加MPL蛋白水平(P＜0.05),敲降Twist-1后MPL mRNA的表达水平明显下降(P＜0.01);AML、CML患者骨髓单核细胞(bone marrow mononuclear cells,BMMCs)中Twist-1 mRNA表达与MPL mRNA表达水平呈显著正相关(P＜0.05).过表达MPL使K562和U937细胞对化疗药物柔红霉素及伊马替尼的敏感性显著降低(P＜0.01),且提高K562-MPL、U937-MPL的细胞增殖、集落形成数目(均P＜0.01);干扰Twist-1并过表达MPL显著降低髓系白血病细胞增殖和集落形成(均P＜0.01).结论:Twist-1通过MPL促进AML、CML白血病细胞的增殖、存活和耐药.