拓扑替康对神经母细胞瘤SH－SY5 Y增殖、侵袭和迁移影响的探讨

目的：神经母细胞瘤（neuroblastoma,NB）早期侵袭和转移是其难治性的主要原因。本文探讨拓扑替康对神经母细胞瘤SH－SY5Y细胞增殖、凋亡、侵袭和迁移能力及其可能机制影响。方法：1nmol／L、10nmol／L、100nmol／L、1000nmol／L拓扑替康干预NB细胞系 SH－SY5Y。Cell counting kit－8（CCK－8）法检测 SH－SY5 Y增殖;划痕试验、Tranwell小室模型检测SH－SY5 Y迁移、侵袭能力;蛋白免疫印迹（Western－blotting, WB）试验检测SH－SY5Y内基质金属蛋白酶9（matrix metalloproteinase 9,MMP9）、基质金属蛋白酶2（matrix metalloproteinase 2,MMP2）表达。结果：我们发现拓扑替康时间－浓度依赖性地抑制SH－SY5Y增殖。拓扑替康浓度依赖性地抑制侵袭和迁移及细胞MMP9、MMP2蛋白表达。结论：拓扑替康能够抑制神经母细胞瘤的增殖,并且可能通过下调MMP9、MMP2蛋白表达抑制神经母细胞瘤侵袭和迁移。     

人参皂苷Rh2对神经母细胞瘤SH-SY5Y的增殖、凋亡、迁移及侵袭的影响

目的:针对神经母细胞瘤（neuroblastoma,NB）早期易转移的特性,研究人参皂苷Rh2（ginsenoside Rh2）对神经母细胞瘤的增殖、凋亡、迁移及侵袭的影响。方法:用不同（5、10、20、40、80 μg/ml）浓度人参皂苷Rh2来干预神经母细胞瘤细胞系SH-SY5Y。Cell counting kit-8(CCK-8)法、细胞划痕试验、Transwell小室模型检测细胞增殖、迁移及侵袭能力;蛋白质印迹法（Western-blot,WB）试验检测不同浓度下神经母细胞瘤细胞内基质金属蛋白酶2（matrix metalloproteinase2,MMP2）、Bax、Bcl-2、β-catenin蛋白的表达。结果:人参皂苷Rh2可以时间-浓度依赖性地抑制神经母细胞瘤增殖、迁移及侵袭,降低迁移相关蛋白MMP2的表达,上调了促凋亡蛋白Bax的表达水平同时降低抗凋亡蛋白Bcl-2的表达。人参皂苷Rh2处理的神经母细胞瘤内β-catenin水平降低。结论:人参皂苷Rh2可以在体外抑制神经母细胞瘤的增殖,下调MMP2蛋白抑制肿瘤细胞迁移及侵袭,通过wnt通路抑制细胞生长。     

Retinoic acid downregulates Rae1 leading to APC(Cdh1) activation and neuroblastoma SH-SY5Y differentiation

In neuroblastoma cells, retinoic acid induces cell cycle arrest and differentiation through degradation of the F-box protein, Skp2, and stabilization of cyclin-dependent kinase inhibitor, p27. However, the mechanism responsible for retinoic acid-mediated Skp2 destabilization is unknown. Since Skp2 is degraded by anaphase-promoting complex (APC)(Cdh1), here we studied whether retinoic acid promotes differentiation of human SH-SY5Y neuroblastoma cells by modulating Cdh1. We found that retinoic acid induced the nuclear accumulation of Cdh1 that paralleled Skp2 destabilization and p27 accumulation. The mRNA and protein abundance of Rae1-a nuclear export factor that limits APC(Cdh1) activity in mitosis-decreased upon retinoic acid-induced inhibition of neuroblastoma cell proliferation. Furthermore, either Rae1 overexpression or Cdh1 inhibition promoted Skp2 accumulation, p27 destabilization and prevented retinoic acid-induced cell cycle arrest and differentiation. Conversely, inhibition of Rae1 accelerated retinoic acid-induced differentiation. Thus, retinoic acid downregulates Rae1, hence facilitating APC(Cdh1)-mediated Skp2 degradation leading to the arrest of cell cycle progression and neuroblastoma differentiation.     

Neuronal differentiation of human neuroblastoma SH-SY5Y cells by gangliosides

Exogenous administration of gangliosides induced neuronal differentiation with prominent neuritogenesis in human neuroblastoma SH-SY5Y cells in vitro. Neuritogenesis was characterized by ruffling of the cell membrane, the development of lamellipodia and filopodia, and the subsequent elongation and branching of the neurites ultrastructurally. Both axons and neurites were identified. Increased numbers of cell organelles in the neurites and cell bodies were noted. Nonsynaptic contacts and gap junctions formed between neurites or between each neurite and cell body. These findings could be implicated in histopathologic changes from neuroblastoma to ganglioneuroblastoma.     

2-TeCD对过氧化氢诱导SH-SY5Y细胞损伤影响的研究

目的:探讨谷胱甘肽过氧化物酶模拟物2-TeCD对H2O2诱导SH-SY5Y细胞损伤影响.方法:用不同浓度的H2O2作用人神经母细胞瘤SH-SY5Y细胞,确定其半数致死浓度(IC50).检测2-TeCD对H2O2损伤细胞的细胞生存率、脂质过氧化物含量(MDA)和DNA裂解率.结果:H2O2对SH-SY5Y细胞的IC50为0.208 mmol/L;0.2 mmol/L的H2O2处理后SH-SY5Y细胞生存率为对照组的52.67％,TeCD保护H2O2损伤SH-SY5Y细胞的有效浓度为10 μmol/L; 10和20 μmol/L的2-TeCD可降低SH-SY5Y细胞中MDA含量,并降低DNA裂解率.结论:2-TeCD对H2O2损伤的SH-SY5Y细胞具有较好保护效果,可成为潜在的抗氧化药物.     

Effects of bryostatins 1 and 2 on morphological and functional differentiation of SH-SY5Y human neuroblastoma cells

SH-SY5Y human neuroblastoma cells can be induced to differentiate to mature ganglion cells when treated with the phorbol ester tetradecanoylphorbol acetate (TPA). Bryostatins are a new class of protein kinase C activators that are structurally unrelated to phorbol esters. This paper describes the effects of bryostatins 1 and 2 on morphological and functional differentiation of SH-SY5Y cells. Both bryostatins induced a rapid translocation of protein kinase C from the cytosol to the membrane fraction. Within 24 h, the bryostatins had caused a nearly complete down-regulation of the enzyme. Bryostatin 1 competed for [3H]phorbol-12,13-dibutyrate binding in intact cells with potency equal to that of TPA, in contrast to bryostatin 2, which exhibited a Ki value 1 order of magnitude higher than those of the two other agents. Bryostatins induced morphological changes similar to those induced by TPA. These changes were, however, only transient, occurring during the first 6 h of incubation in the presence of these compounds. By 72 h, the cells had acquired a morphology typical of untreated cells and, although a wide range of bryostatin concentrations were used, morphological changes characteristic of differentiated SH-SY5Y cells were not detected at 72 h. Bryostatin 1 at 5 nM and bryostatin 2 at 100 nM inhibited DNA synthesis, as measured by incorporation of [3H]thymidine by SH-SY5Y cells, although to a significantly lesser degree than TPA. In spite of the fact that bryostatins failed to induce morphological differentiation in SH-SY5Y cells, these compounds down-regulated c-myc mRNA expression. Bryostatins were significantly weaker in stimulating noradrenaline synthesis, compared with TPA, and high concentrations of these agents blocked the effect of the phorbol ester when they were included together with TPA. When SH-SY5Y cells were incubated in the presence of high concentrations of bryostatins, a decreased sensitivity of cells to muscarinic agonist-induced increases in cytosolic free Ca2+ was observed. The results suggest that down-regulation of protein kinase C activity and c-myc mRNA expression do not necessarily correlate with the morphological differentiation of SH-SY5Y cells.     

Retinoic acid induces neuroblastoma cell death by inhibiting proteasomal degradation of retinoic acid receptor alpha

To seek a novel therapeutic approach to neuroblastoma (NBL), we used three NBL cell lines (SK-N-DZ, NH12, and SK-N-SH) to examine the underlining molecular mechanisms of cellular reactions and sensitivity to all-trans-retinoic acid (ATRA). SK-N-DZ cells expressed relatively high levels of retinoic acid receptor alpha (RAR-alpha) and underwent ATRA-induced cell death that was blocked by an RAR-alpha antagonist. By contrast, RAR-alpha expression gradually decreased in NH12 and SK-N-SH cells, which did not experience increased cell death in response to ATRA. We report here the ubiquitin-dependent down-regulation of RAR-alpha expression during ATRA treatment. Our data suggest that SK-N-DZ cells have a defect in RAR-alpha down-regulation, resulting in sustained high expression of RAR-alpha that confers high sensitivity to ATRA. Accordingly, treatment with a proteasome inhibitor dramatically increased ATRA-induced cell death in NH12 and SK-N-SH cell lines. Our results reveal the crucial involvement of the RAR-alpha signaling pathway in NBL cell death and show that three NBL cell lines are differentially sensitive to ATRA. These data suggest a potential novel therapy for NBL involving retinoic acid treatment combined with the inhibition of RAR-alpha degradation.     

Differential function of lysophosphatidic acid receptors in cell proliferation and migration of neuroblastoma cells

Lysophosphatidic acid (LPA) is a bioactive lipid mediator that induces diverse cellular biological effects and interacts with G protein-coupled transmembrane LPA receptors. In the present study, to assess biological roles of LPA receptors in the pathogenesis of tumor cells, each LPA receptor (Lpar1, Lpar2 or Lpar3)-expressing rat neuroblastoma B103 cells (lpa1-1, lpa2-2 or lpa3-3-2 cells, respectively) were used. In cell motility and invasion assay, lpa2-2 and lpa3-3-2 cells showed significant higher intrinsic activity without LPA treatment than LPA receptor-unexpressing AB2-1bf cells. LPA treatment further increased cell motility of these cells, which was suppressed by the pretreatment with inhibitors of Gi, Gq protein, or ROCK. By contrast, lpa1-1 cells markedly decreased intrinsic cell motility and invasion, compared with AB2-1bf cells. Constitutively active mutant Lpar1-expressing cells (lpa1Δ-1) showed significant high motility, comparable with those of lpa2-2 and lpa3-3-2. In soft agar assay, lpa3-3-2 and lpa1Δ-1 cells showed colony formation, but other cells failed. These results suggest that LPA receptors may play different roles in cell proliferation and migration of rat neuroblastoma cells.     

Differential regulation of p73 variants in response to cisplatin treatment in SH-SY5Y neuroblastoma cells

The present study aims to investigate the role of p73 in response to cisplatin treatment in p53 wild-type neuroblastoma SH-SY5Y cells. Results showed that cisplatin induced a dose-dependent up-regulation of p53, p73, and a number of p53-responsive genes. Interestingly, endogenous Deltaexon2p73-expression was down-regulated by cisplatin treatment. Neither p21 nor GADD45 induction was observed in p53-deficient Lan-1 cells, although endogenous TAp73 expression was markedly induced. In the presence of cisplatin, exogenous TAp73 overexpression in SH-SY5Y cells induced p21 up-regulation without altering the apoptotic sub-G1 cell population. Moreover, siRNA-mediated suppression of TAp73 expression did not alter the sub-G1 population. Collectively, our results suggest that wt-p53 SH-SY5Y cells respond to cisplatin by inducing p73 isoform regulation and sustaining p53-dependent apoptosis that is independent of TAp73alpha.     

2,3-吲哚醌诱导人神经母细胞瘤SH-SY5Y细胞凋亡及周期阻滞

背景与目的:2,3-吲哚醌(isatin,ISA)是存在于哺乳动物体液及组织中的一种天然物质,已发现其对肿瘤细胞的生长有抑制作用,但具体作用机制尚不明。本研究以人神经母细胞瘤细胞SH-SY5Y为靶细胞,观察ISA对SH-SY5Y细胞的作用及其机制。方法:采用荧光染色、流式细胞术(flow cytometry,FCM)及Western blot等方法检测不同浓度ISA(0、100、200、400μmol/L)诱导SH-SY5Y细胞凋亡及细胞周期阻滞的作用机制。结果:400μmol/L ISA作用48h后,在荧光显微镜下观察到SH-SY5Y细胞出现核固缩、DNA断裂等典型的凋亡形态学改变。Western blot结果显示,随ISA浓度的增加,Bcl-2蛋白表达下降、Bax蛋白表达无明显改变,Bcl-2/Bax下降。100、200、400μmol/L ISA处理SH-SY5Y细胞48h,活化Caspase-3的表达率分别为19.28%、25.88%、33.43%,明显高于对照组(P<0.05)。Western blot进一步检测到其下游底物Caspase激活的脱氧核糖核酸酶抑制剂(inhibitor of caspase-activated DNase,ICAD)被降解。细胞周期分析表明,经100、200、400μmol/L ISA处理48h后,G1期SH-SY5Y细胞数明显增加,呈明显的G1期阻滞;磷酸化的ERK蛋白及Cyclin D1(CDK1)蛋白表达显著减少(P<0.05)。结论:ISA能明显诱导SH-SY5Y细胞凋亡和细胞周期G1期阻滞,该作用可能与Bcl-2/Bax降低、Caspase-3激活,以及下调磷酸化ERK和细胞周期因子CDK1表达有关。     

Expression of the neurotrophin receptor TrkA down-regulates expression and function of angiogenic stimulators in SH-SY5Y neuroblastoma cells

Angiogenesis is essential for tumor growth and metastasis and depends on the production of angiogenic factors. Mechanisms regulating the expression of angiogenic factors in tumor cells are largely unknown. High expression of the neurotrophin receptor TrkA in neuroblastomas (NBs) is associated with a favorable prognosis, whereas TrkB is mainly expressed on aggressive, MYCN-amplified NBs. To investigate the biological effects of TrkA and TrkB expression on angiogenesis in NB, we examined the expression of angiogenic factors in the human NB cell line SY5Y and its TrkA and TrkB transfectants. In comparison with parental SY5Y cells, mRNA and protein levels of the examined angiogenic factors were significantly reduced in SY5Y-TrkA cells, whereas SY5Y-TrkB cells did not demonstrate a significant change. Conditioned medium of TrkB transfectants and parental SY5Y cells induced endothelial cell proliferation and migration, but this effect was completely absent in SY5Y-TrkA cells. TrkA expression also resulted in severely impaired tumorigenicity in a mouse xenograft model and was associated with reduced angiogenic factor expression and vascularization of tumors, as determined by immunohistochemistry and an in vivo Matrigel assay. TrkA expression inhibits angiogenesis and tumor growth in SY5Y NB cells by down-regulation of angiogenic factors, whereas expression of TrkB does not down-regulate the production of these angiogenic factors. The biologically different behavior of TrkA- and TrkB-expressing NBs may be explained in part by their effects on angiogenesis.     

口服维甲酸对鼠肝组织中维甲酸受体表达影响的研究

目的:研究口服维甲酸(retinoic acid,RA)对鼠肝中维甲酸受体(RAR)α、β、γ水平的影响。方法:A组被喂以生理学剂量的维甲酸(剂量为3μgRA/g食物),B组被喂以药理学剂量的RA(剂量为30μgRA/g食物),时间为75周。结果:喂食药理学剂量的RA诱导了鼠肝的RAR,RARα提高22倍、RARβ提高14.6倍和RARγ提高12.5倍。在肝细胞的细胞核中,RAR的表达出现了显著的增长。结论:喂食RA可以增强鼠肝中RAR的表达。表明以口服的方式向肝组织施以化学预防用RA是增量调节RA受体的有效方法。     

mTOR通路对神经母细胞瘤SH-SY5 Y细胞自噬作用的影响

目的：研究雷帕霉素靶蛋白（ mammalian target of rapamycin,mTOR）通路对神经母细胞瘤SH-SY5Y细胞自体吞噬作用的影响。方法：应用不同浓度的雷帕霉素作用于神经母细胞瘤细胞,采用实时荧光定量PCR检测雷帕霉素作用前后神经母细胞瘤细胞株的mTOR、LC3及Beclin 1 mRNA表达情况。结果：雷帕霉素能抑制mTOR表达且呈现量效依赖关系,不同浓度的雷帕霉素分别对SH-SY5Y细胞作用72h后,mTOR mR-NA的表达随浓度增加逐渐下降。而LC3及Beclin 1 mRNA的表达随浓度增加逐渐上升,神经母细胞瘤中mTOR与LC3及Beclin 1的表达呈负相关。结论：雷帕霉素通过抑制mTOR信号通路促进神经母细胞瘤的自体吞噬作用,动态观察mTOR可作为神经母细胞瘤治疗效果监测的指标之一。     

吴茱萸碱对神经母细胞瘤SK-N-SH细胞增殖、迁移及侵袭的影响

目的：探讨吴茱萸碱（Evo）是否通过调控lncRNA LINC00858 表达调控神经母细胞瘤SK-N-SH 细胞的增殖、迁移及侵袭。方法：在体外以3、6、12 μmol/L Evo 处理人神经母细胞瘤SK-N-SH 细胞,利用RNA干扰技术分别将si-NC、si-LINC00858转染至SK-N-SH 细胞,将pcDNA、pcDNA-LINC00858 转染至SK-N-SH 细胞并经12 μmol/L Evo 处理,实验分为对照组、Evo 低剂量组、Evo 中剂量组、Evo 高剂量组、si-NC 组、si-LINC00858 组、Evo+pcDNA 组、Evo+pcDNA-LINC00858 组。采用qPCR法检测各组细胞LINC00858 的表达量,MTT、Transwell 实验分别检测细胞的增殖、迁移、侵袭能力,WB 法检测细胞中cyclinD1、MMP-2、 MMP-9和p21 蛋白的表达。结果：与对照组相比,Evo低、中、高剂量组SK-N-SH 细胞中LINC00858 表达均显著降低（均P<0.05）,细胞增殖抑制率显著升高、迁移及侵袭细胞数显著减少（均P<0.01）,cyclinD1、MMP-2、MMP-9 蛋白表达降低、p21 蛋白表达升高（均P<0.01）。与si-NC 组相比,si-LINC00858 组细胞的增殖抑制率、迁移和侵袭细胞数及相关蛋白表达变化同Evo 低、中、高剂量组。与Evo+pcDNA 组相比,Evo+pcDNA-LINC00858 组细胞的增殖抑制率显著降低、迁移及侵袭细胞数均显著增多（均P<0.01）,cyclinD1、MMP-2、MMP-9蛋白表达升高、p21蛋白表达降低（均P<0.05）。结论：Evo 通过下调LINC00858 表达抑制神经母细胞瘤SK-N-SH细胞的增殖、迁移及侵袭。     

沉默Y盒结合蛋白-1表达抑制SH-SY5Y细胞增殖促其凋亡的作用与机制

目的:观察短发夹RNA（shRNA）沉默Y盒结合蛋白-1（YB-1）对人神经母细胞瘤SH-SY5Y细胞增殖、凋亡的影响及其调控机制。方法:构建针对YB-1的短发夹RNA真核表达载体,利用LipofectamineTM2000脂质体转染SH-SY5Y细胞,检测蛋白表达水平,鉴别干扰效果;四甲基偶氮唑蓝比色法（MTT）检测干扰与否对SH-SY5Y细胞增殖的影响;流式细胞技术分析干扰与否对SH-SY5Y细胞凋亡的影响;Western blot法检测CyclinD1、Bcl-2及Bax在蛋白水平的变化。结果:Western blot结果显示转染组YB-1表达低于对照组和无效转染组,后两组无显著差异;MTT法检测显示转染组细胞增殖水平低于对照组,无效转染组细胞增殖水平接近对照组;流式细胞术检测结果显示转染组凋亡细胞数占总细胞数的（23.21±1.90）%,高于对照组（5.05±0.83）%（P<0.01）,无效转染组（6.24±1.05）%与对照组无显著性差异（P>0.05）;Western blot技术检测转染组CyclinD1、Bcl-2蛋白水平较对照组明显下降,Bax升高,无效转染组同对照组无明显差异。结论:shRNA介导的YB-1表达沉默可抑制SH-SY5Y细胞CyclinD1、Bcl-2表达,促进Bax表达,进而抑制细胞增殖、促进凋亡。     

Increasing the intracellular availability of all-trans retinoic acid in neuroblastoma cells

Recent data indicate that isomerisation to all-trans retinoic acid (ATRA) is the key mechanism underlying the favourable clinical properties of 13-cis retinoic acid (13cisRA) in the treatment of neuroblastoma. Retinoic acid (RA) metabolism is thought to contribute to resistance, and strategies to modulate this may increase the clinical efficacy of 13cisRA. The aim of this study was to test the hypothesis that retinoids, such as acitretin, which bind preferentially to cellular retinoic acid binding proteins (CRABPs), or specific inhibitors of the RA hydroxylase CYP26, such as R116010, can increase the intracellular availability of ATRA. Incubation of SH-SY5Y cells with acitretin (50 microM) or R116010 (1 or 10 microM) in combination with either 10 microM ATRA or 13cisRA induced a selective increase in intracellular levels of ATRA, while 13cisRA levels were unaffected. CRABP was induced in SH-SY5Y cells in response to RA. In contrast, acitretin had no significant effect on intracellular retinoid concentrations in those neuroblastoma cell lines that showed little or no induction of CRABP after RA treatment. Both ATRA and 13cisRA dramatically induced the expression of CYP26A1 in SH-SY5Y cells, and treatment with R116010, but not acitretin, potentiated the RA-induced expression of a reporter gene and CYP26A1. The response of neuroblastoma cells to R116010 was consistent with inhibition of CYP26, indicating that inhibition of RA metabolism may further optimise retinoid treatment in neuroblastoma.     

大豆异黄酮对阿特拉津损伤SH-SY5Y细胞的保护作用及其机制

目的：比较大豆异黄酮、槲皮素、茶多酚、姜黄素和白藜芦醇5种植物化合物对阿特拉津（ATR）损伤神经元的保护作用及分子机制。方法：体外培养SH-SY5Y细胞,分别加入浓度为5、10、20、50、100 μmol/L的5种植物化合物,24 h后,加入250 μmol/L ATR,继续培养24 h后,CCK-8法检测细胞活力,Annexin V-FTTC/PI双染检测细胞凋亡情况,DCFH-DA探针检测活性氧（ROS）水平,Western blot检测酪氨酸氢化酶（TH）蛋白表达量,并用SPSSS 20.0进行统计学分析。结果：5种植物化合物在低剂量范围内抗ATR损伤效果显著,剂量分别为大豆异黄酮5 μmol/L、白藜芦醇5 μmol/L、槲皮素50 μmol/L、姜黄素5 μmol/L、茶多酚20 μmol/L,与其他4种植物化合物相比,大豆异黄酮抗ATR损伤SH-SY5Y细胞效果显著,尤其在5 μmol/L,可显著降低ROS水平,增加TH蛋白的表达（P < 0.05）。结论：大豆异黄酮可能通过降低SH-SY5Y细胞内ROS水平,增加TH蛋白的表达,增加细胞活力,抑制细胞凋亡。