COMBINATION OF γ-INTERFERON WITH TRAIL AND CISPLATIN OR ETOPOSIDE INDUCES APOPTOSIS IN HUMAN NEUROBLASTOMA CELL LINE SH-SY5Y

Objective To study the effect of γ-interferon (IFN-γ), tumor necrosis factor related apoptosis inducing ligand (TRAIL), and cisplatin or etoposide induced apoptosis in human neuroblastoma cell line SH-SY5Y and its possible molecular mechanisms.Methods The expressions of Caspase 8 mRNA and protein were detected with RT-PCR and Western blot analysis. The effects of IFNγ, TRAIL, IFNγ TRAIL, IFNγ Caspase 8 inhibitor TRAIL, IFNγ cisplatin TRAIL, and IFNγ etoposide TRAIL on the growth and apoptosis of SH-SY5Y cells were detected with the methods of MTT and flow cytometry. The relative Caspase 8 activity was measured with colorimetric assay.Results Caspase 8 was undetectable in SH-SY5Y cells but an increased expression of Caspase 8 mRNA and protein was found after treatment with IFNγ. SH-SY5Y cells themselves were not sensitive to TRAIL, but those expressing Caspase 8 after treatment with IFNγ were. The killing effect of TRAIL on SH-SY5 Y cells expressing Caspase 8 was depressed by Caspase 8 inhibitor. Cisplatin and etoposide could enhance the sensitivity of TRAIL on SH-SY5Y cells. The relative Caspase 8 activity of SH-SY5Y cells in IFNγ TRAIL group was significantly higher than those of control group, IFNγ group, TRAIL group, and inhibitor group (P ＜0.01). There was no significant difference among IFNγ TRAIL group, IFNγ cisplatin TRAIL group, and IFNγ etoposide TRAIL group.Conclusions IFNγ could sensitize SH-SY5Y cells to TRAIL-induced apoptosis and this may be realized by the up-regulation of Caspase 8. Cisplatin and etoposide could enhance the killing effect of TRAIL on SH-SY5Y cells.     

Influence of silencing soluble epoxide hydrolase with RNA interference on cardiomyocytes apoptosis induced by doxorubicin

In order to investigate the influence of silencing soluble epoxide hydrolase(sEH) with double-stranded small interfering RNA(siRNA) on cardiomyocytes apoptosis induced by doxorubicin(DOX),two plasmids containing siRNA sequences specific to sEH were constructed and transfected into the primary cultured cardiomyocytes by using FuGENE HD transfection agents.The mRNA and protein expression levels of sEH were detected by semiquantitative RT-PCR and Western blotting respectively,and the plasmids that silenced sEH most significantly were selected,and renamed EH-R.The plasmids carrying a nonspecific siRNA coding sequence(PCN) served as the negative control.Cardiomyocytes were divided into four groups:control group,DOX group,PCN+DOX group,and EH-R+DOX group.Apoptosis of cardiomyocytes was induced by DOX at a concentration of 1 μmol/L.Apoptosis rate of cardiomyocytes was determined by flow cytometery.The protein expression levels of Bcl-2 and Bax were detected by Western blotting.The results showed that the expression of sEH was down-regulated by EH-R plasmid.The expression levels of sEH mRNA and protein in the EH-R+DOX group were significantly decreased as compared with other groups(P<0.01).As compared with the control group,the apoptosis rate of cardiomyocytes in three DOX-treated groups was obviously increased,the expression levels of Bax increased,and those of Bcl-2 decreased(P<0.01).However,the expression levels of Bax were decreased,those of Bcl-2 increased and the apoptosis rate of cardiomyocytes obvi-ously decreased in EH-R+DOX group when compared with those in the DOX group and the PCN+DOX group(P<0.01 for each).It was concluded that the recombinant plasmids could be successfully constructed,and transfected into the primary cultured cardiomyocytes.They could ameliorate the DOX-induced cardiomyocytes apoptosis by selectively inhibiting the expression of sEH with RNAi and increasing the expression of Bcl-2.     

ERK1/2-mediated Cytoplasmic Accumulation of hnRNPK Antagonizes TRAIL-induced Apoptosis through Upregulation of XIAP in H1299 Cells

Objective Tumor necrosis factor-related apoptosis-inducing ligand(TRAIL) resistance greatly limits the clinical therapeutic efficacy of TRAIL. Elucidating the molecular mechanism underlying TRAIL resistance will be fundamental to resolving this problem. Methods Nuclear and cytoplasmic protein extraction and immunofluorescence(IF) assay were used to detect changes in heterogeneous nuclear ribonucleoprotein K(hn RNPK) localization in H1299 cells. The evaluation of cell apoptosis in cells transfected with GFP-hn RNPK, GFP-hn RNPK S284/353 A, or GFP-hn RNPK S284/353 D mutant was performed using cleaved caspase-3 antibody. The gene expression of XIAP was tested by quantitative RT-PCR. Results Previously, we reported that hn RNPK antagonized TRAIL-induced apoptosis through inhibition of PKC-mediated GSK3β phosphorylation. In this study, we further demonstrate that TRAIL treatment induces cytoplasmic accumulation of hn RNPK in H1299 cells. The hn RNPK localized in the cytoplasm has a higher capacity to antagonize TRAIL-induced apoptosis. Both ERK1/2 signaling inhibitor U0126 and ERK-phosphoacceptor-site mutant(GFP-hn RNPK S284/353A) diminish cytoplasmic accumulation of hn RNPK induced by TRAIL. Moreover, we show that XIAP is involved in hn RNPK-mediated TRAIL resistance in H1299 cells. Conclusion Taken together, these results give new insights into the understanding of the molecular mechanism associated with TRAIL resistance in lung adenocarcinoma.     

PMN apoptosis and its relationship with the lung injury after chest impact trauma

Background Polymorphonuclear neutrophil (PMN), one of the most important inflammatory cells, functions throughout the initiation, progression and resolution of inflammation. This study aimed at investigating the relationship between PMN apoptosis and the lung injury after chest impact trauma. Methods PMNs were purified from rabbits subjected to the chest impact trauma and their apoptosis, necrosis, survival and respiratory burst were detected by flow cytometry. Meanwhile, lactate dehydrogenase and (LDH) ［Ca2+］i were measured. Results The delayed apoptosis of PMNs in bronchoalveolar lavage fluid was observed from 2 hours to 12 hours after trauma, and viable cells increased. Respiratory burst of PMNs in bronchoalveolar lavage fluid was increased significantly from 2 hours with the peak at 8 hours. Meanwhile, lactate dehydrogenase in bronchoalveolar lavage fluid was higher than that in control (P&lt;0.05) from 4 hours to 24 hours, and intracellular free Ca2+ in PMN was increased temporarilly. Conclusions Retention of PMN in tissues and the abnormality in apoptotic pathway inevitably generate persistent activation of PMN and excessive release of toxic substances, resulting in tissue injury. The temporary increase of intracellular free Ca2+ may be responsible for the delayed apoptosis of PMN.     

Cytotoxic Responses and Apoptosis in Rat Kidney Epithelial Cells Exposed to Lead

正The toxic effects of lead on normal rat kidney epithelial cells(NRK cells)may occur via various pathways.However,the role of intrinsic mitochondrial pathway in Lead-induced apoptosis in NRK cells has not been investigated.The purpose of our study was to investigate cytotoxic responses and cell apoptosis mediated by lead in NRK cells.NRK cells were treated with different     

Effect of Smac on TRAIL-induced apoptosis of prostate cancer cell line PC-3 and the molecular mechanism

The effect of Smac gene on the TRAIL-induced apoptosis of the prostate cancer cell line PC-3 and the molecular mechanism were investigated. The Smac gene was transfected into PC-3 cells under the induction of liposome. The intrinsic Smac gene expression was detected by Western blotting. After treatment with TRAIL as an apoptosis inducer, in vitro cell growth activity was as-sayed by MTT colorimetry. The apoptosis rate of PC-3 cells was determined by annexin Ⅴ-FITC and propidium iodide staining flow cytometry. The expression of cellular XIAP and caspase-3 genes was examined by Western blotting. Smac-transfected cells (PC-3/Smac group) had significantly in-creased Smac protein level as compared with PC-3 controls (P<0.01). After induction with 100-200 ng/mL TRAIL for 12-36 h, cellular proliferation rate in PC-3/Smac group was significantly lower than in PC-3 controls (P<0.05). After induction with 100 ng/mL TRAIL for 24 h, the apoptosis rate in PC-3/Smac group was significantly enhanced as compared with that of PC-3 controls (P<0.05). Ac-cordingly, the XIAP expression level was down-regulated significantly (P<0.05) and caspase-3 sub-unit P20 was up-regulated significantly (P<0.05). It is suggested that the over-expression of cellular Smac can inhibit inhibitor of apoptosis proteins (IAPs), enhance caspases activity and the apoptosis rate of PC-3 cells induced by TRAIL, which may provide a useful experimental basis for prostate cancer therapy.     

Arsenic trioxide up-regulates Fas expression in human osteosarcoma cells

Background Osteosarcoma is a common primary malignant tumor of bone with a poor prognosis due to its propensity for metastasis. The prognosis of patients is highly dependent on the presence or absence of lung metastasis and on the effectiveness of treatment against it. It has been reported that low level expression of Fas protein in human osteosarcoma cell is closely associated with lung metastasis. A large number of studies have shown that arsenic trioxide (ATO) can inhibit proliferation and induce apoptosis of many cancer cell lines; however, its effects on human osteosarcoma cells (Saos-2 cell line) remains unknown. The aim of this study was to investigate the effects of ATO on Saos-2 cells and to characterize its mechanism of Fas-expressing.Methods A group of Saos-2 cells was treated with or without 0.5,1,2,4 and 8 urnol/L ATO for three successive days, and the cytotoxicity of ATO was determined by an 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Morphological changes in cells were studied by acridine orange/ethidium bromide (AO/EB) double staining. Flow cytometry (FCM) was used to assay cell DNA distribution. Another group of cells was pretreated with 10 nmol/L matrix metalloproteinase 7 (MMP-7) for 3 hours. They were then incubated with or without 2 umol/L ATO for 24, 48 and 72 hours. Cytotoxicity, Fas protein and mRNA levels were systematically studied using MTT, Western blotting and real-time PCR, respectively. Cell proliferation, cell cycle progression and apoptosis were examined in this study. Results Proliferation of Saos-2 cells was inhibited by ATO in both a dose- and time-dependent manner. The IC50 values at 24, 48 and 72 hours were 9.30, 5.54 and 3.49 μmol/L, respectively. The survival rate of Saos-2 cells in the MMP-7 and ATO co-treated group was significantly higher than the ATO group, but it was lower than the control group. ATO induced G1 phase arrest of the cell cycle and very efficiently stimulated apoptosis in Saos-2 cells, as evidenced by flow cytometric detection of sub-G1 DNA content and AO/EB staining. Western blotting results indicated that Fas (FasL) protein expression in osteosarcoma cultures markedly increases in a time dependent manner after exposure to ATO. Compared with control, treatment with ATO 2 μmol/L and 4 μmol/L for 48 hours, resulted in increase of Fas gene expression to 28.31% and 56.74%, respectively. Our results indicated that ATO induced-apoptosis of Saos-2 cells may be mediated through the Fas pathway.Conclusions ATO suppressed cell proliferation of Saos-2 cell in a dose- and time-dependent manner and increased Fas protein expression. However, Fas-mediated apoptosis was incompletely interrupted by MMP-7, which suggested that other molecular mechanisms may mediate this process.     

肿瘤坏死因子相关凋亡诱导配体诱导骨肉瘤细胞凋亡的研究

目的：研究肿瘤坏死因子相关凋亡诱导配体（TRAIL）对骨肉瘤OS-732细胞的诱导凋亡作用，探寻骨肉瘤临床化疗的斯方案。方法：将TRAIL应用于体外培养的骨肉瘤OS-732细胞，采用MTr法检测细胞毒性作用，倒置相差显微镜及荧光染色方法观察肿瘤细胞形态改变，扫描及透射电镜在亚细胞形态上证实凋亡细胞。结果：不同浓度TRAIL作用下，细胞抑制率问差别十分显著（P〈0.01）。超微结构观察显示骨肉瘤细胞凋亡。结论：TRAIL诱导骨肉瘤细胞凋亡，且具有浓度依赖性。     

顺铂热化疗对骨肉瘤细胞株细胞毒性的实验研究

目的：研究顺铂热化疗对骨肉瘤细胞株(OS-732)细胞毒性的影响，探讨热疗在骨肉瘤顺铂化疗中增效作用的机理。方法：OS-732细胞株分别经不同温度的热疗、不同浓度顺铂化疗、43℃热疗 顺铂联合作用各1h，采用体外细胞毒性试验(MTT法)、流式细胞仪(FCM)分析及电子显微镜观察其对细胞毒性和细胞周期的影响，以及诱导细胞凋亡的情况。结果：41℃、43℃、45℃热疗对OS-732细胞株有明显的细胞毒性作用。在37℃恒温条件下，细胞株单独与不同浓度的顺铂作用1h，随着顺铂浓度的升高，其细胞毒性作用明显增加。43℃热疗 顺铂共同作用1h，其细胞毒性作用进一步增加，细胞毒性指数最高达72．37％；FCM分析显示对细胞周期有明显的影响，S期细胞比例明显增加，G2与M期细胞比例明显减少。43℃热疗、43℃热疗 顺铂联合作用各1h均出现凋亡细胞峰(亚G1峰)，细胞凋亡比例最高达56．47％；透射电镜观察有典型的细胞凋亡特征性变化。结论：顺铂热化疗有明显的增强OS-732细胞株的细胞毒性作用。43℃热疗、43℃热疗 顺铂均可诱导骨肉瘤细胞凋亡。43℃热疗诱导骨肉瘤细胞凋亡可能是热疗在骨肉瘤顺铂化疗中增效作用的潜在机制之一。     

抗VEGF抗体对骨肉瘤OS-732细胞血管生成及其肿瘤细胞增殖、凋亡的影响

目的：探讨阻断血管内皮生长因子（Vascular endothelial growth factor,VEGF)的血管生成作用对骨肉瘤OS-732细胞及血管内皮细胞增殖、凋亡的影响。方法：应用鸡胚绒毛尿囊膜（CAM）模型,通过解剖显微镜血管计数,光镜HE染色,原位末端标记及PC-NA免疫组化检测观察VEGF抗体对骨肉瘤血管生成及肿瘤增殖,凋亡状态的影响。结果：VEGF抗体组肿瘤区血管数目及瘤细胞数显著低于PBS对照组,肿瘤细胞凋亡指数显著高于PBS对照组,增殖指数两组差异不明显,同时VEGF抗体组凋亡的微血管内皮细胞增多,增殖期微血管内皮细胞少见。结论：VEGF抗体能显著抑制骨肉瘤OS-732血管生成,抑制内皮细胞增殖,促进内皮细胞凋亡,可能是VEGF抗体发挥抗血管生成作用的途径之一,并可能通过抑制血管形成而促进肿瘤细胞凋亡,最终达到抑制瘤细胞生长的作用。     

肿瘤坏死因子相关凋亡诱导配体及其受体与卵巢恶性肿瘤的研究

肿瘤坏死因子相关凋亡诱导配体(TRAIL)是近年来颇受关注的一个新的凋亡分子,可选择性促进肿瘤细胞凋亡,对正常细胞的凋亡作用较弱。目前发现的该家族成员包括TRAIL和它的5个受体。卵巢恶性肿瘤细胞表面表达TRAIL和TRAIL受体,并可以被其诱导凋亡。许多化疗药物能协同TRAIL诱导卵巢肿瘤细胞的凋亡,因此TRAIL在卵巢恶性肿瘤的治疗领域可能具有一定的应用前景。     

康莱特联合顺铂高效杀伤骨肉瘤细胞

目的 研究康莱特联合顺铂对骨肉瘤细胞的杀伤作用及其相关机制，探寻骨肉瘤的中西医结合化疗方案。方法 免疫组化及RT—PCR方法检测不同浓度康莱特作用下骨肉瘤OS732细胞的Fas表达，并将康莱特与顺铂单独及联合应用于OS732细胞，采用MTT法检测细胞毒性作用，流式细胞仪定量分析凋亡细胞所占比例，相差显微镜及荧光显微镜下观察凋亡细胞形态改变。结果 康莱特可上调OS732细胞的Fas表达并诱导凋亡，10μL／mL康莱特与1μg／mL顺铂合用于OS732细胞的抑制率与各自单用时相比明显提升（P〈0．01）。细胞形态观察及凋亡率测定也显示，康莱特与顺铂联用可诱导更多OS732细胞凋亡。结论 康莱特可协同顺铂高效杀伤骨肉瘤细胞，这可能与康莱特上调Fas表达诱导骨肉瘤细胞凋亡有关。     

TRAIL联合化疗药物诱导神经母细胞瘤细胞凋亡的研究

目的：探讨肿瘤坏死因子相关凋亡诱导配体（TRAIL）联合化疗药物治疗神经母细胞瘤（NB）的作用及其可能机制。方法：不同浓度的TRAIL、化疗药物或TRAIL和化疗药物联合处理NB细胞株SMS-KCNR，应用四甲基偶氮唑蓝（MTT）法检测细胞毒作用，应用流式细胞仪（FCM）检测细胞凋亡率，透射电镜对凋亡细胞进行形态学观察。结果：KCNR细胞对TRAIL不敏感，对化疗药物相对敏感，存在剂量依赖性细胞毒效应；TRAIL与亚毒性浓度的化疗药物联用对细胞的杀伤作用显著增强：透射电镜可见到典型的细胞凋亡特征。结论：KCNR对TRAIL不敏感，但TRAIL与亚毒性浓度化疗药物联用可增强杀伤效应，这种细胞毒作用主要由凋亡介导。     

异搏定逆转骨肉瘤多药耐药的体外初步观察

目的：探讨异搏定是否能在体外逆转骨肉瘤多药耐药。方法：应用MTT法测定异搏定与阿霉素共同作用后骨肉瘤细胞的细胞活性。结果：1μg阿霉素单独作用24h，骨肉瘤细胞的细胞活性在90％左右，抑制率为10％，48h抑制率为50％左右，而加入异搏定后，骨肉瘤的细胞活性明显降低，特别是在1μg／ml细胞悬液浓度时，抑制率最高，24h细胞抑制率达50％左右。结论：异搏定体外可逆转骨肉瘤多药耐药。     

不同浓度酒精灭活后的国人成骨肉瘤细胞超微结构的变化

目的 :探讨两种不同浓度的酒精灭活骨肉瘤细胞 (OS- 732 )后细胞内部结构变化和临床应用价值。方法 :75%和 95%酒精灭活骨肉瘤细胞 ,光镜和电镜下观察细胞形态 ,MTT法检测细胞活性。结果 :灭活后的细胞内部结构发生明显改变 ,形成不可逆性损伤。 MTT法检测证明处理后的肿瘤细胞已无生存能力。结论 :两种浓度的酒精对骨肉瘤细胞的灭活是有效的 ,为临床上骨肉瘤的保肢治疗提供良好的选择。     

白杨素敏化TRAIL诱导人胃癌SGC-7901细胞凋亡

目的:研究白杨素(ChR)是否具有增敏肿瘤坏死因子相关凋亡诱导配体(TRAIL)诱导人胃癌SGC-7901细胞凋亡作用.方法:体外培养SGC-7901细胞.碘化丙啶(PI)染色流式细胞术(FCM)分析细胞凋亡率,琼脂糖凝胶电泳检测DNA梯形条带.结果:ChR(40 μmol/L)、TRAIL(100 ng/mL)以及两...     

Caspase 8和Caspase 3在TRAIL诱导神经母细胞瘤细胞凋亡中的作用(英文)

目的探讨Caspase8和Caspase3在肿瘤坏死因子相关凋亡诱导配体（TRAIL）诱导CHP212神经母细胞瘤细胞凋亡中的作用。方法应用流式细胞仪检测TRAIL、Caspase8／Caspase3抑制剂＋TRAIL对CHP212细胞的诱导凋亡作用。应用比色法测定Caspase8、Caspase3的相对活性。应用透射电镜对凋亡细胞进行形态学的观察。结果TRAIL可诱导CHP212细胞的凋亡，并存在剂量依赖性；Caspase8／Caspase3抑制剂能抑制TRAIL对CHP212细胞的诱导凋亡作用。随TRAIL作用时间的延长，Caspase8、Caspase3的活性逐步升高，分别于作用16h、8h后达高峰。透射电镜可见到典型的细胞凋亡特征。结论TRAIL通过Caspase信号传导通路诱导CHP212细胞凋亡并伴随Caspase8和Caspase3活性的增高。