mTEL-cFms激酶结构域融合蛋白真核表达载体的构建及其对信号转导和转录激活因子核转位的影响

目的构建激酶盘真核表达载体,观察豆蔻酰化的TEL转录调节因子HLH结构域与c-Fms激酶结构域融合蛋白(mTEL-cFmskd)的表达对信号转导和转录激活因子1(STAT1)和STAT3核转位的影响。方法利用DNA重组技术,将人的c-Src豆蔻酰化多肽、TEL转录调节因子HLH结构域、c-Fms激酶结构域以及c-Myc标签的DNA序列克隆在pCORON/neo载体上,构建pCORON/neo-HcSrc-Tel-cfmskd-Myc真核表达载体。将载体转染至稳定表达GFP-STAT1的人骨肉瘤细胞(U2OS)和稳定表达EGFP-STAT3的幼仓鼠肾细胞24 h后,采用IN Cell Analyzer1000获取细胞图像,分析细胞内GFP-STAT1或EGFP-STAT3融合蛋白的核转位程度。结果质粒酶切和测序鉴定表明,构建的pCORON/neo-HcSrc-Tel-cfmskd-Myc真核表达载体序列正确。载体转染细胞24 h后,绿色荧光蛋白标记的STAT1和STAT3均进入细胞核,发生核转位现象。c-Fms激酶抑制剂GW2580和Sutent能抑制mTEL-cFmskd诱导EGFP-STAT3核转位的发生。结论成功构建激酶盘真核表达载体pCORON/neo-HcSrc-Tel-cfmskd-Myc。载体在细胞中表达的mTEL-cFmskd豆蔻酰化融合蛋白具有M-CSF/c-Fms配体受体复合物激活下游信号分子的生物学功能。     

白术内酯Ⅰ调控Janus激酶2/信号转导和转录激活因子3通路对分泌性中耳炎大鼠听功能及炎症反应的影响

目的 探究白术内酯Ⅰ调控Janus激酶2(JAK2)/信号转导和转录激活因子3(STAT3)通路对分泌性中耳炎(SOM)大鼠听功能及炎症反应的影响。方法 用卵清蛋白和氢氧化铝致敏构建SOM模型大鼠,并随机分为模型组、联合组和低、高剂量实验组,每组12只;另选12只正常SD大鼠做对照组。低、高剂量实验组分别灌胃给予120和240 mg·kg^-1白术内酯Ⅰ,联合组灌胃给予240 mg·kg^-1白术内酯Ⅰ+21 mg·kg^-1 RO8191;对照组和模型组均灌胃给予等量0.9%NaCl。5组大鼠每天给药1次,连续给药14 d。用听觉脑干诱发电位(ABR)仪检测大鼠听功能(ABR反应阈值),用蛋白质印迹法检测大鼠中耳黏膜组织JAK2/STAT3通路相关蛋白的表达情况。结果 低、高剂量实验组和联合组、模型组、对照组的ABR反应阈值分别为(47.26±5.91)、(26.89±3.75)、(63.37±9.87)、(68.71±10.32)和(24.62±3.53)dB SPL,p-JAK2/JAK2分别为0.48±0.09、0.1...     

靶向STAT3的RNA干扰对人胃癌细胞增殖和侵袭的影响

目的 观察瞬时转染信号转导与转录激活因子3(STAT3)siRNA后对人胃癌细胞SGC-7901增殖、凋亡与侵袭的影响.方法 以人胃癌细胞系SGC-7901培养瞬时转染特异性siRNA的SGC-7901细胞系,应用RT-PCR、MTT、流式细胞术和Transwell体外侵袭实验等检测该siRNA对SGC-7901细胞基因表达、细胞增殖、细胞周期、细胞凋亡及侵袭转移能力的影响.结果 STAT3siRNA转染SGC-7901细胞48h后,STAT3 mRNA水平下降了73.04%,细胞增殖受到明显抑制,抑制率45.73%;STAT3 siRNA组G0-G1期细胞比例增加21.03%,S期细胞比例减少15.24%,细胞凋亡率升高了6.97%;STAT3 siRNA组细胞侵袭力下降了45.26% (P＜0.01).结论 应用siRNA技术能有效抑制SGC-7901 STAT3基因的表达,进而抑制细胞的增殖,诱导细胞凋亡,降低其侵袭力,为以STAT3为靶向的胃癌基因治疗提供了新的思路和手段.     

微 RNA-125、信号转导与转录活化因子 3对卵巢癌细胞的影响及靶向关系验证

目的检测微 RNA(miR)-125a、信号转导与转录活化因子 3(STAT3)在卵巢癌细胞中的表达水平,分析其对卵巢癌细胞增殖、侵袭和凋亡的影响,并验证两者的靶向关系。方法 2020年 1月至 2021年 12月,采用 qRT-PCR检测卵巢癌细胞和正常人卵巢上皮细胞中 miR-125a、STAT3 mRNA水平。利用转染技术将 SKOV3细胞分为 miR-NC(miR-125a阴性对照组质粒)组、 miR-125a(miR-125a过表达质粒)组、 si-NC(沉默 STAT3阴性对照质粒)组、 si-STAT3(沉默 STAT3质粒)组、 miR-125a+si-NC和 miR-125a+si-STAT3组。 MTT实验、 Transwell实验和凋亡实验分别检测不同组间细胞的 OD值、穿膜细胞数和凋亡率。萤光素酶报告基因分析 SKOV3细胞中 miR-125a与 STAT3的靶向关系,蛋白质印迹法检测不同组间 STAT3蛋白表达情况。结果与 HOSEpiC细胞 miR-125a和 STAT3 mRNA水平( 1.00±0.15、0.54±0.08)相比, SKOV3、CAOV3和 PEO1细胞中 miR-125a水平(0.41±0.07、0.56±0.08、0.58±0.10)降低, STAT3 mRNA水平( 1.87±0.22、1.54±0.07、1.54±0.08)增加;选用 SKOV3细胞进行后续实验。与 miR-NC组相比, miR-125a组细胞增殖能力减弱、穿膜细胞数降低、凋亡率增加。与 si-NC组相比, si-STAT3组细胞增殖能力减弱、穿膜细胞数降低、凋亡率增加。与 miR-125a+si-NC组相比, miR-125a+si-STAT3组细胞增殖能力减弱、穿膜细胞数降低、凋亡率增加。 STAT3+miR-125a mimic组与 STAT3 WT组相比, STAT3蛋白表达较弱,且 miR-125a与 STAT存在靶向结合位点。结论卵巢癌细胞中 miR-125a的过表达可靶向 STAT3抑制 SKOV3细胞的增殖和侵袭并诱导细胞凋亡,发挥抗肿瘤活性。     

从 Janus激酶 2/信号转导和转录激活因子 3信号通路探讨牛磺酸对 Aβ25-35所致神经干细胞损伤的保护作用

目的探讨牛磺酸对 Aβ25-35损伤神经干细胞( neural stem cells,NSCs)的保护作用,并初步阐明其作用机制。方法研究自 2019年 3—11月通过 Aβ25-35损伤实验室提取的神经干细胞模型,探讨牛磺酸和 Janus激酶 2/信号转导和转录激活因子3该(JAK2/STAT3)的作用关系。从出生 48 h内的 C57BL/6乳鼠海马区提取 NSCs,以 25 μmol/L浓度 Aβ25-35诱导 NSCs,建立体外阿尔茨海默病( Alzheimer’s disease,AD)样 NSCs模型( AD-NSCs),并利用不同浓度的牛磺酸共同孵育,分为对照组、模型组( 25 μmol/L)、 Aβ25-35+牛磺酸 5 mmol组、 Aβ25-35+牛磺酸 10 mmol组、 Aβ25-35+牛磺酸 15 mmol组及 Aβ25-35+牛磺酸 20 mmol组,共六组。     

信号转导和转录活化因子3与系统性红斑狼疮的研究进展

系统性红斑狼疮(SLE)是以全身免疫异常而致多器官受累为特征的疾病,病理表现为自身抗体产生和免疫复合物沉积。SLE发病机制复杂,为多种基因和环境因素相互作用的结果。这种相互作用激活T细胞,活化的T细胞反过来再激活B细胞,导致过多的自身抗体产生。T细胞和B细胞的功能是通过细胞内信号转导来实现的。信号转导和转录活化因子3(signal     

氯沙坦对糖尿病大鼠肾小球信号转导和转录活化因子1表达的影响

目的探讨糖尿病大鼠肾小球细胞中信号转导和转录活化因子1磷酸化水平及其mRNA水平的改变以及血管紧张素受体1拮抗剂(AT1Ra)氯沙坦的影响。方法♂Wistar大鼠随机分为对照组、糖尿病组和氯沙坦治疗组,腹腔注射STZ诱发糖尿病大鼠模型,每日灌胃给予氯沙坦40mg·kg-1,共2wk。采用免疫组化和Western印迹检测肾小球细胞磷酸化STAT1(pSTAT1)蛋白的表达,RTPCR检测肾小球细胞STAT1mRNA的表达。结果糖尿病组肾小球p-STAT1表达明显高于对照组(P<001),约是对照组的3倍;氯沙坦治疗组大鼠肾小球pSTAT1的表达明显低于糖尿病组(P<005);RTPCR结果表明糖尿病组肾小球细胞STAT1mRNA表达明显上调,约为对照组的34倍;氯沙坦治疗组STAT1mRNA表达与糖尿病组相比无明显差异。结论STAT1信号途径可能参与了糖尿病早期肾脏的发病过程,氯沙坦的肾脏保护作用可能部分是通过影响STAT1的激活而实现。     

小分子干扰RNA干扰蛋白激酶Cα相互作用蛋白1基因对结肠腺癌HT-29细胞增殖凋亡及侵袭的影响

目的研究小分子干扰RNA(siRNA)干扰蛋白激酶Cα相互作用蛋白(PICK)1基因对人结肠腺癌HT-29细胞增殖、凋亡及侵袭的影响。方法设计合成针对PICK1基因的siRNA序列,分为实验组(PICK1-siRNA)、阴性对照组(Negative-siRNA)及对照组。阳离子脂质体(Lipofectamine~(TM) 2000)介导转染至HT-29细胞,四甲基偶氮唑蓝(MTT)检测HT-29细胞增殖活性的改变;蛋白印迹法检测转染前后PICK1蛋白的表达;流式细胞术检测细胞凋亡的变化;细胞侵袭实验检测细胞侵袭能力的变化。结果转染24 h后,PICK1-siRNA组PICK1蛋白的相对表达量低于Negative-siRNA组和对照组(P<0.05)。MTT结果显示,PICK1-siRNA组HT-29细胞的增殖活性受到明显的抑制作用,差异具有统计学意义(P<0.05)。与Negative-siRNA组和对照组相比,PICK1-siRNA组HT-29细胞凋亡比例显著增高,侵袭能力显著下降,差异具有统计学意义(P<0.05)。结论干扰PICK1基因表达可有效抑制HT-29细胞增殖,诱导凋亡,降低侵袭相关蛋白的表达,可作为结肠癌治疗的潜在靶点。     

STAT3shRNA增强胰腺癌细胞Panc-1对吉西他滨化疗敏感性

目的 观察shRNA下调胰腺癌Panc-1细胞STAT3 mRNA表达后对吉西他滨化疗敏感性的影响.方法 构建靶向STAT3 mRNA的shRAN和阴性质粒,分别转染Panc-1细胞(A组和B组);另将非转染的正常Panc-1细胞分为C组和D组.A,B,C三组细胞与吉西他滨共孵育.RT-PCR和Western blot检测Panc-1中STAT3 mRNA和蛋白的表达;MTT法检测Panc-1细胞增殖能力;流式细胞术检测细胞周期.结果 A组STAT3 mRNA水平下降了61.9%,STAT3蛋白水平下降了85.7%(P＜0.01),细胞增殖能力低于B、C组(P＜0.01).与B、C组比较,A组G1期细胞比率增加(P＜0.05),细胞存活率降低(P＜0.01).结论 靶向STAT3 mRAN的shRNA可特异性降低Panc-1细胞中STAT3 mRNA及其蛋白的表达,抑制Panc-1细胞增殖,使其阻滞于G1期,从而增强吉西他滨对G1期细胞的细胞毒效应,增加吉西他滨的化疗敏感性.     

STAT3抑制剂抗肿瘤研究进展

信号转导和转录激活因子3（STAT3）是参与多种生物学功能的转录因子,可将细胞外信号传导到细胞核,进而激活靶基因的转录。STAT3异常激活可诱导肿瘤的发生,促进肿瘤的发展,是一个有吸引力的抗癌靶点。目前STAT3抑制剂快速发展,其主要包括STAT3上游信号抑制剂和STAT3直接抑制剂。重点综述近几年靶向STAT3药物的抗肿瘤研究进展。     

RNAi 靶向沉默 CDX2 基因对白血病细胞生物学行为的影响及其作用机制

Abstract: Objective To detect the effects of siRNA targeting CDX2 gene expression on of BCR-ABL, caspase and Bax expressions, and the mechanisms thereof. Methods According to the earlier experiments, siRNA specifically targeting CDX2 gene (CDX2-siRNA) and the negative control sequence (CDX2-siRNA-NC) were selected, and then were transfected into K562 cells by Roche X-tremeGENE HP DNA Transfection Reagent. The flow cytometry analysis was used to detect the effects of siRNA on cell apoptosis. The expressions of BCR-ABL, caspase- 9, Bax mRNA and protein were tested by RTPCR and Western blot assay. Results MTT and flow cytometry analysis showed that after the silence of CDX2 gene expression, the proliferation of K562 cells was prohibited and the apoptotic rate of K562 cells was distinctly increased compared with that of normal cell group, but the negative control group had no significant change. According to the RT-PCR and Western blot assay, in comparison with the normal cell group and the negative control group, the expression levels of BCR-ABL mRNA and protein were obviously decreased, and the difference was statistic significance. On the other hand, the expressions of caspase- 9 and Bax mRNA and protein were significantly higher than those of other two groups (P＜0.05).Conclusion CDX2-siRNA can promote apoptosis of K562 cells obviously, and the mechanism is related with the downregulation of BCR-ABL and the up-regulation of caspase-9 and Bax.     

Inhibition of STAT3 expression by siRNA suppresses growth and induces apoptosis in laryngeal cancer cells

Aim: To determine the inhibitory effect of the synthetic STAT3 siRNA on the expression of STAT3 gene in human laryngeal cancer cell lines Hep2 and to investigate the effect of STAT3 siRNA on growth and apoptosis in Hep2 cells. Methods: A pair of DNA templates coding siRNA against STAT3-mRNA was synthesized to reconstruct plasmid of pSilencer1.0-U6 siRNA-STAT3. Hep2 cells were transfected with RPMI-1640 media (untreated), plasmid (empty), and STAT3 siRNA, respectively. Northern blot and Western blot analysis of STAT3 and pTyr-STAT3 expression in Hep2 cells and Western blot analysis of Bcl-2 expression in the Hep2 cell was performed 72 h after transfection. MTT, flow cytometry, and AO/EB assay were used for determination of cells proliferation and apoptosis in Hep2 cells. Results: pTyr-STAT3 was markedly expressed in untreated Hep2 cells and the vector-treated Hep2 cells, whereas pTyr-STAT3 expression was significantly reduced in STAT3 siRNA-transfected Hep2 cells, indicating that STAT3 siRNA inhibited the activity of STAT3. Transfection of Hep2 cells with STAT3 siRNA significantly inhibited STAT3 expression at both mRNA and protein level in Hep2 cells and the inhibition was characterized by time-dependent transfection. Treatment of Hep2 cells with STAT3 siRNA resulted in dose-dependent growth inhibition of Hep2, this significantly increased apoptotic cell rate, and decreased Bcl-2 expression level in Hep2 cells. STAT3 siRNA had an effect on induction of either early or late stage apoptosis. Conclusion: This study demonstrates that STAT3 siRNA effectively inhibits STAT3 gene expression in Hep2 cells leading to growth suppression and induction of apoptosis in Hep2 cells. The use of siRNA technique may provide a novel therapeutic approach to treat laryngeal cancer and other malignant tumors expressing constitutively activated STAT3.     

瑞舒伐他汀对家兔动脉粥样硬化的影响及其机制

目的：研究瑞舒伐他汀对家兔动脉粥样硬化的影响及其机制。方法随机将30只纯种雄性大白兔分成三组,正常饮食组(对照组),高脂饮食组(高脂组),高脂饮食加瑞舒伐他汀组(瑞舒伐他汀组)。实验动物喂养8周后检测各实验组血清低密度脂蛋白胆固醇(LDL-C)、甘油三酯(TG)、总胆固醇(TC),用免疫组化的方法检测信号转导及转录激活因子3(STAT3)、白细胞介素-6(IL-6)在组织中的表达。结果实验显示高脂组、瑞舒伐他汀组中LDL-C、TG、TC水平较对照组明显增高(P<0.05);瑞舒伐他汀组LDL-C、TG、TC水平较高脂组降低(P<0.05)。IL-6、STAT3在瑞舒伐他汀组中表达较高脂组明显减少,两者的表达为正相关。结论瑞舒伐他汀可通过抑制炎症反应抑制动脉粥样硬化的发生,其机制与阻断JAK-STAT3信号转导通路有关。     

STAT3-independent inhibition of lysophosphatidic acid-mediated upregulation of connective tissue growth factor (CTGF) by cucurbitacin I

Cucurbitacins are recognised as anti-tumour agents because of their interference with STAT3 signalling, but may also affect the integrity of the actin cytoskeleton. In the present study the effect of cucurbitacin I was investigated in fibroblasts. In these cells, cucurbitacin I interfered with lysophosphatidic acid (LPA) signalling. It inhibited tyrosine phosphorylation of focal adhesion proteins and induction of connective tissue growth factor (CTGF), a potent profibrotic protein. Inhibition of Src family kinases with PP2, but not the inactive analogue PP3, also interfered with LPA-mediated tyrosine phosphorylation and induction of CTGF. Jak2-STAT3 signalling seemed to be the connecting link, because CTGF induction was sensitive to AG490, an inhibitor of Jak2, and cucurbitacin I, an inhibitor of Jak2 and STAT3. However, LPA did not activate tyrosine phosphorylation of STAT3. Furthermore, cucurbitacin I was as effective in STAT3 knock out cells as in control cells. Therefore, the inhibitory effect of cucurbitacin I was not related to inhibition of STAT3. Immunocytochemical analysis of cucurbitacin I-treated cells revealed disassembly of F-actin fibres, reorganisation into F-actin patches and resolution of focal adhesions. The phenotypic changes resembled changes observed after treatment of the cells with cytochalasin D, which has been shown to interfere with CTGF induction. Concentrations of cucurbitacin I, which have been shown to target Jak2-STAT3 signalling, thus, profoundly affect the actin cytoskeleton and may therefore modulate cell morphology, migration, adherence and gene expression also in non-tumour cells.     

RNAi沉默XIAP基因抑制MG-63细胞增殖及其分子机制

目的 探讨RNA干扰(RNAi)抑制NC-63骨肉瘤细胞X-连锁凋亡抑制蛋白(XIAP)基因的表达及其抗肿瘤的机制.方法 构建XIAP基因的短发夹RNA(shRNA)表达载体.将NC-63细胞分为空白组(A组),用空白质粒psiRNA-Con转染(B组),用psiRNA-XIAP转染(C gt).Westernblot检测XIAP蛋白的表达;MTT检测细胞的增殖;流式细胞术检测细胞周期、凋亡及半胱天冬氨酸蛋白酶9(Caspase-9)的表达;ELISA法检测细胞内血管内皮生长因子(VEGF)含量.结果 与A、B组比较,C组细胞XIAP蛋白水平、MTT值及VEGF含量均显著降低,细胞凋亡率、Caspase-9蛋白表达及G2/M期细胞所占比例增高(P＜0.05).结论 RNAi能有效抑制XIAP基因表达,抑制骨肉瘤细胞增殖活性,诱导其凋亡.其机制可能涉及Caspase家族凋亡信号转导通路的活化、DNA合成及肿瘤血管生成的抑制.