miR-98-5p通过降低STAT3水平促进A549细胞凋亡并抑制其侵袭和迁移

目的研究微小RNA-98-5p (miR-98-5p)对肺癌A549细胞生长的影响及机制。方法实时定量PCR检测正常支气管上皮细胞HBE细胞和非小细胞肺癌来源的细胞(A549细胞、H1299细胞和H460细胞)中miR-98-5p的水平,后续选择miR-98-5p水平最低的A549细胞进行实验。CCK-8法检测miR-98-5p模拟物(miR-98-5p mimic)及miR-98-5p抑制物(anti-miR-98-5p)对A549细胞增殖的影响,流式细胞术检测miR-98-5p对A549细胞的凋亡的影响,商品化试剂盒检测胱天蛋白酶3(caspase-3)和caspase-9的活性,TranswellTM小室实验检测miR-98-5p对A549细胞侵袭和迁移的影响,实时定量PCR检测miR-98-5p对A549细胞信号转导子与转录激活子3(STAT3) mRNA水平的影响,Western blot法检测miR-98-5p对A549细胞STAT3蛋白水平的影响。结果与HBE细胞相比,A549细胞、H1299细胞和H460细胞中miR-98-5p的表达水平降低。上调A549细胞miR-98-5p水平后,能够显著抑制A549细胞的增殖、促进细胞凋亡,并抑制细胞侵袭和迁移,同时,miR-98-5p可以显著降低STAT3的表达。结论 miR-98-5p通过降低STAT3水平促进A549细胞凋亡,并抑制其增殖、侵袭和迁移。     

lncRNA TTN-AS1通过miR-519d-3p/MMP2调控肺腺癌A549细胞的活力和侵袭

目的:观察肺腺癌组织中长链非编码RNA(lncRNA)TTN反义RNA 1(TTN-AS1)的表达情况,以及沉默TTN-AS1表达对肺腺癌A549细胞活力和侵袭的影响。方法:RT-qPCR法检测32例肺腺癌和癌旁正常组织中TTN-AS1、微小RNA-519d-3p(miR-519d-3p)和基质金属蛋白酶2(MMP2)的mRNA表达水平。将未转染的A549细胞设为空白组,转染si-NC的为si-NC对照组,转染沉默TTN-AS1表达的siRNA为si-lncRNA组(n=5),采用CCK8和Transwell方法检测沉默TTN-AS1表达对A549细胞活力和侵袭的影响。使用双萤光素酶报告基因实验、RNA免疫沉淀实验、RT-qPCR和Western blot测定TTN-AS1对miR-519d-3p和miR-519d-3p对MMP2的靶向调控作用。结果:32例肺腺癌组织中TTN-AS1的表达水平显著高于对应癌旁正常组织(P0.05)。沉默A549细胞中TTN-AS1的表达可抑制细胞的活力和侵袭。TTN-AS1可通过海绵吸附的方式负调控miR-519d-3p的表达;MMP2是miR-519d-3p的靶基因,受其负调控。过表达MMP2可部分逆转沉默TTN-AS1和过表达miR-519d-3p对A549细胞侵袭的抑制作用。结论:肺腺癌组织中lncRNA TTN-AS1呈现高表达情况,它可能通过miR-519d-3p/MMP2调控肺腺癌A549细胞的活力和侵袭能力。     

miR-99a-5p靶向SLC44A1对肺癌细胞系A549增殖的影响

目的 探讨miR-99a-5p通过靶点SLC44A1对肺腺癌(LUAD)细胞系增殖的抑制作用及可能机制.方法 从基因表达综合数据库(GEO)中检索并筛选GPL18058的microRNA(miRNA)表达阵列,筛选出肺癌与正常组织差异表达的miR-99a-5p后,通过Target Scan Human数据库预测其下游靶点SLC44A1,并利用UALCAN分析SLC44A1在肺癌组织中的表达情况和LUAD预后关系.利用实时荧光定量PCR(qRT-PCR)检测肺腺癌细胞系miR-99a-5p和SLC44A1的表达水平.在A549细胞中转染miR-99a-5p模拟物,通过CCK-8试验、克隆形成实验检测A549的增殖情况;qRT-PCR和Western blot检测SLC44A1的表达.在A549细胞中过表达SLC44A1,评估其对肺癌调节中的miR-99a-5p的选择性作用.结果 在LUAD组织和细胞系中,miR-99a-5p的表达异常下调,过度异位表达的miR-99a-5p抑制A549细胞的增殖(P＜0.05).在LUAD组织和细胞系的基因和蛋白质水平上,miR-99a-5p负性调控SLC44A1(P＜0.05).SLC44A1过度表达有效地逆转了miR-99a-5p在体外对A549细胞增殖的抑制作用.SLC44A1的低表达有利于患者生存率的提高(P＜0.05).结论 miR-99a-5p抑制LUAD中A549细胞系的增殖,并通过负性调控SLC44A1发挥作用.     

miR-24对肺癌A549细胞化疗敏感性的影响

目的:探究微小RNA(miR)-24对肺癌细胞A549化疗敏感性的影响及可能的作用机制。方法:Real-time PCR实验检测肺腺癌细胞系A549及肺腺癌耐药细胞株A549/DDP中miR-24的表达情况。转染miR-24抑制序列(miR-24 inhibitor)下调A549/DDP细胞中的miR-24后,采用CCK-8法检测细胞活力,流式细胞术检测细胞凋亡,Western blot检测Bcl-2、Bax、cleaved caspase-3、cleaved caspase-9、细胞色素C(Cyt C)、磷酸化细胞外信号调节激酶(p-ERK)和P53的蛋白水平。双荧光素酶报告基因实验预测及验证miR-24可能的靶基因。结果:耐药细胞株A549/DDP中miR-24的表达水平明显高于A549细胞(P0.05)。miR-24 inhibitor可诱导肺腺癌耐药细胞株A549/DDP的凋亡,增加细胞对顺铂的敏感性;此外还可下调Bcl-2/Bax比值,同时上调P53、p-ERK、cleaved caspase-9、cleaved caspase-3及Cyt C的蛋白水平。而应用ERK特异性抑制剂U0126可部分恢复miR-24 inhibitor转染的细胞活力。生物信息学分析显示p53是miR-24的可能作用靶点基因,在A549/DDP细胞中共转染miR-24 inhibitor和P53 siRNA可部分逆转miR-24 inhibitor对细胞活力的影响。结论:下调肺腺癌耐药细胞株A549/DDP中miR-24的表达可增加细胞对顺铂的敏感性,其机制可能与靶向p53基因同时激活ERK/P53信号通路后促进细胞经线粒体途径的凋亡有关。     

miR-520c-3p靶向MEX3A调控肺癌细胞增殖、凋亡的分子机制

为研究miR-520c-3p对肺癌细胞增殖和凋亡的影响及其潜在的作用机制,用实时定量RT-PCR检测肺癌细胞H1299、NCI-H460、A549和正常肺上皮细胞BEAS-2B中miR-520c-3p和MEX3同源物A(MEX3 homolog A,MEX3A)的表达水平。将miR-NC、miR-520c-3p、si-NC、si-MEX3A、anti-miR-NC、anti-miR-520c-3p转染至H1299细胞后,用细胞计数试剂盒8(cell counting kit 8,CCK-8)法检测细胞增殖,流式细胞术检测细胞凋亡,Western blotting检测蛋白表达,双荧光素酶报告基因检测实验检测细胞的荧光活性。结果显示,与正常肺上皮细胞BEAS-2B比较,肺癌细胞H1299、NCI-H460、A549中miR-520c-3p的表达水平均显著降低(P0.05),MEX3A mRNA和蛋白的表达水平显著升高(P0.05)。miR-520c-3p过表达、MEX3A抑制表达均可抑制H1299细胞的增殖活力,促进细胞凋亡;miR-520c-3p过表达抑制CyclinD1、Bcl-2蛋白的表达,促进p21、Cleaved Caspase-3、Bax蛋白的表达;MEX3A抑制表达抑制CyclinD1、Bcl-2蛋白的表达,促进p21、Bax蛋白的表达。miR-520c-3p可靶向调控MEX3A的表达;MEX3A过表达逆转了miR-520c-3p过表达对肺癌细胞H1299的增殖抑制和凋亡促进作用。提示miR-520c-3p可抑制肺癌细胞H1299的增殖,促进其凋亡,其机制可能与靶向MEX3A有关,这将为肺癌的预防和治疗提供新靶点。     

miR-148a-3p靶向DNMT1表达调控肺癌细胞A549增殖、迁移和侵袭作用研究

目的 探讨miR-148a-3p靶向DNMT1表达调控肺癌细胞A549增殖、迁移和侵袭的机制.方法 设肺癌细胞A549组、miR-NC组、miR-148-3p mimics组、miR-148-3p inhibitor组,以上各组细胞每孔设6个平行样,培养72 h.采用MTT法检测细胞活力,甲基紫染色测定细胞单克隆形成数...     

雷公藤红素通过miR-17-5p和miR-155-5p靶向抑制cyclin D1阻滞A549细胞周期的研究

目的:研究雷公藤红素对人肺腺癌A549细胞周期的影响,并探讨其机制。方法:梯度浓度的雷公藤红素作用于人肺腺癌A549细胞后,MTT法检测细胞活力的变化,流式细胞术检测细胞凋亡,筛选出雷公藤红素的半数致死浓度;而后用半数致死浓度的雷公藤红素作用于A549细胞,流式细胞术检测细胞周期的变化,Western blot检测细胞周期蛋白D1(cyclin D1)的表达水平; real-time PCR检测微小RNA(miR)-17-5p和miR-155-5p表达的变化;生物学信息软件预测miR-17-5p和miR-155-5p与cyclin D1的相关性;将miR-17-5p mimics和miR-155-5p mimics以及各自的突变体mutant-miR-17-5p和mutant-miR-155-5p分别与pcDNA-GFP-cyclin D1-3'UTR共转染至A549细胞后荧光显微镜和流式细胞术检测GFP表达;最后将miR-17-5p mimics和miR-155-5p mimics转染至A549细胞后,real-time PCR检测miR-17-5p和miR-155-5p表达水平的变化,Western blot检测cyclin D1的表达水平。结果:随雷公藤红素作用浓度的增大,A549细胞的活力抑制率逐渐增高,细胞凋亡率逐渐增加(P0.01),提示雷公藤红素可以有效抑制A549细胞的生长,诱导其凋亡,其中3μmol/L最接近半数致死浓度;应用该浓度雷公藤红素作用于A549细胞后,细胞被阻滞在G_1期,cyclin D1表达水平显著降低(P0.01),miR-17-5p和miR-155-5p的表达水平显著升高(P0.01)。生物学信息软件预测提示cyclin D1的3'UTR存在miR-17-5p和miR-155-5p的结合位点。GFP检测结果显示,miR-17-5p mimics/miR-155-5p mimics和pcDNA-GFP-cyclin D1-3'UTR共转染至A549细胞后,GFP的表达水平降低(P0.05),提示miR-17-5p和miR-155-5p能直接靶向cyclin D1的3'UTR发挥作用;将miR-17-5pmimics/miR-155-5pmimics转染A549细胞后,miR-17-5p/miR-155-5p的表达水平显著升高(P0.01),cyclin D1表达水平均显著降低(P0.01)。结论:雷公藤红素可阻滞A549细胞于G_1期,进一步导致了细胞生长抑制和凋亡增加,其机制可能是通过上调miR-17-5p和miR-155-5p的表达而导致了cyclin D1的靶向抑制。本研究为雷公藤红素作为临床非小细胞肺癌的治疗药物提供新的理论依据。     

circDCUN1D4调节miR-18a-5p/FBP1轴对肺癌细胞增殖、凋亡和免疫逃逸的影响

目的 探讨环状RNA(circRNA)DCUN1D4调节微小RNA(miR)-18a-5p/果糖-1,6-二磷酸酶1(FBP1)轴对肺癌细胞增殖、凋亡和免疫逃逸的影响。方法 选取人肺癌细胞系（H1975、H1650、A549、SPCA-1）和人正常肺表皮细胞（HPL-1）,qRT-PCR检测各种细胞中circDCUN1D4、miR-18a-5p、FBP1 mRNA表达水平。取对数生长期的A549细胞并分为空白组、circDCUN1D4过表达质粒（circDCUN1D4）组、过表达质粒阴性对照（NC）组、circDCUN1D4+miR-18a-5p模拟物阴性对照（circDCUN1D4+mimics NC）组、circDCUN1D4+miR-18a-5p模拟物（circDCUN1D4+miR-18a-5p mimics）组。CCK-8法检测各组A549细胞活力,流式细胞术检测各组A549细胞凋亡水平,qRT-PCR检测各组A549细胞中circDCUN1D4、miR-18a-5p、FBP1 mRNA表达水平,Western blot检测各组A549细胞中FBP1、caspase-3、Ki...     

环状RNA circ0004771对肺腺癌细胞A549的增殖、迁移与侵袭的影响

目的 探讨环状RNA circ0004771对肺腺癌细胞增殖、迁移与侵袭的影响及其机制。方法 培养肺腺癌A549细胞,分为阴性对照（si-NC）组及circ0004771小干扰RNA（siRNA）组（si-circ0004771组）,将si-NC和circ0004771 siRNA分别转染入相应组A549细胞中。si-NC组和si-circ0004771组细胞转染后,通过实时荧光定量聚合酶链反应检测2组细胞circ0004771、miR-339-5p的表达水平,通过细胞计数试剂盒法检测细胞活力,通过EdU实验检测2组细胞增殖能力,通过Transwell小室实验检测2组细胞迁移和侵袭能力。结果 si-NC组和si-circ0004771组A549细胞circ0004771基因的相对表达水平分别为3.07±0.07和0.68±0.04,miR-339-5p相对表达水平分别为1.14±0.13和2.33±0.07,差异均有统计学意义（t=51.34、13.96,P值均<0.001）。si-NC组和si-circ0004771组A549细胞在培养前（0 h）和培养后24、48 h的吸光度值分别为0.21±0.02、0.35±0.05、0.65±0.04和0.21±0.01、0.33±0.04、0.59±0.05,差异均无统计学意义（P值均>0.05）;而在培养后72 h si-circ0004771组吸光度为0.92±0.15, 小于si-NC组的1.32±0.04,差异有统计学意义（t=4.46,P=0.011）。EdU实验中,si-circ0004771组细胞阳性率为47.97%±4.68%,低于si-NC组的58.61%±2.15%,差异有统计学意义（t=3.58,P=0.023）。转染后si-circ0004771组的细胞迁移率、侵袭率分别为52.27%±2.92%、55.33%±6.29%,均低于si-NC组的99.79%±4.23%、98.67%±5.72%,差异均有统计学意义（t=16.26、8.83,P值均<0.001）。结论 下调肺腺癌A549细胞circ0004771的表达水平,可以降低A549细胞的活力和增殖能力,可抑制A549细胞的迁移、侵袭能力,其作用机制可能与上调miR-339-5p的表达有关。     

miR-221-3p 靶向FGF14 调控肺腺癌细胞增殖、凋亡、迁移及侵袭的分子机制

目的：探讨miR-221-3p是否通过靶向FGF14调节肺腺癌细胞增殖、凋亡、迁移及侵袭的生物学行为。方法：采用qRT-PCR法与Western blot法分别检测人支气管上皮细胞（BEAS-2B）、人肺腺癌细胞（A549、A-427、PC-9）中miR-221-3p、FGF14的表达水平;分别将miR-inhibitor-NC、miR-221-3p inhibitor、si-NC、si-FGF14、miR-inhibitor-NC+si-NC、miR-221-3p inhibotor+si-NC、miR-221-3p inhibotor+si-FGF14转染至PC-9细胞;采用MTT实验检测细胞增殖;采用Transwell小室实验检测细胞迁移及侵袭;采用流式细胞术检测细胞凋亡率;双荧光素酶报告实验检测miR-221-3p、FGF14靶向关系;Western blot法检测CyclinD1、MMP-2、MMP-9、Bcl-2、P21、Bax蛋白表达量。结果：与BEAS-2B细胞比较,肺腺癌细胞A549、A-427、PC-9中miR-221-3p的表达水平升高（P<0.05）,FG...     

Lipid A and Anti-Lipid A

Lipid A in free form, in crude antigen preparations, and on Formalin-treated Escherichia coli and Salmonella minnesota R595 was employed in studies of its antigenic composition, immunogenicity, and availability on gram-negative bacteria. Analyses with immunodiffusion and crossed immunoelectrophoresis of isolated lipid A preparations revealed three components. Inhibition experiments with enzyme-linked immunosorbent assay showed that the lipid A structure was not exposed on the tested smooth or rough E. coli strains or on S. minnesota R595. In crude O antigen preparations from some of the strains, however, lipid A was available for reaction with antibodies. The inaccessibility of lipid A on the bacterial surface may explain the poor protective capacity of anti-lipid A antibodies against bacterial infections. An enzyme-linked immunosorbent assay was more sensitive for measuring anti-lipid A antibody activity than indirect hemolysis or indirect hemagglutination. With an enzyme-linked immunosorbent assay it was shown that in rabbits the immunogenicity of lipid A was approximately the same when coated on erythrocytes or, as is more commonly done, when lipid A-coated hydrolyzed bacteria were used. Some antisera from rabbits immunized with E. coli of different serotypes showed activity against lipid A, with a higher frequency for antisera from rabbits immunized with R mutants.     

Novel HLA-A locus alleles including A*01012, A*0306, A*0308, A*2616, A*2617, A*3009, A*3206, A*3403, A*3602 and A*6604

This paper describes 10 novel HLA-A alleles that have been characterized by DNA sequencing. Seven alleles, A*0308, A*2616, A*3009, A*3206, A*3403, A*3602 and A*6604 carry motifs observed in other HLA-A alleles, suggesting that gene conversion has created this diversity. The remaining three alleles, A*01012, A*0306 and A*2617, contain polymorphisms not previously found in any "classical" class I allele. All alleles were identified due to unexpected probe hybridization patterns during routine SSOP typing. Exons 2 and 3 of each allele were subsequently characterized by DNA sequencing.     

A meckelin-filamin A interaction mediates ciliogenesis

MKS3, encoding the transmembrane receptor meckelin, is mutated in Meckel-Gruber syndrome (MKS), an autosomal-recessive ciliopathy. Meckelin localizes to the primary cilium, basal body and elsewhere within the cell. Here, we found that the cytoplasmic domain of meckelin directly interacts with the actin-binding protein filamin A, potentially at the apical cell surface associated with the basal body. Mutations in FLNA, the gene for filamin A, cause periventricular heterotopias. We identified a single consanguineous patient with an MKS-like ciliopathy that presented with both MKS and cerebellar heterotopia, caused by an unusual in-frame deletion mutation in the meckelin C-terminus at the region of interaction with filamin A. We modelled this mutation and found it to abrogate the meckelin-filamin A interaction. Furthermore, we found that loss of filamin A by siRNA knockdown, in patient cells, and in tissues from Flna(Dilp2) null mouse embryos results in cellular phenotypes identical to those caused by meckelin loss, namely basal body positioning and ciliogenesis defects. In addition, morpholino knockdown of flna in zebrafish embryos significantly increases the frequency of dysmorphology and severity of ciliopathy developmental defects caused by mks3 knockdown. Our results suggest that meckelin forms a functional complex with filamin A that is disrupted in MKS and causes defects in neuronal migration and Wnt signalling. Furthermore, filamin A has a crucial role in the normal processes of ciliogenesis and basal body positioning. Concurrent with these processes, the meckelin-filamin A signalling axis may be a key regulator in maintaining correct, normal levels of Wnt signalling.     

Characteristics of transducing group A streptococcal bacteriophages A 5 and A 25

Summary The virulent, transducing, DNA-containing group A streptococcal bacteriophages A5 and A25 are 58 m in head size and have a flexible, noncontractile tail with a length of 180 m. The morphologic outline of the head is hexagonal. Treatment of the bacteriophages with potentially lethal ultraviolet radiation produced damages which were repairable by the Hcr⁺ streptococcal host strain K56, the host-cell reactivable sector being 0.9. These properties together with a demonstrable serological cross reaction show a close relationship between the two phage strains.