肺癌耐顺铂细胞A549/CIS产生肿瘤干细胞特性的分子机制研究

目的 研究人肺癌耐顺铂细胞A549/CIS获得肿瘤干细胞特性的分子机制。方法 微球形成实验比较A549和A549/CIS细胞肿瘤干细胞特性的差别,以及磷脂酰肌醇3-激酶/丝氨酸-苏氨酸激酶(PI3K/AKT)通路抑制剂LY294002对A549/CIS细胞微球形成能力的影响。Western blotting检测A549和A549/CIS细胞中AKT、p65以及MAPK-p38信号通路的活化情况。CCK8实验检测A549和A549/CIS细胞对顺铂的敏感性,以及PI3K/AKT通路抑制剂LY294002对A549/CIS细胞对顺铂敏感性的影响。结果 A549/CIS细胞对顺铂的敏感性以及微球形成能力相对于A549明显增强,Western blotting结果表明:A549/CIS细胞中AKT通路明显被激活,而p65和MAPK-p38通路没有明显变化。LY294002可以抑制A549/CIS细胞的肿瘤干细胞特性,并提高A549/CIS细胞对顺铂的敏感性。结论 相对于敏感株细胞A549,耐药株A549/CIS细胞的肿瘤干细胞特性明显增强,而其机制涉及PI3K/AKT信号通路的激活。     

miR-218抑制卵巢癌细胞A2780对顺铂耐药性的实验研究

目的研究miR-218抑制卵巢癌细胞A2780对顺铂耐药性的影响及可能机制。方法实时定量PCR检测A2780及顺铂耐药细胞株A2780/DDP中miR-218的表达,转染miR-218 inhibitors和mimics改变A2780及A2780/DDP细胞中miR-218的表达,MTT法检测转染前后细胞对顺铂的敏感性,并分析Wnt2B蛋白表达的改变。结果与A2780细胞相比,miR-218在A2780/DDP中的表达明显降低。A2780细胞转染miR-218 inhibitors后,细胞对顺铂的敏感性降低,Wnt2B蛋白表达明显增强;而A2780/DDP细胞转染miR-218mimics后,细胞对顺铂的敏感性增强,Wnt2B蛋白表达明显减少。结论 miR-218可能通过靶向Wnt2B抑制卵巢癌细胞A2780对顺铂的耐药性。     

miR-552通过PTEN/AKT信号通路促进非小细胞肺癌A549细胞的恶性生物学行为

目的 探讨miR-552通过调控PTEN/AKT信号通路促进人非小细胞肺癌A549细胞的恶性生物学行为及其相关机制。方法 通过qRT-PCR检测人肺癌组织样本和人非小细胞肺癌A549细胞系中miR-552、PTEN mRNA的表达情况;通过Western blotting检测PTEN、AKT、p-AKT蛋白的表达情况;通过CCK-8检测miR-552表达对A549细胞增殖能力的影响;通过Transwell小室检测miR-552表达对A549细胞迁移和侵袭能力的影响;通过流式细胞术检测miR-552表达对A549细胞凋亡能力的影响。结果 miR-552在肺癌组织和A549细胞中的表达显著上调。过表达miR-552可显著促进A549细胞的增殖、迁移和侵袭,并抑制细胞凋亡,而抑制其表达则结果相反。与癌旁组织相比,肺癌组织中PTEN表达显著下调。过表达miR-552可下调PTEN蛋白表达,上调p-AKT蛋白表达,对AKT蛋白无影响,而抑制其表达则结果相反。结论 miR-552可能通过PTEN/AKT信号通路促进人非小细胞肺癌A549细胞的恶性生物学行为。     

双氢青蒿素通过PI3K/Akt通路逆转肺癌顺铂耐药A549/DDP细胞的分子机制

摘要：目的:研究双氢青蒿素通过磷脂酰肌醇-3-激酶/丝苏氨酸蛋白激酶（PI3K/Akt）通路逆转肺癌顺铂耐药A549/DDP细胞的分子机制。方法:体外培养人肺癌耐顺铂株（A549/DDP）,给予不同浓度双氢青蒿素(20,40,80,160,200,250,300μmol·L-1)处理48 h后,通过MTT法检测双氢青蒿素对A549/DDP细胞增殖影响,选取双氢青蒿素最佳实验浓度及在不同浓度DDP(0,20,40,60,80,100μmol·L-1)作用下观察并计算顺铂对A549/DDP细胞IC50和双氢青蒿素对A549/DDP逆转倍数;通过流式细胞术检测各组细胞凋亡率,Western blot法检测各组细胞中凋亡相关因子B淋巴细胞瘤-2基因（Bcl-2）和半胱氨酸蛋白酶3（Caspase3）及PI3K/Akt通路相关蛋白PI3K、AKT、磷酸化蛋白激酶B（p-Akt）的表达。结果:随双氢青蒿素浓度升高,细胞增殖抑制率依次升高（P<0.05）,且具有浓度依赖性,IC10（32.07±1.04）μmol·L-1是双氢青蒿素为最佳逆转耐药浓度;随DDP浓度的升高,双氢青蒿素A549/DDP细胞增殖抑制率随之升高（P<0.05）,DDP+双氢青蒿素组顺铂对A549/DDP的IC50为（26.42±1.23）μmol·L-1,顺铂组为（58.16±1.32）μmol·L-1,双氢青蒿素的逆转耐药倍数为2.21;与对照组相比,DDP组、双氢青蒿素组、DDP+双氢青蒿素组细胞凋亡率、caspase-3表达显著升高（P<0.05）,Bcl-2、PI3K、p-Akt/Akt表达显著降低（P<0.05）;与DDP组、双氢青蒿素组相比,DDP+双氢青蒿素组细胞凋亡率、caspase-3表达显著升高（P<0.05）,Bcl-2、PI3K、p-Akt/Akt表达显著降低（P<0.05）。结论:双氢青蒿素通过抑制PI3K/Akt通路促进A549/DDP细胞凋亡,在一定程度上可逆转肺癌A549/DDP细胞株对顺铂的耐药性。     

1MTA2基因沉默对人乳腺癌MCF-7/ADR多药耐药的逆转作用

目的乳腺癌是女性中最常见的恶性肿瘤,本研究探讨MTA2对乳腺癌耐药的作用及机制。方法 CCK-8检测MCF-7/ADR和MCF-7细胞株对阿霉素的耐药情况。体外化学合成MTA2序列特异性的shRNA,经慢病毒转染人乳腺癌细胞系,Western blot检测慢病毒介导的MTA2敲减效率以及PI3K/AKT/NF-κB信号通路蛋白。Annexin V-FITC和DAPI染色检测细胞凋亡情况。结果 MCF-7/ADR细胞中MTA2表达量显著高于MCF-7细胞株,慢病毒介导的基因沉默显著的敲减了MCF-7/ADR细胞中的MTA2。敲除MTA2逆转MCF-7/ADR细胞的耐药作用并促进细胞凋亡。敲除MTA2通过抑制PI3K/AKT通路抑制下游NF-κB通路活化,并下调p-gp蛋白表达而逆转耐药性。结论敲除MTA2可以逆转MCF-7/ADR细胞的耐药作用,表明MTA2可能参与调节乳腺癌多药耐药作用。     

基于miR-9/NF-κB信号通路探讨丙泊酚对鼻咽癌细胞增殖、凋亡的影响

摘要：目的:基于微小RNA-9（miR-9）/核因子-κB（NF-κB）信号通路探讨丙泊酚对鼻咽癌细胞增殖、凋亡的影响。方法:设鼻咽癌细胞（CNE-2Z）采用细胞组、顺铂组(7.5μg·ml-1)、丙泊酚低、高剂量组(25,50μg·ml-1),以上各组每孔设6个平行样,培养72 h,培养结束后,采用四唑盐（MTT）法及Giemsa溶液染色测定细胞增殖及克隆形成数目,Transwell腔室系统测定侵袭迁移水平,流式细胞仪测定凋亡水平,实时荧光定量PCR（qRT-PCR）法及蛋白免疫印迹（WB）法测定miR-9、NF-κB mRNA和蛋白水平。结果:与CNE-2Z细胞组比较,顺铂组、丙泊酚低、高剂量组吸光度（A）值、存活率、克隆形成数目、穿膜数、miR-9、NF-κB mRNA和蛋白水平显著降低,凋亡率显著升高（P<0.05）;与顺铂组比较,丙泊酚低、高剂量组A值、存活率、克隆形成数目、穿膜数、miR-9,NF-κB mRNA和蛋白水平显著升高,凋亡率显著降低（P<0.05）;丙泊酚剂量组间差异有统计学意义（P<0.05）。结论:丙泊酚可抑制鼻咽癌细胞增殖,促进其凋亡;其机制与丙泊酚抑制miR-9、NF-κB mRNA和蛋白表达进而抑制miR-9/NF-κB信号通路激活有关。     

中药单体成分及复方促进骨折愈合的作用机制研究进展

中药在治疗骨折愈合过程中具有多成分、多途径、多靶点的作用特点,对于具有复杂病理机制的骨折具有较好的治疗优势和潜力。笔者对中药单体成分及复方促进骨折愈合的作用机制进行了归纳,发现内脂素A、葛根素等可通过激活丝裂原活化蛋白激酶（MAPK）信号通路,续骨丹、固本增骨方等可通过激活骨形态发生蛋白（BMP）信号通路,黄芩苷、牛膝多糖等可通过激活Wnt/β-catenin信号通路,芹菜素、三七皂苷等可通过激活核因子κB(NF-κB)受体激活蛋白/NF-κB受体激活蛋白配体/护骨因子（RANK/RANKL/OPG）信号通路,活血接骨复方胶囊、健骨颗粒等可通过抑制磷脂酰肌醇3-激酶/蛋白激酶B(PI3K/AKT)信号通路,淫羊藿苷等可通过激活Notch信号通路,桃红四物汤、藏红花素等可通过激活Hippo信号通路,酸枣仁皂苷A、蛇床子素等可通过抑制NF-κB信号通路,发挥促进骨折愈合的作用。     

雷公藤多苷抑制 PI3K/AKT信号通路对肺腺癌细胞迁移和血管形成的影响

目的 探讨雷公藤多苷(TWP)对肺腺癌A549细胞迁移、血管生成及磷脂酰肌醇3-激酶/蛋白激酶B(PI3K/AKT)信号通路的影响.方法 人肺腺癌细胞株A549体外培养,分别用TWP(0、20、40、80μmol/L)处理24、48和72 h,采用CCK-8法、流式细胞仪和Transwell法分别检测A549细胞的增殖、凋亡和迁移情况,Matrigel胶小管形成实验检测血管生成情况,蛋白质印迹法(Western blotting)检测A549细胞中PI3K、磷酸化PI3K(p-PI3K)、AKT、磷酸化AKT(p-AKT)蛋白表达情况.结果 随培养时间延长,20、40、80μmol/L TWP组A549细胞增殖抑制率均显著升高(P<0.05);20、40、80μmol/L TWP组A549细胞凋亡率[(8.78±0.69)％、(10.36±1.13)％、(21.68±2.11)％]均显著升高(P<0.05),穿膜细胞数[(122.08±30.72)、(83.34±19.75)、(43.58±13.29)个]、p-PI3K/PI3K比值[(0.76±0.13)、(0.55±0.12)、(0.36±0.09)]、p-AKT/AKT比值[(0.53±0.14)、(0.35±0.09)、(0.21±0.05)]均显著降低(P<0.05);0、20、40、80μmol/L TWP组A549细胞诱导静脉内皮细胞(HUVEC)成管数量较对照组均显著升高[(35.85±8.72)、(24.13±6.86)、(15.34±4.66)、(9.15±2.25)个比(6.31±1.49)个,P<0.05],A549细胞诱导HUVEC成管数量均随TWP浓度升高而显著降低(P<0.05).结论 TWP可能通过抑制PI3K/AKT信号通路激活,抑制肺腺癌A549细胞的增殖、迁移、血管生成行为,并诱导细胞凋亡.     

ABCG2基因在非小细胞肺癌细胞耐药中的作用和机制探究

目的:分析ABCG2基因在多耐药非小细胞肺癌(non small cell lung cancer,NSCLC)细胞的表达变化及其可能参与的机制。方法:选择肺癌细胞A549及耐药A549进行细胞培养,分别给予顺铂及依托泊苷化疗药物治疗;取耐药A549细胞分为空白组(不处理)、对照组(给予siRNA对照)及siRNA-ABCG2组(给予siRNA-ABCG2)。采用CCK8法检测各组细胞的药物抑制率,采用Western blot法检测3组细胞中ABCG2蛋白表达情况。结果:2组细胞药物抑制率变化呈剂量依赖性,同剂量中耐药A549组药物抑制率明显低于A549组。耐药A549组细胞ABCG2蛋白表达水平明显高于A549组。3组细胞药物抑制率呈剂量依赖性,其中同剂量的siRNA-ABCG2组药物抑制率明显高于空白组及对照组。siRNA-ABCG2组细胞ABCG2、p-AKT、p-mTOR蛋白表达水平明显低于空白组及对照组,分别使用p-AKT、p-mTOR的激活剂后,可显著降低干扰ABCG2基因后导致的顺铂和依托泊苷抑制率的增加。结论:ABCG2通过调控PI3K/AKT信号通路在耐药A549的耐药性中发挥重要作用,沉默ABCG2基因可改善耐药A549细胞的耐药性,提示ABCG2可作为改善NSCLC细胞对顺铂及依托泊苷化疗药物的耐药性的潜在靶点。     

大黄素甲醚-8-O-β-D-葡萄糖苷通过PI3K/AKT/NF-κB通路干预小鼠急性化学性肝损伤北大核心CSCD

目的研究大黄素甲醚-8-O-β-D-葡萄糖苷(physcion-8-O-β-D-monoglucoside,PMG)通过PI3K/AKT/NF-κB信号通路干预四氯化碳(carbon tetrachloride,CCl_(4))急性肝损伤模型小鼠的保肝机制。方法将小鼠随机分为正常对照组、模型组、PMG低、中、高(10、20、40 mg·kg^(-1))剂量组及联苯双酯(300 mg·kg^(-1))阳性对照组。PMG组和联苯双酯组灌胃对应药物混悬液,2次/天,连续3 d,正常对照组和模型组灌胃空白溶剂0.5%羧甲基纤维素钠(CMC-Na)。末次给药1 h后,腹腔注射0.5%CCl_(4)油溶液建立急性肝损伤模型,造模16 h后取材。给药体积均为0.1 mL/10 g体质量。HE染色法评价PMG对肝组织病理变化的改善作用;Hoechst 33342染色法检测肝细胞凋亡数;Western blot法检测肝组织中caspase-3、PI3K、p-PI3K、AKT、p-Akt、IκB、p-IκB总蛋白及NF-κB p65核蛋白表达水平;流式细胞术检测小鼠肝组织中辅助性T细胞17(T helper cell 17,Th17)的细胞比例。结果PMG干预可改善肝组织病理损伤程度,能明显抑制肝细胞凋亡,降低caspase-3蛋白表达水平,并能明显降低NF-κB p65核蛋白表达水平,以及PI3K、AKT、IκB蛋白磷酸化水平,降低肝组织中Th17细胞比例。结论PMG可抑制CCl_(4)致小鼠肝细胞凋亡,抑制肝脏过度炎症反应,其作用可能与其影响PI3K/AKT信号通路调控NF-κB激活有关。     

Genistein promotes M1 macrophage apoptosis and reduces inflammatory response by disrupting miR-21/TIPE2 pathway

Cardiovascular diseases are a major cause of mortality, and vascular injury, a common pathological basis of cardiovascular disease, is deeply correlated with macrophage apoptosis and inflammatory response. Genistein, a type of phytoestrogen, exerts cardiovascular protective activities, but the underlying mechanism has not been fully elucidated. In this study, RAW264.7 cells were treated with genistein, lipopolysaccharide (LPS), nuclear factor-kappa B (NF-κB) inhibitor, and/or protein kinase B (AKT) agonist to determine the role of genistein in apoptosis and inflammation in LPS-stimulated cells. Simultaneously, high fat diet-fed C57BL/6 mice were administered genistein to evaluate the function of genistein on LPS-induced cardiovascular injury mouse model. Here, we demonstrated that LPS obviously increased apoptosis resistance and inflammatory response of macrophages by promoting miR-21 expression, and miR-21 downregulated tumor necrosis factor-α-induced protein 8-like 2 (TIPE2) expression by targeting the coding region. Genistein reduced miR-21 expression by inhibiting NF-κB, then blocked toll-like receptor 4 (TLR4) pathway and AKT phosphorylation dependent on TIPE2, resulting in inhibition of LPS. Our research suggests that miR-21/TIPE2 pathway is involved in M1 macrophage apoptosis and inflammatory response, and genistein inhibits the progression of LPS-induced cardiovascular injury at the epigenetic level via regulating the promoter region of Vmp1 by NF-κB.     

Silver nanoparticles induced changes in the expression of NF-κB related genes are cell type specific and related to the basal activity of NF-κB

Silver nanoparticles (AgNPs) are widely used in industry and medicine but the recent evidence for their cytotoxicity rise a concern about the safety of their use. We have previously shown that human A549 cells are resistant to AgNPs cytotoxicity, as compared with similarly treated HepG2 cells. In order to check for the role of the NF-κB signaling pathway in response of A549 and HepG2 cell lines to the treatment with 20 nm and 200 nm AgNps, we analyzed the expression of 84 key genes related to the functionality of the NF-κB signaling pathway. We observed considerable alternations in gene expression in HepG2 cells treated with 20 nm AgNPs, and minor changes when exposed to 200 nm AgNPs. Surprisingly, no changes in gene expression were observed in A549 cells treated with both size AgNPs. Using the NF-κB luciferase reporter system, we further tested the basal activity and inducibility of the NF-κB pathway in both cell lines and found that the inducibility of NF-κB signaling in A549 cells is approximately 5 times lower than this of HepG2 cells, but the basal activity is approximately 3.5 times higher. In accordance, the NF-κB activation after AgNPs treatment was observed in HepG2 but not in A549. Altogether indicate that NF-kB mediated cellular response to AgNPs is cell type specific and related to the basal activity of NF-κB.     

MicroRNA-21 promotes epithelial-mesenchymal transition and migration of human bronchial epithelial cells by targeting poly (ADP-ribose) polymerase-1 and activating PI3K/AKT signaling

Epithelial-mesenchymal transition (EMT) is known to be involved in airway remodeling and fibrosis of bronchial asthma. However, the molecular mechanisms leading to EMT have yet to be fully clarified. The current study was designed to reveal the potential mechanism of microRNA-21 (miR-21) and poly (ADP-ribose) polymerase-1 (PARP-1) affecting EMT through the PI3K/AKT signaling pathway. Human bronchial epithelial cells (16HBE cells) were transfected with miR-21 mimics/inhibitors and PARP-1 plasmid/small interfering RNA (siRNA). A dual luciferase reporter assay and biotin-labeled RNA pull-down experiments were conducted to verify the targeting relationship between miR-21 mimics and PARP-1. The migration ability of 16HBE cells was evaluated by Transwell assay. Quantitative real-time polymerase chain reaction and Western blotting experiments were applied to determine the expression of Snail, ZEB1, E-cadherin, N-cadherin, Vimentin, and PARP-1. The effects of the PI3K inhibitor LY294002 on the migration of 16HBE cells and EMT were investigated. Overexpression of miR-21 mimics induced migration and EMT of 16HBE cells, which was significantly inhibited by overexpression of PARP-1. Our findings showed that PARP-1 was a direct target of miR-21, and that miR-21 targeted PARP-1 to promote migration and EMT of 16HBE cells through the PI3K/AKT signaling pathway. Using LY294002 to block PI3K/AKT signaling pathway resulted in a significant reduction in the migration and EMT of 16HBE cells. These results suggest that miR-21 promotes EMT and migration of HBE cells by targeting PARP-1. Additionally, the PI3K/AKT signaling pathway might be involved in this mechanism, which could indicate its usefulness as a therapeutic target for asthma.     

穿心莲内酯对人肺腺癌A549细胞NF-κB通路的调控作用

目的探讨穿心莲内酯对肿瘤细胞生长的作用及机制。方法人肺腺癌A549细胞分别与穿心莲内酯1.5～30μmol·L-1作用24h,以及穿心莲内酯30μmol·L-1作用4～24h。用MTT法检测A549细胞存活率;Western印迹法检测在肿瘤坏死因子α(TNF-α)10μg·L-1刺激下,穿心莲内酯30μmol·L-1对NF-κB信号通路中的相关蛋白NF-κB抑制因子α(IκBα)、磷酸化IκBα、IκB激酶β(IKKβ)和磷酸化IKKβ表达的影响;ELISA法检测穿心莲内酯对A549细胞核内NF-κBDNA结合活性的影响。结果穿心莲内酯的浓度和作用时间与A549细胞的存活率密切相关,穿心莲内酯30μmo·lL-1作用24h,A549细胞的存活率下降到(22.0±1.2)%,而穿心莲内酯1.5μmol·L-1作用24h或者穿心莲内酯30μmol·L-1作用4h对A549细胞的存活率几乎无影响。Western印迹法显示,穿心莲内酯能够抑制TNF-α诱导的NF-κB信号通路中IKKβ的磷酸化,抑制IκBα的磷酸化,推迟IκBα的降解,对IKKβ的表达无影响。穿心莲内酯还能够抑制TNF-α诱导的A549细胞核内NF-κBp65蛋白的DNA结合活性,抑制率达32%。结论穿心莲内酯通过影响NF-κB信号通路抑制A549细胞的生长。     

基于Notch信号通路探讨β-榄香烯逆转肺腺癌耐药机制的研究

目的基于Notch信号通路,探讨β-榄香烯逆转肺腺癌耐药的机制。方法选择对A549/DDP细胞无细胞毒性的β-榄香烯浓度处理A549/DDP细胞,设β-榄香烯组与对照组,两组细胞均给予不同浓度的DDP(0.25、0.5、1、2、4、8、16、32μg·mL^-1)处理24h,MTT法检测细胞活力并计算IC₅₀,流式细胞仪检测细胞凋亡,Western blotting检测凋亡相关蛋白(cleaved-caspase 3、cleaved-caspase 9)、耐药相关蛋白(P-gp、survivin、p21)及Notch信号通路蛋白(Notch1、Hes1、Hey2)的表达。A549/DDP细胞在β-榄香烯处理的基础上,联合1μg·mL^-1Notch信号通路激活剂rhNF-κB处理,比较两组的IC₅₀,Western blotting检测P-gp以及Notch1、Hes1、Hey2的表达。结果当β-榄香烯浓度低于20μg·mL^-1时,其对A549/DDP细胞的抑制率小于10%,无细胞毒性。β-榄香烯组DDP的IC₅₀显著低于对照组(t=14.712,P<0.05),逆转倍数为4.452倍。β-榄香烯组细胞凋亡率以及凋亡相关蛋白cleavedcaspase 3和cleaved-caspase 9的表达水平均高于对照组,差异有统计学意义(P<0.05)。β-榄香烯组P-gp、survivin蛋白相对表达量低于对照组,而p21蛋白相对表达量高于对照组,差异均有统计学意义(P<0.05)。β-榄香烯组Notch1、Hes1、Hey2蛋白相对表达量均低于对照组,差异有统计学意义(P<0.05)。β-榄香烯+rhNF-κB组DDP的IC₅₀以及P-gp、Notch1、Hes1、Hey2蛋白表达水平均高于β-榄香烯组,差异有统计学意义(P<0.05)。结论β-榄香烯可通过抑制Notch信号通路促进A549/DDP细胞凋亡,并逆转肺腺癌耐药。