靶向survivin基因不同位点的siRNA对PC-3细胞增殖和凋亡的影响

目的观察靶向survivin基因不同位点的小干扰RNA（siRNA）对人雄激素非依赖性前列腺癌PC-3细胞survivin mRNA表达的抑制作用以及对细胞增殖和凋亡的影响。方法根据survivin mRNA的结构特点,选取2个不同的作用位点,设计和构建负载survivin shRNA片段的2种重组质粒载体。以脂质体法转染PC-3细胞株,荧光显微镜下观察转染效率。实验分为survivin 1组、survivin 2组、阴性对照组和空白对照组。转染后24、48和72h,用半定量逆转录聚合酶链反应（RT—PCR）检测细胞中survivin mRNA的表达,MTT法检测siRNA对PC-3细胞增殖的影响,流式细胞术检测凋亡率。结果与对照组相比,survivin 1组、survivin 2组对survivin mRNA的表达均能产生抑制效应,48h抑制率最高,survivin 1抑制率高,达52％。实验组均能抑制PC-3细胞的增殖,survivin 1抑制细胞增殖的能力强。转染48h后,细胞凋亡最明显,survivin 1组凋亡率高,达13．6％±1．8％。结论在RNAi研究巾,根据特定靶基因mRNA的结构特点来进行siRNA的设计和筛选,在前列腺癌的基因治疗中具有一定的实际应用价值。     

核糖核酸干扰沉默survivin基因对A549细胞增殖及顺铂敏感性的影响

目的：利用核糖核酸干扰（RNA interference,RNAi）技术沉默抗凋亡基因survivin,观察其对人肺腺癌细胞A549增殖以及顺铂药物敏感性的影响。方法：将靶向survivin的基因片段插入带有绿色荧光蛋白基因的载体后构建重组质粒,将其导入A549细胞,RT-PCR分析转染前后survivin mRNA的表达情况,免疫荧光及Western blot分析转染前后survivin蛋白的表达情况,TUNEL法检测细胞凋亡情况,MTT法检测转染后A549细胞对顺铂的敏感性变化。结果：成功构建pGenesil1。1-survivin重组质粒。与对照组相比,转染重组质粒后,survivin mRNA和蛋白的表达明显降低,抑制率分别为65%和71%;细胞凋亡率增加;转染前顺铂对A549细胞的IC50为转染后的7.68倍,两者比较,差异有统计学意义（P〈0.05）。结论：靶向survivin的RNA干扰表达载体能下调survivin基因表达,增强A549细胞对顺铂药物敏感性。     

稳定转染靶向bcl-2的shRNA对胃癌SGC-7901细胞株增殖影响

目的探讨稳定转染靶向bcl-2的小发夹RNA（shRNA）对胃癌细胞株SGC-7901的长效影响。方法构建针对bcl-2的shRNA质粒表达载体,转入SGC-7901细胞,筛选稳定转染的细胞克隆继续压力培养。RT-PCR方法检测稳定转染后SGC-7901细胞bcl-2 mRNA的表达以及对细胞增殖和凋亡的影响。结果稳定转染shRNA后,SGC-7901细胞的bcl-2 mRNA表达明显下降;细胞增殖能力及凋亡率无明显变化。结论稳定转染shRNA能长效抑制SGC-7901细胞bcl-2 mRNA的表达,为后续基因治疗研究提供了实验依据。     

RNA干扰MBP-1基因对胃癌细胞SGC-7901增殖影响

目的：探讨 MBP-1（c-myc promter binding protein 1,MBP-1）基因表达沉默对胃癌细胞株 SGC-7901细胞增殖影响。方法实验分3组：空白对照组（未转染胃癌细胞）、阴性对照组（转染错义序列）和干扰组（转染 MBP-1 shRNA）。设计2条针对MBP-1基因的小干扰 RNA 片段及1条阴性对照 siRNA,并构建入 pSIREN-retroQ 质粒。将构建的重组 pSIREN-retroQ 质粒通过 Lipofectamine 2000脂质体转染胃癌 SGC-7901细胞,嘌呤霉素筛选稳转株细胞。Real time PCR 和 Western blot 分别检测MBP-1表达。MTT 法对 MBP-1干扰后 SGC-7901细胞增殖进行检测。结果通过 PCR 扩增阳性克隆及测序,说明已成功构建MBP-1干扰及对照重组 pSIREN-retroQ 质粒。通过 Lipofectamine 2000脂质体将重组质粒转染胃癌 SGC-7901细胞,并通过嘌呤霉素筛选2周,说明已成功构建 MBP-1干扰及对照 SGC-7901稳转株细胞。Real time PCR 检测,干扰组 MBP-1 mRNA 相对表达量与空白对照组相比显著下调（P ＜0.05）。Western blot 检测 MBP-1蛋白表达,干扰组 MBP-1表达量与空白对照组相比也都显著下调。MTT 法检测结果表明,MBP-1干扰组细胞在48、72、96和120 h 增殖能力比空白对照组都有显著的升高（P ＜0.05）。结论下调 MBP-1基因表达能明显促进胃癌细胞 SGC-7901的增殖,从而为胃癌基因治疗提供了新靶点。     

PLK1基因缄默在K562细胞凋亡中的作用

目的观察缄默PLK1基因的短发夹状RNA(short hairpin RNA,shRNA)对K562细胞内PLK1表达和细胞凋亡的影响,探讨PLK1在白血病发病中的作用,寻找更为有效的白血病治疗途径。方法设计合成针对PLK1基因1416~1436位点的shRNA片段,并将其克隆于绿色荧光蛋白的表达载体pEGFP-H1中,命名为pEGFP-H1/PLK1。通过电穿孔转染法将其导入K562细胞中,分为对照组、pEGFP-H1空载体转染组和pEGFP-H1/PLK1shRNA重组质粒转染组,转染后24,48h,分别通过RT-PCR和Western blot检测各组细胞PLK1基因和蛋白水平的变化,以MTT方法测各组细胞的增殖活性,比色法检测各组细胞的半胱天冬酶3(caspase-3)蛋白酶活性,并通过流式细胞仪检测各组细胞的凋亡和G2/M期转变情况。结果PLK1mRNA相对水平(与内参的灰度比值)对照组为1.25±0.07,空载体转染24,48h组分别为1.21±0.08和1.23±0.09,shRNA重组质粒转染24,48h组分别为0.52±0.04和0.25±0.02,shRNA重组质粒转染组较其他两组明显降低(P<0.01)。各组细胞PLK1的蛋白水平变化趋势与PLK1mRNA表达相似。相应地,对照组、空载体转染48h组、shRNA重组质粒转染24,48h组的凋亡率分别为(8.3±0.6)%、(8.7±0.7)%、(49.7±3.8)%和(82.3±6.9)%,后两者与前两组之间差异有统计学意义(P<0.05)。此外,与对照组和空载体转染组相比,shRNA重组质粒转染组的细胞增殖能力明显下降(P<0.05),且位于G2/M期的细胞较对照组和空载体转染组显著增加。以上结果均于转染后48h时较明显(P<0.05)。结论构建的shRNA能明显抑制转染细胞PLK1的表达和增殖,并可促进转染细胞的凋亡,并使停留于G2/M期的细胞显著增加。     

短发夹RNA诱导survivin基因缄默对Jurkat细胞凋亡和增殖的影响

目的研究应用载体表达短发夹 RNA(short hairpin RNA,shRNA)干扰技术抑制人 T 淋巴细胞白血病细胞株 Jurkat 细胞 survivin 基因的表达,探讨 survivin 基因表达缄默对 Jurkat 细胞凋亡和增殖的影响。方法构建针对 survivin 基因的 shRNA 重组质粒并转染至 Jurkat 细胞,分别用多重 PCR和 Western blot 法检测瞬时转染和稳定转染细胞 survivin 基因 mRNA 和蛋白表达水平的变化;流式细胞术检测瞬时转染和稳定转染细胞凋亡指数的变化,绘制细胞生长曲线,探讨 survivin shRNA 转染对细胞生长和增殖的影响。结果多重 PCR 结果示与无功能(对照组)shRNA 处理组和磷酸盐缓冲液处理组比较,survivin shRNA 瞬时转染和稳定转染细胞 surivivin 基因 mRNA 表达均显著下降,抑制率分别为66.675% 和60.69%(P<0.05);Western blot 结果显示 survivin shRNA 瞬时转染和稳定转染细胞survivin 蛋白表达水平亦显著降低,抑制率分别为63.41% 和60.18%(P<0.05)。流式细胞术检测瞬时转染和稳定转染细胞的凋亡率显著增加,分别为(22.41±2.83)% 和(20.73±2.56)%(与对照组比较,P均<0.05),细胞倍增时间显著延长。生长曲线显示稳定转染细胞的生长显著减慢。结论shRNA 重组质粒介导的 RNA 干扰能明显抑制 Jurkat 细胞 survivin 基因 mRNA 和蛋白产物的表达,诱导细胞凋亡和生长抑制。     

外源性线粒体融合素基因-2转染对肝癌细胞体外生物学行为的影响

目的 研究外源性线粒体融合素基因-2(mitofusin-2 gene，mfn2)对肝癌细胞株HepG2体外生物学行为的影响。 方法 基因重组构建并鉴定mfn2真核表达质粒pEGFPmfn2，用脂质体将质粒转染培养人肝癌细胞株HepG2，经G418筛选阳性细胞克隆，逆转录-聚合酶链反应检测转染后细胞mfn2 mRNA的表达水平；Western-blot检测线粒体融合蛋白的表达，四甲基偶氮唑蓝法(MTT)检测mfn2对HepG2细胞增殖的影响，Annnexin-V/PI双标流式细胞术检测转染细胞凋亡的变化。结果 重组真核表达质粒pEGFPmfn2经限制性内切酶双酶切，电泳后显示约约2.3kp的mfn2片段和4.7kb的pEGFP-N2¬载体片段。RT-PCR及Western-blot显示转染组有mfn2基因mRNA及其蛋白表达。MTT实验提示转染mfn2基因后，HepG2细胞增殖受到抑制；流式细胞分析显示转染组与转染空质粒组和空白对照组相比可促进细胞凋亡。结论 成功构建了pEGFPmfn2真核表达质粒，外源性mfn2基因可抑制肝癌细胞的增殖，并可诱导肝癌细胞凋亡。     

新型hGLP-1基因对β-TC-6胰岛瘤细胞凋亡的影响

目的探讨新型人胰高血糖素样肽-1(hGLP-1)类似物基因(2×Val2-hGLP-1)对四氧嘧啶(AXN)诱导凋亡的β-TC-6胰岛瘤细胞株的影响。方法脂质体介导重组质粒pIRES2-EGFP/2×Val2-hGLP-1转染β-TC-6胰岛瘤细胞,荧光显微镜观察绿色荧光蛋白(GFP),酶联免疫吸附法(ELISA)检测目的蛋白表达;以AXN诱导细胞凋亡后观察细胞形态,Hoechst染色及四甲基偶氮唑盐光吸收法(WST-1)检测目的基因表达对细胞凋亡的影响。结果荧光显微镜观察到GFP表达;ELISA显示重组质粒转染组细胞培养液吸光度值为(2.53±0.05),高于其他研究组(P<0.05);细胞形态观察及Hoechst染色显示,AXN可诱导β-TC-6细胞凋亡;WST-1显示转染重组质粒的细胞组存活率为66.23%,高于其他研究组(P<0.05);Hoechst染色显示,经重组质粒转染的细胞凋亡减少。结论 2×Val2-hGLP-1的表达对胰岛β细胞凋亡具有一定抑制作用,为糖尿病基因治疗提供了相关试验研究基础。     

5-aza-dC、TSA联合MeCP2的RNA干扰质粒对人肺腺癌细胞株A549生物学行为的影响

目的探讨DNA甲基化转移酶抑制剂5-氮-2'-脱氧胞(5-aza-dC)、组蛋白去乙酰化酶抑制剂曲古抑菌素A(TSA)和甲基化结合蛋白MeCP2的RNA干扰载体Psilencer-2.1-U6-MeCP2对人肺腺癌细胞株A549生物学行为的影响。方法人肺腺癌细胞株A549细胞用含10%胎牛血清的DMEM培养液培养。利用阳离子脂质体将Psilencer-2.1-U6-MeCP2重组质粒转染到A549细胞中。用5μmol/L的5-aza-dC和(或)300nmol/L的TSA处理A549细胞和稳定转染的A549细胞。Annexin V/PI双染法测定各组细胞培养72h后的凋亡情况;应用RT-PCR检测各组细胞培养72h后C/EBPαmRNA的表达。结果 (1)Psilencer-2.1-U6-MeCP2重组质粒能够稳定转染到A549细胞中;(2)5-aza-dC、TSA和Psilencer-2.1-U6-MeCP2重组质粒均能够上调A549细胞C/EBPα基因mRNA的表达、诱导细胞凋亡,且两两联合处理组A549细胞中C/EBPαmRNA的表达水平及凋亡率均明显高于单处理组(均P0.01)、细胞C/EBPαmRNA的相对表达量及凋亡率在三者联合处理组与两两联合处理组组间比较,差别均有统计学意义(P0.05);(3)5-aza-dC组、TSA组和Psilencer-2.1-U6-MeCP2重组质粒组在诱导细胞凋亡、增强C/EBPαmRNA的表达方面比较,差别均无统计学意义。结论与单用5-aza-dC、TSA、Psilencer-2.1-U6-MeCP2重组质粒相比,联合运用能够更好的诱导人肺腺癌A549细胞凋亡,增强C/EBPα基因mRNA的表达,且三者联合运用的效果最显著,这将为去甲基化多药联合治疗肺癌提供理论依据。     

血管内皮细胞生长因子受体KDR基因靶向RNA干扰质粒的构建

目的:应用RNA干扰技术设计构建针对血管内皮细胞生长因子受体KDR的小干扰RNA,并观察脂质体转染肺癌细胞A549后的干扰效果。方法:实验于2005-03/2006-01在沈阳医学院生物化学及分子生物学教研室完成。①设计针对KDR编码区有短发夹结构的3条mRNA序列,经退火成互补双链,克隆到pGCsi.H1/neo/GFP载体中构建3个重组质粒,分别命名为KDR-siRNA1、KDR-siRNA2和KDR-siRNA3。②设立5组:小干扰RNA组,分别转染KDR-siRNA1、KDR-siRNA2和KDR-siRNA3;阳性对照组,转染pGCsi.H1/neo/siGFP,该质粒载体中的插入序列为针对绿色荧光蛋白的小干扰RNA,不干扰待研究的内源性基因;阴性对照组,转染pGCsi.H1/neo/GFP/NON,该载体为不干扰任何内源性基因的小干扰RNA;空白对照组,转染pGCsi.H1/neo/GFP空载体;正常对照组,不进行任何转染。③对重组质粒进行酶切鉴定、DNA测序分析;脂质体法转染质粒至肺癌A549细胞株后,实时定量PCR检测KDRmRNA的水平变化;细胞计数法绘制细胞生长曲线。结果:①小干扰RNA表达载体的鉴定:KDR-siRNA1、KDR-siRNA2和KDR-siRNA3表达载体用限制性内切酶NdeⅠ和SmaⅠ进行单酶切后,均产生约713bp、5480bp和2403bp、3790bp两个片段,与预期结果相同。测序结果与设计的编码相应短发夹状KDR-小干扰RNA的寡核苷酸序列一致,证明KDR-小干扰RNA真核表达载体构建成功。②KDR-小干扰RNA对A549细胞中KDRmRNA水平的影响:与阳性对照组、阴性对照组、空白对照组和正常对照组的A549细胞相比,KDR-siRNA1,2,3表达载体转染后的A549细胞KDR基因表达水平均明显受到抑制,抑制率分别为64%、81%和72%,其中以KDR-siRNA2抑制作用最为明显。③KDR-小干扰RNA对A549细胞生长的影响:阳性对照组、阴性对照组、空白对照组、正常对照组的A549细胞生长趋势较为一致,且生长速度均明显高于转染3种KDR-小干扰RNA表达载体的A549细胞,从接种第2天开始差异有显著性意义(t=15.29～17.65,P均<0.01)。结论:血管内皮细胞生长因子受体KDR靶向RNA干扰重组质粒构建成功,该载体能有效抑制肺癌A549细胞KDR基因表达与细胞增殖。     

Autocrine stimulation of VEGFR-2 activates human leukemic cell growth and migration

Emerging data suggest that VEGF receptors are expressed by endothelial cells as well as hematopoietic stem cells. Therefore, we hypothesized that functional VEGF receptors may also be expressed in malignant counterparts of hematopoietic stem cells such as leukemias. We demonstrate that certain leukemias not only produce VEGF but also express functional VEGFR-2 in vivo and in vitro, resulting in the generation of an autocrine loop that may support leukemic cell survival and proliferation. Approximately 50% of freshly isolated leukemias expressed mRNA and protein for VEGFR-2. VEGF(165) induced phosphorylation of VEGFR-2 and increased proliferation of leukemic cells, demonstrating these receptors were functional. VEGF(165) also induced the expression of MMP-9 by leukemic cells and promoted their migration through reconstituted basement membrane. The neutralizing mAb IMC-1C11, specific to human VEGFR-2, inhibited leukemic cell survival in vitro and blocked VEGF(165)-mediated proliferation of leukemic cells and VEGF-induced leukemic cell migration. Xenotransplantation of primary leukemias and leukemic cell lines into immunocompromised nonobese diabetic mice resulted in significant elevation of human, but not murine, VEGF in plasma and death of inoculated mice within 3 weeks. Injection of IMC-1C11 inhibited proliferation of xenotransplanted human leukemias and significantly increased the survival of inoculated mice. Interruption of signaling by VEGFRs, particularly VEGFR-2, may provide a novel strategy for inhibiting leukemic cell proliferation.     

塞来昔布对肺癌细胞的增殖抑制作用研究

目的研究非甾体类抗炎药塞来昔布对肺癌细胞的体外抑制作用。方法选用肺癌A549细胞系体外培养,在不同塞来昔布浓度作用下,MTT法检测肺癌细胞的增殖抑制,流式细胞仪测定肺癌细胞周期分布以及RTPCR法观察肺癌细胞血管内皮生长因子mRNA(VEGFmRNA)的表达水平。结果塞来昔布对肺癌细胞增殖有抑制作用,且呈剂量依赖关系,IC50为50μmol/L;塞来昔布可将肺癌细胞阻滞在G0/G1期,有剂量依赖性;RTPCR法中,对照组肺癌细胞VEGFmRNA的表达水平高于药物组(P<0.05),药物组中肺癌细胞VEGFmRNA表达水平与塞来昔布浓度相关。结论塞来昔布对肺癌细胞有明显的体外增殖抑制作用,与VEGFmRNA的表达下调和阻滞细胞周期在G/G期有关。     

Quantitative analysis of gene expressions of vascular endothelial growth factor-related factors and their receptors in renal cell carcinoma

Vascular endothelial growth factor (VEGF)-related factors are believed to regulate angiogenesis, an essential event in the growth of solid tumors. In this study, we investigated the expression of VEGF-related factor genes (VEGF, VEGF-B, and VEGF-C) and their receptor genes (VEGFR-1 and VEGFR-2) in renal cell carcinoma (RCC). There were significant differences in the expression level of VEGF, VEGFR-1 and VEGFR-2 between RCC and the corresponding normal renal tissue. The expression level of VEGF in the tumor tissue significantly correlated with those of VEGFR-1 and VEGFR-2. Expression levels VEGF-B and VEGF-C genes were not significantly different between RCC and normal renal tissue. A moderate to high protein expression for VEGF, VEGFR-1, and VEGFR-2 was observed in both the tumor cells and the endothelial cells, whereas the protein expression was low for VEGF-B and VEGF-C. The present results suggested that VEGF and its receptors VEGFR-1 and VEGFR-2 cooperates to play a crucial role in the angiogenesis of RCC, while VEGF-B and VEGFR-C may not. Furthermore, since VEGFR-1 and VEGFR-2 proteins were expressed in the tumor cells as well as in the endothelial cells, these receptors may also be responsible for the progression of RCC.     

ShRNA靶向沉默VEGFR1基因对U937细胞增殖、迁移和凋亡的影响

目的 探讨慢病毒载体介导shRNA(short harpin RNA,siRNA前体)靶向沉默血管内皮生长因子受体1(VEGFR-1)基因对U937细胞增殖、迁移和凋亡的影响.方法 构建针对VEGFR-1基因干扰序列和无关序列的shRNA慢病毒载体,与慢病毒包装质粒通过脂质体转染293T细胞,包装产生的病毒液感染U937细胞(U937-shVEGFR-1 KD组).采用实时荧光定量PCR、Western blot法检测RNA干扰对U937细胞VEGFR-1 mRNA和蛋白表达的影响;ELISA法检测细胞培养上清液VEGF表达水平的变化;CCK-8法检测常规培养条件下和不同浓度阿糖胞苷(Ara-C)作用下细胞增殖率和抑制率变化;流式细胞术检测经Ara-C作用后细胞凋亡率变化;Transwell小室检测不同条件下细胞迁移数量的变化.结果 成功构建VEGFR-1基因shRNA慢病毒载体,转染U937细胞后,U937-shVEGFR-1 KD组细胞VEGFR-1 mRNA和蛋白表达均显著下降;细胞培养上清液VEGF表达水平明显下降,细胞增殖速度减慢;Ara-C作用下,U937-shVEGFR-1 KD组细胞增殖抑制率及凋亡率较U937无关序列shRNA阴性对照(NC)组和U937空白对照(CON)组细胞明显增高.无药物及VEGF作用下,U937-shVEGFR-1 KD组细胞迁移数量均低于U937 NC组和U937 CON组细胞;Bevacizumab作用下,U937 NC组和U937 CON组细胞迁移数量降低,而U937-shVEGFR-1 KD组细胞迁移数量无明显变化.结论 慢病毒载体介导的shRNA干扰VEGFR-1基因可有效抑制U937细胞增殖、迁移,并能够增强U937细胞对Ara-C的敏感性.     

Microtumor growth initiates angiogenic sprouting with simultaneous expression of VEGF, VEGF receptor-2, and angiopoietin-2

Tumors have been thought to initiate as avascular aggregates of malignant cells that only later induce vascularization. Recently, this classic concept of tumor angiogenesis has been challenged by the suggestion that tumor cells grow by co-opting preexisting host vessels and thus initiate as well-vascularized tumors without triggering angiogenesis. To discriminate between these two mechanisms, we have used intravital epifluorescence microscopy and multi-photon laser scanning confocal microscopy to visualize C6 microglioma vascularization and tumor cell behavior. To address the mechanisms underlying tumor initiation, we assessed the expression of VEGF, VEGF receptor-2 (VEGFR-2), and angiopoietin-2 (Ang-2), as well as endothelial cell proliferation. We show that multicellular aggregates (< 1 mm(3)) initiate vascular growth by angiogenic sprouting via the simultaneous expression of VEGFR-2 and Ang-2 by host and tumor endothelium. Host blood vessels are not co-opted by tumor cells but rather are used as trails for tumor cell invasion of the host tissue. Our data further suggest that the established microvasculature of growing tumors is characterized by a continuous vascular remodeling, putatively mediated by the expression of VEGF and Ang-2. The results of this study suggest a new concept of vascular tumor initiation that may have important implications for the clinical application of antiangiogenic strategies.     

硼替佐米对急性单核细胞白血病细胞株SHI-1诱导凋亡作用及其对Bcl2112、Bcl-2和Bax基因表达影响

本研究探讨蛋白酶抑制剂硼替佐米对急性单核细胞白血病细胞株SHI-1增殖和凋亡的影响及Bcl2112、Bcl-2和Bax基因在其中的作用。用MTT比色法观察硼替佐米对SHI-1细胞的生长抑制作用，用Annexin—V标记、线粒体跨膜电位（△ψm）和DNA凝胶电泳分析细胞凋亡，用RT—PCR方法检测0、6，12和24小时Bcl2112、Bcl-2和Bax基因表达。结果表明，硼替佐米呈时间和剂量依赖性抑制SHI-1细胞生长，24小时和48小时半数抑制浓度分别为54．13nmol／L和5．45nmol／L；硼替佐米能够诱导SHI-1细胞凋亡，在6小时Annexin-V阳性细胞就开始增高并呈时间依赖性，ACm减低，形态学可见明显细胞核凝聚、固缩和碎裂，DNA凝胶电泳显示DNA片段化；RT-PCR显示，Bcl2112表达增高，Bcl-2表达减低，但Bax表达无明显改变。结论：硼替佐米抑制SHI-1细胞增殖，并可能通过上调Bcl2112基因和下调Bcl-2基因，使线粒体膜电位下降而促使SHI-1细胞发生凋亡。     

Activation of nonsteroidal anti-inflammatory drug-activated gene-1 via extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase revealed a isochaihulactone-triggered apoptotic pathway in human lung cancer A549 cells

The novel lignan isochaihulactone inhibits cell proliferation and is an effective inducer of apoptosis in a variety of carcinoma cell lines. To determine the mechanisms underlying these effects, we examined isochaihulactone-induced changes in gene expression using oligodeoxynucleotide-based microarray screening of a human lung carcinoma cell line, A549. Isochaihulactone-inducible genes included the early growth response gene-1 (EGR-1) and nonsteroidal anti-inflammatory drug-activated gene (NAG-1). Isochaihulactone increased EGR-1 and then NAG-1 mRNA and protein expression. Pure isochaihulactone induced phosphorylation of extracellular signal-regulated kinase (ERK) 1/2. Isochaihulactone-induced increases in EGR-1 and NAG-1 expression were reduced by the mitogen-activated protein kinase kinase 1/2 inhibitor 2'-amino-3'-methoxyflavone (PD98059), and this effect was not blocked by the phosphatidylinositol 3-kinase/protein kinase B pathway inhibitor 2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride (LY294002). Inhibition of isochaihulactone-induced NAG-1 expression by EGR-1 small interfering RNA blocked isochaihulactone-induced apoptosis in A549 cells, suggesting that induction of EGR-1 expression decreases survival of A549 cells. RNA interference using double-stranded RNA specific for NAG-1 also inhibited isochaihulactone-induced apoptosis, and cells transfected to increased NAG-1 expression had a greater apoptotic response to isochaihulactone and reduced colony formation efficiency. In addition, treatment of nude mice with isochaihulactone increased the in vivo NAG-1 expression as examined by immunohistochemistry from tumor biopsy. Isochaihulactone treatment increased the luciferase activity of NAG-1 in A549 cells transfected with the NAG-1 promoter construct. This induction increased expression of NAG-1 that was p53-independent and Sp1-dependent. Our findings suggest that NAG-1 expression is up-regulated by isochaihulactone through an ERK-dependent pathway involving the activation of EGR-1.     

Inhibition of VEGF receptors causes lung cell apoptosis and emphysema

Pulmonary emphysema, a significant global health problem, is characterized by a loss of alveolar structures. Because VEGF is a trophic factor required for the survival of endothelial cells and is abundantly expressed in the lung, we hypothesized that chronic blockade of VEGF receptors could induce alveolar cell apoptosis and emphysema. Chronic treatment of rats with the VEGF receptor blocker SU5416 led to enlargement of the air spaces, indicative of emphysema. The VEGF receptor inhibitor SU5416 induced alveolar septal cell apoptosis but did not inhibit lung cell proliferation. Viewed by angiography, SU5416-treated rat lungs showed a pruning of the pulmonary arterial tree, although we observed no lung infiltration by inflammatory cells or fibrosis. SU5416 treatment led to a decrease in lung expression of VEGF receptor 2 (VEGFR-2), phosphorylated VEGFR-2, and Akt-1 in the complex with VEGFR-2. Treatment with the caspase inhibitor Z-Asp-CH(2)-DCB prevented SU5416-induced septal cell apoptosis and emphysema development. These findings suggest that VEGF receptor signaling is required for maintenance of the alveolar structures and, further, that alveolar septal cell apoptosis contributes to the pathogenesis of emphysema.     

Low‐level EFCAB1 promoted progress by upregulated DNMT3B and could be as a potential biomarker in lung adenocarcinoma

BackgroundLung adenocarcinoma (LUAD) incidence is on the rise. We found that EFCAB1 (EF‐Hand Calcium Binding Domain 1) was significantly downregulated in LUAD tissues, but the mechanism of EFCAB1 is unknown.MethodsOne hundred and two LUAD samples and corresponding NT samples were prospectively collected from patients at the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China, from August 2018 to August 2021.EFCAB1 expression was estimated in LUAD cells and tissues by qPCR. In‐vitro cytology assays were used to detect the role of EFCAB1 in LUAD cells.ResultsEFCAB1 expression level of LUAD was significantly lower than it''s adjacent cancer tissues and that of LUAD with big tumor size (>2 cm) was significantly lower than that of small tumor size (≤2 cm) group. It shown that expression levels of EFCAB1 from A549, HCC827, PC9 were lowly expressed. The cell migration, invasion, colony formation, proliferation ability of EFCAB1 OE A549, PC9 were lower than that of EFCAB1 OE A549, PC9 NC group, while the apoptotic cells percentage of the EFCAB1 OE A549, PC9 group were significantly increased. We found that DNMT1 mRNA expression level of PC9 was higher than that of BEAS‐2B, while these of A549, HCC827 decreased. Compared with BEAS‐2B, DNMT3A mRNA expression level of PC9 increased. DNMT3B mRNA expression level of PC9, HCC827 were higher than these of BEAS‐2B.ConclusionThe EFCAB1 mRNA in LUAD patients and cell lines were downregulated; EFCAB1 overexpression inhibited cell proliferation, migration, invasion, while promoted apoptosis. EFCAB1 was expected to become a biomarker of LUAD.     

Vascular endothelial growth factor stimulates skeletal muscle regeneration in vivo.

Vascular endothelial growth factor (VEGF) is a major regulator of blood vessel formation during development and in the adult organism. Recent evidence indicates that this factor also plays an important role in sustaining the proliferation and differentiation of different cell types, including progenitor cells of different tissues, including bone marrow, bone, and the central nervous system. Here we show that the delivery of the 165-aa isoform of VEGF-A cDNA using an adeno-associated virus (AAV) vector exerts a powerful effect on skeletal muscle regeneration in vivo. Following ischemia-, glycerol-, or cardiotoxin-induced damage in mouse skeletal muscle, the delivery of AAV-VEGF markedly improved muscle fiber reconstitution with a dose-dependent effect. The expression of both VEGF receptor-1 (VEGFR-1) and VEGFR-2 was upregulated both in the satellite cells of the damaged muscles and during myotube formation in vitro; the VEGF effect was mediated by the VEGFR-2, since the transfer of PlGF, a VEGF family member interacting with the VEGFR-1, was ineffective. These results are consistent with the observation that VEGF promotes the growth of myogenic fibers and protects the myogenic cells from apoptosis in vitro and prompt a therapeutic use for VEGF gene transfer in a variety of muscular disorders.