Effects of paclitaxel on cell proliferation and apoptosis and its mechanism in human lung adenocarcinoma A549 cells

INTRODUCTION Primary bronchogenic carcinoma is one of thecommonest malignancy tumors in the world.The incidence and mortality rate are rising in recent30 years. Adenocarcinoma accounts for about 25%of all primary bronchogenic carcinomas, the curativerate is not ideal by traditional chemotherapy and ra-diotherapy[1-4]. Paclitaxel is a extensive anti-cancerdrug whose mechanism is anti-microtubules and sta-bilizes cell microtubules specially, and has also beenused widely in ovarian cancer, b…     

姜黄素对A549细胞亚群SP和NON-SP的NF-κB、VEGF及Notch通路的影响

[目的] 通过动物实验了解姜黄提取物-姜黄素抗肿瘤血管生成的具体作用机制。[方法] 将40只BALB/C雄性裸小鼠分为4组,每组10只。分别为A组(SP亚群细胞姜黄素组)、B组(SP亚群细胞荷瘤对照组)、C组(NON-SP亚群细胞姜黄素组)、D组(NON-SP亚群细胞荷瘤对照组).A、B两组于实验前建立肺腺癌A549 SP细胞亚群荷瘤模型,C、D两组建立肺腺癌A549 NON-SP细胞亚群荷瘤模型,建立模型后观察16 d,于A组、C组小鼠腹腔注射姜黄素,隔天1次,B、D两组注射生理盐水。16 d后将小鼠称重后处死,剥离瘤块组织,比较各组瘤质量;免疫组化法检测肿瘤组织中血管生长因子(VEGF)、核因子-κB(NF-κB)的表达;逆转录-聚合酶链反应(RT-PCR)检测Notch1 mRNA含量。[结果] 肺腺癌A549 SP细胞亚群荷瘤模型组小鼠瘤体与NON-SP细胞亚群荷瘤模型组小鼠相比体积较大;SP亚群细胞姜黄素组抑瘤作用及抗肿瘤血管生成优于NON-SP亚群细胞姜黄素组,两组相比差异具有统计学意义。[结论] 姜黄素可以抑制肿瘤生长,考虑可能与其抑制NF-kB的表达,下调Notch1 mRNA含量,阻断Notch信号通路,抑制肿瘤组织中VEGF的表达有关。     

Interleukin-13 inhibits cytokines synthesis by blocking nuclear factor-κB and c-Jun N-terminal kinase in human mesangial cells

Objective： Monocytes/macrophages, proinflammatory cytokines and chemokines are important in the pathogenesis of glomerulonephritis. Interleukin （IL） -13 has been shown to exert potent anti-inflammatory properties. This study was designed to investigate the effect of IL-13 on the expression of proinflammatory cytokines, chemokines and profibrogenic cytokines and the involved molecular mechanism in cultured human mesangial cells （HMCs）. Methods： The expressions of proinflammatory cytokines, chemokines and profibrogenic cytokines were determined by ribonuclease protection assay （RPA）. Activity of nuclear factor-kappa B （NF-κB） and activa- tor protein-1 （AP-1） was examined by electrophoretic mobility shift assay （EMSA）. NF-κB subunit p65 nuclear transportation and c-Jun N-terminal kinase （JNK） activity were assayed by immunoblot. Results： Recombinant IL-13 inhibited tumor necrosis factor-α （TNF-u）, IL-1α, IL-1β, monocyte chemoattractant protein-1 （MCP-1）, IL-8, and transforming growth factor-β1 （TGF-β1） mRNA expressions in a dose-dependent manner. Lipopoly- sacchorides （LPS） dramatically increased NF-κB DNA binding activity of HMCs, which was inhibited by IL-13 in a dose-dependent manner. LPS-activated NF-κB contained p50 and p65 dimers, but not c-Rel subunit. IL-13 blocked LPS-induced NF-κB subunit p65. LPS stimulated JNK/AP-1 activation, which was inhibited by IL-13 in a dose-dependent manner. Conclusion： IL-13 inhibits proinflammatory cytokines, chemokines, and profibrogenic cytokines synthesis by blocking NF-κB and JNK/AP-1 activation. These observations point to the importance of IL-13 in the modulation of inflammatory processes in the renal glomerulus.     

核因子-κB抑制剂联合顺铂对A549细胞株的影响

目的　探讨核因子κB(NF κB)抑制剂吡咯烷二硫氨基甲酸(PDTC)与顺铂(DDP)联合应用治疗肺癌的效应及其机制。方法　培养人肺癌A5 4 9细胞株,分为对照组、PDTC组、DDP组及PDTC DDP组,观察A5 4 9细胞的生长情况,MTT比色法检测细胞生长抑制率,流式细胞术检测细胞凋亡率,Westernblot检测caspase 3表达。结果　DDP及PDTC均可有效抑制A5 4 9细胞的生长、诱导凋亡,二者联用具有协同作用;PDTC DDP组caspase 3表达显著高于PDTC组和DDP组(P <0 0 1) ,三组均显著高于对照组(P <0 0 1)。结论　PDTC和DDP均可抑制肺癌细胞的生长、诱导凋亡,联合后有协同作用,其机制可能与caspase 3被激活有关     

Expression of nerve growth factor and hypoxia inducible factor-1α and its correlation with angiogenesis in non-small cell lung cancer

Summary： In order to investigate the expression of nerve growth factor （NGF） and hypoxia inducible factor-1α （HIF-1α） and its correlation with angiogenesis in non-small cell lung cancer （NSCLC）, paraffin-embedded tissue blocks from 20 patients with NSCLC were examined. Twenty corresponding para-cancerous lung tissue specimens were obtained to serve as a control. The expression of NGF, HIF-1α, and vascular endothelial growth factor （VEGF） in the NSCLC tissues was detected by using immunohistochemistry. The microvascular density （MVD） was determined by CD31 staining. The resuits showed that the expression levels ofNGF, HIF-1α and VEGF in the NSCLC tissues were remarkably higher than those in the para-cancerous lung tissues （P〈0.05）. There was significant difference in the MVD between the NSCLC tissues （9.19±1.43） and para-cancerous lung tissues （2.23±1.19） （P〈0.05）. There were positive correlations between NGF and VEGF, between HIF-1α and VEGF, and between NGF and HIF-1α in NSCLC tissues, with the spearman correlation coefficient being 0.588, 0.519 and 0.588, respectively. In NSCLC tissues, the MVD had a positive correlation with the three factors （P〈0.05）. Theses results suggest that NGF and HIF-1α are synergically involved in the angiogenesis of NSCLC.     

缺氧对PC12细胞HIF-1/JAK2/NF-κB信号级联的影响

目的 研究缺氧对PC12细胞HIF-1/JAK2/NF-κB信号级联的影响.方法 制备缺氧细胞模型,采用EMSA、半定量RT-PCR技术和Western blot法检测JAK2、HIF-1α、HIF-1β基因mRNA和蛋白表达水平以及NF-κB活性.结果 PC12细胞JAK2、HIF-1α、HIF-1β mRNA和蛋白在缺氧后表达增强,6h达到高峰,显著高于正常对照组;PC12细胞核内NF-κB活性在缺氧后6h达到高峰,12h下降.加入JAK2抑制剂AG490后缺氧6h NF-κB活性明显降低.结论 缺氧能增强JAK2、HIF-1α、HIF-1β的表达.HIF-1能激活JAK2,对缺氧受损脑组织有保护作用.     

Metformin inhibits nuclear factor-κB activation and inflammatory cytokines expression induced by high glucose via adenosine monophosphate-activated protein kinase activation in rat glomerular mesangial cells in vitro

Background The renoprotective mechanisms of adenosine monophosphate （AMP）-activated protein kinase （AMPK） agonist-metformin have not been stated clearly.We hypothesized that metformin may ameliorate inflammation via AMPK interaction with critical inflammatory cytokines The aim of this study was to observe the effects of metformin on expression of nuclear factor-κB （NF-κB）,monocyte chemoattractant protein-1 （MCP-1）,intercellular adhesion molecule-1 （ICAM-1） and transforming growth factor-beta 1 （TGF-β1） induced by high glucose （HG） in cultured rat glomerular mesangial cells （MCs）.Methods MCs were cultured in the medium with normal concentration glucose （group NG,5.6 mmol/L）,high concentration glucose （group HG,25 mmol/L） and different concentrations of metformin （group M1,M2,M3）.After 48-hour exposure,the supernatants and MCs were collected.The expression of NF-κB,MCP-1,ICAM-1,and TGF-β1 mRNA was analyzed by real time polymerase chain reaction.Westem blotting was used to detect the expression of AMPK,phospho-Thr-172 AMPK （p-AMPK）,NF-κB p65,MCP-1,ICAM-1,and TGF-β1 protein.Results After stimulated by HG,the expression of NF-κB,MCP-1,ICAM-1,TGF-β1 mRNA and protein of MCs in group HG increased significantly compared with group NG （P ＜0.05）.Both genes and protein expression of NF-κB,MCP-1,ICAM-1,TGF-β1 of MCs induced by high glucose were markedly reduced after metformin treatment in a dose-dependent manner （P ＜0.05）.The expression of p-AMPK increased with the rising of metformin concentration,presenting the opposite trend,while the level of total-AMPK protein was unchanged with exposure to HG or metformin.Conlusion Metformin can suppress the expression of NF-κB,MCP-1,ICAM-1 and TGF-β1 of glomerular MCs induced by high glucose via AMPK activation,which may partlv contribute to its reno-protection.     

Dexamethasone impairs the differentiation and maturation of murine dendritic cells by Toll-like receptor 4-nuclear factor-κB pathway

Background Recent studies have demonstrated that dexamethasone （DEX） interferes with immune responses by targeting key functions of dendritic cells （DCs） at the earliest stage. However, the cellular and molecular mechanisms are still incompletely understood. This study aimed to explore the possible mechanisms by investigating the roles of DEX on differentiation, maturation ＆ function of murine DCs and the effects of DEX on DCs via Toll-like receptor 4 （TLR4）-nuclear factor （NF）-KB mediated signal pathway. Methods Immature DCs （imDCs） were cultured from murine bone marrow （BM） cells. We added DEX into culture medium at different time. The expression of CD11c, CD86 and I-Ab （mouse MHC class II molecule） was determined by flow cytometry. We determined the expression of NF-κB and its inhibitory protein I-κBα by electrophoretic mobility shift assay （EMSA） and Western blotting, respectively. The productions of interleukin （IL）-12p70 and IL-10 in cell culture supernatants were determined by enzyme-linked immunosorbent assay （ELISA）. Results DEX impaired differentiation of DCs from murine bone marrow progenitors, and inhibited lipopolysaccharide （LPS） induced maturation of DCs. DEX significantly inhibited NF-κB expression of normal DCs, the higher the DEX concentration or the longer the DEX treatment time, the more obvious the effect. However, DEX had little effect on LPS-induced NF-KB activation, and partially impaired LPS-induced I-κBα degradation. DEX significantly decreased LPS induced IL-12p70 production by DCs. Interestingly, our results showed a synergistic effect between DEX and LPS on the production of IL-10 by DCs. Conclusions DEX inhibits the differentiation and maturation of murine DCs involved in TLR4-I-κB-NF-κB pathway, and also indirectly impairs Thl development and interferes with the Thl-Th2 balance through IL-12 and/or IL-10 secretion by DCs.     

不可分型流感嗜血杆菌诱导A549细胞分泌和表达前炎症细胞因子及机制研究

目的 探讨不可分型流感嗜血杆菌(NTHi)作用于呼吸道上皮细胞株(A549),表达前炎症细胞因子的变化及其干预措施.方法 用NTHi、NTHi 红霉素(10 mg/L)、NTHi 庆大霉素(100 mg/L)、NTHi 地塞米松(100 μmol/L)分别感染A549细胞,用核因子κB(NF-κB)抑制剂二硫氨基甲酸吡啶(PDTC,200 μmol/L)预处理NTHi感染的A549细胞,24 h后观察细胞的形态学改变,并检测上清液中白细胞介素8(IL-8)、肿瘤坏死因子α(TNF-α)的水平和细胞间黏附分子1(ICAM-1)的表达.结果 NTHi作用A549细胞24 h后,引起部分上皮细胞变形、死亡.NTHi能显著诱导A549细胞株分泌IL-8、表达ICAM-1,红霉素能够抑制其诱导作用;庆大霉素具有杀灭NTHi作用,但不能抑制IL-8分泌和ICAM-1表达;地塞米松能抑制A549分泌IL-8,降低ICAM-1的表达,但不能杀灭NTHi.PDTC(200 μmol/L)能阻断A549细胞在NTHi作用后IL-8的高表达.TNF-α在各组培养上清中均不能检测到.结论 NTHi显著诱导人肺上皮细胞系表达前炎症因子,该作用可能通过NF-κB通路.红霉素在杀灭NTHi的同时还具有抗炎作用.