VEGF-specific siRNAs modified with 2′-deoxy effectively suppress VEGF expression and inhibit growth of nasopharyngeal carcinoma xenograft in a mouse model

Vascular endothelial growth factor (VEGF) is up-regulated in the vast majority of human tumors. The up-regulation of VEGF not only plays important roles in tumor angiogenesis, but also provides a target for tumor treatment with small interfering RNA (siRNA) that targets VEGF; however, it is unclear whether a quite high up-regulation of VEGF will affect the efficiency of RNA interference strategies targeting VEGF. A high level expression of VEGF was found in CNE cells from a nasopharyngeal carcinoma cell line. In this study, we investigate whether VEGF-specific siRNAs can effectively suppress VEGF expression in CNE cells, and study the methods for the use of VEGF-specific siRNAs as potential therapeutic agents. CNE cells with high VEGF expression induced by hypoxia were transfected with VEGF-specific siRNAs. The expression of VEGF was effectively suppressed by VEGF-specific siRNAs, measured by ELISA, Western blot analysis and RT-PCR. Furthermore, experiments in nude mice bearing nasopharyngeal carcinoma xenograft were initiated 5 d after injection of CNE cells. VEGF-specific siRNAs were modified with 2′-deoxy, then injected into the tumors, and a liposome-mediated siRNA transfection system and ultrasound exposure were used to help delivery of the siRNAs. Tumor growth was reduced significantly after 3 weeks' treatment. These studies suggest that VEGF-specific siRNAs still can effectively suppress VEGF expression even in tumor cell lines with a relatively high level of VEGF expression, such as CNE, and VEGF-specific siRNAs modified with 2′-deoxy can be used as potential agents for tumor therapy.     

敲低hsa_circ_0007637抑制神经胶质瘤细胞的增殖、迁移及侵袭

本文旨在探讨hsa_circ_0007637在神经胶质瘤细胞中的敲低效率,以及其对神经胶质瘤细胞增殖、迁移、侵袭能力的影响.采用荧光实时定量PCR(qRT-PCR)验证siRNA的沉默效率;采用CCK8法检测hsa_circ_0007637对神经胶质瘤细胞增殖能力的影响;划痕愈合实验对癌细胞迁移能力进行评估;以及运用T...     

敲减XAGE-1b基因表达降低ACCM和A673肿瘤细胞的增殖能力

XAGE是通过生物信息学方法发现的新一类肿瘤 睾丸抗原(cancer/testis antigen,CT抗原)基因,其主要表达亚型为XAGE-1b.已有的研究表明,该基因可能与肿瘤细胞的生长相关．本研究构建了针对XAGE-1b进行RNA干扰的重组腺病毒载体Adv-Sh1和Adv-Sh2．半定量和定量RT-PCR显示,Adv-Sh1比Adv-Sh2对XAGE-1b的干扰效率更高. 细胞荧光干扰实验显示,Adv-Sh1对XAGE-1b有显著的干扰作用．在细胞增殖和集落形成实验中,感染Adv-Sh1后的细胞增殖能力显著降低(Ｐ<0.01),形成的单克隆集落数也显著减少．研究结果表明,下调XAGE-1b基因表达使ACCM和A673肿瘤细胞的增殖能力均有降低,提示XAGE-1b在肿瘤生长过程中可能发挥重要作用．本研究为进一步深入研究XAGE-1b的功能和致癌机制打下了良好基础．     

Sulfiredoxin基因敲低对HeLa细胞恶性生物学行为的影响

Sulfiredoxin（SRX)作为一种重要的抗氧化蛋白质,最近研究发现其对某些肿瘤细胞生物学行为及细胞恶性转化有重要作用,而SRX对宫颈癌细胞恶性生物学行为有何影响尚未见报道.本研究选取宫颈癌HeLa细胞株,分别设为Wild-type（WT）组,Non-target（NT）组,Knock-down（KD）组. 利用siRNA技术干扰SRX基因在HeLa细胞中的内源性表达,采用MTT法、平板克隆形成实验、Transwell实验、流式细胞术分别检测肿瘤细胞增殖力、浸润、迁移能力、细胞凋亡情况,并分别用3组HeLa细胞上清液处理人脐静脉内皮细胞,观察各组条件培养基对内皮细胞血管形成能力的影响.结果表明,与两对照组比较,SRX干扰组细胞增殖力、浸润、迁移力显著降低,且干扰组上清使内皮细胞体外血管形成能力也明显下降（P<0.05）,而凋亡率则明显增加（P<0.05）.而两对照组之间结果均无显著差异（P>0.05）.实验结果表明,SRX基因对宫颈癌HeLa细胞恶性生物学行为具有促进作用,说明SRX可能与宫颈癌恶性进展有密切关系.     

抑制CYP4A11基因表达的siRNAs优选及对血管收缩相关因子的影响

为了考察人细胞中细胞色素P450 4A11(CYP4A11)表达受抑制之后是否会影响血管相关收缩因子的表达,在线设计多个抑制细胞中代谢酶编码基因CYP4A11表达的siRNAs并通过BLAST验证;选择效果好的3对siRNAs合成并转染至EA.hy926细胞株,通过荧光染色和定量多聚酶链反应(quantitative polumerase chain reaction,qPCR)初步检测后,再采用表达量相对更高的MG63细胞系进行验证,发现25 nmol/L的siRNA2抑制效果最好;随后使用25 nmol/L siRNA2抑制CYP4A11在EA.hy926细胞株中的表达,并通过qPCR与Western-blot检测血管收缩相关因子的表达情况,发现促血管收缩相关因子内皮素1受体(endothelin 1 receptor,ET1R)、血管紧张素1型受体(angiotensin type 1 receptor,AT1R)表达下调(P0.05),而内皮型一氧化氮合酶(endothelial nitric oxide synthase,eNOS)的表达显著上调(P0.001)。因此,siRNA2能通过显著抑制EA.hy926细胞中CYP4A11的表达,调节血管紧张的相关指标,有促血管松弛作用的趋势。     

VEGF特异的2’-脱氧修饰siRNA能够有效的抑制VEGF的表达和小鼠鼻咽癌异体移植瘤的生长

血管内皮生长因子（vascular endothelial growth factor,VEGF）在肿瘤血管生成中起重要作用,并在多数肿瘤中表达上调,为使用针对VEGF的小干扰RNA（VEGF siRNA）治疗肿瘤提供了重要的作用靶点,然而,不清楚VEGF表达的大幅上调是否会影响VEGF siRNA的干扰效率．本文研究VEGF siRNA能否在VEGF的表达大幅上调的鼻咽癌细胞（CNE）中有效抑制VEGF的表达,并进一步研究VEGF siRNA作为潜在的抗癌制剂的应用方法．为增加siRNA的稳定性,对VEGFsiRNA进行了2’-脱氧（2＇-deoxy）化学修饰,再将修饰后的VEGF siRNA导入经低氧诱导而高表达VEGF的CNE细胞,30h后用ELISA,Western blot结果分析和RT-PCR等方法鉴定其抑制CNE细胞表达VEGF的效果,结果证明VEGF的表达被明显抑制,用化学修饰的VEGF siRNA治疗裸鼠的鼻咽癌移植瘤,将VEGF siRNA与脂质体混合后,注射到肿瘤局部,然后进行超声照射,每周治疗2次,3周以后处死裸鼠、分离肿瘤并测量瘤重．结果显示上述治疗能明显抑制鼻咽癌移植瘤的生长．     

小干扰RNA靶向VEGF基因体内外抑制乳腺癌细胞MCF-7的增殖

 血管生成与肿瘤生长、侵袭、转移密切相关.血管内皮生长因子能特异地促进内皮细胞分裂、增殖及迁移,在肿瘤新生血管生成过程中起着至关重要的作用.通过RNAi抑制VEGF表达的抗血管生成疗法可有效应用于肿瘤治疗.本研究采用化学修饰的siRNA在体内外抑制VEGF基因表达,探讨化学修饰的siRNA介导的RNA干扰技术在乳腺癌基因治疗的可行性和特异性.选用阳离子脂质体Lipofectamine^TM2000作为转染试剂,将针对人VEGF基因的小干扰RNA(small interfering RNA,siRNA)转染人类乳腺细胞株MCF-7和裸鼠移植瘤,在体内外诱导RNAi.采用四甲基偶氮唑蓝（MTT）法,逆转录聚合酶链反应(RT-PCR),蛋白印迹实验等检测siRNA治疗组和对照组VEGF基因表达及细胞增殖变化.体外实验结果显示：靶向VEGF基因siRNA转染乳腺癌MCF-7细胞后,细胞生长抑制率达52.5%;VEGF的mRNA和蛋白表达水平显著降低（P<0.01）;裸鼠体内实验结果显示：siRNA治疗组瘤组织的增长受到明显抑制;RT-PCR结果同时表明治疗组VEGF表达下调.体内外对照组各指标无显著变化.化学修饰的siRNA介导的RNAi在体内外均能成功下调靶基因VEGF的表达,抑制MCF-7细胞增殖,是潜在的肿瘤治疗新方法.     

敲减FST基因对猪成纤维细胞中相关基因表达的影响

旨在获得敲减FST基因的猪胎儿成纤维细胞,并探讨对相关基因表达的影响。将构建成功并鉴定准确的发夹RNA真核表达载体FR1-shRNA利用脂质体转染至猪胎儿成纤维细胞中,并进行G418筛选,获得稳定转染细胞株,并利用Real-time检测了相关基因表达的变化。结果表明,在稳定转染的细胞株中,FST基因的表达受到显著抑制,结果导致了ActivinRⅡA、Myostatin和Bmp4基因的表达出现下调趋势,并且极显著地降低MyoD基因的表达。     

RNAi沉默整合素连接激酶基因表达对膀胱癌细胞BIU-87增殖的影响

为了研究整合素连接激酶(integrin-linked kinase,ILK)基因沉默对膀胱癌BIU-87细胞系增殖产生的影响,应用RNA干扰(RNA interference,RNAi)技术,合成了4条针对ILK的miRNA干扰载体pcDNATM6.2-GW/EmGFP-ILK-miR(miR-1、miR-2、miR-3、miR-4)作为实验组,另设1条为阴性对照组,分别转染膀胱癌BIU-87细胞系.经杀稻瘟菌素持续压力筛选和有限稀释法培养获得稳定转染细胞株.采用RT-PCR和Western-blot检测各组对ILK基因的抑制作用,实验组miRNA对BIU-87细胞ILK mRNA和蛋白的表达均有明显的抑制作用,以miR-3组抑制效应最强.通过流式细胞术检测发现,miR-3组细胞周期G0/G1期细胞所占比例较未转染组明显增加,而S期则明显减少(P0.05).四甲基偶氮唑盐(MTT)比色法检测发现,转染组细胞在体外的增殖能力较对照组明显下降(P0.05).证明RNA干扰技术能有效抑制靶基因ILK的表达,进而抑制了膀胱癌细胞系BIU-87的增殖.     

沉默EVL表达抑制肝癌细胞SMMC-7721的增殖和迁移能力

Ena/VASP 样蛋白（Ena/VASP like protein,EVL）是Ena/VASP家族成员之一,它参与肌动蛋白细胞骨架重组,以及细胞迁移、收缩环形成和细胞间附着.EVL在肝癌SMMC-7721细胞中高表达. 抑制EVL蛋白表达后,SMMC-7721细胞的增殖与迁移能力降低.为研究EVL在肝癌细胞的功能,构建了靶向shRNA干扰表达载体,稳定转染肝癌SMMC-7721细胞. MTT实验和细胞集落形成实验显示,与转染对照比较,沉默EVL蛋白表达可明显抑制SMMC-7721肝癌细胞的增殖、集落形成能力. Transwell实验证明,沉默EVL表达导致SMMC-7721细胞迁移能力降低. 进而,流式细胞术揭示,沉默EVL表达的SMMC-7721细胞G0/G1期细胞比例增多.研究结果提示,EVL蛋白可促进肝癌细胞的增殖与迁移;该结果可解释EVL在肝癌细胞中高表达的意义.     

慢病毒介导RNA干扰HPIP蛋白抑制肿瘤细胞增殖

目的:建立高效稳定的造血相关的PBX相互作用蛋白质(HPIP)小干扰RNA(siRNA)细胞导入方法,检测HPIP的表达对肿瘤细胞生长增殖的影响。方法:构建人HPIP慢病毒siRNA干扰载体,将重组质粒转染人胚肾293T细胞,通过实时定量RT-PCR及Western印迹分析检测Lenti-H1 HPIP siRNA的干扰效果;将Lenti-H1 HPIPsiRNA与4个包装质粒共同转染293T细胞,包装成慢病毒后,感染宫颈癌HeLa和肝癌HepG2细胞,经嘌呤霉素筛选2周后,收集细胞进行Western印迹检测;用结晶紫实验检测其对肿瘤细胞生长增殖的影响。结果:构建的Lenti-H1 HPIP siRNA能有效抑制HPIP的表达;结晶紫实验显示,慢病毒介导的HPIP siRNA导致细胞增殖的显著抑制。结论:慢病毒介导的HPIP敲减能明显抑制肿瘤细胞的增殖,HPIP可能是一个潜在的肿瘤治疗新靶点。     

Knockdown of miR-214 Promotes Apoptosis and Inhibits Cell Proliferation in Nasopharyngeal Carcinoma

MicroRNA-214 (MiR-214) is aberrantly expressed in several human tumors such as ovarian cancer and breast cancer. However, the role of miR-214 in nasopharyngeal carcinoma (NPC) is still unknown. In this study, we report that miR-214 was overexpressed in NPC cell lines and tissues. Silencing of miR-214 by LNA-antimiR-214 in NPC cells resulted in promoting apoptosis and suppressing cell proliferation in vitro, and suppressed tumor growth in nude mice in vivo. Luciferase reporter assay was performed to identify Bim as a direct target of miR-214. Furthermore, this study showed that low Bim expression in NPC tissues correlated with poor survival of NPC patients. Taken together, our findings suggest that miR-214 plays an important role in NPC carcinogenesis.     

Knockdown of DIXDC1 Inhibits the Proliferation and Migration of Human Glioma Cells

DIX domain containing 1 (DIXDC1), the human homolog of coiled-coil-DIX1 (Ccd1), is a positive regulator of Wnt signaling pathway. Recently, it was found to act as a candidate oncogene in colon cancer, non-small-cell lung cancer, and gastric cancer. In this study, we aimed to investigate the clinical significance of DIXDC1 expression in human glioma and its biological function in glioma cells. Western blot and immunohistochemistry analysis showed that DIXDC1 was overexpressed in glioma tissues and glioma cell lines. The expression level of DIXDC1 was evidently linked to glioma pathological grade and Ki-67 expression. Kaplan–Meier curve showed that high expression of DIXDC1 may lead to poor outcome of glioma patients. Serum starvation and refeeding assay indicated that the expression of DIXDC1 was associated with cell cycle. To determine whether DIXDC1 could regulate the proliferation and migration of glioma cells, we transfected glioma cells with interfering RNA-targeting DIXDC1; investigated cell proliferation with Cell Counting Kit (CCK)-8, flow cytometry assays, and colony formation analyses; and investigated cell migration with wound healing assays and transwell assays. According to our data, knockdown of DIXDC1 significantly inhibited proliferation and migration of glioma cells. These data implied that DIXDC1 might participate in the development of glioma, suggesting that DIXDC1 can become a potential therapeutic strategy for glioma.     

Knockdown of FRAT1 Expression by RNA Interference Inhibits Human Glioblastoma Cell Growth,Migration and Invasion

Background

FRAT1 positively regulates the Wnt/β-catenin signaling pathway by inhibiting GSK-3-mediated phosphorylation of β-catenin. It was originally characterized as a protein frequently rearranged in advanced T cell lymphoma, but has recently also been identified as a proto-oncogene involved in tumorigenesis. Our previous studies showed that FRAT1 was dramatically overexpressed in gliomas and its expression level was significantly increased along with clinicopathological grades.

Methods

In the current study, we used RT-PCR and Western blotting to assess the mRNA and protein levels of FRAT1 in three glioma cell lines. In addition, to evaluate its functional role in gliomas, we examined the effects of FRAT1 knockdown on proliferation, migration and invasion in vitro and tumor growth in vivo using glioblastoma U251 cells and RNAi.

Results

FRAT1 was highly expressed in all three glioma cell lines. RNAi-mediated down-regulation of endogenous FRAT1 in human glioblastoma U251 cells resulted in suppression of cell proliferation, arrest of cell cycle, inhibition of cell migration and invasion in vitro. Moreover, FRAT1 depletion significantly impaired tumor xenograft growth in nude mice.

Conclusions

Our results highlight the potential role of FRAT1 in tumorigenesis and progression of glioblastoma. These findings provide a biological basis for FRAT1 as a potential molecular marker for improved pathological grading and as a novel candidate therapeutic target for glioblastoma management.     

Bcl-2/C-Raf双基因“敲低”抑制人结肠癌细胞增殖

 RNA干扰是一种具有序列特异性的基因沉默,能够触发具有相应序列的mRNA的降解.构建具有双靶点的RNAi质粒表达载体,与单靶点表达载体比较,探讨其对结肠癌细胞增殖的抑 制作用.本研究分别构建了针对Bcl-2、C-Raf 和Bcl-2/C-Raf靶基因的质粒表达载体,通过Lipofectamine TM2000介导转染人结肠癌细胞系HCT-8后,检测相应转染组靶基因的mRNA和蛋白质表达量,测定各组细胞活性,研究RNAi对各组癌细胞增殖的抑制率.结果表明,分别转染3种质粒表达载体后,3组结肠癌细胞中相应靶基因的mRNA和蛋白质表达量均降低;转染双靶点干扰质粒的试验组;其细胞活性低于单靶点组;对于针对Bcl-2, C-Raf和Bcl-2/C-Raf基因的3组干扰实验,RNAi对结肠癌细胞增殖的抑制率分别为43.87%,40.64% 和63.85%.RNAi是结肠癌细胞中的一种功能途径,以质粒作为表达载体,同时具备Bcl-2/C-Raf双靶点的表达载体,对结肠癌细胞增殖的抑制作用要明显优于单靶点表达载体,双靶点质粒表达载体在结肠癌的基因治疗中是有潜力的.     

Src-Mediated Cross-Talk between Farnesoid X and Epidermal Growth Factor Receptors Inhibits Human Intestinal Cell Proliferation and Tumorigenesis

Besides its essential role in controlling bile acid and lipid metabolism, the farnesoid X receptor (FXR) protects against intestinal tumorigenesis by promoting apoptosis and inhibiting cell proliferation. However, the mechanisms underlying these anti-proliferative actions of FXR remain to be elucidated. In the present study, we examined the effects of FXR activation (FXR overexpression and treatment with an FXR agonist GW4064) and inactivation (treatment with FXR siRNA and an FXR antagonist guggulsterone) on colon cancer cell proliferation in vitro using human colon cancer cell lines (H508, SNU-C4 and HT-29) and in vivo using xenografts in nude mice. Blocking FXR activity with guggulsterone stimulated time- and dose-dependent EGFR (Tyr845) phosphorylation and ERK activation. In contrast, FXR overexpression and activation with GW4064 attenuated cell proliferation by down-regulating EGFR (Tyr845) phosphorylation and ERK activation. Treatment with guggulsterone and GW4064 also caused dose-dependent changes in Src (Tyr416) phosphorylation. In stably-transfected human colon cancer cells, overexpression of FXR reduced EGFR, ERK, Src phosphorylation and cell proliferation, and in nude mice attenuated the growth of human colon cancer xenografts (64% reduction in tumor volume; 47% reduction in tumor weight; both P<0.01). Moreover, guggulsterone-induced EGFR and ERK phosphorylation and cell proliferation were abolished by inhibiting activation of Src, EGFR and MEK. Collectively these data support the novel conclusion that in human colon cancer cells Src-mediated cross-talk between FXR and EGFR modulates ERK phosphorylation, thereby regulating intestinal cell proliferation and tumorigenesis.     

敲低去泛素化酶USP13抑制K562细胞的增殖*

目的:研究去泛素化酶USP13对人慢性髓系白血病细胞系K562增殖和凋亡的影响,并进行初步的机制探究。方法:构建pLKO.1-shUSP13-GFP慢病毒干涉载体,慢病毒包装后感染并建立稳定敲低USP13的K562细胞株。免疫印迹检测K562细胞中USP13蛋白的敲低效率。流式细胞术分析敲低USP13对K562细胞增殖和凋亡的影响。免疫共沉淀和蛋白质泛素化实验探究USP13调控K562细胞的分子机制。结果:成功构建pLKO.1-shUSP13-GFP慢病毒干涉载体,同时利用慢病毒体系获得稳定敲低USP13的K562细胞株。流式细胞术结果显示,敲低USP13促进K562细胞凋亡、抑制细胞增殖。分子机制研究发现,敲低USP13通过增强c-Myc泛素化进而导致其蛋白质水平降低。结论:初步揭示了USP13调控K562细胞增殖和凋亡的分子机制,为治疗慢性髓系白血病提供了潜在的靶点。     

LPLUNC1基因对鼻咽癌细胞HNE1生长增殖的抑制作用研究

LPLUNC1在正常的鼻咽组织及人胚鼻咽组织中高表达,而在71%的鼻咽癌中表达下调或缺失,是与鼻咽癌的发生发展密切相关的新基因.通过研究LPLUNC1基因对鼻咽癌细胞系HNE1的影响,进一步确定其与鼻咽癌发生发展的关系.将LPLUNC1基因全长cDNA克隆入pcDNA3.1( )真核表达载体中,通过脂质体介导稳定转染入LPLUNC1低表达鼻咽癌细胞系HNE1中,通过RT-PCR及RNA印迹筛选LPLUNC1高表达的细胞株,并利用细胞生长曲线、MTT、BrdU掺入、流式细胞仪检测、软琼脂集落形成实验及裸鼠成瘤等实验,研究了LPLUNC1对鼻咽癌细胞系HNE1细胞生长、增殖的影响.结果发现,稳定转染LPLUNC1的HNE1细胞的生长速度明显减慢,在MTT与BrdU掺入实验发现LPLUNC1可明显地抑制鼻咽癌细胞的增殖,并且通过流式细胞仪检测也发现,LPLUNC1基因可明显延缓HNE1细胞的细胞周期进程,使G0/G1期细胞增多而S期细胞相对减少.进一步通过软琼脂集落形成及裸鼠成瘤实验发现,LPLUNC1稳定转染后的HNE1细胞集落形成率与集落的大小均小于空白载体细胞,同时能明显地抑制HNE1细胞的体外成瘤.结果表明,LPLUNC1基因能明显抑制鼻咽癌细胞HNE1的生长增殖,是鼻咽癌发生发展中的重要候选抑瘤基因之一.     

Knockdown of VEGFR2 Inhibits Proliferation and Induces Apoptosis in Hemangioma-Derived Endothelial Cells

Angiogenesis is a process of development and growth of new capillary blood vessels from pre-existing vessels. Angiogenic growth factors play important roles in the development and maintenance of some malignancies, of which vascular endothelial growth factor (VEGF)/VEGFR2 interactions are involved in proliferation, migration, and survival of many cancer cells. The aim of this study was to investigate the function of VEGFR2 in human hemangiomas (HAs). Using immunohistochemistry assay, we examined the expression levels of VEGF, VEGFR2, Ki-67, glucose transporter-1 (Glut-1), phosphorylated protein kinase B (p-AKT) and p-ERK in different phases of human HAs. Positive expression of VEGF, VEGFR2, Ki-67, Glut-1, p-AKT and p-ERK was significantly increased in proliferating phase HAs, while decreased in involuting phase HAs (P=0.001; P=0.003). In contrast, cell apoptotic indexes were decreased in proliferating phase HAs, but increased in involuting phase HAs (P<0.01). Furthermore, we used small hairpin RNA (shRNA)-mediated VEGFR2 knockdown in primary HA-derived endothelial cells (HemECs) to understand the role of VEGF/VEGFR2 signaling. Knockdown of VEGFR2 by Lv-shVEGFR2 inhibited cell viability and induced apoptosis in primary HemECs companied with decreased expression of p-AKT, p-ERK, p-p38MAPK and Ki-67 and increased expression of caspase-3 (CAS-3); Overexpression of VEGFR2 promoted cell viability and blocked apoptosis in Lv-VEGFR2-transfected HemECs. Taken together, our findings demonstrate that, increased expression of VEGFR2 is involved in the development of primary HemECs possibly through regulation of the AKT and ERK pathways, suggesting that VEGFR2 may be a potential therapeutic target for HAs.Key words: vascular endothelial growth factor receptor 2, hemangioma, proliferation, apoptosis