HES4抑制急性T淋巴细胞白血病细胞系Jurkat对阿糖胞苷的敏感性

摘要 目的：研究hes家族bHLH转录因子4（HES4）与急性T淋巴细胞白血病（T-ALL）细胞系Jurkat对化疗药物阿糖胞苷（Ara-C）的敏感性作用。方法：构建Lenti-pCDH-HES4-puro质粒,包装慢病毒感染Jurkat细胞,感染空载体Lenti-pCDH-puro为对照组,puromycin筛选阳性细胞,Realtime-PCR检测转录水平HES4过表达情况,CCK8法检测Jurkat对Ara-C敏感性,Ara-C终浓度为0.1、1、10、100、1000、10000 nmol?L^-1;设计3对针对于HES4的特异sgRNA序列,构建LentiGuide-sgRNA1-puro、LentiGuide-sgRNA2-Puro、LentiGuide-sgRNA3-puro质粒,LentiGuide-puro空载体为对照组,包装慢病毒感染Jurkat细胞,puromycin筛选,提取基因组DNA,PCR扩增sgRNA的靶序列,一代测序检测HES4的敲除效率,CCK8法检测敲除HES4后Jurkat对Ara-C敏感性,Ara-C终浓度为0.1、1、10、100、1000、10000 nmol?L^-1。结果：与对照组相比,HES4在Jurkat中过表达（2.37 ± 0.09）倍（P < 0.001）,在Ara-C为1 nmol?L-1、100 nmol?L^-1 浓度下,过表达HES4使Jurkat对Ara-C的药物敏感性降低（P值分别小于0.01、0.05）; sgRNA1、sgRNA 2、sgRNA 3敲除分值分别为83、71、63,其中sgRNA1的敲除效果最佳,在Ara-C为1000 nmol?L^-1浓度下,敲除HES4促进Jurkat对Ara-C的敏感性（P < 0.05）,3条sgRNAs之间无明显区别（P > 0.05）。结论：HES4抑制T-ALL细胞系Jurkat对Ara-C的敏感性,为T-ALL化疗耐受的机制研究提供指导。     

Gamma secretase inhibitors enhance vincristine-induced apoptosis in T-ALL in a NOTCH-independent manner

Activating mutations in the NOTCH1 gene are found in over 50 % of T-ALL cases. Since Notch signaling contributes to the leukemia cell survival and growth, targeting Notch signaling using γ-secretase inhibitors (GSI) has been proposed as a molecularly targeted therapy for the treatment of T-ALL. However, not all T-ALL with NOTCH1 activating mutations respond to GSI treatment. We examined whether GSI could enhance the cytotoxic effect of anti-leukemic agents in the GSI-resistant T-ALL cells although GSI does not have anti-tumor effect as a single agent. GSI significantly increased cell death induced by Vincristine (VCR) but not other anti-leukemic drugs (Methotrexate, Asparaginase, and Cytarabine). The GSI effect in enhancing VCR efficacy was not the result of inhibition of Notch signaling. GSI augmented VCR-induced mitotic arrest, followed by apoptosis. GSI accelerated VCR-triggered loss of mitochondrial membrane potential and caspase-mediated apoptosis. Our finding suggests that GSI has other functions besides inhibiting Notch signaling in T-ALL and incorporating GSI into the conventional regimen containing VCR may offer therapeutic advantage by potentiating VCR treatment in leukemia patients.     

Proteomic analysis reveals a novel role for the actin cytoskeleton in vincristine resistant childhood leukemia--an in vivo study

Intrinsic or acquired resistance to vincristine (VCR), an antimicrotubule agent used in the treatment of childhood acute lymphoblastic leukemia (ALL), is a major clinical problem. Using a clinically relevant NOD/SCID mouse xenograft model of ALL, we established that alterations in the actin and tubulin cytoskeleton are involved in in vivo VCR resistance. Altered protein expression between VCR-sensitive ALL xenografts, and xenografts with intrinsic or acquired VCR resistance, was identified using 2-D DIGE coupled with MS. Of the 19 proteins displaying altered expression, 11 are associated with the actin cytoskeleton. Altered expression of the actin- and/or tubulin-binding proteins gelsolin, moesin, ezrin, tropomyosin, CAP-G, HSP27, HSP70, TCP-1, and stathmin were associated with in vivo VCR resistance. The actin-regulating protein gelsolin was increased in both acquired and resistant leukemia as confirmed by immunoblotting and gene expression. The major cytoskeletal protein, gamma-actin, was down-regulated in the VCR-resistant leukemia xenografts; in contrast, there was no significant change in beta-actin expression. This study provides the first evidence for a role of the actin cytoskeleton in intrinsic and acquired in vivo antimicrotubule drug resistance in childhood leukemia and highlights the power of 2-D DIGE for the discovery of resistance markers, pharmacoproteomics, and signaling pathways in cancer.     

p21WAF1 modulates drug-induced apoptosis and cell cycle arrest in B-cell precursor acute lymphoblastic leukemia

p21^WAF1 is a well-characterized mediator of cell cycle arrest and may also modulate chemotherapy-induced cell death. The role of p21^WAF1 in drug-induced cell cycle arrest and apoptosis of acute lymphoblastic leukemia (ALL) cells was investigated using p53-functional patient-derived xenografts (PDXs), in which p21^WAF1 was epigenetically silenced in T-cell ALL (T-ALL), but not in B-cell precursor (BCP)-ALL PDXs. Upon exposure to diverse cytotoxic drugs, T-ALL PDX cells exhibited markedly increased caspase-3/7 activity and phosphatidylserine (PS) externalization on the plasma membrane compared with BCP-ALL cells. Despite dramatic differences in apoptotic characteristics between T-ALL and BCP-ALL PDXs, both ALL subtypes exhibited similar cell death kinetics and were equally sensitive to p53-inducing drugs in vitro, although T-ALL PDXs were significantly more sensitive to the histone deacetylase inhibitor vorinostat. Transient siRNA suppression of p21^WAF1 in the BCP-ALL 697 cell line resulted in a moderate depletion of the cell fraction in G1 phase and marked increase in PS externalization following exposure to etoposide. Furthermore, stable lentiviral p21^WAF1 silencing in the BCP-ALL Nalm-6 cell line accelerated PS externalization and cell death following exposure to etoposide and vorinostat, supporting previous findings. Finally, the Sp1 inhibitor, terameprocol, inhibited p21^WAF1 expression in Nalm-6 cells exposed to vorinostat and also partially augmented vorinostat-induced cell death. Taken together, these findings demonstrate that p21^WAF1 regulates the early stages of drug-induced apoptosis in ALL cells and significantly modulates their sensitivity to vorinostat.     

利用cut&tag技术探究LHX9基因在颗粒细胞的调控机制

摘要 目的：在人卵巢颗粒细胞癌细胞株KGN中探索转录因子LHX9下游主要的靶基因及其调控。方法：首先我们采用实时荧光定量PCR观察KGN细胞在卵泡刺激素（FSH）干预前后性腺分化和性激素合成过程中重要基因的表达情况，同时我们利用cut&tag测序技术在两组细胞中识别LHX9下游靶基因，并采用双荧光素酶报告实验对重要靶基因NR5A1的调控进行了验证。结果：实时荧光定量PCR结果显示，通过加FSH处理12小时后，LHX9和NR5A1基因的mRNA水平表达降低，相反的，StAR和CYP19A1基因的mRNA水平表达增高；通过cut&tag测序技术和生物信息学分析，我们发现LHX9下游基因主要分布在内吞作用、细胞衰老、肿瘤相关通路、细胞周期、凋亡、卵母细胞减数分裂、雌激素信号转导等通路上。LHX9可以转录调控性腺分化以及类固醇激素合成的一些重要基因，其中包括NR5A1和SOX9等，荧光素酶报告基因证实了LHX9可以直接结合NR5A1基因的启动子区。结论：本研究利用cut&tag测序技术，发现转录因子LHX9对性腺分化和性激素合成的关键基因有转录调控作用，对深入理解LHX9基因对生殖系统的作用具有重要意义。     

Investigation of deregulated genes of Notch signaling pathway in human T cell acute lymphoblastic leukemia cell lines and clinical samples

In diagnostic research challenges, quantitative real-time PCR (QPCR) has been widely utilized in gene expression analysis because of its sensitivity, accuracy, reproducibility, and most importantly, quantitativeness. Real-time PCR base kits are wildly applicable in cancer signaling pathways, especially in cancer investigations. T-cell acute lymphoblastic leukemia (T-ALL) is a type of leukemia that is more common in older children and teenagers. Deregulation of the Notch signaling pathway promotes proliferation and inhibits apoptosis of the lymphoblastic T cells. The aim of this study was to investigate the effect of Notch signaling activation on the expression of target genes using real-time QPCR and further use this method in clinical examination after validation. Two T-ALL cell lines, Jurkat and Molt-4, were used as models for activation of the Notch signaling via over-expression of the Notch1 intracellular domain. Expression analysis was performed for six downstream target genes (NCSTN, APH1, PSEN1, ADAM17, NOTCH1 and C-MYC) which play critical roles in the Notch signaling pathway. The results showed significant difference in the expression of target genes in the deregulated Notch signaling pathway. These results were also verified in 12 clinical samples bearing over-expression of the Notch signaling pathway. Identification of such downstream Notch target genes, which have not been studied inclusively, provides insights into the mechanisms of the Notch function in T cell leukemia, and may help identify novel diagnoses and therapeutic targets in acute lymphoblastic leukemia.     

纳米形貌诱导干细胞成骨分化的相关信号通路

目的:探究纳米形貌诱导间充质干细胞(MSC)分化中的作用以及相关分子机制。方法:利用阳极氧化法制备二氧化钛纳米管形貌,使用qRT-PCR技术,RNA-seq技术,分析接种在纳米形貌表面的间充质干细胞的基因表达情况。并筛选对成骨相关的信号通路中的成员,观察他们基因上调或下调情况。结果:在钛金属表面构建出了纳米形貌,利用实时定量PCR确定了成骨相关的基因:碱性磷酸酶(ALP),骨桥蛋白(OPN)和骨钙素(OCN)相比没有纳米形貌的钛片上培养的细胞均发生上调。通过对这些基因相关的成骨信号通路进行转录组数据分析(筛选基因P<0.05),发现在BMP2信号通路中的相关蛋白基因表达没有太大变化,同时Notch以及Wnt非经典信号通路中相关蛋白基因发生较为明显变化。结论:通过分析间充质干细胞成骨分化相关基因,以及转录组数据分析表明在纳米形貌诱导BMSC分化过程中,相对于平坦的表面,纳米形貌启动了Notch以及非经典的Wnt信号通路,因此表现出更加优良的促成骨分化的效果。     

Identification of an Epi-metabolic dependency on EHMT2/G9a in T-cell acute lymphoblastic leukemia

Genomic studies have identified recurrent somatic alterations in genes involved in DNA methylation and post-translational histone modifications in acute lymphoblastic leukemia (ALL), suggesting new opportunities for therapeutic interventions. In this study, we identified G9a/EHMT2 as a potential target in T-ALL through the intersection of epigenome-centered shRNA and chemical screens. We subsequently validated G9a with low-throughput CRISPR-Cas9-based studies targeting the catalytic G9a SET-domain and the testing of G9a chemical inhibitors in vitro, 3D, and in vivo T-ALL models. Mechanistically we determined that G9a repression promotes lysosomal biogenesis and autophagic degradation associated with the suppression of sestrin2 (SESN2) and inhibition of glycogen synthase kinase-3 (GSK-3), suggesting that in T-ALL glycolytic dependent pathways are at least in part under epigenetic control. Thus, targeting G9a represents a strategy to exhaust the metabolic requirement of T-ALL cells.Subject terms: Translational research, Cancer metabolism, Acute lymphocytic leukaemia     

Expansion and CD2/CD3/CD28 stimulation enhance Th2 cytokine secretion of human invariant NKT cells with retained anti-tumor cytotoxicity

Background aimsKey obstacles in human iNKT cell translational research and immunotherapy include the lack of robust protocols for dependable expansion of human iNKT cells and the paucity of data on phenotypes in post-expanded cells.MethodsWe delineate expansion methods using interleukin (IL)-2, IL-7 and allogeneic feeder cells and anti-CD2/CD3/CD28 stimulation by which to dependably augment Th2 polarization and direct cytotoxicity of human peripheral blood CD3⁺Vα24⁺Vβ11⁺ iNKT cells.ResultsGene and protein expression profiling demonstrated augmented Th2 cytokine secretion (IL-4, IL-5, IL-13) in expanded iNKT cells stimulated with anti-CD2/CD3/CD28 antibodies. Cytotoxic effector molecules including granzyme B were increased in expanded iNKT cells after CD2/CD3/CD28 stimulation. Direct cytotoxicity assays using unstimulated expanded iNKT cell effectors revealed α-galactosyl ceramide (α-GalCer)-dependent killing of the T-ALL cell line Jurkat. Moreover, CD2/CD3/CD28 stimulation of expanded iNKT cells augmented their (α-GalCer-independent) killing of Jurkat cells. Co-culture of expanded iNKT cells with stimulated responder cells confirmed contact-dependent inhibition of activated CD4⁺ and CD8⁺ responder T cells.DiscussionThese data establish a robust protocol to expand and novel pathways to enhance Th2 cytokine secretion and direct cytotoxicity in human iNKT cells, findings with direct implications for autoimmunity, vaccine augmentation and anti-infective immunity, cancer immunotherapy and transplantation.     

Prostaglandin E2 induces growth inhibition, apoptosis and differentiation in T and B cell-derived acute lymphoblastic leukemia cell lines (CCRF-CEM and Nalm-6)

Despite advances in the treatment of ALL, in most patients long-term survival rates remain unsatisfactory. The objective of the present study was to investigate the anti-cancer effects of Prostaglandin E2 (PGE2) in two different ALL cell lines (CCRF-CEM (T-ALL) and Nalm-6 (B-ALL)). The anti-leukemic effects of PGE2 were also compared with two epigenetic compounds (trichostatin A and 5-aza-2'-deoxycytidine). MTT assay was used to assess growth inhibition by anti-cancer drugs in these cells. All three compounds were shown to induce apoptosis in both ALL cell lines using flow cytometry and Western blotting. To evaluate the differentiation induction by these agents, the expressions of CD19 and CD38 markers on Nalm-6 cell line and CD7 marker on CCRF-CEM cell line were assayed. Surprisingly, the flow cytometric analysis showed a significant increase in CD markers expression in response to PGE2 treatments. We, for the first time, provide evidences that PGE2 has anti-leukemic effects and induces differentiation at micromolar ranges in both T- and B-cell derived ALL cell lines. Since T-ALL cells are insensitive to current chemotherapies, these findings may help the designing of new protocols for T-ALL differentiation therapy in the future.     

去甲斑蝥素对白血病Jurkat细胞增殖的影响

目的:观察不同浓度去甲斑蝥素(NCTD)对急性T淋巴细胞白血病细胞株Jurkat增殖的影响。方法:体外培养的Jurkat细胞,用0、5、10、20、40 mg/LNCTD作用6、12、24、48、72 h后,通过倒置显微镜观察细胞形态、密度变化,MTT法检测细胞增殖抑制率,确定其最佳作用浓度及时间。然后将细胞分为NCTD组、长春新碱组、NCTD+长春新碱组,作用24、48、72 h后观察细胞形态、密度变化,MTT法检测细胞增殖抑制率。结果:倒置显微镜显示:随NCTD浓度增加、作用时间延长,细胞形态不规则,胀大、固缩,分布稀疏,大量死亡;MTT法显示:随NCTD浓度增加、作用时间延长,细胞增殖抑制率渐升高,20 mg/L作用72 h时最高(59.24%)。NCTD组与长春新碱组比较差异无统计学意义(P0.05),NCTD+长春新碱组抑制率(77.40%)明显高于NCTD组,差异有统计学意义(P0.05)。结论:NCTD可以浓度和时间依赖性方式抑制Jurkat细胞的增殖,与长春新碱联合后作用增强。     

结核分枝杆菌Rv3586结构域基因真核表达载体的构建及鉴定

目的:构建结核分枝杆菌(Mycobacterium tuberculosis,Mtb)环二腺苷酸(cyclic diadenosine monophosphate,c-di-AMP)合成酶Rv3586结构域基因的真核表达载体,并在COS-7细胞中表达。方法:以Mtb基因组为模板PCR扩增Rv3586三个结构域基因,分别克隆入pEGFP-N3真核表达质粒,用菌落PCR、质粒酶切和测序方法对插入序列进行鉴定。通过脂质体将重组质粒转染COS-7细胞,间接免疫荧光法检测目的基因在COS-7细胞内的表达。结果:PCR成功扩增出Rv3586三个结构域基因,菌落PCR、质粒酶切和质粒测序鉴定结果表明成功插入目的片段,包含Rv3586的三个结构域基因的真核表达载体构建成功。间接免疫荧光法结果显示,Rv3586三个结构域蛋白在COS-7细胞中表达成功。结论:成功构建Rv3586三个结构域基因的真核表达载体,并在COS-7细胞中表达成功,为后续Mtb Rv3586结构域的功能和应用研究奠定了基础。     

AMG-232, a New Inhibitor of MDM-2, Enhance Doxorubicin Efficiency in Pre-B Acute Lymphoblastic Leukemia Cells

Background:Doxorubicin (DOX)-induced cardiotoxicity appears to be a growing concern for extensive use in acute lymphoblastic leukemia (ALL). The new combination treatment strategies, therefore might be an effective way of decreasing its side effects as well as improving efficacy. AMG232 (KRT-232) is a potential MDM-2 inhibitor, increasing available p53 through disturbing p53-MDM-2 interaction. In this study, we examined the effects of AMG232 on DOX-induced apoptosis of NALM-6 cells.Methods:The anti-leukemic effects of Doxorubicin on NALM-6 cells, either alone or in combination with AMG232, were confirmed by MTT assay, Annexin/PI apoptosis assay, and cell cycle analysis. Expression of apoptosis and autophagy-related genes were further evaluated by Real time-PCR method. To investigate the effect of AMG232 on NALM-6 cells, the activation of p53, p21, MDM-2, cleaved Caspase-3 proteins was evaluated using western blot analysis.Results:The results showed that AMG232 inhibition of MDM-2 enhances Doxorubicin-induced apoptosis in NALM-6 cells through caspase-3 activation in a time and dose-dependent manner. Furthermore, co-treatment of AMG232 with Doxorubicin hampered the transition of NALM-6 cells from G1 phase through increasing p21 protein. In addition, this combination treatment led to enhanced expression of apoptosis and autophagy-related genes in ALL cell lines.Conclusion:The results declared that AMG232 as an MDM-2 inhibitor could be an effective approach to enhance antitumor effects of Doxorubicin on NALM-6 cells as well as an effective future treatment for ALL patients.Key Words: Acute Lymphoblastic Leukemia, AMG 232, Autophagy, Doxorubicin, p53     

Bortezomib enhances cytotoxicity of ex vivo-expanded gamma delta T cells against acute myeloid leukemia and T-cell acute lymphoblastic leukemia

Engagement between the natural killer group 2, member D (NKG2D) receptor and its ligands is one of the main mechanisms used by immune cells to target stressed cells for cell death. NKG2D ligands are known markers of cellular stress and are often upregulated on tumor cells. Certain drugs can further increase NKG2D ligand levels, thereby making tumor cells more susceptible to immune cell detection and destruction. However, the effectiveness of this approach appears to be limited with drug treatment alone, possibly due to immune dysregulation in the setting of malignancies. We hypothesized that a more effective approach would be a combination of NKG2D ligand-inducing drugs, such as the proteasome inhibitor bortezomib, and ex vivo-expanded peripheral blood γδ T cells (i.e., Vγ9Vδ2 T cells). Acute myeloid leukemia (AML) is a high-risk hematologic malignancy, and treatment has shown limited benefit with the addition of bortezomib to standard chemotherapy regimens. Two AML cells lines, Nomo-1 and Kasumi-1, were treated with increasing concentrations of bortezomib, and changes in NKG2D ligand expression were measured. Bortezomib treatment significantly increased expression of the NKG2D ligand UL16 binding protein (ULBP) 2/5/6 in both cell lines. Vγ9Vδ2 T cells were expanded and isolated from peripheral blood of healthy donors to generate a final cellular product with a mean of 96% CD3⁺/γδ T-cell receptor-positive cells. Combination treatment of the AML cell lines with γδ T cells and bortezomib resulted in significantly greater cytotoxicity than γδ T cells alone, even at lower effector-to-target ratios. Based on the positive results against AML and the generalizable mechanism of this combination approach, it was also tested against T-cell acute lymphoblastic leukemia (T-ALL), another high-risk leukemia. Similarly, bortezomib increased ULBP 2/5/6 expression in T-ALL cell lines, Jurkat and MOLT-4 and improved the cytotoxicity of γδ T cells against each line. Collectively, these results show that bortezomib enhances γδ T-cell-mediated killing of both AML and T-ALL cells in part through increased NKG2D ligand-receptor interaction. Furthermore, proof-of-concept for the combination of ex vivo-expanded γδ T cells with stress ligand-inducing drugs as a therapeutic platform for high-risk leukemias is demonstrated.