去泛素化酶JOSD2促进肝癌细胞的存活和转移

蛋白质泛素化是一种可逆的蛋白质翻译后修饰,在信号转导和蛋白质稳定性调控中发挥关键作用。去泛素化酶调控在许多种肿瘤中的作用机制尚不清楚。本文对63种去泛素化酶在肝细胞癌病人的生存和预后进行分析,发现去泛素化酶JOSD2(josephin domain containing 2)在肝细胞癌组织中表达显著高于癌旁(P<0.0001),且与总生存期相关(P<0.05)。JOSD2属于去泛素化酶MJD(machado josephin domain)亚家族成员,该家族其它成员与肝细胞癌发生无显著的相关性。对TCGA(The Cancer Genome Atlas)数据中JOSD2高表达样本和低表达样本的差异基因进行功能富集分析,显示JOSD2高表达样本中与细胞增殖相关通路显著富集(FDR<0.05)。在肝癌细胞系中过表达JOSD2,发现其能促进肝癌细胞的存活、迁移和侵袭(P<0.01)。综上所述,本文发现去泛素化酶JOSD2在肝细胞癌组织中高表达,高表达JOSD2的肝细胞癌病人总生存期显著降低(P=0.041),过表达JOSD2能促进肝癌细胞的存活和转移,提示JOSD2可能促进肝细胞癌的转移。     

慢病毒介导的RNA干扰ppGalNAc-T2基因表达抑制Jurkat细胞增殖和迁移

在肿瘤中,黏蛋白O-糖基化有着重要的生物学功能.控制O-糖基化起始合成的是多肽∶N-乙酰氨基半乳糖转移酶家族,研究该酶家族对阐明O-糖基化在肿瘤中的作用机制有重要的意义.探讨了靶向干扰ppGalNAc-T2基因表达对白血病Jurkat细胞株增殖及迁移的影响.首先合成ppGalNAc-T2特异shRNA干扰及对照序列,将其连接至慢病毒干扰载体YH1;重组载体经双酶切、测序鉴定正确后与包装质粒共转染293T细胞,获得的病毒颗粒经过滤纯化后感染Jurkat细胞,流式细胞分选仪进行细胞分选以获得ppGalNAc-T2基因稳定干扰表达的Jurkat细胞,然后使用RT-PCR和Western blot方法对各组别细胞中ppGalNAc-T2基因表达情况进行分析,以确定ppGalNAc-T2基因表达被有效干扰;进一步利用MTT实验和Transwell实验分析ppGalNAc-T2基因干扰表达对Jurkat细胞增殖及迁移的影响.结果表明,成功构建了靶向干扰ppGalNAc-T2基因表达的慢病毒载体,感染Jurkat细胞后能稳定干扰ppGalNAc-T2基因表达.MTT和Transwell实验研究发现,下调ppGalNAc-T2基因表达对Jurkat细胞增殖和迁移有抑制作用.     

重楼皂苷Ⅶ抑制肺癌H460细胞增殖和迁移能力研究

为研究重楼皂苷Ⅶ(polyphyllin Ⅶ)抑制人肺癌H460细胞增殖、迁移能力和诱导凋亡的作用和机制.本实验采用MTT法检测重楼皂苷Ⅶ处理后H460细胞生长抑制率,Hoechst 33258染色观察细胞形态,细胞集落形成实验考察细胞的增殖能力,划痕实验和Transwell小室实验研究H460细胞迁移和侵袭能力的改变...     

桑根酮C通过促进β-catenin的泛素化水平抑制胶质母细胞瘤的迁移侵袭能力

胶质母细胞瘤属于浸润性的恶性肿瘤,目前其化疗新药物的寻找和治疗仍待突破。桑根酮C (Sanggenon C, SC)来源于桑白皮,在多种癌症中发挥着抗肿瘤功效。本研究利用显微镜拍摄、transwell实验和免疫荧光实验验证了SC对胶质母细胞瘤的迁移侵袭能力的影响;基因富集、实时荧光定量PCR (real-time qPCR)以及泛素化实验用于阐明SC抑制胶质母细胞瘤迁移侵袭能力的分子机制。显微镜拍摄结果显示,对胶质母细胞瘤进行加药处理后细胞形态明显回缩,细胞迁移侵袭能力被削弱;Transwell实验和免疫荧光实验也验证了SC能抑制胶质母细胞瘤迁移侵袭能力的猜测;基因富集实验结果表明SC可能调控迁移侵袭相关基因的表达,并且影响Wnt/β-catenin信号通路的活性;Western blotting揭示了SC可调控β-catenin的泛素化水平,并且抑制β-catenin及其下游蛋白的表达;Real-time qPCR实验结果在转录水平上佐证Western blotting的结果。SC通过调控β-catenin的泛素化水平抑制胶质母细胞瘤的迁移侵袭能力,为胶质母细胞瘤的治疗提供了新的思路。     

CRISPR/Cas9沉默PAK5抑制乳腺癌细胞增殖并促进细胞衰老

p21活化激酶5(p21-activated kinase 5,PAK5)是一种丝氨酸/苏氨酸激酶,调节多种细胞进程,包括细胞骨架重构、细胞增殖、迁移和侵袭.研究表明,PAK5是调控乳腺癌进程的关键因子,但与衰老关系的研究尚未见报道.本研究利用CRISPR/Cas9慢病毒感染方法,构建敲低PAK5的人乳腺癌MDA-MB...     

FGFC1经PI3K/Akt/mTOR途径抑制非小细胞肺癌细胞增殖和迁移

FGFC1(Fungi fibrinolytic compound1)是从海洋长孢葡萄穗霉菌FG216中提取的一类具有良好生物活性的双吲哚化合物.然而,尚未有研究揭示其抗肿瘤活性.本研究探讨了 FGFC1对非小细胞肺癌细胞增殖、凋亡、迁移及侵袭能力的作用及其机制.首先,以不同浓度的FGFC1处理人非小细胞肺癌PC9细胞...     

MCM2通过抑制p53信号通路促进胆管癌细胞的增殖、迁移和侵袭

微小染色体维持蛋白2(minichromosome maintenance protein 2,MCM2)的异常表达与多种恶性肿瘤的发生发展密切相关.为探索MCM2基因对胆管癌细胞肿瘤生物学行为的影响及其潜在的作用机制,本研究首先采用cell counting kit-8(CCK-8)、平板细胞克隆形成、Transwe...     

抑制eIF3I蛋白的泛素化降解促进人宫颈癌细胞增殖

目的:研究eIF3I蛋白在细胞中的泛素化修饰,阐明其对人宫颈癌细胞系Hela增殖的影响.方法:通过点突变技术获得突变体K282R,与野生型eIF3I比较泛素化的水平,研究细胞内的泛素化修饰调控.经流式细胞仪分析细胞周期,研究野生型蛋白eIF3I和突变体K282R对Hela细胞的细胞周期影响.再从周期蛋白水平研究eIF3I对细胞增殖的调控作用.结果:突变体K282R比野生型eIF3I蛋白的外源表达量大.在Hela细胞中K282R突变体的泛素化水平低,抑制了该蛋白的泛素-蛋白酶体途径降解.过表达eIF3I能上调周期蛋白Cyclin D1的表达量,促进细胞进入由G1期进入S期.同时,泛素化程度低的突变体K282R具有较强的促进细胞增殖的作用.结论:抑制eIF3I的泛素-蛋白酶体途径降解能上调周期蛋白CyclinD1的表达,促进肿瘤细胞增殖,提示eIF3I在细胞增殖和肿瘤发生发展中发挥作用.     

KLF4过表达对RAW264.7巨噬细胞和C2C12肌原细胞增殖的影响

为探讨Krueppel样因子4（Krueppel-like factor 4,KLF4）过表达对Raw264．7巨噬细胞和C2C12小鼠肌原细胞生长的影响,采用脂质体转染KLF4的真核表达质粒于Raw264．7巨噬细胞和C2C12细胞中,G418筛选阳性克隆,Western blotting鉴定高表达克隆;观察各转染细胞生长情况,CCk-8法检测细胞增殖情况,流式细胞术检测细胞周期分布,凋亡百分率,发现与空质粒转染细胞相比,KLF4过表达对Raw264．7巨噬细胞的生长曲线、细胞周期分布、凋亡百分率没有明显的影响,而C2C12细胞生长速度减慢,细胞凋亡百分率明显高于空载体组,上述结果表明KLF4基因对Raw264．7巨噬细胞增殖没有明显影响,而对C2C12细胞增殖起负调控作用．     

莱茵衣藻E2泛素结合酶CrUBC23调控油脂积累

【目的】为研究莱茵衣藻(Chlamydomonas reinhardtii)泛素结合酶(ubiquitin-conjugating enzymes,E2)CrUBC23在莱茵衣藻油脂代谢中的作用,为高产油微藻基因工程改良和揭示藻类油脂合成及代谢调控机理奠定基础。【方法】qRT-PCR分析莱茵衣藻在低氮、低磷胁迫下泛素结合酶CrUBC23表达情况;克隆CrUBC23同源基因干涉片段和全长基因,构建RNAi干涉载体和过量表达载体,转化莱茵衣藻并检测生物量和油脂含量;构建CrUBC23-GFP融合表达载体,用农杆菌浸染洋葱表皮细胞进行亚细胞定位。【结果】莱茵衣藻在低氮、低磷胁迫下CrUBC23基因表达量显著增加,增加幅度分别为正常培养的4.98–5.80倍和1.85–5.20倍。RNAi干扰结果显示,转基因藻细胞中性脂含量降低5.5%,总脂含量降低3.16%–17.6%。过量表达结果显示,转基因藻细胞中性脂含量增加8.8%,总脂含量增加4.51%–14.03%。【结论】CrUBC23正向调控莱茵衣藻油脂代谢,该基因定位于细胞核。     

TRIM59 Promotes the Proliferation and Migration of Non-Small Cell Lung Cancer Cells by Upregulating Cell Cycle Related Proteins

TRIM protein family is an evolutionarily conserved gene family implicated in a number of critical processes including inflammation, immunity, antiviral and cancer. In an effort to profile the expression patterns of TRIM superfamily in several non-small cell lung cancer (NSCLC) cell lines, we found that the expression of 10 TRIM genes including TRIM3, TRIM7, TRIM14, TRIM16, TRIM21, TRIM22, TRIM29, TRIM59, TRIM66 and TRIM70 was significantly upregulated in NSCLC cell lines compared with the normal human bronchial epithelial (HBE) cell line, whereas the expression of 7 other TRIM genes including TRIM4, TRIM9, TRIM36, TRIM46, TRIM54, TRIM67 and TRIM76 was significantly down-regulated in NSCLC cell lines compared with that in HBE cells. As TRIM59 has been reported to act as a proto-oncogene that affects both Ras and RB signal pathways in prostate cancer models, we here focused on the role of TRIM59 in the regulation of NSCLC cell proliferation and migration. We reported that TRIM59 protein was significantly increased in various NSCLC cell lines. SiRNA-induced knocking down of TRIM59 significantly inhibited the proliferation and migration of NSCLC cell lines by arresting cell cycle in G2 phase. Moreover, TRIM59 knocking down affected the expression of a number of cell cycle proteins including CDC25C and CDK1. Finally, we knocked down TRIM59 and found that p53 protein expression levels did not upregulate, so we proposed that TRIM59 may promote NSCLC cell growth through other pathways but not the p53 signaling pathway.     

转录因子WSTF对肺癌细胞增殖和侵袭的实验研究

目的:研究转录因子WSTF对肺癌细胞增殖和侵袭作用的影响。方法:采用慢病毒介导的基因转染方法建立A549细胞WSTF高表达细胞系A549-WSTF和空质粒对照细胞系A549-control。细胞增殖实验和克隆形成实验观察ING5过表达对肺癌A549细胞增殖能力的影响;Trans-well迁移实验和侵袭实验观察WSTF对肺癌细胞迁移和侵袭能力的影响。结果:Western blot验证A549-WSTF细胞WSTF蛋白水平显著高于对照细胞A549-control,P=0.0004。WSTF高表达明显促进了肺癌细胞的增殖能力(1-4天P值分别为0.002、0.0004、0.0002和3.21×10-5)和克隆形成能力(P=0.004);WSTF过表达还显著促进了肺癌细胞从trans-well小室迁移到下室的作用,其OD570值分别为0.626±0.013(A549-WSTF)和0.322±0.010(A549-control),P=2.37×10-5;WSTF还促进肺癌细胞穿透基质胶迁移到下室,其OD570值分别为0.600±0.027(A549-WSTF)和0.333±0.017(A549-control),P=0.0004。结论:WSTF可以促进肺癌细胞的增殖和侵袭能力而发挥促癌作用。     

长链非编码RNA SNHG1促进肺癌细胞增殖

近年来,大量证据表明长链非编码RNA (long non-coding RNAs, lncRNAs) 在肿瘤发生发展中发挥重要的作用。本研究通过生物信息学预测发现,核仁小分子RNA宿主基因1(small nucleolar RNA host gene 1,SNHG1)无蛋白质编码功能,且主要定位于细胞质。qRT-PCR结果显示,SNHG1在肺癌细胞中的表达量显著高于正常肺上皮细胞。在肺癌细胞NCI-H1299中,敲低SNHG1发现,该细胞增殖能力明显下降;在正常肺上皮细胞BEAS-2B中,过表达SNHG1可显著促进该细胞的增殖能力。深入研究发现,SNHG1可上调CDK4和下调p27kip1在蛋白质水平的表达,而对其mRNA水平表达量无影响。此外,在肺癌临床组织中也发现SNHG1高表达,且高表达的SNHG1与肺癌瘤体大小、TNM分期和远端转移正相关,而与患者年龄及吸烟史无关。综上所述,SNHG1在肺癌中高表达,通过上调CDK4和下调p27kip1推进肺癌进程。     

miR-146a Inhibits Cell Growth,Cell Migration and Induces Apoptosis in Non-Small Cell Lung Cancer Cells

Aberrant expression of microRNA-146a (miR-146a) has been reported to be involved in the development and progression of various types of cancers. However, its role in non-small cell lung cancer (NSCLC) has not been elucidated. The aim of this study was to investigate the contribution of miR-146a to various aspects of the malignant phenotype of human NSCLCs. In functional experiments, miR-146a suppressed cell growth, induced cellular apoptosis and inhibited EGFR downstream signaling in five NSCLC cell lines (H358, H1650, H1975, HCC827 and H292). miR-146a also inhibited the migratory capacity of these NSCLC cells. On the other hand, miR-146a enhanced the inhibition of cell proliferation by drugs targeting EGFR, including both TKIs (gefitinib, erlotinib, and afatinib) and a monoclonal antibody (cetuximab). These effects were independent of the EGFR mutation status (wild type, sensitizing mutation or resistance mutation), but were less potent compared to the effects of siRNA targeting of EGFR. Our results suggest that these effects of miR-146a are due to its targeting of EGFR and NF-κB signaling. We also found, in clinical formalin fixed paraffin embedded (FFPE) lung cancer samples, that low expression of miR-146a was correlated with advanced clinical TNM stages and distant metastasis in NSCLC (P<0.05). The patients with high miR-146a expression in their tumors showed longer progression-free survival (25.6 weeks in miR-146a high patients vs. 4.8 weeks in miR-146a low patients, P<0.05). miR-146a is therefore a strong candidate prognostic biomarker in NSCLC. Thus inducing miR-146a might be a therapeutic strategy for NSCLC.     

IscU2对非小细胞肺癌增殖、迁移、侵袭能力的影响及其作用机制的研究

该文通过shRNA干扰技术敲低IscU2干扰细胞IscU2的表达,研究了干扰IscU2对非小细胞肺癌(NSCLC)细胞NCI-H520增殖、迁移及侵袭能力的影响。构建了稳定低表达IscU2的非小细胞肺癌细胞系NCI-H520;采用CCK-8和平板克隆实验检测细胞的增殖能力;流式细胞仪检测细胞周期、凋亡、ROS、线粒体膜电位变化情况;Transwell实验检测细胞迁移及侵袭能力;Western blot检测相关蛋白的表达。结果表明,干扰IscU2后,非小细胞肺癌细胞的增殖及克隆形成能力降低;细胞周期停滞在G1/G0期,同时伴随有p-AKT和Cyclin D1蛋白含量的下降;细胞晚期凋亡率明显增加,凋亡蛋白Cleaved-caspase3和Cleaved-PARP表达上调;细胞迁移和侵袭能力降低,上皮标志物E-Cadherin表达上调,间质标志物N-Cadherin和Snail表达下调;细胞ROS积累和线粒体膜电位下降。该研究结果表明,干扰IscU2显著抑制非小细胞肺癌的增殖、迁移、侵袭能力和上皮–间质转化,这为非小细胞肺癌的诊断和治疗提供了新的潜在靶点和视角。     

Rho Isoform-specific Interaction with IQGAP1 Promotes Breast Cancer Cell Proliferation and Migration

We performed a proteomics screen for Rho isoform-specific binding proteins to clarify the tumor-promoting effects of RhoA and C that contrast with the tumor-suppressive effects of RhoB. We found that the IQ-motif-containing GTPase-activating protein IQGAP1 interacts directly with GTP-bound, prenylated RhoA and RhoC, but not with RhoB. Co-immunoprecipitation of IQGAP1 with endogenous RhoA/C was enhanced when RhoA/C were activated by epidermal growth factor (EGF) or transfection of a constitutively active guanine nucleotide exchange factor (GEF). Overexpression of IQGAP1 increased GTP-loading of RhoA/C, while siRNA-mediated depletion of IQGAP1 prevented endogenous RhoA/C activation by growth factors. IQGAP1 knockdown also reduced the amount of GTP bound to GTPase-deficient RhoA/C mutants, suggesting that IQGAP enhances Rho activation by GEF(s) or stabilizes Rho-GTP. IQGAP1 depletion in MDA-MB-231 breast cancer cells blocked EGF- and RhoA-induced stimulation of DNA synthesis. Infecting cells with adenovirus encoding constitutively active RhoA^L63 and measuring absolute amounts of RhoA-GTP in infected cells demonstrated that the lack of RhoA^L63-induced DNA synthesis in IQGAP1-depleted cells was not due to reduced GTP-bound RhoA. These data suggested that IQGAP1 functions downstream of RhoA. Overexpression of IQGAP1 in MDA-MB-231 cells increased DNA synthesis irrespective of siRNA-mediated RhoA knockdown. Breast cancer cell motility was increased by expressing a constitutively-active RhoC^V14 mutant or overexpressing IQGAP1. EGF- or RhoC-induced migration required IQGAP1, but IQGAP1-stimulated migration independently of RhoC, placing IQGAP1 downstream of RhoC. We conclude that IQGAP1 acts both upstream of RhoA/C, regulating their activation state, and downstream of RhoA/C, mediating their effects on breast cancer cell proliferation and migration, respectively.