The aim of this study was to investigate the effects of Avastin on aquaporin4 (AQP4) expression in human retinal Müller cells in vitro under hypoxia, so as to explore the mechanism of Avastin treating retinal edema. The human Müller cells were cultured using the enzymatic digestion method. Müller cells were identified under the transmission electron microscopy and by using immunofluorescence staining. By using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), the expression of AQP4 mRNA and VEGF mRNA in Müller cells cultured with 500 μmol/L CoCl(2) for 0, 3, 6, 12 and 24 h, and with 0, 100, 300, 500 and 700 μmol/L CoCl(2) for 24 h was detected. The expression of AQP4 mRNA in Müller cells cultured with 50 ng/mL exogenous vascular endothelial growth factor (VEGF) for 0, 0.5, 1, 2 and 4 h, and with 0, 25, 50 and 75 ng/mL VEGF for 24 h was detected. Amplified cDNA products of AQP4 mRNA in Müller cells cultured with 500 μmol/L CoCl(2) and 200 μg/mL Avastin for 24 h were detected. The results showed that more than 95% cells displayed positive immunofluorescence reaction. Characteristic 8-10 nm intracellular filaments could be seen in the cytoplasm under the transmission electron microscopy. In the CoCl(2) experimental groups, the expression of AQP4 mRNA and VEGF mRNA in Müller cells was increased as compared with the control group. Alteration of AQP4 mRNA and VEGF mRNA levels showed a significantly positive correlation (r (2)=0.822, P<0.05). The expression of AQP4 mRNA in Müller cells was increased by VEGF. The expression of AQP4 mRNA was significantly decreased by Avastin as compared with the control group. It is suggested that Avastin can decrease the expression of AQP4 mRNA in human Müller cells under chemical hypoxic conditions partially via VEGF path, which may be one of the mechanisms of Avastin treating retinal edema.
Antibodies, Monoclonal, Humanized ; pharmacology ; Aquaporin 4 ; genetics ; metabolism ; Bevacizumab ; Cells, Cultured ; Ependymoglial Cells ; metabolism ; Gene Expression ; drug effects ; genetics ; Humans ; Hypoxia ; genetics ; metabolism

Vascular damage is followed by vascular endothelial growth factor (VEGF) expression at high levels, which is an important mechanism for cerebral radiation necrosis (CRN) development. Antiangiogenic agents (Bevacizumab) alleviates brain edema symptoms caused by CRN through inhibiting VEGF and acting on vascular tissue around the brain necrosis area. Many studies have confirmed that Bevacizumab effectively relieves symptoms caused by brain necrosis, improves patients' performance status and brain necrosis imaging. Considering that the efficacy of antiangiogenic therapy is mainly related to the duration of drug action, low-dose antiangiogenic agents can achieve favorable efficacy. Prevention is the best treatment. The occurrence of CRN is associated with tumor-related factors and treatment-related factors. By controlling these factors, CRN can be effectively prevented.
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Angiogenesis Inhibitors/pharmacology* ; Bevacizumab/therapeutic use* ; Brain/metabolism* ; Consensus ; Humans ; Lung Neoplasms/drug therapy* ; Necrosis/etiology* ; Radiation Injuries/etiology* ; Vascular Endothelial Growth Factor A/metabolism*

INTRODUCTIONThis study reports a case of bevacizumab administered to treat choroidal neovascularisation in a woman later discovered to be pregnant.

CLINICAL PICTUREA 25-year-old pregnant woman developed myopic choroidal neovascularisation in both eyes.

TREATMENTBoth eyes were treated with a total of 3 intravitreal injections of bevacizumab sequentially.

OUTCOMEVision improved significantly in both eyes. There were no evident pregnancy-related complications at 1 year postpartum.

CONCLUSIONAlthough anti-vascular endothelial growth factor (VEGF) therapy did not result in any detectable short-term adverse event in this mother and baby, the potential toxicity of these agents must be carefully considered in pregnant patients.

Adult ; Angiogenesis Inhibitors ; administration & dosage ; pharmacology ; therapeutic use ; Antibodies, Monoclonal ; administration & dosage ; pharmacology ; therapeutic use ; Antibodies, Monoclonal, Humanized ; Bevacizumab ; Choroidal Neovascularization ; drug therapy ; Female ; Humans ; Pregnancy ; Pregnancy Complications ; drug therapy ; Treatment Outcome

OBJECTIVETo evaluate the effects of Bevacizumab on the tumor growth, proliferation and apoptosis of gastric cancer xenograft, and the impacts on the VEGF and Sp1 expression.

METHODSGastric cancer xenografts in nude mice were established using SGC-7901 gastric cancer cell line. The nude mice were randomly divided into two groups, Bevacizumab treatment group and PBS group. The tumor sizes were measured for tumor growth curve. The proliferation and angiogenesis were evaluated by immunohistochemistry (IHC) staining of Ki67 and CD34. TUNEL assay was used for apoptosis evaluation. The expression of VEGF and Sp1 in tumor cells were detected by IHC and Western blot.

RESULTSCompared to the PBS group, the tumor growth decreased significantly (P<0.05), the proliferation of tumor cells and angiogenesis decreased, and apoptosis index increased significantly [(5.3 ± 1.8)% vs. (16.7 ± 6.7)%, P<0.01] in Bevacizumab group. The results of IHC and Western blot demonstrated that the expression of VEGF and the microvessel density (MVD) was decreased (4.0 ± 1.0 vs. 16.3 ± 1.5, P<0.001) in Bevacizumab treatment group. No obvious changes of Sp1 expression were observed in Bevacizumab treatment group.

CONCLUSIONSBevacizumab can inhibit the growth of gastric cancer xenografts in nude mice, decrease the VEGF expression and MVD. However, the compensatory up-regulation of transcription factor Sp1 is not affected by Bevacizumab.

Animals ; Antibodies, Monoclonal, Humanized ; pharmacology ; Apoptosis ; Bevacizumab ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Mice ; Mice, Nude ; Sp1 Transcription Factor ; metabolism ; Stomach Neoplasms ; metabolism ; pathology ; Vascular Endothelial Growth Factor A ; metabolism ; Xenograft Model Antitumor Assays

Hypoxia is a common phenomenon in solid tumors. Resistance of hypoxic tumor cells to radiation is a significant reason of failure in the local control of tumors. The growth and metastasis of solid tumors rely on blood vessels. Antiangiogenic agents mainly target tumor blood vessels, and radiation therapy mainly targets tumor cells. Combination of antiangiogenic treatment and radiation exhibits synergistic effect, which improves the response of tumors to radiation therapy. The mechanisms of interaction between antiangiogenic agents and ionizing radiation are complex and involve interactions between tumor cells and tumor microenvironment, including tumor oxygenation, stroma, and vasculature. The original mechanism of antiangiogenesis is to induce ischemia and hypoxia in tumors, thereby, "starve" the tumors. However, recently, emerging data suggest that antiangiogenic agents could reduce the proportion of hypoxic cells through normalizing tumor vasculature, decreasing oxygen consumption, and other mechanisms. The use of antiangiogenic agents provides a new approach to overcome the hypoxia problem, and ultimately improves the efficacy of radiation therapy. In this review, we discuss tumor hypoxia, tumor angiogenesis and its regulation, mechanisms of antiangiogenic therapy combined with radiation therapy, and how antiangiogenic therapy overcomes tumor hypoxia.
Angiogenesis Inhibitors ; pharmacology ; therapeutic use ; Animals ; Antibodies, Monoclonal ; pharmacology ; therapeutic use ; Antibodies, Monoclonal, Humanized ; pharmacology ; therapeutic use ; Apoptosis ; drug effects ; Bevacizumab ; Cell Hypoxia ; drug effects ; Combined Modality Therapy ; Endostatins ; pharmacology ; therapeutic use ; Humans ; Neoplasms ; blood supply ; drug therapy ; metabolism ; radiotherapy ; Neovascularization, Pathologic ; drug therapy ; Oxygen Consumption ; drug effects ; radiation effects

OBJECTIVETo study the effect and mechanism of bevacizumab on proliferation and invasion of human lung cancer A549 cells.

METHODSA549 cells were treated with bevacizumab. Proliferation and invasion of the bevacizumab-treated A549 cells were detected using cell counting kit CCK-8 and Transwell assay, respectively. The expression of the mRNA and protein of MMP-2, MMP-9 and c-Met were detected by real-time PCR and Western blotting, respectively.

RESULTSProliferation activity was inhibited at the concentration of 10 µg/ml and promoted at the concentration of 100 µg/ml bevacizumab. Bevacizumab in the concentration of 50 µg/ml had a stronger inhibitory effect on the invasion of A549 cells (16 406.19 ± 5 674.23 penetrated cells) than that of control group (36 108.68 6 263.83, P<0.05). The real-time PCR showed that bevacizumab had a stronger inhibitory effect on the expression of MMP-2 and MMP-9 mRNA at the concentration of 50 µg/ml and on the expression c-Met mRNA at the concentration of 10 µg/ml bevacizumabin the A549 cells. However bevacizumab at the concentration of 100 µg/ml showed a promoting effect on the expression of MMP-2, MMP-9 and c-Met mRNA (1.82 ± 0.31, 1.60 ± 0.25, 2.63 ± 0.48), significantly higher than that of the control group (1.00 ± 0.19, 1.00 ± 0.23, 1.00 ± 0.22, P<0.05). The expression of MMP-2, MMP-9 and c-Met mRNA and protein was inhibited by 10 µg/ml bevacizumab in a time-dependent manner. The Western blot assay showed that bevacizumab had a bi-directional effect on the expression of MMP-2 and c-Met proteins in the A549 cells: a promoting effect at 100 µg/ml and inhibitory effect on the expression of MMP-2 at 50 µg/ml bevacizumab, and inhibitory effect on the expression of c-Met protein at 10 µg/ml bevacizumab.

CONCLUSIONSOur findings indicate that in a certain range of concentrations, bevacizumab has prominent inhibitory effect on the proliferation and invasion of A549 cells. However,over the concentration of 100 µg/ml, bevacizumab shows a weakening anti-invasion effect, even has a promoting effect on cell proliferation. This phenomenon may be related to the inhibiting effect on the expression of MMP-2 and c-Met proteins in a non-concentration-dependent manner by bevacizumab.

Angiogenesis Inhibitors ; pharmacology ; Bevacizumab ; pharmacology ; Blotting, Western ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; drug effects ; Enzyme Inhibitors ; pharmacology ; Humans ; Lung Neoplasms ; metabolism ; pathology ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Neoplasm Invasiveness ; Proto-Oncogene Proteins c-met ; metabolism ; RNA, Messenger ; metabolism ; Real-Time Polymerase Chain Reaction

OBJECTIVETo observe the anti-proliferation effect of bevacizumab and SN-38 (active metabolite of irinotecan), and investigate the possible mechanisms of these two agents.

METHODSHuman colon cancer LoVo cells were cultured under hypoxic conditions. Inhibition of cell proliferation was evaluated by MTT assay. The drug modulation on HIF-1alpha, VEGF, ERK and AKT were assessed by the following assays. The mRNA expression of HIF-1alpha and VEGF were measured by RT-PCR. The protein expression of HIF-1alpha, ERK and AKT were evaluated by Western blot analysis, and VEGF by ELISA assay.

RESULTSAmong different combination schedules, Bevacizumab given after SN-38 show most synergistic anti-proliferation effect. Under hypoxic conditions, the expression of HIF-1alpha and VEGF increased as time accumulated, Bevacizumab combined with SN-38 almost completely inhibited the expression of HIF-1alpha and VEGF. Moreover, the MAP kinase pathway was involved in the drug modulation of HIF-1alpha and VEGF.

CONCLUSIONThese findings suggest the anti-proliferation effect of bevacizumab and SN-38 was schedule-dependent, and the synergistic effect of Bevacizumab and SN-38 was related to drug modulation of the HIF-1alpha and MAP kinase pathway.

Antibodies, Monoclonal ; pharmacology ; Antibodies, Monoclonal, Humanized ; Antineoplastic Agents, Phytogenic ; pharmacology ; Bevacizumab ; Camptothecin ; analogs & derivatives ; pharmacology ; Cell Hypoxia ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Colonic Neoplasms ; metabolism ; pathology ; Drug Synergism ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Signal Transduction ; Time Factors ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

Aged ; Angiogenesis Inhibitors ; administration & dosage ; pharmacology ; therapeutic use ; Antibodies, Monoclonal ; administration & dosage ; pharmacology ; therapeutic use ; Antibodies, Monoclonal, Humanized ; Asia ; ethnology ; Bevacizumab ; Choroidal Neovascularization ; drug therapy ; ethnology ; Female ; Humans ; Male ; Middle Aged ; Myopia ; physiopathology ; Prospective Studies ; Treatment Outcome ; Vitreous Body ; blood supply

PURPOSE: To evaluate the effects of bevacizumab on expression of B-cell leukemia/lymphoma (Bcl)-2 and apoptosis in retinal pigment epithelial (RPE) cells under oxidative stress conditions. METHODS: RPE cells were treated with H2O2 (0, 100, 200, 300, and 400 microM) and bevacizumab at or above the doses normally used in clinical practice (0, 0.33, 0.67, 1.33, and 2.67 mg/mL). Cell apoptosis was measured using flow cytometry with annexin V-fluorescein isothiocyanate. The expression of Bcl-2 mRNA was determined using reverse transcription polymerase chain reaction. RESULTS: Under low oxidative stress conditions (H2O2 100 microM), cell apoptosis was not significantly different at any concentration of bevacizumab, but Bcl-2 mRNA expression decreased with increasing concentration of bevacizumab (0.33, 0.67, 1.33, and 2.67 mg/mL). Under moderate oxidative stress conditions (H2O2 200 microM), Bcl-2 mRNA expression decreased with increasing concentration of bevacizumab (0.33, 0.67, 1.33, and 2.67 mg/mL), but cell apoptosis increased only at 2.67 mg/mL of bevacizumab. Under high oxidative stress (300 microM) conditions, cell apoptosis increased at high concentrations of bevacizumab (1.33 and 2.67 mg/mL), but it did not correlate with Bcl-2 expression. CONCLUSIONS: Withdrawal of vascular endothelial growth factor can lead to RPE cell apoptosis and influences the expression of anti-apoptotic genes such as Bcl-2 under oxidative stress conditions. Since oxidative stress levels of each patient are unknown, repeated injections of intravitreal bevacizumab, as in eyes with age-related macular degeneration, might influence RPE cell survival.
Angiogenesis Inhibitors/*pharmacology ; Apoptosis/*drug effects ; Bevacizumab/*pharmacology ; Cell Line ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Gene Expression Regulation/physiology ; Humans ; Hydrogen Peroxide/toxicity ; Oxidative Stress/drug effects ; Proto-Oncogene Proteins c-bcl-2/*genetics ; RNA, Messenger/genetics ; Real-Time Polymerase Chain Reaction ; Retinal Pigment Epithelium/*drug effects/metabolism/pathology ; Vascular Endothelial Growth Factor A/antagonists & inhibitors

OBJECTIVETo study the effect of bevacizumab (Avastin) on pulmonary microvascular angiogenesis induced by lung cancer.

METHODSThe effects of Avastin on cell growth, cell cycle and apoptosis of lung microvascular endothelial cells were assayed by flow cytometry.

RESULTSAvastin inhibited the growth of lung microvascular endothelial cells and induced increase of cell apoptosis index in a concentration-dependent manner. With the increment of Avastin concentration from 25 to 100 microg/ml, avascular area increased from 0.944-/+0.073 cm square to 5.189-/+0.192 cm square, and the cell apoptosis index increased from 32.5%-/+1.5% to 39.25-/+1.6%.

CONCLUSIONAvastin can inhibit the growth and induce apoptosis of lung microvascular endothelial cells in three-dimensional culture, possibly in association with cell cycle arrest in G(0/1) phase.

Adenocarcinoma ; blood supply ; pathology ; Angiogenesis Inhibitors ; pharmacology ; Animals ; Antibodies, Monoclonal ; pharmacology ; Antibodies, Monoclonal, Humanized ; Apoptosis ; drug effects ; Bevacizumab ; Capillaries ; pathology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cells, Cultured ; Endothelial Cells ; pathology ; Flow Cytometry ; Humans ; Lung Neoplasms ; blood supply ; pathology ; Neovascularization, Pathologic ; pathology ; Rats