Revealing the role of honokiol in human glioma cells by RNA-seq analysis

Background:Glioma is a kind of tumor that easily deteriorates and originates from glial cells in nerve tissue.Honokiol is a bisphenol compound that is an essential monomeric compound extracted from the roots and bark of Magnoliaceae plants.It also has anti-infection,antitumor,and immunomodulatory effects.In this study,we found that honokiol induces cell apoptosis in the human glioma cell lines U87-MG and U251-MG.However,the mechanism through which honokiol regulates glioma cell apoptosis is still unknown.Methods:We performed RNA-seq analysis of U251-MG cells treated with honokiol and control cells.Protein-protein interaction(PPI)network analysis was performed,and the 10 top hub unigenes were examined via real-time quantitative PCR.Furthermore,MAPK signaling and ferroptosis were detected via western blotting.Results:332 differentially expressed genes(DEGs)were found,comprising 163 increased and 169 decreased genes.Analysis of the DEGs revealed that various biological processes were enriched,including‘response to hypoxia’,‘cerebellum development cellular response to hypoxia,’‘iron ion binding,’‘oxygen transporter activity,’‘oxygen binding,’‘ferric iron binding,’and‘structural constituent of cytoskeleton.’Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis revealed that the DEGs were enriched in the following pathways:‘mitogen-activated protein kinases(MAPK)’,‘Hypoxia-inducible factor 1(HIF-1)’,‘ferroptosis,’‘Peroxisome proliferator-activated receptor(PPAR),’‘Phosphatidylinositol-4,5-bisphosphate 3-kinase(PI3K)-protein kinase B(Akt),’and‘phagosome.’Among these pathways,the MAPK signaling pathway and ferroptosis were verified.Conclusion:This study revealed the potential mechanism by which honokiol induces apoptosis and provided a comprehensive analysis of DEGs in honokiol-treated U251-MG cells and the associated signaling pathways.These data could lead to new ideas for future research and therapy for patients with glioma.

Inhibitory Effects of Ginsenoside Rb1 on Apoptosis Caused by HSV-1 in Human Glioma Cells

To investigate the inhibitory effects of Ginsenoside Rbl （GRbl） on apoptosis caused by Herpes Simplex Virus-1 （HSV-1） in Human Glioma Cells （U251）, U251 cells were infected by HSV-1 at a multiplicity of infection of 5 and GRbl, GRbl＋HSV-1, HSV-1 and control groups. MTT and cell apoptosis assays were used to detect the inhibitory effects of GRbl on the apoptosis of U251 cells that caused by HSV-1 infection for various concentrations of drug and virus treatments by MTT assay. We found that in the 400 μg/mL GRb 1 and 400 μg/mL GRbl＋HSV-1 groups, MTT values were higher than control group at all times （P〈0.05）. Moreover, the apoptosis rate in the 400 μg/mL GRbl＋HSV-1 group was lower than the HSV-1 group （P〈0. 05）. These results confirmed that, at appropriate concentrations, GRbl could inhibit nerve cell apoptosis in HSV-1 infections.

Activation of CD40 by Soluble Recombinant Human CD40 Ligand Inhibits Human Glioma Cells Proliferation via Nuclear Factor-κB Signaling Pathway

As CD40 transduces activation signals involved in inflammatory and immune disorders,we explored the expression and response to CD40 engagement in human glioma cell lines in this study.The CD40 expression in BT-325 and U251 cells was flow cytometrically detected.The cells were incubated with srhCD40L for 72 h to assess its effects on cell growth in vitro.TNF-α expression was quantified by real-time PCR,and protein expression was analyzed by ELISA.The I-κb mRNA was detected by RT-PCR.I-κB expression decreased after stimulation with 1 μg/mL srhCD40L,but it was upregulated after the cells were pretreated with CD40 antibody.srhCD40L significantly inhibited the proliferation of the CD40+ human glioma cells.The stimulation of CD40+ glioma cells with soluble CD40L (CD154) up-regulated the expression of TNF-α at both mRNA and protein levels.We are led to conclude that CD40L/CD40 could inhibit human glioma cells through I-κb signaling pathway.Interferon-γ can augment CD40 expression and the inhibitory effect of CD40 ligand on cell growth in vitro.These results suggest that srhCD40L may benefit the therapy strategy of glioma.

THE STUDIES ON MONOCLONAL ANTIBODY SZ-39 AGAINST HUMAN GLIOMA CELLS

A hybridoma cell line SZ-39 secreting monoclonal antibody against the human glioma cell has been established by a fusion between NS-1 myeloma cells and spleen cells from mice immunized with human glioma cell lines. Monoclonal antibody (McAb) SZ-39 was analyzed by ELISA, quantitative absorption, indirect immunofluorescence and ABC immunohistology. McAb SZ-39 strongly bound to 9/10 glioma cell lines, 17/20 glioma tissues, weakly bound to one liver cancer cell line and 1/2 lung cancer line, but they did not band with other tested human cancer linse. NcAb SZ-39 have no cross-reaction with lymphocyte, ABC red blood cells, white blood cells, blood platelet, normal bone marrow cells, fibroblast cells and 12 normal human tissues.The result indicated the antigen recognized by McAb SZ-39 may be a glioma-associated antigen <GAA). This GAA was analyzed by means of Western blotting. It was a MW 180 Kd glycopro-tein. The 131I-McAb SZ-39 specifically localized in human glioma xenografted in nude mice that indicate it may be useful in radioimmunoimaging and as a target for immunotherapy on human glioma.

Adiponectin Supports Human Glioma Cells Survival against Temozolomide through Enhancement of Autophagic Response in Glioma Cells

Objective: To investigate the role of adiponectin in human glioma cell lines against the temozolomide and the molecular regulation mechanism. Methods: Human glioma cell lines U251 and U-87MG were cultured in Dulbecco’s modified eagle medium (DMEM) containing 4500 mg/L glucose. MTT was used to measure cell growth ratio. Western blot was used to detect the protein levels of autophagy-related protein (Beclin 1, LC3 I/II, p62) and phosphorylated AMPK (p-AMPK) in human glioma cell lines. After AICAR and Compound C were administered, the change of p-AMPK and the autophagy level were examined by western blot. Results: While adiponectin stimulates AMPK in phosphatase and up-regulates the level of autophagy, human glioma cell lines obtain more resistance against the temozolomide, which is facilitated by AICAR and weakened by Compound C. Conclusion: As an important adipokine, adiponectin can up-regulate the glioma cell autophagy by activating the AMPK signaling pathway which increases the resistance of glioma cells to temozolomide.

The influence of small interfering RNA on the expression of Survivin in human glioma cells

Objective This study aims to investigate the feasibility of knockdown of Survivin gene with small interfering RNA and to observe the apoptosis in gliomas which is influenced by siRNA. Methods Survivin specific siRNA oligonucleotides were designed and synthesized artificially. This siRNA

DAPT suppresses the proliferation of human glioma cell line SHG-44

Objective:To explore the suppressing effect ofγ-secretase inhibitor DAPT on proliferation of human glioma cell line SHG-44 in vitro and its mechanism.Methods:The SHG-44 cell was treated by DAPT with different concentration.The proliferation of cells was detected by MTT assay;cell cycle and TSC of CD133^+were determined by flow cytometry analysis technique;the key factor in Notch signaling pathway(Notch-1,Delta-1,Hes-1)was measured by reverse transcrip tase-polymerase chain reaction and western blotting.Results:DAPT inhibited the growth and proliferation of SHG-44 cells significantly(P<0.05).And the inhibiting effect on SHG-44 cells produced by DAPT showed a dose-dependent manner.DAPT increased the rate of cells in G_0/G_1 phase of SHG-44 cells,while it decreased the rate of cells in S phase.TSC of CD133^+was significantly reduced after DAPT treated SHC-44 cells.The expression of protein and mRNA of Notch-1,Delta-1 and Hes-1 were gradually downregulated with the increase of DAPT doses.Conclusions:DAPT can downregulate these key factor in Notch signaling pathway,reduce the TSC of CD133+and inhibit the proliferation of SHC-44 cells.

Radio-resistance induced by nitric oxide to heavy ion irradiation in A172 human glioma cells

To investigate effects of nitric oxide on cellular radio-sensitivity, three human glioma cell lines, i.e. A172, A172 transfected green fluorescence protein (EGFP) gene (EA172) and A172 transfected inducible nitric oxide synthesis (iNOS) gene (iA172), were irradiated by 12C6+ ions to 0, 1 or 2Gy. Productions of nitric oxide and glutathione (GSH) in A172, EA172 and iA172 were determined by chemical methods, cell cycle was analyzed by flow cytometry at the 24th hour after irradiation, and survival fraction of the cells was measured by colorimetric MTT assay at the 5th day after irradiation. The results showed that the concentrations of nitric oxide and GSH in iA172 were significantly higher than in A172 and EA172; the G2/M stage arrest induced by the 12C6+ ion irradiation was observed in A172 and EA172 but not in iA172 at the 24th hour after exposure; and the survival fraction of iA172 was higher than that of EA172 and iA172. Data suggest that the radio-sensitivity of the A172 was reduced after the iNOS gene transfection. The increase of GSH production and the change of cellular signals such as the cell cycle control induced by nitric oxide may be involved in this radio-resistance.

Antitumor effect of tumor necrosis factor-related apoptosis inducing ligand combined with mevastatin on a human glioma cell line SWO-38

BACKGROUND： Previous studies have reported that statins are less toxic to the human body and have greater antitumor activity; however, few studies have addressed the antitumor effect of statins combined with tumor necrosis factor-related apoptosis inducing ligand （TRAIL）. OBJECTIVE： To explore the effect of TRAIL combined with mevastatin on the proliferation and apoptotic cell death of a human glioma cell line SWO-38, and to study its mechanism of action. DESIGN, TIME AND SETTING： An in vitro control experiment was performed at the Central Laboratory of the Third Hospital Affiliated to Sun Yat-sen University, between January and April 2009. MATERIALS： The human SWO-38 cell line was provided by Cell Research, Department of Animal Experimental Center of Sun Yat-sen University; human recombinant soluble TRAIL by R＆D, USA; and mevastatin by Sigma, USA. METHODS： SWO-38 cells were separately incubated in TRAIL （100, 200, 300, 400, and 500 tJg/L） and mevastatin （5, 10, 20, 30, and 40 pmol/L） for 72 hours. In addition, SWO-38 cells were incubated in TRAIL （300 μg/L）, mevastatin （30 μmol/L）, and a solution containing both TRAIL and mevastatin for 12, 24, 48 and 72 hours. MAIN OUTCOME MEASURES： Cell proliferation was detected using methyl thiazolyl tetrazolium assay; cell apoptosis was observed using Hoechst 33258 staining and fluorescence microscopy and was measured using Annexin V/propidium iodide flow cytometry; TRAIL R1/DR4 and TRAIL R2/DR5 protein expressions levels were measured using indirect immunofluorescence staining combined with flow cytometry in the recombinant soluble TRAIL （rsTRAIL, 300 tJg/L）, mevastatin （30 IJmol/L） and combination groups; TRAIL R1/DR4 and TRAIL R2/DR5 mRNA expression was detected using real-time polymerase chain reaction. RESULTS： rsTRAIL, mevastatin and their combination inhibited tumor proliferation in a time- and dose-dependent manner. The proliferation inhibitory rate and apoptosis rate of human SWO-38 cells in the combined group were significantly greater than the rsTRAIL or mevastatin alone group （P 〈 0.01）. TRAIL R1/DR4 and TRAIL R2/DR5 protein and mRNA expressions were increased in the combination group compared with mevastatin or rsTRAIL alone after 72 hours （P 〈 0.01）. CONCLUSION： Both rsTRAIL and mevastatin inhibit the proliferation and apoptosis of the human glioma cell line SWO-38, while their combination enhances the anti-tumor effect. The mechanism of action possibly correlates to the upregulation of TRAIL R1/DR4 and TRAIL R2/DR5 mRNA expression by mevastatin, thereby enhancing the cell sensitivity to rsTRAIL.

Inhibition of epidermal growth factor receptor signaling protects human malignant glioma cells from hypoxia - induced cell death

Epidermal growth factor receptor(EGFR)signaling has become an importanttarget for drug development becauseEGFR signaling enhances tumor cell proliferation,migration,and invasion and inhibits apoptosis.However,theresults of clinical trials using EGFR inhibitors in patients with solid tumors have been disappointing.Here,wereport a protective effect of the EGFR inhibitors AG1478 and PD153035 against cell death induced by acute hy-poxia,which contrasts with their proapoptotic effects under normoxia.Under hypoxic conditions,both agents re-

Cloning and identification of a novel human glioma differentiation related gene GDR1

In order to identify the genes associated with glioblastoma differentiation, some ESTs, expressed differentially in the control cell and the differentiated human glioblastoma cell line BT-325 induced by the all-trans retinoid acid, have been isolated by the method of DDRT-PCR. Of the 46 ESTs sequenced, 19 are from new genes. A full-length 1 535-bp cDNA, termed gene GDR1, has been isolated from the human cDNA library using the probe designed according to one of the novel ESTs, HGBB098. The open reading frame of GDR1 gene encodes a putative protein containing 334 amino acid residues. Blast against the current GenBank DMA and protein sequence database did not reveal significant homology with any known proteins. RT-PCR shows that GDR1 mRNA level increased in the differentiated BT-325 cells after being treated with RA. The different expression patterns of GDR1 mRNA in human tissues have been detected through the multiple tissue Northern blot hybridization.

Biocharacterizations of T lymphocytes infiltrating human primary brain gliomas

Glioma-infiltrating lymphocytes(GIL)were isolated from 9 surgical biopsy specimens of pri-mary brain gliomas using mechanical and enzymatic digestion and discontinuous density gradientcentfifugation.Durng culture in the presence of interleukin-2(IL-2)for a period of four weeks,GIL were expanded by 48.4-fold on the avea-age,even up to 118-fold.GIL activated by IL-2 hadspcific cytolytic activity against autologous glioma cells.Analysis of cell surface phenotypes offreshly isolated GIL showed that CD3^+ cells were 71.0±11.9％,CD4^+ cells 34.2±6.1％ and CD8^+cells 37.0±7.6％.Ability of IL-2-activated GIL to secrete γ-interferon(γ-IFN)was significantlyhigher than that of freshly isolated GIL and autologous peripheral blood lymphocytes(PBL).Theresults suggest that GIL have many advantages as an adoptive immunotherapy for patients withgliomas and as a new type of antitumor immune effector.

环状RNA同源性蛋白激酶3靶向微RNA-338促进胶质瘤细胞侵袭、迁移的实验研究

目的探讨人血清环状RNA同源性蛋白激酶3(CircHIPK3)靶向微RNA-338(miR-338)对胶质瘤细胞U251细胞侵袭、迁移的影响。方法2021年2-12月,在武汉大学人民医院科研中心将U251细胞分为空白(NG)组、CircHIPK3阴性对照(shcontrol)组、HIPK3敲减(sh-CircHIPK3)组,实时荧光定量PCR(qRT-PCR)检测U251细胞中CircHIPK3、miR-338表达水平;Transwell检测细胞迁移与侵袭;划痕法检测细胞迁移;流式细胞术检测细胞周期;通过Circular RNA Interactome、RegRNA2.0、CircBank Database网站预测CircHIPK3(ID:hsa_circ_0000284)的靶向miRNA并用双萤光素酶实验验证,蛋白质印迹法检测基质金属蛋白酶(MMP)-2、MMP-9蛋白表达。结果与NG组、sh-control组比较,sh-CircHIPK3组中CircHIPK3(1.00±0.00、1.06±0.26比0.56±0.06)表达水平显著降低(P<0.05),miR-338(1.00±0.00、1.12±0.19比1.89±0.28)表达、G1期细胞比例[(58.72±0.36)%、(58.45±0.27)%比(64.72±0.47)%]升高(P<0.05),U251细胞侵袭数目[(164.89±12.55)个、(165.77±12.16)个比(80.13±11.37)个]、划痕愈合率[(25.66±2.37)%、(26.38±2.53)%比(10.36±1.53)%]、迁移细胞数目[(196.72±18.75)个、(194.65±17.86)个比(95.58±8.66)个]、S期细胞比例[(26.45±0.39)%、(26.57±0.41)%比(20.72±0.18)%]明显降低(P<0.05);miR-338是CircHIPK3的靶基因。与NG组、sh-control组比较,sh-CircHIPK3组MMP-2(1.31±0.23、1.33±0.20比0.61±0.05)、MMP-9(1.16±0.22、1.15±0.21比0.85±0.19)蛋白表达水平均显著降低(P<0.05)。结论沉默CircHIPK3通过靶向上调miR-338表达能抑制胶质瘤细胞U251细胞迁移和侵袭。

人脑胶质瘤预后相关基因模型的建立与验证

目的:通过生物信息学分析方法筛选人脑胶质瘤预后不良相关基因,分析预后基因模型在人脑胶质瘤预后预测中的价值。方法:分别从GTEx数据库、TCGA数据库中下载正常人大脑皮层测序数据、人脑胶质瘤(胶质母细胞瘤和低级别胶质瘤)相关转录组测序数据和患者生存资料,验证集CGGA325和CGGA693测序数据来源于CGGA数据库,从人脑胶质瘤和正常人大脑皮层测序数据之间筛选出差异表达基因,对其进行单因素Cox回归、Lasso回归和CGGA325和CGGA693生存分析验证;筛选与人脑胶质瘤患者生存密切相关的基因,分析高、低风险评分预后基因模型对脑胶质瘤患者总生存期的影响;ROC曲线评估预后模型预测脑胶质瘤患者总生存期的价值。结果:在TCGA中,共筛选出12709个差异表达基因,其中表达上调的基因7120个,表达下调的基因5589个,经单因素Cox、Lasso回归分析结合验证集CGGA325和CGGA693生存分析验证,最终确定DDX47、DIABLO、GABARAP、SMARCE1、ZNF410均与脑胶质瘤患者预后相关(P<0.05),在TCGA中,高风险评分预后模型(DDX47+DIABLO+GABARAP+SMARCE1+ZNF410)组患者的预后较低风险评分组差(P<0.05),预后模型预测脑胶质瘤患者1年、3年和5年总生存期的曲线下面积(AUC)分别为0.779、0.750和0.742;在验证集CGGA325和CGGA693中,预后模型高风险评分组患者的预后均较低风险评分组差(P<0.05),预后模型在CGGA325中预测脑胶质瘤患者1、3和5年总生存期的AUC分别为0.673、0.778和0.830,在CGGA693中预测脑胶质瘤患者1、3和5年总生存期的AUC分别为0.680、0.700和0.709。结论:DDX47、DIABLO、GABARAP、SMARCE1和ZNF410可能为脑胶质瘤患者生存相关基因,具有作为人脑胶质瘤预后分子标志物的潜能,高风险评分预后模型(DDX47+DIABLO+GABARAP+SMARCE1+ZNF410)与患者预后不良相关,且对预测患者3、5年总生存期具有潜在价值。

咖啡因通过FAK/AKT/ROCK通路调控人脑胶质瘤U-373MG细胞的恶性生物学行为

目的:探讨咖啡因通过调节FAK/AKT/ROCK信号通路来影响人脑胶质瘤U-373MG细胞的增殖、迁移和侵袭能力。方法:常规培养U-373MG细胞,将其分为对照组、咖啡因低剂量(1 mmol/L)组、咖啡因高剂量(2 mmol/L)组、PF573228组(FAK抑制剂,1μmol/L)、咖啡因高剂量+SC79组(AKT激活剂,8mg/L)。用CCK-8法、Transwell小室实验、流式细胞术和WB法分别检测各组U-373MG细胞的增殖、迁移、侵袭及凋亡,以及U-373MG细胞中p-FAK、p-AKT、p-ROCK、Ki67、MMP-9蛋白表达水平。建立U-373MG细胞裸鼠移植瘤模型,观察咖啡因对移植瘤生长的影响,WB法检测移植瘤组织中相关蛋白的表达。结果:咖啡因、PF573228可显著抑制U-373MG细胞的增殖、迁移、侵袭能力,促进U-373MG细胞凋亡,抑制p-FAK、p-AKT、p-ROCK、Ki67、MMP-9蛋白的表达(均P<0.05),SC79则可部分逆转咖啡因对U-373MG细胞的作用(均P<0.05)。咖啡因可显著抑制移植瘤的生长及移植瘤组织中上述相关蛋白的表达(均P<0.05)。结论:咖啡因可通过抑制FAK/AKT/ROCK信号通路抑制U-373MG细胞的增殖、迁移和侵袭能力,并促进其凋亡。

hUMSCs外分泌上清联合替莫唑胺在不同胶质瘤细胞系中的协同增敏作用

目的:探讨人脐带间充质干细胞外分泌上清(hUMSC-CM)联合替莫唑胺(TMZ)在不同胶质瘤细胞系中的协同增敏作用及潜在机制。方法:采用2种血清剥夺法(24和48 h分批次撤血清法)收集hUMSC-CM并制备成冻干粉,设置5种浓度(0、1、3、6和9 g/L)处理大鼠恶性胶质瘤细胞系RG-2、人星形细胞瘤细胞系U251和人胶质母细胞瘤细胞系LN-428。通过CCK-8实验检测hUMSC-CM作用于胶质瘤细胞24、48和72 h后的肿瘤抑制可行性及敏感度。HE染色结合CCK-8法确定6种浓度(0、25、50、100、200和400µmol/L)的TMZ作用于胶质瘤细胞48 h后化疗敏感性的差异。筛选出低、高2种浓度(3和9 g/L)的hUMSC-CM和低、中、高3种浓度(50、100和200µmol/L)的TMZ配伍,作用于胶质瘤细胞后检测细胞活力和病理形态学变化。TUNEL染色检测细胞凋亡;流式细胞术分析细胞周期变化;Western blot检测凋亡相关蛋白cleaved caspase-3、cleaved caspase-8和cleaved PARP1,以及自噬相关蛋白beclin-1和LC3的表达变化,探讨hUMSC-CM与TMZ体外联合给药协同增敏的作用机制。结果:3种胶质瘤细胞系对hUMSC-CM和TMZ的敏感度为RG-2>U251>LN-428。hUMSC-CM(3和9 g/L)与TMZ(50、100和200µmol/L)配伍给药对胶质瘤细胞生长的抑制作用比单独给药组显著增强(P<0.05),且随着配伍药物剂量的增加而增强。其中,9 g/L hUMSC-CM(C9)与50µmol/L TMZ(T50)配伍可有效抑制胶质瘤细胞生长。与C9或T50组相比,CCK-8实验显示C9+T50组细胞活力显著下降(P<0.05),HE染色和TUNEL检测结果显示C9+T50组细胞形态变化明显,出现典型凋亡形态学特征,流式细胞术结果显示C9+T50可诱导胶质瘤细胞周期发生阻滞,Western blot结果显示C9+T50组细胞中cleaved caspase-3、cleaved caspase-8、cleaved PARP1、beclin-1和LC3-II/LC3-I水平显著升高(P<0.01)。结论:(1)hUMSC-CM与TMZ配伍给药对胶质瘤细胞的抑制作用具有广谱性,且两者之间存在增敏作用,在不同细胞系中呈现不同的增敏效果。(2)hUMSC-CM提高胶质瘤细胞对TMZ敏感度的机制可能与调节caspase-8/caspase-3/PARP1信号通路及自噬通路、诱导胶质瘤细胞发生凋亡和自噬有关。

ncRNA介导的EphB4上调与低级别胶质瘤不良预后及肿瘤免疫浸润的相关性

目的探讨促红细胞生成素生成人肝细胞受体B4(erythropoietin-producing human hepatocellular receptors B4,EphB4)在低级别胶质瘤(lower-grade glioma,LGG)组织中的表达、其上游靶点以及与患者预后及肿瘤免疫浸润的相关性,分析其作为治疗靶点的潜在作用。方法首先应用癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库胶质瘤数据分析EphB4在胶质瘤与正常脑组织中的表达差异,并用基因表达谱交互分析(Gene Expression Profiling Interactive Analysis,GEPIA)数据库分析EphB4对不同癌症生存期的影响。用R语言和starBase数据库分析EphB4可能上游调节非编码RNA(non-coding RNA,ncRNA)。用肿瘤免疫评估资源(Tumor Immune Estimation Resource,TIMER)数据库进行EphB4表达与肿瘤免疫细胞浸润、免疫细胞生物学标志物和免疫检查点相关性分析。结果UBA6-AS1/hsa-miR-346轴是最有潜力影响LGG中EphB4表达的上游ncRNA相关通路。同时,EphB4水平与LGG肿瘤免疫细胞浸润、免疫细胞生物学标志物、免疫检查点表达均呈显著正相关。结论ncRNA介导的EphB4上调与LGG的不良预后和肿瘤免疫浸润相关。

姜黄素对人脑胶质瘤细胞凋亡作用及其对Bcl-2与Caspase8诱导表达的影响

背景与目的:人脑胶质瘤是主要的颅内恶性肿瘤,其死亡率高且暂无有效的治疗和预防手段。姜黄素是从姜黄属植物根茎中提取的一种多酚类物质,前期研究发现其具有抗氧化、抗突变等药效。本研究中药姜黄素对人脑胶质瘤细胞SHG44中Bcl-2与Caspase8差异性表达和促进其凋亡的分子机制。方法:体外培养人脑胶质瘤细胞SHG44;利用MTT比色法检测姜黄素对于SHG44的增殖抑制影响;利用流式细胞术(flowcytometry,FCM)分析药物处理前后SHG44的细胞周期变化;利用吖啶橙染色法鉴定药物处理前后SHG44形态学上的差异及凋亡程度;提取药物处理前后SHG44细胞总蛋白,利用Western印迹法检测Bcl-2与Caspase8蛋白的表达情况。结果:姜黄素对SHG44细胞体外增殖抑制呈明显的剂量依赖性[IC50为(13.6±2.2)nmol/L,P<0.01];FCM分析SHG44细胞在姜黄素处理前后细胞周期均呈现明显的差异,并且药物组细胞表现为G0/G1期阻滞,其中药物组G0/G1期比例为(57.2±0.8)%,空白对照组为(64.6±0.6)%,sub-G0峰明显(25.9±0.2)%(P<0.01)。AO染色表明药物组细胞有明显凋亡迹象,并伴少量细胞坏死现象,而在阴性对照组中细胞形态完好。Western印迹法检测发现(13.6±2.2)nmol/L(IC50剂量)的姜黄素处理SHG44细胞前后,Caspase8的表达量为(96±23)%明显高于对照组(P=0.0013),而Bcl-2的表达量为(33±8)%,则低于对照组(P=0.0014),提示药物组细胞有进入凋亡途径的现象。结论:中药姜黄素可以调控体外培养的人脑胶质瘤细胞SHG44的周期进程,诱导Bcl-2及Caspase8的差异性表达,并且具有显著抑制肿瘤细胞增殖及促凋亡的作用。

姜黄素通过改变FAK表达和激活caspase诱导人脑胶质瘤U251细胞凋亡

目的研究姜黄素诱导U251细胞凋亡机制。方法20～100μmol·L^-1姜黄素分别处理U251细胞24h后，MTT法测定姜黄素对U251细胞的细胞抑制作用及各种caspase抑制剂对姜黄素作用的影响；通过流式细胞仪检测细胞凋亡；透射电镜观察细胞形态学变化；用免疫细胞化学分析姜黄素对FAK（focal adhesion kinase，粘着斑激酶）蛋白质表达的影响；荧光分光光度法检测caspase-3活性的改变。结果姜黄素明显抑制U251细胞的增殖；诱导U251细胞凋亡；FAK蛋白表达减少；easpase-3活性增强，各种caspase抑制剂可抑制姜黄素诱导的U251细胞凋亡。结论姜黄素通过抑制FAK蛋白的表达和激活caspase途径可诱导U251细胞凋亡。