Dan-Deng-Tong-Nao softgel capsule promotes angiogenesis of cerebral microvasculature to protect cerebral ischemia reperfusion injury via activating HIF-1α-VEGFA-Notch1 signaling pathway.

BACKGROUND: A proprietary Chinese herbal product called Dan-Deng-Tong-Nao softgel capsule (DDTNC) is used to treat ischemic stroke. However, the preventive mechanisms of DDTNC against cerebral ischemia reperfusion injury (CIRI) haven not been characterized. OBJECTIVE: To explore the mechanisms of protective effects of DDTNC against CIRI from both internal and external levels. METHODS: Chemical characterization was performed using UPLC. The potential protective mechanisms of DDTNC against CIRI were predicted using network pharmacology. Model of middle cerebral artery occlusion/reperfusion (MCAO/R) was established in rats. An model of brain microvascular endothelial cells (BMECs) induced by oxygen-glucose deprivation/reoxygenation (OGD/R) was also established. We evaluated neurological deficits, cerebral infarct volume, cortical neuron damage, and mitochondrial swelling in vivo. We evaluated the expression of VEGFR2, VEGFA, HIF-1α, CD31, and CD34 in ischemic cortex, and VEGF, bFGF, BDNF, angiostatin, and endostatin in serum of rats and in BMEC supernatants. We also evaluated cell viability, cytotoxicity, intracellular ROS, apoptosis, and migration ability in vitro. RESULTS: Seven components were detected in DDTNC. KEGG enrichment analysis showed that DDTNC may modulate angiogenesis via the HIF-1 signaling pathway. DDTNC treatment reduced neurological score and infarct volume, and improved cell morphology of damaged neurons. Transmission electron microscopy showed that DDTNC reduced mitochondria swelling in cortical neurons. Furthermore, DDTNC reduced intracellular ROS and inhibited apoptosis. DDTNC boosted the expression of CD31, CD34, VEGFR2, VEGFA and HIF-1α, highlighting its involvement in angiogenesis, according to immunofluorescence studies. Furthermore, DDTNC enhanced tube formation and migration of BMECs in vitro. ELISA and western blotting indicated that DDTNCCSF induced the expression of VEGF, BDNF and bFGF, reduced the level of angiostatin and endostatin, increased the protein expression of VEGFA, Notch1 and HIF-1α in vitro and in vivo. CONCLUSIONS: DDTNC promoted angiogenesis to protect brain tissue against MCAO/R, and exerted protective effects against OGD/R in BMECs via activating HIF-1α-VEGFA-NOTCH1 signal transduction pathway.

Remodeling the homeostasis of pro- and anti-angiogenic factors by Shenmai injection to normalize tumor vasculature for enhanced cancer chemotherapy.

ETHNOPHARMACOLOGICAL RELEVANCE: Normalization of the tumor vasculature can enhance tumor perfusion and the microenvironment, leading to chemotherapy potentiation. Shenmai injection (SMI) is a widely used traditional Chinese herbal medicine for the combination treatment of cancer in China. AIM OF THIS STUDY: This study aimed to investigate whether SMI can regulate tumor vasculature to improve chemotherapy efficacy and identify the underlying mechanism. MATERIALS AND METHODS: The antitumor effect of SMI combined with 5-florouracil (5-FU) was investigated in xenograft tumor mice. Two-photon microscopy, laser speckle contrast imaging and immunofluorescence staining were used to investigate the effects of SMI on tumor vasculature in vivo. The mRNA and protein expression of pro- and anti-angiogenic factors were measured by Q-PCR and ELISA. Histone acetylation and transcriptional regulation were detected by Western blot and ChIP assay. RESULTS: SMI promoted normalization of tumor microvessels within a certain time window, which was accompanied by enhanced blood perfusion and 5-FU distribution in tumors. SMI significantly increased the expression of antiangiogenic factor angiostatin and decreased the pro-angiogenic factors VEGF, FGF and PAI-1 by day 10. SMI combined with neoadjuvant chemotherapy in colorectal cancer patients also showed a significant increase in angiostatin and decrease in VEGF and FGF in surgically resected tumors when compared to the neoadjuvant chemotherapy group. Further in vitro and in vivo studies revealed that SMI downregulated VEGF, FGF and PAI-1 mRNA expression by inhibiting histone H3 acetylation at the promoter regions. The enhanced production of angiostatin was attributed to the regulation of the plasminogen proteolysis system via SMI-induced PAI-1 inhibition. CONCLUSION: SMI can remodel the homeostasis of pro- and anti-angiogenic factors to promote tumor vessel normalization, and thus enhance drug delivery and anti-tumor effect. This study provides additional insights into the pharmacological mechanisms of SMI on tumors from the perspective of vascular regulation.

The Role of Angiogenesis in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) accounts for about 90% of all primary liver cancers and is the second leading cause of cancer-related deaths worldwide. The hypervascular nature of most HCC tumors underlines the importance of angiogenesis in the pathobiology of these tumors. Several angiogenic pathways have been identified as being dysregulated in HCC, suggesting they may be involved in the development and pathogenesis of HCC. These data provide practical targets for systemic treatments such as those targeting the vascular endothelial growth factor receptor and its ligand. However, the clinical relevance of other more recently identified angiogenic pathways in HCC pathogenesis or treatment remains unclear. Research into molecular profiles and validation of prognostic or predictive biomarkers will be required to identify the patient subsets most likely to experience meaningful benefit from this important class of agents.

Effect of the transdermal low-level laser therapy on endothelial function.

The effect of low-level laser therapy (LLLT) on the cardiovascular system is not fully established. Since the endothelium is an important endocrine element, establishing the mechanisms of LLLT action is an important issue.The aim of the study was to evaluate the effect of transdermal LLLT on endothelial function.In this study, healthy volunteers (n = 40, age = 20-40 years) were enrolled. N = 30 (14 female, 16 male, mean age 30 ± 5 years) constituted the laser-irradiated group (LG). The remaining 10 subjects (6 women, 4 men, mean age 28 ± 5 years) constituted the control group (CG). Participants were subjected to LLLT once a day for three consecutive days. Blood for biochemical assessments was drawn before the first irradiation and 24 h after the last session. In the LG, transdermal illumination of radial artery was conducted (a semiconductor laser λ = 808 nm, irradiation 50 mW, energy density 1.6 W/cm(2) and a dose 20 J/day, a total dose of 60 J). Biochemical parameters (reflecting angiogenesis: vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), angiostatin; antioxidative status: glutathione (GSH) and the nitric oxide metabolic pathway: symmetric dimethylarginine (SDMA), asymmetric dimethylarginine (ADMA) and L-arginine) were assessed. In the LG, a significant increase in GSH levels and considerable decrease in angiostatin concentration following the LLLT were observed. No significant differences in levels of the VEGF, FGF, SDMA, ADMA were observed.LLLT modifies vascular endothelial function by increasing its antioxidant and angiogenic potential. We found no significant differences in levels of the nitric oxide pathway metabolites within 24 h following the LLLT irradiation.

Aerobic training and l-arginine supplementation promotes rat heart and hindleg muscles arteriogenesis after myocardial infarction.

Arteriogenesis is a main defense mechanism to prevent heart and local tissues dysfunction in occlusive artery disease. TGF-ß and angiostatin have a pivotal role in arteriogenesis. We tested the hypothesis that aerobic training and l-arginine supplementation promotes cardiac and skeletal muscles arteriogenesis after myocardial infarction (MI) parallel to upregulation of TGF-ß and downregulation of angiostatin. For this purpose, 4 weeks after LAD occlusion, 50 male Wistar rats were randomly distributed into five groups: (1) sham surgery without MI (sham, n = 10), (2) control-MI (Con-MI, n = 10), (3) l-arginine-MI (La-MI, n = 10), (4) exercise training-MI (Ex-MI, n = 10), and (5) exercise and l-arginine-MI (Ex + La-MI). Exercise training groups running on a treadmill for 10 weeks with moderate intensity. Rats in the l-arginine-treated groups drank water containing 4 % l-arginine. Arteriolar density with different diameters (11-25, 26-50, 51-75, and 76-150 µm), TGF-ß, and angiostatin gene expression were measured in cardiac (area at risk) and skeletal (soleus and gastrocnemius) muscles. Smaller arterioles decreased in cardiac after MI. Aerobic training and l-arginine increased the number of cardiac arterioles with 11-25 and 26-50 µm diameters parallel to TGF-ß overexpression. In gastrocnemius muscle, the number of arterioles/mm(2) was only increased in the 11 to 25 µm in response to training with and without l-arginine parallel to angiostatin downregulation. Soleus arteriolar density with different size was not different between experimental groups. Results showed that 10 weeks aerobic exercise training and l-arginine supplementation promotes arteriogenesis of heart and gastrocnemius muscles parallel to overexpression of TGF-ß and downregulation of angiostatin in MI rats.

[Effect of yifei qinghua granule on VEGF, bFGF, angiostatin, and endostatin in Lewis lung cancer mice: an experimental study].

OBJECTIVE: To observe the effect of Yifei Qinghua Granule (YQG) on vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), angiostatin, and endostatin in tumor tissue of Lewis Lung cancer mice, and to explore its anti-tumor mechanisms. METHODS: Totally 70 C57BL/6 mice were randomly divided into the model group, the low, medium, and high dose YQG groups, the gefitinib group, the gefitinib plus medium dose YQG group, and the cyclophosphamide (CTX) group, 10 in each group. The models were established by subcutaneously injecting Lewis lung cancer cells from the right axilla of C57BL/6 mice. Mice in the model group were given with 0.4 mL pure water by gastrogavage, once daily. Mice in the low and medium dose YHG groups were given with YHG at the daily dose of 5 and 10 g/kg by gastrogavage, once daily. Those in the high dose YHG group were given with YHG at 10 g/kg by gastrogavage, twice daily. Those in the gefitinib group were given with gefitinib 100 mg/ kg by gastrogavage, once daily. Those in the gefitinib plus medium dose YHG group were given with gefitinib at 100 mg/kg by gastrogavage in the morning and YHG at 10 g/kg by gastrogavage in the afternoon. All medication was started from the 2nd day of inoculation, lasting 14 successive days. Those in the CTX group were given CTX at 60 mg/kg by peritoneal injection on the 3rd and the 7th day of the experiment. Mice were sacrificed at the fifteenth day of the experiment. Tumors were taken out. Expressions of VEGF, bFGF, angiostatin, and endostatin in the tumor tissue were detected using immunohistochemical assay. RESULTS: Compared with the model group, the expression of VEGF significantly decreased, expressions of angiostatin and endostatin significantly increased in each group (P < 0.01). The expression of bFGF significantly decreased in the gefitinib group (P < 0.05). There was no statistical difference in VEGF among all groups (P > 0.05). The angiostatin expression was significantly higher in the CTX group than in the low dose YQG group (P < 0.01). The expression of endostatin was significantly higher in the high dose YQG group and the gefitinib plus medium dose YQG group than in the low and the medium dose YQG groups (P < 0.01). The expression of endostatin was significantly higher in the gefitinib plus medium dose YQG group than in the gefitinib group (P < 0.05). CONCLUSION: The action mechanism of YQG in treating lung cancer might be achieved through reducing the expression of angiogenesis promoting factor VEGF and increasing expressions of angiogenesis inhibitors angiostatin and endostatin.

Transient repetitive exposure to low level light therapy enhances collateral blood vessel growth in the ischemic hindlimb of the tight skin mouse.

The tight skin mouse (Tsk(-/+)) is a model of scleroderma characterized by impaired vasoreactivity, increased oxidative stress, attenuated angiogenic response to VEGF and production of the angiogenesis inhibitor angiostatin. Low-level light therapy (LLLT) stimulates angiogenesis in myocardial infarction and chemotherapy-induced mucositis. We hypothesize that repetitive LLLT restores vessel growth in the ischemic hindlimb of Tsk(-/+) mice by attenuating angiostatin and enhancing angiomotin effects in vivo. C57Bl/6J and Tsk(-/+) mice underwent ligation of the femoral artery. Relative blood flow to the foot was measured using a laser Doppler imager. Tsk(-/+) mice received LLLT (670 nm, 50 mW cm(-2), 30 J cm(-2)) for 10 min per day for 14 days. Vascular density was determined using lycopersicom lectin staining. Immunofluorescent labeling, Western blot analysis and immunoprecipitation were used to determine angiostatin and angiomotin expression. Recovery of blood flow to the ischemic limb was reduced in Tsk(-/+) compared with C57Bl/6 mice 2 weeks after surgery. LLLT treatment of Tsk(-/+) mice restored blood flow to levels observed in C57Bl/6 mice. Vascular density was decreased, angiostatin expression was enhanced and angiomotin depressed in the ischemic hindlimb of Tsk(-/+) mice. LLLT treatment reversed these abnormalities. LLLT stimulates angiogenesis by increasing angiomotin and decreasing angiostatin expression in the ischemic hindlimb of Tsk(-/+) mice.

Effect of yifei qinghua granule on VEGF, bFGF, angiostatin, and endostatin in Lewis lung cancer mice: an experimental study / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effect of Yifei Qinghua Granule (YQG) on vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), angiostatin, and endostatin in tumor tissue of Lewis Lung cancer mice, and to explore its anti-tumor mechanisms.</p><p><b>METHODS</b>Totally 70 C57BL/6 mice were randomly divided into the model group, the low, medium, and high dose YQG groups, the gefitinib group, the gefitinib plus medium dose YQG group, and the cyclophosphamide (CTX) group, 10 in each group. The models were established by subcutaneously injecting Lewis lung cancer cells from the right axilla of C57BL/6 mice. Mice in the model group were given with 0.4 mL pure water by gastrogavage, once daily. Mice in the low and medium dose YHG groups were given with YHG at the daily dose of 5 and 10 g/kg by gastrogavage, once daily. Those in the high dose YHG group were given with YHG at 10 g/kg by gastrogavage, twice daily. Those in the gefitinib group were given with gefitinib 100 mg/ kg by gastrogavage, once daily. Those in the gefitinib plus medium dose YHG group were given with gefitinib at 100 mg/kg by gastrogavage in the morning and YHG at 10 g/kg by gastrogavage in the afternoon. All medication was started from the 2nd day of inoculation, lasting 14 successive days. Those in the CTX group were given CTX at 60 mg/kg by peritoneal injection on the 3rd and the 7th day of the experiment. Mice were sacrificed at the fifteenth day of the experiment. Tumors were taken out. Expressions of VEGF, bFGF, angiostatin, and endostatin in the tumor tissue were detected using immunohistochemical assay.</p><p><b>RESULTS</b>Compared with the model group, the expression of VEGF significantly decreased, expressions of angiostatin and endostatin significantly increased in each group (P < 0.01). The expression of bFGF significantly decreased in the gefitinib group (P < 0.05). There was no statistical difference in VEGF among all groups (P > 0.05). The angiostatin expression was significantly higher in the CTX group than in the low dose YQG group (P < 0.01). The expression of endostatin was significantly higher in the high dose YQG group and the gefitinib plus medium dose YQG group than in the low and the medium dose YQG groups (P < 0.01). The expression of endostatin was significantly higher in the gefitinib plus medium dose YQG group than in the gefitinib group (P < 0.05).</p><p><b>CONCLUSION</b>The action mechanism of YQG in treating lung cancer might be achieved through reducing the expression of angiogenesis promoting factor VEGF and increasing expressions of angiogenesis inhibitors angiostatin and endostatin.</p>

High-dose atorvastatin improves hypercholesterolemic coronary endothelial dysfunction without improving the angiogenic response.

BACKGROUND: Although 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) can restore endothelial function in coronary disease, in vitro and murine studies have shown their effects on myocardial angiogenesis to be biphasic and dose dependent. We investigated the functional and molecular effects of high-dose atorvastatin on the endogenous angiogenic response to chronic myocardial ischemia in hypercholesterolemic swine. METHODS AND RESULTS: Yucatan pigs were fed either a normal (NORM group; n=7) or high-cholesterol diet, with (CHOL-ATR group; n=7) or without (CHOL group; n=6) atorvastatin (3 mg/kg per day) for 13 weeks. Chronic ischemia was induced by ameroid constrictor placement around the circumflex artery. Seven weeks later, microvessel relaxation responses, myocardial perfusion, and myocardial protein expression were assessed. The CHOL group demonstrated impaired microvessel relaxation to adenosine diphosphate (29+/-3% versus 61+/-6%, CHOL versus NORM; P<0.05), which was normalized in the CHOL-ATR group (67+/-2%; P=NS versus NORM). Collateral-dependent myocardial perfusion, adjusted for baseline, was significantly reduced in the CHOL group (-0.27+/-0.07 mL/min per gram versus NORM; P<0.001) as well as the CHOL-ATR group (-0.35+/-0.07 mL/min per gram versus NORM; P<0.001). Atorvastatin treatment was associated with increased phosphorylation of Akt (5.7-fold increase versus NORM; P=0.001), decreased vascular endothelial growth factor expression (-68+/-8%; P<0.001 versus NORM), and increased expression of the antiangiogenic protein endostatin (210+/-48%; P=0.004 versus NORM). CONCLUSIONS: Atorvastatin improves hypercholesterolemia-induced endothelial dysfunction without appreciable changes in collateral-dependent perfusion. Increased myocardial expression of endostatin, decreased expression of vascular endothelial growth factor, and chronic Akt activation associated with atorvastatin treatment may account for the diminished angiogenic response.

Anti-angiogenesis therapy can overcome endothelial cell anergy and promote leukocyte-endothelium interactions and infiltration in tumors.

Tumor escape from immunity, as well as the failure of several anti-cancer vaccination and cellular immunotherapy approaches, is suggested to be due to the angiogenesis-mediated suppression of endothelial cell (EC) adhesion molecules involved in leukocyte-vessel wall interactions. We hypothesized that inhibition of angiogenesis would overcome this escape from immunity. We investigated this in vivo by means of intravital microscopy and ex vivo by immunohistochemistry in two mouse tumor models. Angiogenesis inhibitors anginex, endostatin, and angiostatin, and the chemotherapeutic agent paclitaxel were found to significantly stimulate leukocyte-vessel wall interactions by circumvention of EC anergy in vivo, i.e., by the up-regulation of endothelial adhesion molecules in tumor vessels. This was confirmed by in vitro studies of cultured EC at the protein and mRNA levels. The new angiostatic designer peptide anginex was most potent at overcoming EC anergy; the enhanced leukocyte-vessel interactions led to an increase in the numbers of tumor infiltrating leukocytes. While anginex inhibited tumor growth and microvessel density significantly, the amount of infiltrated leukocytes (CD45), as well as the number of CD8+ cytotoxic T lymphocytes, was enhanced markedly. The current results suggest that immunotherapy strategies can be improved by combination with anti-angiogenesis.

Low dose adjuvant angiostatin decreases hepatic micrometastasis in murine ocular melanoma model.

PURPOSE: To investigate the effect of different doses of adjuvant angiostatin affecting hepatic micrometastasis in a murine model of metastatic ocular melanoma. METHODS: Angiostatin and plasminogen expression was detected in three murine melanoma cell lines (Queens, B16F10, and B16LS9). The three cell lines were heterotopically inoculated into the posterior compartment (PC) of the right eyes of C57BL/6 mice. After enucleation, the mice were given injections of 100 microl PBS and low dose (0.1 microg/microl) or high dose (0.3 microg/microl) murine recombinant angiostatin every day for 14 days after enucleation. The mice were sacrificed at 21 days post-enucleation and hepatic micrometastases were counted. In vitro migration/invasion assays were performed with low (0.1 microg/microl) and high (50 microg/microl) concentration angiostatin supplementation. Quantitative RT-PCR detected mRNA and Western analysis determined protein expression of VEGF for all cell lines. Evaluation of TdT mediated dUTP nick end labeling (TUNEL) and MIB1 immunostaining of the micrometastases determined apoptosis and proliferation ratios. RESULTS: There was a decrease in micrometastasis in the low dose group for Queens (p<0.05), B16F10 (p<0.05), and B16LS9 melanoma (p<0.01) cell lines. Two of the cell lines (B16F10 and B16LS9) elaborated plasminogen and were able to cleave plasminogen into K1-K4 (angiostatin). There was a decrease in the in vitro migration and invasion after supplementation with low concentration compared to high concentration angiostatin (p<0.01). VEGF mRNA and protein expression decreased in all cells lines in low concentration angiostatin, with the greatest decrease in B16LS9 cells (p<0.05). Apoptosis ratios were increased (p<0.01) and proliferation ratios were decreased (p<0.01) in hepatic micrometastases after treatment with low dose angiostatin. CONCLUSIONS: There were significantly fewer micrometastases in treated compared to controls with low dose compared to high dose angiostatin. This treatment results in apoptosis in the micrometastases. The mechanism appears to be related an anti-migratory effect and altered VEGF expression by melanoma cells.

Angiogenesis inhibition by angiostatin, endostatin and TNP-470 prevents cyclophosphamide induced cystitis.

Angiogenesis, the induction of vessel growth is involved in numerous physiological and pathological processes. While the anti-tumor effect of angiogenesis inhibitors has been extensively investigated in malignant tumors, there is very little information on the effect of angiogenesis inhibitors on inflammation induced angiogenesis. In this report, we utilized a murine model of acute chemically induced cystitis to investigate the ability of three different angiogenesis inhibitors, angiostatin, endostatin and TNP-470, to inhibit the angiogenesis stimulated by this injury. We demonstrate herein, that prophylactic application of the angiogenesis inhibitors led to a significant reduction of each of the inflammatory parameters that were measured. We conclude that anti-angiogenic therapy with angiostatin, endostatin and TNP-470 inhibits inflammation associated angiogenesis induced in this model. We also propose that anti-angiogenic agents may serve as a valuable addition to a standard cyclophosphamid chemotherapy regimen to help reduce the chemotherapy-related side effects while potentially adding an anti-tumor effect.

N-acetyl-cysteine promotes angiostatin production and vascular collapse in an orthotopic model of breast cancer.

The antioxidant N-acetyl-cysteine (NAC) has been shown to be chemopreventive in clinical studies, and in recent studies, has shown promise in preventing tumor progression. Although the effects of NAC on tumorigenesis have been associated with decreased angiogenesis, the mechanism of the anti-angiogenic activity has not been determined. In the following study, we describe a novel mechanism whereby NAC therapy blocks MDA-MB-435 breast carcinoma cell proliferation and metastasis in an in vivo tumorigenic model. Athymic nude mice bearing MDA-MB-435 xenografts were treated with systemic NAC daily for 8 weeks. NAC treatment resulted in endothelial cell apoptosis and reduction of microvascular density within the core of the tumor leading to significant tumor cell apoptosis/necrosis. Angiostatin accumulated in tumors from NAC-treated but not control animals. Additional studies using a vascular endothelial growth factor-dependent chicken chorioallantoic membrane angiogenic assay recapitulated NAC-induced endothelial apoptosis and coordinate production of angiostatin, a potent endothelial apoptotic factor. In vitro studies showed angiostatin was formed in endothelial cultures in a vascular endothelial growth factor- and NAC-dependent manner, a process that requires endothelial cell surface plasminogen activation. These results suggest that systemic NAC therapy promotes anti-angiogenesis through angiostatin production, resulting in endothelial apoptosis and vascular collapse in the tumor.

[The study of biological properties of gliomas].

In order to explore the new methods of biological treatment of human gliomas, this project is to study the biological properties of gliomas from four different aspects, the results show that there is a IL-6 autocrine loop in human gliomas and the growth of gliomas will be inhibited when the autocrine loop is broken. There is a magnificent predominant expression of Th2 cytokines in human gliomas and human glioma cells, the switching of Th2 to Th1 can inhibit the proliferation of glioma cells. The dosage of 100 micrograms/ml of erythromycin is the best of therapeutic effect. Angiostatin can not only inhibit the vascular endothelial growth, but also have the inhibitory role on the growth of glioma cells in vivo. The above studies have provided some new ideas and will be very helpful for the treatment of glioma patients.

The study of biological properties of gliomas / 中国医学科学院学报

In order to explore the new methods of biological treatment of human gliomas, this project is to study the biological properties of gliomas from four different aspects, the results show that there is a IL-6 autocrine loop in human gliomas and the growth of gliomas will be inhibited when the autocrine loop is broken. There is a magnificent predominant expression of Th2 cytokines in human gliomas and human glioma cells, the switching of Th2 to Th1 can inhibit the proliferation of glioma cells. The dosage of 100 micrograms/ml of erythromycin is the best of therapeutic effect. Angiostatin can not only inhibit the vascular endothelial growth, but also have the inhibitory role on the growth of glioma cells in vivo. The above studies have provided some new ideas and will be very helpful for the treatment of glioma patients.

New chemotherapeutic agents: update of major chemoradiation trials in solid tumors.

The institution of combined modality therapy for unresected solid tumors has resulted in significant improvements in tumor control and survival benefit compared with radiotherapy (RT) alone. A number of chemotherapy agents that can enhance the effectiveness of RT, such as cisplatin and 5-fluorouracil, are now considered standard treatment for patients with a number of cancer types. There is growing interest in a number of additional agents that have also been found to have radiosensitizing ability. These include paclitaxel, docetaxel, irinotecan, gemcitabine, and vinorelbine, as well as biologic agents. Other agents may be of value because they act to counter dose-limiting toxicities associated with RT. This article provides an update of some important, recently completed and ongoing clinical trials evaluating novel chemoradiation protocols, with examples taken primarily from studies conducted by the Radiation Therapy Oncology Group (RTOG). Theoretical approaches to the development of new agents and combined modality regimens are also discussed.

Angiogenesis inhibitors in lung cancer.

Lung cancer is a major public health problem and the leading cause of cancer-related death worldwide. Its survival rates have changed little over the past 20 years. The best clinical benefit (ie, survival rates) with combination cytotoxic therapies in non-small-cell lung cancer (NSCLC) may have been reached. The need for improved survival rates in NSCLC has driven the development of novel, rationally designed, targeted therapies. Inhibitors of angiogenesis have been developed and are increasingly studied. Potential targets for therapy include inhibitors of vascular endothelial growth factor receptor, endogenous angiogenesis inhibitors, and cyclooxygenase inhibitors. Combining targeted molecules with traditional cytotoxic therapies usually results in lower required chemotherapy doses and fewer, less severe side effects. A number of ongoing randomized studies are underway to evaluate this idea. It is anticipated that these new targeted therapies will play an important role, along with cytotoxic and radiation therapies, in the management of metastatic disease.

Effect of antiangiogenic therapy on slowly growing, poorly vascularized tumors in mice.

BACKGROUND: Angiogenesis is essential for tumor growth and progression. Therefore, inhibition of angiogenesis is being studied as a new anticancer therapy. Because cytotoxic chemotherapy is more effective on rapidly growing tumors than on slowly growing tumors, it has been assumed that antiangiogenic therapy will also be effective only on rapidly growing, highly vascularized tumors. We compared the effects of two angiogenesis inhibitors, TNP-470 and angiostatin, on slowly growing, poorly vascularized and rapidly growing, highly vascularized human tumors in mice. METHODS: Slowly growing (RT-4) and rapidly growing (MGH-U1) human bladder carcinoma cell lines were grown in severe combined immunodeficiency mice. Established tumors were treated with one of the two angiogenesis inhibitors. Tumor volumes, vascularity, and proliferation indices were determined. The in vitro effects of TNP-470 and of angiostatin on the proliferation of RT-4 and MGH-U1 cells were also investigated. All statistical tests were two-sided. RESULTS: RT-4 and MGH-U1 tumor growth was statistically significantly inhibited by both angiogenesis inhibitors (P<.001). Both inhibitors decreased the blood vessel density in both tumor types but did not alter the in vivo proliferation indices of the tumors. TNP-470, but not angiostatin, marginally decreased the in vitro proliferation of MGH-U1 cells. CONCLUSION: Slowly growing, poorly vascularized tumors in animal models respond as well as rapidly growing, highly vascularized tumors to therapy with the angiogenesis inhibitors TNP-470 and angiostatin.

Responses to anti-angiogenic therapies.

Vascular tumors occur in approximately 10% of infants, and range from small cherry-red lesions to large, life-threatening tumors. Although the majority of these tumors involute after several years, there are few therapeutic options and their use is limited by the risk of side-effects. The recent increase in understanding of angiogenesis has led to investigations of new antiangiogenic treatment options using models of vascular tumors in mice. These studies have demonstrated the success of a variety of antiangiogenic approaches, including systemic administration of the antiangiogenic proteins AGM-1470 and angiostatin or of the matrix metalloproteinase inhibitor batimastat, and gene gun therapy with interleukin-12. Although these trials provide further evidence of the role of angiogenesis in the enlargement of these vascular tumors, their potential utility and safety await future trials in patients.

Anti-angiogenic treatment strategies for malignant brain tumors.

The use of angiogenesis inhibitors may offer novel strategies in brain tumor therapy. In contrast to traditional cancer treatments that attack tumor cells directly, angiogenesis inhibitors target at the formation of tumor-feeding blood vessels that provide continuous supply of nutrients and oxygen. With respect to brain tumor therapy, inhibitors of angiogenesis display unique features that are unknown to conventional chemotherapeutic agents. The most important features are independence of the blood-brain barrier, cell type specificity, and reduced resistance. Malignant brain tumors, especially malignant gliomas, are among the most vascularized tumors known. Despite multimodal therapeutic approaches, the prognosis remains dismal. Thus, angiogenesis inhibitors may be highly effective drugs against these tumors. In a clinical setting, they could be applied in the treatment of multiple tumors or postsurgically as an adjuvant therapy to prevent recurrence. This article provides an overview of current anti-angiogenic treatment strategies with emphasis on substances already in clinical trials or candidate substances for clinical trials. The cellular and molecular basis of these substances is reviewed.