EMP1 inhibits nasopharyngeal cancer cell growth and metastasis through induction apoptosis and angiogenesis

This study aimed to analyze the expression, clinical significance of epithelial membrane protein-1 (EMP1) in nasopharyngeal carcinoma, and the biological effect in its cell line by EMP1 overexpression. Immunohistochemistry and Western blot were used to analyze the EMP1 protein expression in 75 cases of nasopharyngeal cancer and 31 cases of normal tissues to study the relationship between EMP1 expression and clinical factors. Recombinant lentiviral vector was constructed to overexpress EMP1 and then infect nasopharyngeal cancer CNE2 cell line. Quantitative real-time RT-PCR and Western blot were used to detect the mRNA level and protein of EMP1. MTT assay, cell apoptosis, migration, and invasion assays were also conducted to determine the influence of the upregulated expression of EMP1 that might be found on CNE2 cells’ biological effect. Immunohistochemistry and Western blot: The level of EMP1 protein expression was found to be significantly lower in nasopharyngeal cancer tissue than in the normal tissues (P?<?0.05). Decreased expression of EMP1 was significantly correlated with T stages, lymph node metastasis, clinic stage, and histological grade of patients with nasopharyngeal cancer (P?<?0.05). Meanwhile, the loss of EMP1 expression correlated significantly with poor overall survival time by Kaplan–Meier analysis (P?<?0.05). The result of biological function has shown that CNE2 cell-transfected EMP1 had a lower survival fraction, higher cell apoptosis, significant decrease in migration and invasion, higher caspase-9, and lower vascular endothelial growth factor C protein expression compared with CNE2 cell-untransfected EMP1 (P?<?0.05). EMP1 expression decreased in nasopharyngeal cancer and correlated significantly T stages, lymph node metastasis, clinic stage, histological grade, and poor overall survival, suggesting that EMP1 may play important roles as a negative regulator to nasopharyngeal cancer cell.     

Vaccination with xenogeneic tumor endothelial proteins isolated in situ inhibits tumor angiogenesis and spontaneous metastasis

Angiogenesis is critical for tumor growth and metastasis. Tumor tissues induce the expression of angiogenesis‐associated proteins on endothelial surface that can be targeted for tumor immunotherapy. In our study, the rat tumor endothelial proteins (EP) were isolated in situ via biotinylation of tumor vascular endothelial luminal surface followed by streptavidin affinity chromatography. The isolated tumor EP contained numerous up‐regulated angiogenesis‐associated endothelial proteins. The administration of these tumor EP as a vaccine to mice reduced the microvessel density in subcutaneous primary LLC tumors, delayed spontaneous LLC tumor metastasis and prolonged post‐surgery life span. T lymphocytes from tumor EP‐vaccinated mice lysed human umbilical vascular endothelial cells, but not tumor cells in vitro, in a dose‐dependent manner. Furthermore, adoptive transfer of antitumor EP antibodies in vivo targeted to tumor endothelium and inhibited spontaneous LLC tumor metastasis. This study provides a successful preclinical exploration of the active immunotherapy for tumor by targeting tumor angiogenesis. © 2009 UICC     

Gabexate mesilate inhibits colon cancer growth, invasion, and metastasis by reducing matrix metalloproteinases and angiogenesis.

Gabexate mesilate (GM), a synthetic protease inhibitor, has an antiproteinase activity on various types of plasma serine proteases. However, its role on matrix metalloproteinases (MMPs) has not been identified. In this study, we investigated the effect of GM on MMPs and on the invasion and metastasis of human colon cancer cell lines and neoangiogenesis. The activities of MMPs secreted from these cells were significantly reduced by GM but unaffected by the serine protease inhibitor aprotinin. GM directly inhibited purified progelatinase A derived from T98G human glioblastoma cells. In vitro, GM significantly reduced the invasive ability of colon cancer cells but not cellular motility, whereas aprotinin affected neither. Liver metastatic ability and tumorigenic potential in nude mice were remarkably reduced on treatment with GM. Immunohistochemical analysis of GM-treated tumors in mice showed a marked increase in apoptosis and a significant reduction in tumor angiogenesis. Human umbilical vein endothelial cell proliferation, tube formation, and neoangiogenesis in the rabbit cornea and Matrigel implanted in mice were significantly inhibited by GM. These results suggest that GM is a novel inhibitor of MMPs and that it may inhibit the invasion and metastasis of human colon cancer cells by blocking MMPs and neoangiogenesis.     

Multikinase inhibitor regorafenib inhibits the growth and metastasis of colon cancer with abundant stroma

Interaction between tumor cells and stromal cells plays an important role in the growth and metastasis of colon cancer. We previously found that carcinoma‐associated fibroblasts (CAFs) expressed platelet‐derived growth factor receptor‐β (PDGFR‐β) and that PDGFR targeted therapy using imatinib or nilotinib inhibited stromal reaction. Bone marrow‐derived mesenchymal stem cells (MSCs) migrate to tumor stroma and differentiate into CAFs. A novel oral multikinase inhibitor regorafenib inhibits receptor tyrosine kinases expressed on stromal cells (vascular endothelial growth factor receptor 1–3, TIE2, PDGFR‐β, and fibroblast growth factors) and tumor cells (c‐KIT, RET, and BRAF). These molecules are involved in tumor growth, angiogenesis, lymphangiogenesis, and stromal activation. Therefore, we examined whether regorafenib impaired the tumor‐promoting effect of CAFs/MSCs. KM12SM human colon cancer cells alone or KM12SM cells with MSCs were transplanted into the cecal wall of nude mice. Co‐implantation of KM12SM cells with MSCs into the cecal wall of nude mice produced tumors with abundant stromal component and promoted tumor growth and lymph node metastasis. Single treatment with regorafenib inhibited tumor growth and metastasis by inhibiting both tumor cells and stromal reaction. This tumor‐inhibitory effect of regorafenib was more obvious in tumors developed by co‐implanting KM12SM cells with MSCs. Our data suggested that targeting of the tumor microenvironment with regorafenib affected tumor cell–MSC interaction, which in turn inhibited the growth and metastasis of colon cancer.     

血管生成抑制剂治疗结肠癌肝转移的研究进展

血管生成抑制剂与传统的细胞毒化疗药物不同，可作用于包含多种变异的正常细胞。因此，血管生成抑制剂与细胞毒药物临床应用的传统策略不同。许多临床研究正在用一种新的途径评价这些涉及到抑制细胞生长繁殖不同时期的药物。     

人血管能抑素抑制小鼠Lewis肺癌移植瘤生长、转移及血管新生

目的:探讨人血管能抑素(canstatin)对小鼠Lewis肺癌移植瘤生长、转移和血管新生的影响.方法:将pCMV-Script/canstatin及空载体pCMV-Script通过电穿孔的方法转染A549细胞,G418筛选获得阳性克隆.RT-PCR检测转染后细胞中canstatin mRNA的表达,Western blotting检测转染后细胞中canstatin蛋白的表达.建立Lewis肺癌小鼠移植瘤模型,观察pCMV-Script/canstatin组A549细胞培养上清对小鼠Lewis肺癌移植瘤的治疗作用,免疫组化检测各治疗组荷瘤小鼠移植瘤的微血管密度.结果:pCMV-Script/canstatin转染A549细胞在G418筛选后成功形成克隆,转染的A549细胞能有效表达canstatin mRNA和蛋白.pCMV - Script/canstatin治疗组小鼠肿瘤体积明显小于pCMV-Script组和NS组[(1.47 ±0.21)cm3 vs(2.43 ±0.15) cm3、(2.53 ±0.18) cm3,P ＜0.01);pCMV-Script/canstatin组、pCMV - Script组和NS组的肺转移结节数分别为(3.00±1.00)、(7.80±1.48)、(7.60 ±2.41)个,pCMV-Script/canstatin组肿瘤转移受到显著的抑制(P＜0.01);pCMV-Script/canstatin组小鼠的肿瘤组织微血管数明显少于pCMV-Script组和NS组[(84.40 ±8.83) vs (188.68 ±11.15)、(190.24±12.91)个,P＜0.01].结论:pCMV-Script/canstatin能在A549细胞中表达并分泌至细胞外,canstatin可明显抑制Lewis肺癌移植瘤的生长、转移和血管新生.     

Angiopoietin-1 inhibits vascular permeability,angiogenesis, and growth of hepatic colon cancer tumors

Angiopoietin (Ang)-1 and -2 are critical regulators of embryonic and postnatal neovascularization. Ang-1 activates the endothelial cell-specific tyrosine kinase receptor Tie-2, which in turn leads to enhanced endothelial cell survival and stabilization. The effects of Ang-1 on tumor angiogenesis remain controversial; although we have previously demonstrated that Ang-1 overexpression in colon cancer cells leads to a decrease in s.c. tumor growth, others have shown that Ang-1 may be proangiogenic. Few studies have addressed the role of the Angs in tumors growing in the organ of metastatic growth. We hypothesized that overexpression of Ang-1 may inhibit the growth of colon cancers growing in the liver by inhibition of angiogenesis. We also wanted to investigate the mechanisms by which Ang-1 affects angiogenesis in vivo. Human colon cancer cells (HT29) were stably transfected with an Ang-1 construct or an empty vector (pcDNA) and injected directly into the livers of nude mice. After 37 days, livers were harvested and weighed, and tumor sizes were measured. In an additional experiment, to validate the paracrine effect of Ang-1, various mixtures of control cells and Ang-1-transfected cells were injected into livers, and tumor growth was assessed. Direct effects of recombinant Ang-1 on angiogenesis were studied with an in vivo Gelfoam angiogenesis assay. The impact of Ang-1 on vascular permeability was investigated using an intradermal Miles assay with conditioned media from transfected cells. Liver weights (P < 0.05), tumor volumes (P < 0.05), vessel counts (P < 0.01), and tumor cell proliferation (P < 0.01) in the Ang-1 group were significantly lower than those in the control (pcDNA) group. Tumor vessels in the Ang-1 group developed a significantly higher degree of pericyte coverage (P < 0.02) than vessels in pcDNA tumors. In the cell mixture experiment, even as few as a 1:10 mixture of Ang-1-transfected cells/control cells resulted in a significant reduction of hepatic tumor volumes (P < 0.04). In the angiogenesis assay, vessel counts in Gelfoam implants were significantly decreased by the addition of Ang-1 (P < 0.01). Finally, conditioned medium from Ang-1-transfected cells decreased vascular permeability more than that from control cells (P < 0.05). Our results suggest that Ang-1 is an important regulator of angiogenesis and vascular permeability and that this effect may be secondary to increasing periendothelial support and vessel stabilization. Thus, Ang-1 could potentially serve as an antineoplastic or anti-permeability agent for patients with metastatic colorectal cancer.     

Curcumin inhibits lung cancer progression and metastasis through induction of FOXO1

Recent population studies provide clues that the use of curcumin may be associated with reduced incidence and improved prognosis of certain cancers. In the present study, we demonstrated that curcumin acted as a growth inhibitor for lung cancer cells. Our results found that curcumin inhibited cell proliferation, which was associated with upregulation of the cyclin-dependent kinase inhibitors, p27 and p21, and downregulation of cyclin D1. In addition, we showed that curcumin induced the expression of forkhead box protein O1 (FOXO1) through activation of extracellular signal-regulated kinase 1/2 signaling. These findings provide evidence for a mechanism that may contribute to the antineoplastic effects of curcumin and justify further work to explore potential roles for activators of FOXO1 in the prevention and treatment of lung cancer.     

Blockade of insulin-like growth factor I receptor function inhibits growth and angiogenesis of colon cancer.

Purpose and Experimental Design: Insulin-like growth factors (IGFs) I and II and their principle receptor, IGF-I receptor (IGF-IR), are frequently expressed in human colon cancers and play a role in preventing apoptosis, enhancing cell proliferation, and inducing expression of vascular endothelial growth factor (VEGF). To elucidate the in vitro and in vivo effects of IGF-IR in human colon cancer growth and angiogenesis, HT29 cells were transfected with a truncated dominant-negative (DN) form of IGF-IR or vector alone. RESULTS: IGF-I increased VEGF expression in parental and vector-transfected cells, whereas IGF-I induction of VEGF mRNA and protein was abrogated in IGF-IR DN cells. The IGF-IR DN cells demonstrated inhibited growth in both monolayer culture and soft agar (P < 0.05). s.c. injections of IGF-IR DN cells in nude mice led to significantly decreased tumor growth (P < 0.05). Immunohistochemical analyses revealed that IGF-I DN tumors demonstrated decreased tumor cell proliferation, VEGF expression, and vessel count and increased tumor cell apoptosis (P < 0.05 for all parameters compared with controls). Furthermore, IGF-IR DN-transfected cells yielded significantly decreased tumorigenicity and growth in the liver. CONCLUSIONS: These studies demonstrate that the IGF ligand-receptor system plays an important role in multiple mechanisms that mediate human colon cancer growth including regulation of VEGF and angiogenesis.     

Endothelial Robo4 suppresses breast cancer growth and metastasis through regulation of tumor angiogenesis

Targeting tumor angiogenesis is a promising alternative strategy for improvement of breast cancer therapy. Robo4 (roundabout homolog 4) signaling has been shown to protect endothelial integrity during sepsis shock and arthritis, and inhibit Vascular Endothelial Growth Factor (VEGF) signaling during pathological angiogenesis of retinopathy, which indicates that Robo4 might be a potential target for angiogenesis in breast cancer. In this study, we used immune competent Robo4 knockout mouse model to show that endothelial Robo4 is important for suppressing breast cancer growth and metastasis. And this effect does not involve the function of Robo4 on hematopoietic stem cells. Robo4 inhibits breast cancer growth and metastasis by regulating tumor angiogenesis, endothelial leakage and tight junction protein zonula occludens protein‐1 (ZO‐1) downregulation. Treatment with SecinH3, a small molecule drug which deactivates ARF6 downstream of Robo4, can enhance Robo4 signaling and thus inhibit breast cancer growth and metastasis. SecinH3 mediated its effect by reducing tumor angiogenesis rather than directly affecting cancer cell proliferation. In conclusion, endothelial Robo4 signaling is important for suppressing breast cancer growth and metastasis, and it can be targeted (enhanced) by administrating a small molecular drug.     

IDIBELL cancer conference on metastasis and angiogenesis

The IDIBELL Cancer Conference (ICC) on Metastasis and Angiogenesis was held in Barcelona, Spain, on May 26-27, 2011. The program content was developed by Dr. Manel Esteller, director of the Cancer Epigenetics and Biology Program (PEBC-IDIBELL), Dr. Oriol Casanovas and Dr. Francesc Vi?als Canals of the Catalan Institute of Oncology (ICO-IDIBELL), and Dr. Danny R. Welch from the University of Kansas Cancer Center. The topics discussed during the meeting included the latest advances in epigenetic control of metastasis and tumor cell invasion, and molecular mechanisms of angiogenesis and tumoral angiogenesis, and were presented by invited keynote speakers. One issue that recurred throughout the meeting was the increased appreciation of tumor-stromal/microenvironment interactions and how the tumor cells respond to these signals in the cancer dissemination process.     

Livistona extract inhibits angiogenesis and cancer growth

In a screen for naturally occurring angiogenic inhibitors, we have identified an extract from the seed of the plant Livistona chinensis, which has potent anti-angiogenic and anti-tumor activity. The aqueous extract inhibits the in vitro proliferation of endothelial cells and multiple tumor cell lines including mouse fibrosarcoma and human breast and colon cancer. In mouse experiments, this extract suppresses the growth of the subcutaneous fibrosarcoma tumors. When the seed is separated into different components, the shell including the seed skin appears more potent than the inner kernel in tumor suppression. Our results suggest that the extract from the shell of Livistona chinensis may be a potential supplemental source for cancer treatment.     

Thiazolidinedione, a peroxisome proliferator-activated receptor-gamma ligand, inhibits growth and metastasis of HT-29 human colon cancer cells through differentiation-promoting effects

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligands inhibit the growth of PPAR-gamma expressing cancer cells through terminal differentiation. However, there are few studies examining the effect of a PPAR-gamma ligand on metastatic potential of cancer cells in an animal model and the underlying molecular mechanisms. We have recently developed a rectal cancer xenograft animal model in which anti-tumor and anti-metastatic efficacy of agents can be evaluated. This study was designed to examine whether a representative PPAR-gamma ligand, thiazolidinedione (TZD), could inhibit growth and metastasis of PPAR-gamma positive HT-29 human colon cancer cells through the induction of terminal differentiation. TZD caused G1 arrest in association with a marked increase in p21Waf-1, Drg-1, and E-cadherin expression. In untreated cancer cells, fluorescence immunostaining demonstrated beta-catenin in the nucleus and/or cytoplasm; in TZD-treated cancer cells, beta-catenin localization shifted to the plasma membrane, in association with increased E-cadherin at this site and reduced tyrosine phosphorylation of beta-catenin. In addition, TZD completely inhibited lymph node and lung metastases in the xenograft animal model, and TZD inhibited growth of primary xenografts by 40%. These results suggest that TZD can function as a cytostatic anti-cancer agent to inhibit growth and metastasis of HT-29 colon cancer cells through differentiation-promoting effects. These effects involve not only modulation of the E-cadherin/beta-catenin system, but also up-regulation of Drg-1 gene expression.     

p38 MAPK inhibits breast cancer metastasis through regulation of stromal expansion

p38 MAPK signaling controls cell growth, proliferation and the cell cycle under stress conditions. However, the function of p38 activation in tumor metastasis is still not well understood. We report that p38 activation in breast cancer cells inhibits tumor metastasis but does not substantially modulate primary tumor growth. Stable p38 knockdown in breast cancer cells suppressed NF‐κB p65 activation, inhibiting miR‐365 expression and resulting in increased IL‐6 secretion. The inhibitory effect of p38 signaling on metastasis was mediated by suppression of mesenchymal stem cell (MSC) migration to the primary tumor and sites of metastasis, where MSCs can differentiate into cancer‐associated fibroblasts to promote tumor metastasis. The migration of MSCs to these sites relies on CXCR4‐SDF1 signaling in the tumor microenvironment. Analysis of human primary and metastatic breast cancer tumors showed that p38 activation was inversely associated with IL‐6 and vimentin expression. This study suggests that combination analysis of p38 MAPK and IL‐6 signaling in patients with breast cancer may improve prognosis and treatment of metastatic breast cancer.     

Angiopoietin-3 inhibits pulmonary metastasis by inhibiting tumor angiogenesis

Angiopoietins (Ang-1, Ang-2, and Ang-3) are the ligands of Tie-2 receptor tyrosine kinase. The essential roles of Ang-1 and Tie-2 in embryonic angiogenesis have been established, and studies have demonstrated the involvement of Ang-1 and Ang-2 in tumor angiogenesis. However, the role of Ang-3 in tumor angiogenesis and metastasis and the mechanism underlying its function are totally unknown. We have shown recently that Ang-3 is tethered on cell surface via heparan sulfate proteoglycans. In our current study, we have demonstrated that overexpression of Ang-3 inhibits pulmonary metastasis of Lewis lung carcinoma and TA3 mammary carcinoma (TA3) cells by inhibiting tumor angiogenesis and promoting apoptosis of the tumor cells. In addition, we have demonstrated that the binding of Ang-3 to the cell surface is required for the effective inhibition of Ang-3 on tumor metastasis and that Ang-3 inhibits endothelial cell proliferation and survival and blocks Ang-1- and vascular endothelial growth factor-induced activation of extracellular signal-regulated kinase 1/2 and Akt kinases, which likely underlie the Ang-3-mediated inhibition on tumor angiogenesis and metastasis.