ING5 suppresses proliferation,apoptosis, migration and invasion,and induces autophagy and differentiation of gastric cancer cells: a good marker for carcinogenesis and subsequent progression

Here, we found that ING5 overexpression increased autophagy, differentiation, and decreased proliferation, apoptosis, migration, invasion and lamellipodia formation in gastric cancer cells, while ING5 knockdown had the opposite effects. In SGC-7901 transfectants, ING5 overexpression caused G₁ arrest, which was positively associated with 14-3-3 overexpression, Cdk4 and c-jun hypoexpression. The induction of Bax hypoexpression, Bcl-2, survivin, 14-3-3, PI3K, p-Akt and p70S6K overexpression by ING5 decreased apoptosis in SGC-7901 cells. The hypoexpression of MMP-9, MAP1B and flotillin 2 contributed to the inhibitory effects of ING5 on migration and invasion of SGC-7901 cells. ING5 overexpression might activate both β-catenin and NF-κB pathways in SGC-7901 cells, and promote the expression of down-stream genes (c-myc, VEGF, Cyclin D1, survivin, and interleukins). Compared with the control, ING5 transfectants displayed drug resistance to triciribine, paclitaxel, cisplatin, SAHA, MG132 and parthenolide, which was positively related to their apoptotic induction and the overexpression of chemoresistance-related genes (MDR1, GRP78, GRP94, IRE, CD147, FBXW7, TOP1, TOP2, MLH1, MRP1, BRCP1 and GST-π). ING5 expression was higher in gastric cancer than matched mucosa. It was inversely associated with tumor size, dedifferentiation, lymph node metastasis and clinicopathological staging of cancer. ING5 overexpression suppressed growth, blood supply and lung metastasis of SGC-7901 cells by inhibiting proliferation, enhancing autophagy and apoptosis in xenograft models. It was suggested that ING5 expression might be employed as a good marker for gastric carcinogenesis and subsequent progression by inhibiting proliferation, growth, migration, invasion and metastasis. ING5 might induce apoptotic and chemotherapeutic resistances of gastric cancer cells by activating β-catenin, NF-κB and Akt pathways.     

Emodin inhibits vascular endothelial growth factor-A-induced angiogenesis by blocking receptor-2 (KDR/Flk-1) phosphorylation

Emodin (1,3,8-trihydroxy-6-methylanthraquinone), an active component in the root and rhizome of Rheum palmatum, is a tyrosine kinase inhibitor with a number of biological activities, including antitumor effects. Here, we examine the effects of emodin on vascular endothelial growth factor (VEGF)-A-induced angiogenesis, both in vitro and in vivo. In vitro, emodin dose-dependently inhibits proliferation, migration into the denuded area, invasion through a layer of Matrigel and tube formation of human umbilical vein endothelial cells (HUVECs) stimulated with VEGF-A. Emodin also inhibits basic fibroblast growth factor-induced proliferation and migration of HUVECs and VEGF-A-induced tube formation of human dermal microvascular endothelial cells. Specifically, emodin induces the cell cycle arrest of HUVECs in the G0/G1 phase by suppressing cyclin D1 and E expression and retinoblastoma protein phosphorylation, and suppresses Matrigel invasion by inhibiting the basal secretion of matrix metalloproteinase-2 and VEGF-A-stimulated urokinase plasminogen activator receptor expression. Additionally, emodin effectively inhibits phosphorylation of VEGF-A receptor-2 (KDR/Flk-1) and downstream effector molecules, including focal adhesion kinase, extracellular signal-regulated kinase 1/2, p38 mitogen-activated protein kinase, Akt and endothelial nitric oxide synthase. In vivo, emodin strongly suppresses neovessel formation in the chorioallantoic membrane of chick and VEGF-A-induced angiogenesis of the Matrigel plug in mice. Our data collectively demonstrate that emodin effectively inhibits VEGF-A-induced angiogenesis in vitro and in vivo. Moreover, inhibition of phosphorylation of KDR/Flk-1 and downstream effector molecules is a possible underlying mechanism of the anti-angiogenic activity of emodin. Based on these data, we propose that an interaction of emodin with KDR/Flk-1 may be involved in the inhibitory function of emodin toward VEGF-A-induced angiogenesis in vitro and responsible for its potent anti-angiogenic in vivo.     

IRX5 promotes colorectal cancer metastasis by negatively regulating the core components of the RHOA pathway

Colorectal cancer (CRC) is one of the most common malignant tumors worldwide. As tumor metastasis is the leading cause of death in patients with CRC, it is important to elucidate the molecular mechanisms that drive CRC metastasis. Studies have shown a close relationship between Iroquois homeobox (IRX) family genes and multiple cancers, while the mechanism by which IRX5 promotes CRC metastasis is unclear. Therefore, we focused on the involvement of IRX5 in CRC metastasis. In this study, analyses of clinical data indicated that the expression of IRX5 was coincided with metastatic colorectal tumors tissues and was negatively correlated with the overall survival of patients with CRC. Functional analysis showed that IRX5 promoted the migration and invasion of CRC cells, accompanied by a large number of cellular protrusions. IRX5‐overexpressing cells were more likely to form metastatic tumors in nude mice. Further analysis demonstrated that the core components of the RHOA/ROCK1/LIMK1 pathway were significantly inhibited in IRX5‐overexpressing cells. Overexpression of LIMK1 effectively reversed the enhanced cellular motility caused by IRX5 overexpression. Moreover, we found that high levels of IRX5 in intestinal tissues were correlated with the inflammatory response. IRX5 was significantly increased in azoxymethane/dextran sodium sulfate intestinal tissue of mice and IRX5‐overexpressing may also enhance chemokines CXCL1 and CXCL8. In summary, our findings suggested that IRX5 promoted CRC metastasis by inhibiting the RHOA‐ROCK1‐LIMK1 axis, which correlates with a poor prognosis.     

转染FRZB基因对人胃癌SGC-7901细胞生长和转移的影响

背景与目的:FRZB(frizzled motif associated with bone development)是sFRP(secreted frizzled related protein)家族的成员,在胚胎发育过程中起重要作用。有文献报道FRZB的表达能抑制基质金属蛋白酶-2(matrix metalloproteinase 2,MMP-2)和MMP-9表达而与前列腺癌的侵袭能力相关。本研究拟探讨FRZB基因对人胃癌SGC-7901细胞成瘤性和侵袭能力的影响,及其可能的机制。方法:构建FRZB真核表达载体并转染SGC-7901细胞,经G418筛选获得稳定表达克隆。用MTT法检测并绘制细胞增殖曲线,软琼脂培养和裸鼠皮下注射的体外和体内实验检测细胞成瘤性变化。用细胞免疫化学检测转染FRZB后细胞中MMP-2、MMP-7、MMP-9的表达变化,体外侵袭和粘附实验检测细胞侵袭能力变化。结果:筛选稳定表达细胞株经定量PCR检测,FRZB表达显著提高。体内外实验证实,转染FRZB的细胞(SGC-7901/FRZB)生长抑制率约为60%,克隆形成能力和成瘤性减弱。免疫细胞化学显示MMP-2、MMP-7、MMP-9在细胞浆内的阳性表达降低或接近阴性,对细胞外基质成分(CollagenI、IV、Vitronectin、Fibronectin、Laminin)粘附能力均增高,比空载体转染对照组(SGC-7901/vector)增加12.8%、19.8%、59.8%、26.7%、15.2%,差异具有显著性(P<0.05),而空载体转染对照组与亲本细胞间差异无统计学意义(P>0.05)。SGC-7901、SGC-7901/vector和SGC-7901/FRZB细胞侵袭能力分别是每高倍视野55.90±5.68、54.80±6.97、6.60±2.63,差异具有统计学意义(P<0.05)。结论:FRZB高表达在体内体外均可抑制SGC-7901细胞的增殖、成瘤性和侵袭能力,具有肿瘤抑制基因的功能。FRZB抑制肿瘤细胞的生长和抑制MMP-2、MMP-7、MMP-9的表达为抑癌功能相关机制之一。     

Functional significance of VEGF-a in human ovarian carcinoma: role in vasculogenic mimicry

Ovarian cancer is a silent killer, and shows early extensive tumor invasion and peritoneal metastasis. The microcirculation of most tumors includes cooperation of pre-existing vessels, intussusceptive microvascular growth, postnatal vasculogenesis, glomeruloid angiogenesis and vasculogenic mimicry (VM). VM is critical for a tumor blood supply and is asscociated with aggressive features and metastasis. Our studies highlight the plasticity of aggressive human ovarian carcinoma cells and call into question the underlying significance of their ability to form VM in vitro induced by VEGF-a. These studies also show their clinicalpathological features of the cancers with human Paraffin-embedded tumor tissue samples. Results show that the process: VEGF-a-->EphA2-->MMPs-->VM is the main pathway for VM formation and VEGF-a appears to play an important role in the formation of VM based on our in vitro assays and clinical immunohistochemical analyses. VM-targeting strategies for ovarian cancer include anti-VEGF-a treatment, knocking down the EphA2 gene and using antibodies against human MMPs if the tumor is VM positive. This strategy may be of significant value in laying the foundation for a more explicit anti-tumor angiogenesis therapy.     

lncRNA 00707 通过miR-613 调控胃癌MGC-803、SGC-7901 细胞的恶性生物学行为

[摘要] 目的:探讨长链非编码RNA 00707（lncRNA 00707）和微小RNA-613(miR-613)对胃癌细胞增殖和转移的调控作用及其相关机制。方法：收集2014 年1 月至2018 年6 月青海省人民医院肿瘤外科89 例原发性胃癌组织及癌旁组织标本以及胃癌MGC-803、SGC-790、BGC-823 细胞,采用qPCR实验检测胃癌组织和细胞系中lncRNA 00707、miR-613 的表达水平。分别建立lncRNA00707 低表达和过表达细胞模型,采用CCK-8 实验检测MGC-803、SGC-7901 细胞增殖能力,Transwell 法检测MGC-803、SGC-7901 细胞迁移和侵袭能力。用双荧光素酶基因报告实验验证lncRNA 00707 与miR-613 的靶向关系。结果：与癌旁组织相比,胃癌组织中lncRNA 00707 呈明显高表达(P<0.01),lncRNA 00707 表达水平与WHO分期呈正相关(P<0.05);与正常细胞系GES-1 相比,胃癌细胞系中lncRNA 00707 表达明显上调(P<0.05)。敲低lncRNA 00707 可明显抑制SGC-7901 细胞的增殖、侵袭和迁移能力(均P<0.05);lncRNA 00707 过表达可明显提高MGC-803 细胞的增殖和迁移能力(P<0.05)。与阴性对照组相比,lncRNA00707 过表达显著降低了miR-613 荧光素酶报告载体的荧光素酶活性,而下调MGC-803 和SCG-7901 细胞中lncRNA 00707,miR-613 的表达显著增加（均P＜0.01）。结论：lncRNA 00707 在胃癌组织和细胞系中发挥促癌效应,其可以通过抑制miR-613 而促进胃癌MGC-803 和SCG-7901细胞的增殖和转移。     

巴佛洛霉素A1抑制胃癌SGC-7901细胞中VEGF-C的表达

目的:研究巴佛洛霉素A1(Bafilomycin A1)对胃癌细胞株SGC-7901的增殖、迁移和血管生成的影响,并探讨可能的机制.方法:巴佛洛霉素A1(10 nmol/mL)处理SGC-7901细胞后,检测液泡-ATP酶(vacular-ATPases,V-ATPases)活性及培养液pH值,并分别用CCK-8法检测...     

EYA1 通过调控PTEN/PI3K/AKT信号通路抑制胃癌SGC-7901 细胞的恶性生物学行为

[摘要] 目的:探讨EYA1(eyes absent 1)通过调控PTEN/PI3K/AKT信号通路抑制胃癌SGC-7901细胞的恶性进展及其相关机制。方法:收集2016年6月至2018年6月陆军军医大学附属西南医院全军普通外科中心29例胃癌组织及其癌旁组织标本,采用Wb和qPCR实验检测胃癌组织和癌旁组织中EYA1 mRNA和蛋白的表达水平。人胃癌细胞株SGC-7901培养完成后,采用过表达EYA1质粒或siRNA干扰质粒转染胃癌SGC-7901细胞;分别采用MTT、流式细胞术、划痕愈合和Transwell实验检测胃癌SGC-7901细胞的增殖、凋亡、迁移和侵袭能力。结果:胃癌组织中EYA1 mRNA 和蛋白表达水平较癌旁组织均明显降低（P<0.01）;过表达EYA1可明显提高SGC-7901 细胞的增殖、迁移和侵袭能力（均P<0.05）、抑制细胞凋亡（P<0.05）。过表达EYA1 可明显促进PTEN的表达、抑制PI3K/AKT通路的激活（均P<0.05或P<0.01）;但在PTEN干扰后以上作用均受到了明显抑制（均P<0.05或P<0.01）。结论:EYA1可通过促进PTEN的表达抑制PI3K/AKT信号通路,从而抑制胃癌SGC-7901细胞的恶性生物学行为。     

Influence of different hypoxia models on metastatic potential of SGC-7901 gastric cancer cells

Gastric cancers are one of the most common gastrointestinal tumors with proclivity to metastasis. Hypoxia is an important feature in solid tumor microenvironment; accumulating evidence suggests that chronic and repetitive exposure to hypoxia and reoxygenation seems to provide an advantage to tumor growth. However, mechanisms of intermittent hypoxia regulating gastric cancer metastatic potential remain to be elucidated. In the present study, we established the continuous and intermittent gastric cancer hypoxia models, and we compared the effects of these models on gastric cancer cell metastatic potential. Hypoxia-inducible factor-1α (HIF-1α) and hypoxia target protein/genes expression in response to different hypoxia models were analyzed by Western blot, immunofluorescence, and real-time PCR assays. Gastric cancer cell migration and invasion ability were analyzed by wound healing and Boyden chamber assay. Colony formation and tumor spheroid formation assays were used to assess the ability of self-renewal. Stem-related protein OCT4 and HIF-1α expression were also analyzed by confocal immunofluorescence in single tertiary generation spheroid. We demonstrated that the intermittent hypoxia model upregulated expression of both HIF-1α and hypoxia target protein/genes in a time-dependent manner compared with that of SGC-7901 cells cultured under normoxia. Remarkably, HIF-1α protein was more prone to being located in the nucleus of SGC-7901 cells under conditions of intermittent hypoxia. Gastric cancer cells’ migration and invasion ability were significantly enhanced after hypoxic culture; moreover, intermittent hypoxia-conditioned SGC-7901 cells exhibited higher invasiveness than the continuous hypoxia-conditioned SGC-7901 cells. Gastric cancer stem/progenitor cell subpopulation was also enlarged which indicated an enhanced self-renewal ability in hypoxic cultured SGC-7901 cells. Our study emphasizes the significance of hypoxia in regulating gastric cancer cell metastasis potential. Compared with continuous hypoxia, intermittent hypoxia is a more effective and potent hypoxic stimulus. These results provide a new insight to investigate the hypoxic microenvironment within solid tumors.     

miR-1284过表达对人胃癌SGC-7901细胞基因表达谱及侵袭转移的影响

背景与目的：人胃癌组织微小RNA表达谱芯片筛选研究报道miR-1284与胃癌淋巴结转移有关,但其在胃癌中的具体作用鲜见报道。该研究探讨miR-1284过表达对人胃癌SGC-7901细胞基因表达谱及侵袭转移的影响。方法：以慢病毒介导miR-1284过表达转染胃癌SGC-7901细胞为实验组(LV-miR-1284组),转染空载体慢病毒载体的细胞为阴性对照组(LV-NC-GFP组),未转染慢病毒载体的细胞为空白组(Control组)。采用荧光定量PCR检测各组细胞miR-1284的表达,芯片检测各组细胞差异表达基因,生物信息学预测miR-1284的靶基因,Transwell侵袭实验检测各组细胞侵袭能力,裸鼠皮下移植瘤模型检测各组细胞转移能力。结果：PCR结果显示,与LV-NC-GFP组和Control组比较,LV-miR-1284组细胞miR-1284表达明显增高;芯片结果显示,LV-miR-1284组有20个基因表达显著上调,17个基因表达显著下调;生物信息学预测miR-1284的靶基因有138个基因;Transwell侵袭实验结果显示,LV-miR-1284组侵袭细胞数为70.00±2.37,其细胞侵袭能力较LV-NCGFP组(168.67±4.55)和Control组(170.33±3.08)明显减弱;体内裸鼠实验结果显示,LV-miR-1284组肝脏转移率为14.29%,其细胞转移能力较LV-NC-GFP组(85.71%)和Control组(85.71%)明显减弱。结论：miR-1284过表达能抑制人胃癌SGC-7901细胞侵袭转移,其机制可能与调控SUMO1、JUN基因表达有关。     

Maspin基因与胃癌侵袭转移

Maspin基因是从乳腺上皮细胞中分离出的抑癌基因,属于丝氨酸蛋白酶抑制剂超家族的成员。Maspin基因在胃癌侵袭和转移过程中发挥重要作用。研究表明,Maspin基因主要通过诱导肿瘤细胞凋亡、抑制肿瘤血管生成、甲基化修饰作用以及通过促进同质黏附、抑制异质黏附等方式来抑制胃癌的发生、发展和转移。     

丹参酮Ⅰ对人胃腺癌细胞SGC-7901增殖、凋亡的影响

目的：研究丹参酮I（Tan I）对SGC-7901人胃腺癌细胞增殖、凋亡的影响。方法：体外培养SGC-7901细胞,实验分为对照组,5-FU250μg/ml,Tan I 0.5μg/ml,Tan I 1μg/ml,Tan I 2μg/ml,Tan I 4μg/ml。MTT法检测SCG-7901细胞增殖情况;Hoechst33258/PI双荧光活染法观察凋亡细胞核形态学改变;流式细胞仪检测细胞周期分布,免疫细胞化学SABC法检测SGC-7901人胃腺癌细胞中Bcl-2的表达。结果：Tan I对胃腺癌细胞的生长有明显的抑制作用;Tan I作用后胃腺癌细胞表现为凋亡特征性的形态改变;Tan I可浓度依赖性引起G1期细胞数量增多,S期细胞减少;Tan I作用组胃腺癌细胞Bcl-2表达明显减少。结论：TanI对体外培养的SGC-7901人胃腺癌细胞的生长有明显的抑制作用,可通过促进其凋亡、影响细胞周期分布及抑制SGC-7901人胃腺癌细胞Bcl-2的表达发挥其抗肿瘤作用。     

P21-activated protein kinase 1 is overexpressed in gastric cancer and induces cancer metastasis

P21-activated protein kinase (Pak1), a main downstream effector of small Rho GTPases, plays an important role in the regulation of cell morphogenesis, motility, mitosis and angiogenesis. However, the role of Pak1 in gastric cancer metastasis remains unclear. Here, we showed that Pak1 is overexpressed in gastric cancer tissues from 74 patients by immunohistochemistry. Overexpression of Pak1 was associated with metastasis and prognosis of gastric cancer. In addition, overexpression of Pak1 increased gastric cancer cell motility and invasion, whereas downregulation of Pak1 expression reduced gastric cancer cell migration and invasion. In further study, data showed that activated Pak1 inhibited stress fiber and focal adhesion complex formation in gastric cancer cells and led to the formation of motile phenotypes. Importantly, activated Pak1 elicited phosphorylation of the ERK and JNK-dependent pathway in gastric cancer cell lines. In conclusion, our results suggest that Pak1 is overexpressed in gastric cancer and plays an important role in the metastasis of gastric cancer. The mechanism by which Pak1 induces cancer metastasis may involve activation of ERK and JNK.     

丹参酮Ⅰ对人胃腺癌细胞SGC-7901增殖、凋亡的影响

目的:研究丹参酮I(Tan I)对SGC-7901人胃腺癌细胞增殖、凋亡的影响。方法:体外培养SGC-7901细胞,实验分为对照组,5-FU250μg/ml,Tan I 0.5μg/ml,Tan I 1μg/ml,Tan I 2μg/ml,Tan I 4μg/ml。MTT法检测SCG-7901细胞增殖情况;Hoechst33258/PI双荧光活染法观察凋亡细胞核形态学改变;流式细胞仪检测细胞周期分布,免疫细胞化学SABC法检测SGC-7901人胃腺癌细胞中Bcl-2的表达。结果:Tan I对胃腺癌细胞的生长有明显的抑制作用;Tan I作用后胃腺癌细胞表现为凋亡特征性的形态改变;Tan I可浓度依赖性引起G1期细胞数量增多,S期细胞减少;Tan I作用组胃腺癌细胞Bcl-2表达明显减少。结论:TanI对体外培养的SGC-7901人胃腺癌细胞的生长有明显的抑制作用,可通过促进其凋亡、影响细胞周期分布及抑制SGC-7901人胃腺癌细胞Bcl-2的表达发挥其抗肿瘤作用。     

miR-106a靶向调控TIMP2对人胃癌细胞增殖、转移及EMT的影响

目的 探讨微小RNA-106a(miR-106a)在人胃癌组织中的表达及其与癌细胞增殖、转移的关系。方法 收集人胃癌和配对癌旁福尔马林固定-石蜡包埋样本共50对,Real-time PCR法检测miR-106a在人胃癌组织中的表达;培养人低分化胃癌细胞系SGC-7901、BGC-823、MKN-45和永生化人胃黏膜上皮细胞GES-1,Real-time PCR法检测miR-106a在人胃癌细胞中的表达;MTT法检测细胞增殖,Transwell法检测细胞迁移和侵袭,生物信息学和双荧光素酶法鉴定miR-106a靶基因,Western blot检测靶蛋白TIMP2、MMP2、MMP9、E-cadherin、N-cadherin表达。结果 Real-time PCR检测显示,与癌旁组织比较,miR-106a在人胃癌组织中高表达,差异有统计学意义(P＜0.001);与GES-1细胞比较,miR-106a在人胃癌细胞SGC-7901、BGC-823、MKN-45中普遍高表达,差异有统计学意义(P＜0.001)。MTT检测显示抑制miR-106a后胃癌细胞SGC-7901、BGC-823增殖能力下降(P＜0.01)。Transwell显示胃癌细胞BGC-823迁移、侵袭能力下降(P＜0.001)。双荧光素酶法显示TIMP2野生型报告基因与miR-106a mimic共转后,其荧光素酶活性较miR-106a NC组明显下降(P＜0.001),但TIMP2突变型报告基因无明显变化。Western blot显示抑制miR-106a后TIMP2表达升高,MMP2、MMP9表达下降,E-cadherin表达升高,N-cadherin表达下降。结论 miR-106a在人胃癌中的高表达可能通过靶向TIMP2而影响癌细胞的增殖、转移和上皮-间质转化。     

川陈皮素抑制胃癌SGC-7901细胞侵袭能力的机制探讨

目的:观察川陈皮素（nobiletin,Nob）对胃癌SGC-7901细胞侵袭能力的影响,并探讨其可能的作用机制。方法:不同浓度的川陈皮素（0、30、60、120 mg/L）体外处理SGC-7901细胞。CCK8法检测细胞增殖能力;Transwell小室法检测细胞侵袭能力的改变;免疫印迹法检测细胞上皮间质转化（epithelial-mesenchymal transition,EMT)标志物（E-cadherin、Vimentin、Fibronectin）蛋白、MMP-9、STAT3、p-STAT3蛋白表达的改变。结果:CCK8和Transwell小室法检测结果显示,与对照组（0 mg/L）比较,川陈皮素可显著抑制SGC-7901细胞的增殖和侵袭能力;免疫印迹结果显示,随着川陈皮素浓度的增加,SGC-7901细胞E-cadherin蛋白表达逐渐上调,同时Vimentin、Fibronectin蛋白的表达量降低,MMP-9蛋白表达下调,STAT3总量未发生变化,但p-STAT3表达逐渐降低。结论:川陈皮素可降低胃癌SGC-7901细胞侵袭能力,其机制可能为通过抑制STAT3通路,继而抑制EMT。     

Calcium carbonate nanoparticle delivering vascular endothelial growth factor-C siRNA effectively inhibits lymphangiogenesis and growth of gastric cancer in vivo

A nonviral gene carrier, calcium carbonate (CaCO3) nanoparticle, was evaluated for efficient in vitro and in vivo delivery of small interfering RNA (siRNA) targeting vascular endothelial growth factor-C (VEGF-C). The chemically synthesized CaCO3 nanoparticle has a 58 nm diameter and +28.6 mV positive surface charge. It is capable of forming a CaCO3 nanoparticle-DNA complex and transferring DNA into targeted cells with high transfection efficiency while effectively protecting the encapsulated DNA from degradation. Furthermore, the CaCO3 nanoparticle-DNA complex has no obvious cytotoxicity for SGC-7901 cells, while a liposome-DNA complex exhibited measurable cytotoxicity. SGC-7901 cells transfected with a VEGF-C-targeted siRNA via CaCO3 nanoparticle exhibit significantly reduced VEGF-C expression as measured by real-time PCR and enzyme-linked immunosorbent assay; whereas no decrease in VEGF-C expression is observed in cells treated by control transfection. Transfection of SGC-7901 cells with VEGF-C siRNA via CaCO3 nanoparticle also dramatically suppresses tumor lymphangiogenesis, tumor growth and regional lymph-node metastasis in subcutaneous xenografts. Significant downregulation of VEGF-C messenger RNA expression in a subcutaneous xenograft derived from VEGF-C siRNA-treated SGC-7901 cells was confirmed by real-time PCR as compared to controls. We conclude that CaCO3 nanoparticle is a novel and nonviral system for effective delivery of siRNA for cancer gene therapy.     

沉默乙酰肝素酶基因对胃癌生物学行为的影响

目的 探讨乙酰肝素酶(HPA)沉默对人胃癌裸鼠移植瘤生长、转移和血管形成的影响.方法 利用人胃癌SGC-7901细胞和HPA被沉默的SGC-7901-HPA-细胞,分别建立6只裸鼠皮下移植瘤模型,观察成瘤的时间、肿瘤生长速度和体积.应用逆转录聚合酶链反应(RT-PCR)和Western blot方法分别检测皮下移植瘤组织中HPA mRNA和蛋白的表达,应用免疫组织化学SP法检测皮下移植瘤组织的微血管密度(MVD).将皮下移植瘤细胞分别注射入6只裸鼠腹腔,建立腹腔转移瘤,并观察成瘤情况.结果 SGC-7901细胞和SGC-7901-HPA-细胞在裸鼠皮下均能生长出移植瘤,分别在接种后第4天后和第7天后出现肉眼可见的肿瘤,接种SGC-7901-HPA-细胞的裸鼠移植瘤生长较慢,MVD为(11.35±1.94)个/高倍视野,明显低于接种SGC-7901细胞组[(20.69±1.20)个/高倍视野,P＜0.05].接种SGC-7901-HPA-细胞与接种SGC-7901细胞的裸鼠皮下移植瘤组织相比,HPA mRNA和蛋白的表达均降低.由SGC-7901细胞皮下移植瘤组织建立腹腔转移瘤的裸鼠,有3只成瘤,在肝脏、大网膜、肠系膜、右肾形成了4处转移灶,且体积较大.而接种SGC-7901-HPA-细胞皮下移植瘤组织的裸鼠,仅有1只在肝脏和右肾形成了转移灶,而且瘤体较小.结论 HPA沉默后抑制了人胃癌在裸鼠体内的生长、转移和血管形成,HPA有可能成为预防和治疗胃癌的一个新靶H点.