Notch信号转导对小细胞肺癌的调控及其机制研究

目的 探讨Notch信号转导对小细胞肺癌的调控作用及可能机制.方法 应用重组质粒转染的方法,在小细胞肺癌细胞株NCI-H446中表达组成性活化的Notch1(NIC转染组),同时设立转染空质粒组和未转染组作为对照组,待筛选出稳定细胞株后,以MTT法检测细胞活力,应用半定量RT-PCR技术测定Notch1及其下游基因(HES1和hASH1)表达,并应用免疫细胞化学标记和Westernblot技术对神经内分泌标志物嗜铬粒素A(CgA)、神经元特异性烯醇化酶(NSE)的表达行半定量[阳性单位(PU)值]分析.结果 未转染组和转染空质粒组Notch1及其下游基因HES1表达不明显,而hASH1表达显著,转染组细胞Notch1及HES1表达升高,同时伴有hASH1表达明显降低.与两对照组比较,转染组细胞增殖速度显著降低,连续6 d测得的吸光度(A)值均小于未转染组和转染空质粒组(均P<0.05).免疫细胞化学染色显示,NIC转染组、转染空质粒组、未转染组的CgA染色的PU值分别为8.81±0.77、38.10±1.55、38.97±0.80,NSE染色的PU值分别为7.21±0.59、28.25±1.46、30.57±1.31,NIC转染组CgA和NSE的PU值均小于转染空质粒组和未转染组(均P<0.01).Western blot检测结果中,将未转染组的条带灰度值设为1.00,NIC转染组、转染空质粒组的CgA条带灰度值分别为0.54±0.03、0.99±0.05,NSE条带灰度值分别为0.43±0.02、1.07±0.09,NIC转染组cgA和NSE条带的灰度值均小于转染空质粒组和未转染组(均P<0.01).结论 Notch信号途径对小细胞肺癌的调控可能是通过靶基因HES1对分化效应基因hASH1的转录抑制来实现的;Notch信号途径可以抑制小细胞肺癌细胞的增殖,降低其神经内分泌标志物的表达.     

Notch inhibition by the ligand DELTA-LIKE 3 defines the mechanism of abnormal vertebral segmentation in spondylocostal dysostosis

Mutations in the DELTA-LIKE 3 (DLL3) gene cause the congenital abnormal vertebral segmentation syndrome, spondylocostal dysostosis (SCD). DLL3 is a divergent member of the DSL family of Notch ligands that does not activate signalling in adjacent cells, but instead inhibits signalling when expressed in the same cell as the Notch receptor. Targeted deletion of Dll3 in the mouse causes a developmental defect in somite segmentation, and consequently vertebral formation is severely disrupted, closely resembling human SCD. In contrast to the canonical Notch signalling pathway, very little is known about the mechanism of cis-inhibition by DSL ligands. Here, we report that Dll3 is not presented on the surface of presomitic mesoderm (PSM) cells in vivo, but instead interacts with Notch1 in the late endocytic compartment. This suggests for the first time a mechanism for Dll3-mediated cis-inhibition of Notch signalling, with Dll3 targeting newly synthesized Notch1 for lysosomal degradation prior to post-translational processing and cell surface presentation of the receptor. An inhibitory role for Dll3 in vivo is further supported by the juxtaposition of Dll3 protein and Notch1 signalling in the PSM. Defining a mechanism for cis-inhibition of Notch signalling by Dll3 not only contributes greatly to our understanding of this ligand's function during the formation of the vertebral column, but also provides a paradigm for understanding how other ligands of Notch cis-inhibit signalling.     

Notch信号通路对胶质瘤干细胞的调控作用研究进展

胶质瘤干细胞(GSCs)是胶质瘤放化疗耐受和复发的重要原因.而Notch信号通路对GSCs形成、维持及胶质瘤患者放化疗耐受中起关键的调控作用.因此,深入研究GSCs中Notch信号通路调控机制对开发以该通路为靶向的治疗药物具有积极意义.     

Notch信号通路调控骨肉瘤细胞增殖的机制研究*

目的 观察Notch通路阻断剂DAPT和Notch通路激动剂Jagged1对人骨肉瘤143B细胞和MG63细胞体外增殖和体内成瘤的影响,探讨Notch信号通路在骨肉瘤细胞增殖中的调控作用。方法 体外培养人骨肉瘤143B细胞和MG63细胞,采用CCK-8法、集落形成试验以及BrdU染色法检测DAPT和Jagged1对两种细胞增殖的影响;在体内利用裸鼠成瘤试验,观察DAPT对于骨肉瘤细胞体内成瘤能力的调控作用,并对肿瘤组织进行切片染色,观察肿瘤组织恶性程度的变化情况。结果 CCK-8法检测结果表明DAPT显著抑制143B细胞和MG63细胞的增殖,且和浓度呈正相关,但10 μM的DAPT与20 μM的DAPT对143B细胞的增殖抑制能力无明显差异。肿瘤集落形成试验结果表明DAPT能够显著抑制肿瘤集落的形成。BrdU染色结果显示DAPT组的BrdU阳性细胞明显少于对照组和Jagged1组,而Jagged1组的阳性细胞数明显多于对照组。体内裸鼠成瘤实验结果显示,与对照组相比,DAPT组能够明显抑制肿瘤大小,Ki67阳性率降低。HE染色结果显示,DAPT组肿瘤组织中的细胞核数量和血管数量明显减少,且组织内部更加疏松。 结论 Notch信号通路参与调控人骨肉瘤143细胞和MG63细胞的体外增殖与体内成瘤行为,抑制Notch通路的表达可能成为骨肉瘤治疗的重要靶点。     

Abnormal vertebral segmentation and the notch signaling pathway in man.

Abnormal vertebral segmentation (AVS) in man is a relatively common congenital malformation but cannot be subjected to the scientific analysis that is applied in animal models. Nevertheless, some spectacular advances in the cell biology and molecular genetics of somitogenesis in animal models have proved to be directly relevant to human disease. Some advances in our understanding have come through DNA linkage analysis in families demonstrating a clustering of AVS cases, as well as adopting a candidate gene approach. Only rarely do AVS phenotypes follow clear Mendelian inheritance, but three genes-DLL3, MESP2, and LNFG-have now been identified for spondylocostal dysostosis (SCD). SCD is characterized by extensive hemivertebrae, trunkal shortening, and abnormally aligned ribs with points of fusion. In familial cases clearly following a Mendelian pattern, autosomal recessive inheritance is more common than autosomal dominant and the genes identified are functional within the Notch signaling pathway. Other genes within the pathway cause diverse phenotypes such as Alagille syndrome (AGS) and CADASIL, conditions that may have their origin in defective vasculogenesis. Here, we deal mainly with SCD and AGS, and present a new classification system for AVS phenotypes, for which, hitherto, the terminology has been inconsistent and confusing.     

Notch信号通路及其在肺癌发生中的作用

Notch信号通路存在于多种动物体内,是许多细胞信号转导通路的交汇点,不仅对正常组织、细胞的分化、发育起重要作用,而且和一些肿瘤的发生、发展相关。Notch信号在肺癌中的作用多样，在不同类型肺癌中呈现出不同的促癌或抑癌功能。了解Notch和肺癌的关系有利于进一步阐明肺癌发生机制,提出预防和治疗肺癌的新途径，为肿瘤基因治疗提供一个新的有希望的靶点。     

Notch1通过非经典的Notch信号通路调节胰腺星形细胞的活化

目的:探讨Notch1在胰腺星形细胞(pancreatic stellate cells,PSCs)活化中的作用。方法:利用免疫组织化学法与免疫荧光双标法检测Notch1在人胰腺导管腺癌(pancreatic ductal adenocarcinoma,PDAC)组织的表达情况;原代分离培养小鼠PSCs,利用油红O染色、Western blot及RT-qPCR法对其进行鉴定,并利用Western blot及RT-qPCR检测Notch1及其下游关键分子HES1的表达情况;转染Notch1小干扰RNA(Notch1 siRNA)至小鼠PSCs后,利用Western blot检测α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)、纤连蛋白(fibronectin)、I型胶原(collagen typeⅠ,ColⅠ)、Notch1及HES1的表达情况;利用划痕实验与CCK-8实验检测Notch1 siRNA对小鼠PSCs迁移与细胞活力的影响。结果:免疫组化与免疫荧光双标染色结果显示,Notch1表达在α-SMA阳性的PDAC间质细胞中;成功培养了小鼠PSCs细胞,且...     

Wnt和Notch信号通路在肿瘤干细胞自我更新中的作用

肿瘤干细胞是一类能够导致肿瘤发生的具有自我更新能力的细胞，它与干细胞具有很多相似性，其中最重要的一点是自我更新能力。它们具有相似的自我更新调节通路，如：Wnt，Notch和Shh(Sonic hedgehog)。Wnt和Notch信号通路通过其受体和配体的相互作用在自我更新的增殖和分化中都起着重要的作用，两者均能促进干细胞增殖而抑制其分化，但各自侧重不同。此外，Wnt和Notch信号通路之间相互作用、协调共同完成干细胞的自我更新。对肿瘤干细胞的Wnt和Notch信号通路研究将为未来肿瘤的靶向治疗提供新的方向。     

The somite segmentation clock: it takes a licking and keeps on ticking.

This primer describes molecular mechanisms critical for somite segmentation clock function. In addition, two investigators of the segmentation clock, Olivier Pourquie, and Yun-Jin Jiang, give their perspectives on current research and on the future of the field.     

The Notch/Jagged pathway inhibits proliferation of human hematopoietic progenitors in vitro.

The cell surface receptor Notch1 is expressed on CD34+ hematopoietic precursors, whereas one of its ligands, Jagged1, is expressed on bone marrow stromal cells. To examine the role of Notch signaling in early hematopoiesis, human CD34+ cells were cultured in the presence or absence of exogenous cytokines on feeder layers that either did or did not express Jagged1. In the absence of recombinant growth factors, Jagged1 decreased myeloid colony formation by CD34+ cells, as well as 3H-thymidine incorporation and entry into S phase. In the presence of a strong cytokine signal to proliferate and mature, (interleukin 3 [IL-3] and IL-6, stem cell factor [SCF], and G-CSF), Jagged1 did not significantly alter either the fold expansion or the types of colonies formed by CD34+ cells. However, in the presence of SCF alone, Jagged1 increased erythroid colony formation twofold. These results demonstrate that Notch can modulate a growth factor signal, and that in the absence of growth factor stimulation, the Jagged1-Notch pathway preserves CD34+ cells in an immature state.     

Deregulation of the Notch pathway as a common road in viral carcinogenesis

The Notch pathway is a conserved signaling pathway and a form of direct cell‐cell communication related to many biological processes during development and adulthood. Deregulation of the Notch pathway is involved in many diseases, including cancer. Almost 20% of all cancer cases have an infectious etiology, with viruses responsible for at least 1.5 million new cancer cases per year. Seven groups of viruses have been classified as oncogenic: hepatitis B and C viruses (HBV and HCV respectively), Epstein‐Barr virus (EBV), Kaposi sarcoma‐associated herpesvirus (KSHV), human T lymphotropic virus (HTLV‐1), human papillomavirus (HPV), and Merkel cell polyomavirus (MCPyV). These viruses share the ability to manipulate a variety of cell pathways that are critical in proliferation and differentiation, leading to malignant transformation. Viral proteins interact directly or indirectly with different members of the Notch pathway, altering their normal function. This review focuses exclusively on the direct interactions of viral oncoproteins with Notch elements, providing a deeper understanding of the dual behavior of the Notch pathway as activator or suppressor of neoplasia in virus‐related cancers.     

Notch信号通路在孤独症谱系障碍中的研究进展

正孤独症谱系障碍(Autism spectrum disorders,ASDs)是一组病因复杂、发病机制尚不明确的神经发育障碍性疾病。ASDs包括典型孤独症、阿斯伯格综合症、Rett综合征、童年瓦解性障碍及其它待分类的非特异性广泛发育障碍。其主要的行为表现有社交障碍、语言发育障碍以及重复刻板的兴趣或行为等。近年来,ASDs由于发病率在不同国家均有所上升,而成为研究的一大热点。ASDs发病机制尚不清楚,目前主要