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.
.
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*

The NCCN has recently released its 2017 version 1.0 guideline for colorectal cancer. There are several updates from this new version guideline which are believed to change the current clinical practice. Update one, low-dose aspirin is recommended for patients with colorectal cancer after colectomy for secondary chemoprevention. Update two, biological agents are removed from the neoadjuvant treatment regimen for resectable metastatic colorectal cancer (mCRC). This update is based on lack of evidence to support benefits of biological agents including bevacizumab and cetuximab in the neoadjuvant setting. Both technical criteria and prognostic information should be considered for decision-making. Currently biological agents may not be excluded from the neoadjuvant setting for patients with resectable but poor prognostic disease. Update three, panitumumab and cetuximab combination therapy is only recommended for left-sided tumors in the first line therapy. The location of the primary tumor can be both prognostic and predictive in response to EGFR inhibitors in metastatic colorectal cancer. Cetuximab and panitumumab confer little benefit to patients with metastatic colorectal cancer in the primary tumor originated on the right side. On the other hand, EGFR inhibitors provide significant benefit compared with bevacizumab-containing therapy or chemotherapy alone for patients with left primary tumor. Update four, PD-1 immune checkpoint inhibitors including pembrolizumab or nivolumab are recommended as treatment options in patients with metastatic deficient mismatch repair (dMMR) colorectal cancer in second- or third-line therapy. dMMR tumors contain thousands of mutations, which can encode mutant proteins with the potential to be recognized and targeted by the immune system. It has therefore been hypothesized that dMMR tumors may be sensitive to PD-1 inhibitors.
Antibodies, Monoclonal ; pharmacology ; therapeutic use ; Antibodies, Monoclonal, Humanized ; therapeutic use ; Antineoplastic Agents ; therapeutic use ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Aspirin ; administration & dosage ; therapeutic use ; Bevacizumab ; therapeutic use ; Biological Products ; therapeutic use ; Brain Neoplasms ; drug therapy ; genetics ; Cetuximab ; therapeutic use ; Clinical Decision-Making ; methods ; Colorectal Neoplasms ; drug therapy ; genetics ; pathology ; prevention & control ; therapy ; Contraindications ; Humans ; Mutation ; physiology ; Neoadjuvant Therapy ; standards ; Neoplasm Metastasis ; drug therapy ; Neoplastic Syndromes, Hereditary ; drug therapy ; genetics ; Practice Guidelines as Topic ; Prognosis ; Secondary Prevention ; methods ; standards

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 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

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

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

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

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

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

BACKGROUNDBevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor, has shown promising activity in recurrent malignant gliomas. We reported the treatment response for the combination of bevacizumab and chemotherapy in a series of six patients with recurrent malignant glioma and investigated the molecular alterations in cancer pathways using the surgical biopsies from these patients.

METHODSStandard therapy with primary resection followed by adjuvant chemoradiotherapy had failed in all patients. Bevacizumab was administered at a dose of 10 mg/kg every 2 weeks. Concomitantly, four patients received temozolomide (50 mgxm(-2)xd(-1)), one patient irinotecan (125 mg/m(2) every 2 weeks) and one patient topotecan (1.2 mgxm(-2)xd(-1)). Response to therapy was mainly determined by magnetic resonance imaging. The expression of Ras, phosphorylated mitogen activated protein kinase (p-MAPK), phosphorylated AKT (p-AKT), phosphorylated mammalian target of rapamycin (p-mTOR) and phosphorylated signal transducer and activator of transcription 3 (p-STAT3) were semiquantitatively assessed by immunohistochemistry using surgical biopsies before the initial treatment.

RESULTSFive of the six patients had a radiographic response. Three were complete response, and two were partial response. Only one patient had progressive disease. The 6-month progession-free survival (PFS) was 33% and the median PFS was 15 weeks, with a range of 6 to more than 60 weeks. Of the three core pathways analyzed in this study, the Ras/MAPK and phosphatidylinositol-3-kinase (PI3K)/AKT/mTOR pathways were more likely to be associated with the treatment response to bevacizumab. In two younger patients (ages < 50) with complete response, simultaneous overexpression of p-MAPK, p-AKT and p-mTOR might be the crucial feature.

CONCLUSIONSBevacizumab in combination with chemotherapeutic agents may be an effective strategy for patients with recurrent malignant glioma. Activated MAPK and AKT might be possible biomarkers for selecting suitable patients for this targeted therapy.

Adolescent ; Adult ; Angiogenesis Inhibitors ; therapeutic use ; Antibodies, Monoclonal ; therapeutic use ; Antibodies, Monoclonal, Humanized ; Antineoplastic Agents, Phytogenic ; pharmacology ; Antineoplastic Combined Chemotherapy Protocols ; Bevacizumab ; Camptothecin ; analogs & derivatives ; therapeutic use ; Disease-Free Survival ; Female ; Glioma ; drug therapy ; metabolism ; mortality ; pathology ; Humans ; Immunohistochemistry ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Young Adult