Norcantharidin anti-angiogenesis activity possibly through an endothelial cell pathway in human colorectal cancer

The present study was based on the unexpected discovery that norcantharidin exerted anti-angiogenesis activity when effects on growth of human colon cancer were studied. The aim was to further verify this finding and explore possible mechanisms using a tumor xenograft model in nude mice. We confirmed that norcantharidin (5 or 15 mg/kg) could inhibit angiogenesis of human colon cancer in vivo. In vitro, crossing river assay, cell adhesion assay and tube formation assay indicated that NCTD could reduce the migration, adhesion and vascular network tube formation ability of HUVECs. At the same time, the expression levels of VEGF and VEGFR-2 proteins which play important roles in angiogenesis were reduced as examined by western blotting analysis. Taken together, the results firstly showed NCTD could inhibit angiogenesis of human colon cancer in vivo, probably associated with effects on migration, adhesion and vascular network tube formation of HUVECs and expression levels of VEGF and VEGFR-2 proteins.     

汉防己甲素抑制血管生成的作用

背景与目的:血管生成在肿瘤从良性向恶性转变、癌细胞进入血液循环、转移灶发展和破裂中都起着重要作用.本研究探讨汉防己甲素对体外、体内血管生成的抑制作用及其可能的机制.方法:采用M1_r法观察汉防己甲素对人脐静脉血管内皮细胞(human umbilical vein endothelial cell HUVEC)和人肠癌LoVo细胞增殖的影响.通过Transwell小室趋化实验、体外小管形成实验观察汉防己甲素对HUVEC迁移、成血管能力的影响.建立裸鼠kIVo细胞皮下移植瘤模型.给予汉防己甲素灌胃,观察用药对肿瘤微血管密度的影响.结果:2-8 μg/mL的汉防己甲素作用48 h时对HUVEC的细胞增殖抑制率为24.6%-76.9%,对LoVo细胞增殖抑制率为11.6%～14.0%;体外小管形成实验发现.2～8 μg/mL的汉防己甲素作用24 h时HUVEC小管形成数目减少,且管腔不完整,与对照组比较差异有统计学意义(P值均＜0.001).经2-8 μg/mL的汉防己甲素处理12 h后HUVEC迁移数明显少于对照组(P值均＜O.001).在裸鼠皮下移植瘤体内实验中,80 mg/kg汉防己甲素作用于裸鼠LoVo细胞皮下移植瘤后其微血管密度与生理盐水对照组比较.差异具有统计学意义(p0.035).结论:汉防己甲素在体外能有效抑制血管生成,其机制可能与抑制HUVEC增生、迁移和小管形成,诱导HUVEC凋亡,抑制HUVEC DNA的合成有关.汉防己甲素在体内对裸鼠LoVo移植瘤具有抗血管生成作用.     

Penta-O-galloyl-beta-D-glucose suppresses tumor growth via inhibition of angiogenesis and stimulation of apoptosis: roles of cyclooxygenase-2 and mitogen-activated protein kinase pathways

Recent studies have revealed that 1,2,3,4,6-penta-O-galloyl-beta-d-glucose (PGG) has anti-tumorigenic activity in vitro. In the present work, we evaluated the in vitro and in vivo antiangiogenic and antitumor activities of PGG and examined its molecular mechanisms. PGG significantly inhibited the proliferation and tube formation in basic fibroblast growth factor (bFGF)-treated human umbilical vein endothelial cells (HUVECs) at non-cytotoxic concentrations. PGG effectively disrupted the bFGF-induced neo-vascularization in chick chorioallantoic membrane (CAM) and in Matrigel plugs in the mice. When mice were intraperitoneally injected, PGG also significantly inhibited tumor angiogenesis induced by Lewis lung carcinoma (LLC) and the growth of LLC by 57 and 91% of control tumor weight at 4 and 20 mg/kg, respectively. Immunohistochemical analysis revealed decreased microvessel density, decreased expression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF), reduced tumor cell proliferation and increased tumor cell apoptosis. Similarly, PGG significantly attenuated the expression of COX-2 and VEGF and reduced the secretion of VEGF and prostaglandin E2 in bFGF-treated HUVECs. Furthermore, the COX-2 inhibitor NS398 significantly inhibited tube formation and neo-vascularization in CAM, supporting the role of COX-2 in PGG inhibition of angiogenesis. PGG diminished the phosphorylation of extracellular signal regulated kinase 1/2, Jun NH2-terminal kinase and activated phospho-p38 mitogen-activated protein kinase (MAPK) in a dose-dependent manner in bFGF-treated HUVECs. In addition, p38 inhibitor SB203580 abolished the downregulation of COX-2, VEGF and the antiproliferative activity by PGG. Taken together, our data demonstrate that PGG exerts antitumor activity primarily via inhibition of angiogenesis through COX-2 and MAPK- dependent pathways.     

姜黄素抗血管生成分子机制的探讨

目的：研究姜黄素抑制血管生成的分子机制。方法：采用MTT法、流式细胞术（FCM）观察姜黄素对人脐静脉内皮细胞（HUVECs）的抑制作用及促凋亡作用。采用RT-PCR法及Western-blot法检测姜黄素作用人肺腺癌A2细胞不同时间后血管生成素（Ang-1、Ang-2）、血小板反应素（TSP）mRNA的表达水平和血管内皮生长因子（VEGF）,基质金属蛋白酶（MMP-9）的蛋白表达水平。结果：姜黄素能抑制HUVECs的增殖,呈时间及浓度依赖性,且能诱导HUVECs凋亡,凋亡率明显高于对照组（P〈0.01）。A2细胞经100μmol/L姜黄素作用不同时间后Ang-1、Ang-2、TSPmRNA的表达率明显下降;VEGF与MMP-9的蛋白表达也明显减少。结论：姜黄素可能通过下列途径抑制肿瘤的血管生成：1）直接抑制血管内皮细胞增殖并促进其凋亡;2）抑制血管生成促进因子（VEGF,Ang-1,Ang-2）的表达;3）促进血管生成抑制因子TSP的表达;4）降低基质金属蛋白酶MMP-9的活性从而抑制细胞外基质降解。     

Norcantharidin inhibits tumor angiogenesis via blocking VEGFR2/MEK/ERK signaling pathways

Norcantharidin (NCTD), the demethylated form of Cantharidin, a reagent isolated from blister beetles, has been shown to be an anti‐tumor agent capable of inhibiting proliferation as well as inducing apoptosis in many cancer cell lines. However, little is known about the effect of NCTD in tumor angiogenesis. In this study, we demonstrated that NCTD inhibited vascular endothelial growth factor (VEGF)‐induced cell proliferation, migration, invasion, and capillary tube formation of primary human umbilical vein endothelial cells (HUVECs) in a dose‐dependent manner. Furthermore, we showed NCTD inhibited tumor growth and angiogenesis of colon cancer cells (LOVO) in vivo. We then mechanistically described that NCTD specifically abrogated the phosphorylation/activation of vascular endothelial growth factor receptor‐2 (VEGFR2)/MEK/ERK pathway kinases, with little effect on the phosphorylation of p38 MAPK and Akt, and on Cox‐2 expression. In summary, our results indicate that NCTD is a potential inhibitor of tumor angiogenesis by blocking VEGFR2/MEK/ERK signaling.     

环氧合酶-2抑制剂塞来昔布对人肝癌HepG2裸小鼠移植瘤生长和肿瘤血管生成的抑制作用

背景与目的:有研究证实,环氧合酶-2(cyclooxygenase-2,COX-2)与肿瘤,特别是与消化系统肿瘤形成的关系较为密切,而其抑制剂则具有抗肿瘤作用。本研究探讨特异性抑制剂塞来昔布对人肝癌HepG2裸小鼠移植瘤生长和肿瘤血管生成的抑制作用。方法:将肝癌细胞HepG2种植至裸鼠背侧皮下,4天后开始用塞来昔布治疗,58天后处死。观测裸鼠移植瘤的体积和质量。并采用免疫组化和逆转录-聚合酶链反应法(RT-PCR)检测裸鼠移植瘤组织中COX-2、血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)、碱性成纤维生长因子(basicfibroblastgrowthfactor,bFGF)和血管生成素-2(angiopoientin-2,Ang-2)的表达,用免疫组化法检测微血管密度(microvesseldensity,MVD)。结果:治疗组切除的移植瘤平均体积和质量分别是(709.11±108.53)mm3和(2.63±0.34)g,对照组分别为(1417.55±69.50)mm3和(5.32±0.98)g,两组比较差异有显著性(P<0.01)。治疗组肿瘤增殖率为55.21%。②对照组COX-2、VEGF、bFGF、Ang-2的表达和MVD值分别是4.50±0.25、5.43±0.58、4.03±0.47、5.53±0.54和128.24±9.82,而在塞来昔布组分别是2.42±0.29、2.80±0.30、2.23±0.41、2.88±0.25和29.23±1.52。两组相比较,COX-2、VEGF、bFGF、Ang-2的表达和MVD值差异有显著性(P<0.01)。COX-2与VEGF、bFGF、Ang-2和MVD有明显的相关性(r分别为0.862、0.882、0.857,P分别<0.01)。结论:塞来昔布有效抑制了人肝癌细胞HepG2裸小鼠移植瘤的生长和血管生成,其作用途径是抑制了COX-2的表达。     

Angiogenesis in cholangiocellular carcinoma: expression of vascular endothelial growth factor, angiopoietin-1/2, thrombospondin-1 and clinicopathological significance

Angiogenesis in cholangiocellular carcinoma (CCC) has rarely been investigated. The aim of this study was to determine the angiogenesis status of CCC and assess its relationship with angiogenic factors and clinicopathological characteristics. We examined 33 surgically resected CCC specimens. Tumor angiogenesis was assessed by microvessel density (MVD) using the anti-CD34 antibody, and the expression of VEGF, Ang-1, Ang-2, and TSP-1 was determined by immunohistochemistry. The mean (+/- SD) MVD was 87.2+/-52.6/mm2 (range, 0-229/mm2). A total of 75.6% cases were positive for VEGF expression, 36% for Ang-1, 57.6% for Ang-2 and 45.5% for TSP-1. VEGF and Ang-2 expression was associated with a significantly higher level of MVD (p=0.004 and 0.015, respectively). TSP-1 expression was associated with a significantly lower level of MVD (p=0.005) and a higher level of intrahepatic metastasis (46.7% vs. 5.6%, p=0.012). There was no significant correlation between VEGF, Ang-1, Ang-2, and TSP-1 expression and tumor size, capsule formation, infiltration of capsule, portal vein invasion, intrahepatic metastasis or CCC differentiation. There was no significant correlation between MVD levels, VEGF, Ang-1, Ang-2, and TSP-1 expression and postoperative survival. A considerable degree of angiogenesis, comparable to that of other solid tumors, was observed in CCC. VEGF and Ang-2 might play a proangiogenic role, and TSP-1 may play an inhibitory role in CCC. Although TSP-1 may increase intrahepatic CCC metastases, neither MVD levels nor the expression of VEGF, Ang-1, or Ang-2 was associated with clinicopathological factors and prognosis.     

血管内皮生长因子介导的卵巢恶性肿瘤浸润生长的实验研究

 目的探讨血管内皮生长因子(VEGF)在卵巢癌细胞肿瘤血管形成及浸润中的作用。方法脂质体介导VEGFcDNA转染卵巢癌细胞OVCAR3,并经Northernblot和Westernblot法检测转染VEGFcDNA前后卵巢癌细胞中的VEGFmRNA和蛋白表达水平。将VEGF表达阳性的细胞接种于裸鼠皮下观察负荷瘤生长速度、重量并采用免疫组化的方法检测其微血管密度(MVD)。结果(1)VEGFcDNA转染后的卵巢癌细胞系VEGFmRNA和蛋白表达水平明显高于转染前(P<0.05)。(2)体外实验显示转染与非转染细胞系生长曲线基本相同。(3)VEGFcDNA转染后的卵巢癌细胞系接种裸鼠后其负荷瘤生长速度和重量均明显高于未转染的裸鼠负荷瘤(P<0.05)。(4)VEGF表达阳性的裸鼠负荷瘤其MVD也明显高于VEGF表达阴性的裸鼠负荷瘤(P<0.05)。结论VEGF通过促进肿瘤新生血管的增多进而在卵巢癌浸润生长中发挥作用。     

Inhibition of human leukemia xenograft in nude mice by adenovirus-mediated tissue inhibitor of metalloproteinase-3.

Considerable studies have demonstrated the pivotal roles of matrix metalloproteinases (MMPs) in leukemia dissemination and extramedullary infiltration. Tissue inhibitors of matrix metalloproteinases (TIMPs) are multifunctional proteins with MMPs inhibitory effects. However, little is known about the application of TIMPs in the treatment of leukemia. Here, we investigated the effects of TIMP-3 overexpression via adenoviral gene delivery on the in vitro growth and invasiveness of leukemic cells and the in vivo progress of K562-derived xenografts in nude mice. The in vitro invasiveness of K562 cells was markedly impaired by AdTIMP-3 infection. Moreover, TIMP-3 significantly inhibited K562-derived angiogenic factors-induced proliferation, migration and bFGF-induced tube formation of endothelial cells (ECs) in vitro, and reduced VEGF-induced gelatinases expression and activation in ECs. Although TIMP-3 overexpression had no direct effect on the growth of K562 cells in vitro, repeated intratumoral injection of AdTIMP-3 significantly inhibited the growth of K562 xenografts in nude mice. Furthermore, lower microvessel density, less vessel maturity and increased apoptosis were observed in AdTIMP-3-treated K562 xenografts, suggesting the importance of antiangiogenic action of TIMP-3. These data demonstrated the potential of applying AdTIMP-3 as an effective antiangiogenic adjuvant in the treatment of leukemia progression.     

Antitumor and anti-metastatic effects of cyclooxygenase-2 inhibition by celecoxib on human colorectal carcinoma xenografts in nude mouse rectum

We examined the effects of the preferential cyclooxygenase-2 (COX-2) inhibitor celecoxib on tumorigenesis, angiogenesis, apoptosis, vascular endothelial growth factor (VEGF) protein expression and metastasis in HT-29 human colorectal carcinoma cell xenografts in nude mouse rectum. COX-2 mRNA expression was examined in the xenograft and metastatic sites. The antitumor effect of celecoxib in the xenografts was evaluated by measuring the weight of the peri-ano-rectal tumor. The anti-metastatic effect of celecoxib was assessed by quantification of lymph node and lung metastases by amplification of a cancer-related human DNA by TaqMan PCR. The effects of celecoxib on angiogenesis, apoptosis, prostaglandin E2 (PGE2) production and VEGF protein expression in the xenografts were evaluated by means of microvessel density (MVD) counting, terminal deoxynucleotidyl transferase-mediated nick end labeling assay, quantitative enzyme-linked immunosorbent assay and western blotting, respectively. The rectal xenograft model showed lymph node and lung metastases with enhanced expression of COX-2 mRNA in each organ. Celecoxib inhibited rectal xenograft growth in a dose-dependent manner as follows: 150?ppm, 33.0% (p=0.000220); 750?ppm, 46.4% (p=0.0000292); 1500?ppm, 63.4% (p=0.0000109). Celecoxib inhibited lymph node metastasis in a dose-dependent manner as follows: 150?ppm, 86.7% (p=0.0263); 750?ppm, 90.3% (p=0.00638); 1500?ppm, 96.0% (p=0.000894). Celecoxib also inhibited lung metastasis as follows: 750?ppm, 53.3% (p=0.0107); 1500?ppm, 78.3% (p=0.00022). Celecoxib (1500?ppm) significantly inhibited PGE2 production by 68.4% (p=0.000157) and MVD counting by 48.2% (p=1.3x10-12) and induced apoptosis 2.5-fold (p=3.0x10-14) in the rectal xenograft. Celecoxib suppressed VEGF protein expression in the rectal xenograft. These studies demonstrate that celecoxib reduces the growth and metastatic potential of colorectal carcinoma in mice through COX-2 inhibition, anti-angiogenesis and apoptosis induction. The studies using HT-29 human colorectal carcinoma cell xenografts in nude mouse rectum also provide important information that supports that the COX-2 inhibitor celecoxib has a high potential for use as a clinical agent for inhibition of hematological and lymphatic metastases of colorectal cancer.     

血管内皮生长因子、血管生成素在食管鳞状细胞癌组织中的表达及其意义

目的 研究血管内皮生长因子(VEGF)、血管生成素(Ang)-1及Ang-2在食管鳞状细胞癌(ESCC)中的表达及其与预后的关系.方法 用免疫组织化学二步法检测60份ESCC、20份食管癌旁组织及10份正常食管黏膜上皮组织中VEGF、Ang-1及Ang-2的表达,计数微血管密度(MVD).结果 ESCC与食管癌旁组织及食管正常鳞状上皮组织比较,Ang-1表达率显著降低,而VEGF及Ang-2表达率则显著升高(P＜0.05).MVD在Ang-1阴性表达组显著高于阳性表达组(P=0.000);MVD在VEGF、Ang-2阳性表达组显著高于阴性表达组(P＜0.05).Ang-1表达与肿瘤分化程度显著相关(P=0.013).T3、T4期VEGF和Ang-2表达率显著高于T1、T2期(P＜0.05);VEGF及Ang-2在有淋巴结转移者显著高于无淋巴结转移者(P＜0.001).VEGF及Ang-2表达阳性组术后3年生存率低于阴性表达组(P＜0.05),Ang-1表达阳性和阴性组比较,差异无统计学意义(P=0.749).结论 Ang-1表达的降低及Ang-2、VEGF表达的增高可能与食管癌的发生、发展密切相关;VEGF及Ang-2在食管癌中表达提示预后不良.     

Angiopoietin 2 expression in invasive ductal carcinoma of the breast: its relationship to the VEGF expression and microvessel density

Summary Angiopoietin (Ang) is a ligand for the endothelium-specific tyrosine kinase receptor Tie-2, while a shift in the Ang-1:Ang-2 expression ratio in favor of Ang-2 was found to be associated with tumor angiogenesis. In the present study, we analyzed the immunohistochemical expression of Ang-2 in a series of 198 breast cancers, in which VEGF expression and microvessel density (MVD) were previously determined. Ang-2 expression was negative in 24 (12%), positive in 50 (25%) and strongly positive in 124 (63%) of 198 cases. A significant correlation was found between Ang-2 and VEGF expressions (p=0.0004) and between Ang-2 expression and MVD (p=0.0006), while a high MVD was found in 10 (77%) of 13 tumors with a strongly positive VEGF and positive Ang-2 expression and in 40 (71%) of 56 tumors with a strongly positive VEGF and strongly positive Ang-2 expression. Although there was no difference in the disease free survival (DFS) stratified according to Ang-2 expression alone, the 69 patients with a strongly positive VEGF and a strongly positive or positive Ang-2 expression had a significantly (p=0.0316) worse DFS than those with other combinations of VEGF and Ang-2 expressions. A multivariate analysis indicated lymph node metastasis and MVD to be independently significant prognostic factors for DFS, while the combination of VEGF and Ang-2 expressions was not a significant factor for DFS. In conclusion, the Ang-2 expression was found to be closely correlated with VEGF expression and MVD in breast cancer, while a high MVD was frequently found in tumors with a high expression of both VEGF and Ang-2. The survival analysis demonstrated a high MVD, which was induced by a high expression of both VEGF and Ang-2, to therefore have a strong prognostic significance in breast cancer.     

3,3'-Diindolylmethane inhibits angiogenesis and the growth of transplantable human breast carcinoma in athymic mice

Studies have linked the consumption of broccoli and other cruciferous vegetables to a reduced risk of breast cancer. The phytochemical indole-3-carbinol (I3C), present in cruciferous vegetables, and its major acid-catalyzed reaction product 3,3'-diindolylmethane (DIM) have bioactivities relevant to the inhibition of carcinogenesis. In this study, the effect of DIM on angiogenesis and tumorigenesis in a rodent model was investigated. We found that DIM produced a concentration-dependent decrease in proliferation, migration, invasion and capillary tube formation of cultured human umbilical vein endothelial cells (HUVECs). Consistent with its antiproliferative effect, which was significant at only 5 microM DIM, this indole caused a G1 cell cycle arrest in actively proliferating HUVECs. Furthermore, DIM downregulated the expression of cyclin-dependent kinases 2 and 6 (CDK2, CDK6), and upregulated the expression of CDK inhibitor, p27(Kip1), in HUVECs. We observed further in a complementary in vivo Matrigel plug angiogenesis assay that, compared with vehicle control, neovascularization was inhibited up to 76% following the administration of 5 mg/kg DIM to female C57BL/6 mice. Finally, this dose of DIM also inhibited the growth of human MCF-7 cell tumor xenografts by up to 64% in female athymic (nu/nu) mice, compared with the vehicle control. This is the first study to show that DIM can strongly inhibit the development of human breast tumor in a xenograft model and to provide evidence for the antiangiogenic properties of this dietary indole.     

三阴性乳腺癌组织Angs/Tie-2和VEGF的表达及其意义的探讨

目的:研究Ang-1、Ang-2和Tie-2及VEGF蛋白在三阴性乳腺癌(TNBC)组织中的表达及其与MVD的关系,并分析其与TNBC临床病理学特征及其预后的关系。方法:应用免疫组化SP法对45例TNBC组织中Ang-1、Ang-2和Tie-2及VEGF蛋白表达进行检测,并用同样方法检测45例TNBC组织中CD34的表达以评估MVD。结果:TNBC肿瘤组织中Ang-1、Ang-2和Tie-2及VEGF蛋白表达率分别为31.1%(14/45)、57.8%(26/45)、44.4%(20/45)和66.7%(30/45)。Ang-2蛋白表达与Tie-2蛋白表达呈正相关(r=0.312,P=0.037),Ang-2蛋白表达与VEGF蛋白表达呈正相关(r=0.350,P=0.018)。MVD在Ang-2蛋白阳性表达组显著高于阴性表达组(t=-9.110,P=0.000);MVD在VEGF蛋白阳性表达组显著高于阴性表达组(t=-0.889,P=0.000)。Ang-1、Ang-2、和Tie-2及VEGF蛋白表达与年龄、绝经状态、病理分期、肿瘤大小、淋巴结转移均无相关性(P均>0.05)。TNBC术后生存时间与Ang-1...     

Inhibition of infiltration and angiogenesis by thrombospondin-1 in papillary thyroid carcinoma.

PURPOSE: Angiogenesis is essential for tumor growth and is controlled by the balance between angiogenic and antiangiogenic factors. We studied the expression of angiogenic factors and antiangiogenic factors in papillary thyroid carcinoma. EXPERIMENTAL DESIGN: We investigated immunohistochemically the expression patterns and levels of antiangiogenic factor and its receptor, thrombospondin-1 (TSP-1) and CD36, and four angiogenic factors, vascular endothelial growth factor (VEGF), VEGF-C, angiopoietin-2 (Ang-2), and Tie-2, in the primary tumors of 75 papillary thyroid carcinoma patients. We also examined the microvessel count (MVC), using CD31 staining. RESULTS: VEGF expression strongly correlated with other angiogenic factors. The cytoplasm of cancer cells stained positive for all factors. Tie-2 and TSP-1 receptor also appeared in endothelia of microvessels. TSP-1 inversely correlated with the degree of invasion of the primary tumor to other adjacent organs and with MVC. A higher MVC correlated with poorer survival. To clarify the balance between angiogenic and antiangiogenic factors in the same tumor, we calculated the ratio of each angiogenic factor against TSP-1 as the antiangiogenic factor. The ratios VEGF/TSP-1, VEGF-C/TSP-1, and Ang-2/TSP-1 significantly correlated with a higher MVC. Furthermore, the ratios VEGF/TSP-1 and Ang-2/TSP-1 significantly correlated with the degree of infiltration. CONCLUSIONS: To the best of our knowledge, this is the first report demonstrating that the balance between angiogenic and antiangiogenic factors correlates with distinct invasion to other organs and neovascularization of papillary thyroid carcinoma.     

人骨肉瘤细胞系OS—732 CAM移植瘤中VEGF、bFGF的表达及意义

目的：研究人骨肉瘤细胞系OS－732血管生成相关作用。方法：应用鸡胚绒毛尿囊膜模型,通过解剖显微镜及透射电镜观察该细胞系促血管生成特点,并以免疫组化方法检测人骨肉瘤细胞系OS－732鸡胚绒毛尿囊膜移植瘤中血管内皮生长因子（vascular endothelial growth factor,VEGF),碱性成纤维细胞生长因子（Basic fibroblast growth factor,bFGF)的表达。结果：该细胞系具较强的诱导血管生成能力,解剖显微镜下可见血管辐辏现象,透射电镜下可见新生血管壁由单层内皮细胞构成,内皮细胞裂隙增宽,基底膜不完整,缺乏平滑肌成分,移植瘤组织发VEGF和bFGF均呈阳性表达,其中VEGF呈高表达。结论：肿瘤诱导的新生血管在病理,生理及形态功能方面都具有特征性,其诱导血管生成过程中可能有多种血管生长因子的共同参与,针对血管生长因子为靶点进行抗血管生成治疗对改善骨肉瘤预后可能具有重要意义。     

泰素帝对荷瘤小鼠肿瘤组织VEGF和TSP1表达的影响

目的：观察泰素帝对裸鼠人大肠癌LOVO细胞皮下移植瘤血管生成抑制作用及其作用机理。方法：通过建立裸鼠人大肠癌LOVO细胞皮下移植瘤模型,观察泰素帝的抑瘤作用,并采用免疫组织化学法检测泰素帝对肿瘤组织MVD、VEGF、TSP1表达的影响。结果：泰素帝的抑瘤率为72．4％。泰素帝能显著降低肿瘤微血管密度,下调VEGF和上调TSP1的表达。结论：泰素帝可能通过抑制肿瘤血管生成而发挥抗肿瘤作用;下调VEGF可能是泰素帝抗血管生成作用机理之一;上调TSP1可能是泰素帝抗血管生成另一作用机理。     

Antiangiogenic effect of ZSTK474, a novel phosphatidylinositol 3-kinase inhibitor

Angiogenesis is known to be required for tumour growth and metastasis. Recent reports indicated that phosphatidylinositol 3-kinase (PI3K) promoted angiogenesis by inducing expressions of HIF-1α and vascular endothelial growth factor (VEGF). The present study aims to investigate the antiangiogenic effect of ZSTK474, a novel pan-PI3K inhibitor. ZSTK474 significantly inhibited tumour growth in the RXF-631L xenograft model. Immunohistochemical staining of the tumour tissue with anti-von Willebrand Factor antibody showed a significantly reduced number of microvessels in the ZSTK474-treated mice, suggesting the highly promising antiangiogenic activity in vivo. In human umbilical vein endothelial cells (HUVECs), submicromolar concentrations of ZSTK474 inhibited cell growth, blocked VEGF-induced cell migration and the tube formation, and thus revealed potent in vitro antiangiogenic activity. Furthermore, ZSTK474 inhibited phosphorylation of Akt at submicromolar concentrations. In RXF-631L cancer cells, on the other hand, ZSTK474 treatment inhibited the expression of HIF-1α and secretion of VEGF. Together, these results suggest that ZSTK474 has potent antiangiogenic activity, which could be attributed to dual-target inhibitory properties: inhibition of VEGF secretion by cancer cells and inhibition of PI3K in endothelial cells.     

促血管生成素-2对胃癌血管生成的双向效应

目的　探讨促血管生成素 2 (Ang 2 )在胃癌血管生成中的作用。方法　运用RT PCR和S P免疫组化方法检测Ang 2mRNA、血管内皮生长因子 (VEGF)、CD34蛋白在 36例胃癌及其相应癌旁胃黏膜组织中的表达。结果　胃癌组织及其相应癌旁胃黏膜组织均见有Ang 2mRNA阳性表达 ,胃癌组织Ang 2mRNA的总体表达水平与微血管密度 (MVD)未见明显相关。胃癌组织Ang 2mRNA表达水平低于癌旁胃黏膜组织者 2 7例 ,其癌组织中 ,Ang 2mRNA的表达水平与MVD呈正相关 (r=0 .4 11,P <0 .0 5 ) ;同时 ,VEGF阳性表达者的MVD(45 .4 5± 10 .30 )明显高于VEGF阴性染色者 (30 .15± 8.6 9,P <0 .0 5 ) ,即在Ang 2表达上调的情况下VEGF促进血管生成。胃癌组织Ang 2mRNA表达水平高于癌旁组织者 9例 ,其癌组织中Ang 2mRNA的表达水平与肿瘤组织的MVD呈负相关 (r =- 0 .75 8,P <0 .0 5 ) ,VEGF的阳性表达者与阴性染色者间 ,MVD差异无显著性 ,即Ang 2抑制血管生成与VEGF的表达无相关性。结论　Ang 2对胃癌血管生成具有双向调节作用。     

Combination therapy of interferon-alpha and 5-fluorouracil inhibits tumor angiogenesis in human hepatocellular carcinoma cells by regulating vascular endothelial growth factor and angiopoietins

We recently reported that interferon-alpha (IFN-alpha) and 5-fluorouracil (5-FU) combination therapy in advanced hepatocellular carcinoma (HCC) achieved excellent clinical results. However, the mechanism underlying this combination therapy remains to be elucidated. In this study, we examined the anti-tumor effects of IFN-alpha and 5-FU combination therapy in vivo and aimed to reveal its anti-angiogenic effects by investigating the expression of vascular endothelial growth factor (VEGF) and angiopoietins (Ang-1 and Ang-2). Human HCC cells, HuH7, were subcutaneously injected in nude mice. Ten days later, groups of mice received treatment with IFN-alpha alone, 5-FU alone, or with a combination of IFN-alpha and 5-FU for four weeks. Immunohistochemical examinations of proliferating cell nuclear antigen (PCNA), cell differentiation antigen 34 (CD34), Ang-1, -2 and VEGF, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and quantification of VEGF, Ang-1 and-2 mRNA using real-time RT-PCR were performed. Results showed that IFN-alpha and 5-FU combination therapy significantly inhibited the growth of human HCC cells compared with the control group or single agent treatment. The combination therapy decreased PCNA-positive cells as well as microvessel density (MVD) and induced apoptosis of (TUNEL-positive cells) more than other treatment groups. Immunohistochemical analysis revealed that the combination therapy significantly decreased the expression of VEGF and Ang-2 and increased that of Ang-1. The ANG2/ANG1 mRNA expression ratio was significantly lower in the combination therapy group. In conclusion, our results suggested that IFN-alpha and 5-FU combination therapy has anti-proliferative and anti-angiogenic effects and can induce apoptosis in vivo. The synergistic and anti-angiogenic effects may in part be attributable to the regulation of Ang-1, -2 and VEGF.