Molecular Imaging of Melanoma VEGF-expressing Tumors through [99mTc]Tc-HYNIC-Fab(Bevacizumab).

BACKGROUND: Angiogenesis is a process that many tumors depend on for growth, development, and metastasis. Vascular endothelial growth factor (VEGF) is one of the major players in tumor angiogenesis in several tumor types, including melanoma. VEGF inhibition is achieved by bevacizumab, a humanized monoclonal antibody that binds with high affinity to VEGF and prevents its function. In order to successfully enable in vivo VEGF expression imaging in a murine melanoma model, we previously labeled bevacizumab with [99mTc]Tc. We observed that this was feasible, but it had prolonged blood circulation and delayed tumor uptake. OBJECTIVE: The aim of this study was to develop a radiolabeled Fab bevacizumab fragment, [99mTc]Tc-HYNICFab( bevacizumab), for non-invasive in vivo VEGF expression molecular imaging. METHODS: Flow cytometry was used to examine VEGF presence in the murine melanoma cell line (B16-F10). Bevacizumab was digested with papain for six hours at 37°C to produce Fab(bevacizumab), which was then conjugated to NHS-HYNIC-Tfa for radiolabeling with [99mTc]Tc. Stability and binding affinity assays were also evaluated. Biodistribution and single photon emission computed tomography/computed tomography (SPECT/CT) were performed at 1, 3, and 6 h (n = 4) after injection of [99mTc]Tc-HYNIC-Fab(Bevacizumab) in normal and B16-F10 tumor-bearing C57Bl/6J mice. RESULTS: Using flow cytometry, it was shown that the B16-F10 murine melanoma cell line has intracellular VEGF expression. Papain incubation resulted in the complete digestion of bevacizumab with good purity and homogeneity. The radiolabeling yield of [99mTc]Tc-HYNIC-Fab(bevacizumab) was 85.00 ± 6.06%, with a specific activity of 291.87 ± 18.84 MBq/mg (n=3), showing in vitro stability. Binding assays demonstrated significant intracellular in vitro VEGF expression. Fast blood clearance and high kidney and tumor uptake were observed in biodistribution and SPECT/CT studies. CONCLUSIONS: We present the development and evaluation of [99mTc]Tc-HYNIC-Fab(bevacizumab), a novel molecular VEGF expression imaging agent that may be used for precision medicine in melanoma and potentially in other VEGF-expressing tumors.

Effects of aflibercept and bevacizumab on cell viability, cell metabolism and inflammation in hypoxic human Müller cells.

Anti-VEGF (vascular endothelial growth factor) drugs such as aflibercept (AFL) and bevacizumab (BVZ) inhibit pathological neo-angiogenesis and vascular permeability in retinal vascular diseases. As cytokines and growth factors are produced by Müller glial cells under stressful and pathological conditions, we evaluated the in vitro effect of AFL (Eylea®, 0.5 mg/mL) and BVZ (Avastin®, 0.5 mg/mL) on cell viability/metabolism, and cytokine/growth factor production by Müller cells (MIO-M1) under cobalt chloride (CoCl2)-induced hypoxia after 24h, 48h and 72h. Cell viability/metabolism were analyzed by Trypan Blue and MTT assays and cytokine/growth factors in supernatants by Luminex xMAP-based multiplex bead-based immunoassay. Cell viability increased with AFL at 48h and 72h and decreased with BVZ or hypoxia at 24h. BVZ-treated cells showed lower cell viability than AFL at all exposure times. Cell metabolism increased with AFL but decreased with BVZ (72h) and hypoxia (48h and72h). As expected, AFL and BVZ decreased VEGF levels. AFL increased PDGF-BB, IL-6 and TNF-α (24h) and BVZ increased PDGF-BB (72h). Hypoxia reduced IL-1ß, -6, -8, TNF-α and PDGF-BB at 24h, and its suppressive effect was more prominent than AFL (EGF, PDGF-BB, IL-1ß, IL-6, IL-8, and TNF-α) and BVZ (PDGF-BB and IL-6) effects. Hypoxia increased bFGF levels at 48h and 72h, even when combined with anti-VEGFs. However, the stimulatory effect of BVZ predominated over hypoxia for IL-8 and TNF-α (24h), as well as for IL-1ß (72h). Thus, AFL and BVZ exhibit distinct exposure times effects on MIO-M1 cells viability, metabolism, and cytokines/growth factors. Hypoxia and BVZ decreased MIO-M1 cell viability/metabolism, whereas AFL likely induced gliosis. Hypoxia resulted in immunosuppression, and BVZ stimulated inflammation in hypoxic MIO-M1 cells. These findings highlight the complexity of the cellular response as well as the interplay between anti-VEGF treatments and the hypoxic microenvironment.

Glycosylation differences of an anti-VEGF monoclonal antibody (PRO-169) and its extensive comparison with Bevacizumab.

PRO-169 is an anti-VEGF monoclonal antibody developed by Laboratorios Sophia that shares its sequence with Bevacizumab (BVZ); though, PRO-169 is intended for intravitreal administration. In this study, analytical characterization showed that PRO-169 had glycosylation differences in comparison to BVZ reference product (RP); since it had more content of G1F, G2F, sialic acid and high mannose. Further investigation was performed to evaluate if differences between both products would affect the efficacy and safety profile of PRO-169. PRO-169 had no alteration in its in vitro biological activity; moreover, no cytotoxicity or immunogenicity concerns should be expected as demonstrated by different orthogonal methods at analytical, in vitro and in vivo assays. These results support moving to the clinical testing of PRO-169 since no major complications will be expected with its clinical use for the treatment of ophthalmic diseases.

The effect of bevacizumab, 5-fluorouracil, and triamcinolone on the healing modulation of surgical wounds in rats.

In this study, we aimed to analyze the effect of 5-fluorouracil, triamcinolone, and bevacizumab on scar modulation in an experimental rat model of surgical lesions. Rats (Rattus norvegicus albinus) were divided into four groups: bevacizumab, 5-fluorouracil + triamcinolone, bevacizumab + 5-fluorouracil + triamcinolone, and control (received no medication) groups. A linear, dorsal incision was created and sutured for the first intention wound healing, mimicking the surgical incision of upper blepharoplasty. Treatments were initiated on day 7, and the rats were euthanized on day 14. Only in the 5-fluorouracil + triamcinolone group was there a difference in the number of infiltrated monocytes. There was 56%, 86%, and 85% decrease in the number of neovessels in the bevacizumab, 5-fluorouracil + triamcinolone, and bevacizumab + 5-fluorouracil + triamcinolone groups, respectively, compared with the control. Picrosirius red staining showed higher collagen density and more organized collagen in the treatment groups than in the control group. Scar modulation was observed in all groups, but the 5-fluorouracil + triamcinolone group presented the best results. To our knowledge, this is the first study to evaluate the influence of three medications in combination on healing. When used together, these medications can prevent the development of unsightly scars, and are therefore promising alternatives to corticosteroids.

Circulating galectin-1 delineates response to bevacizumab in melanoma patients and reprograms endothelial cell biology.

Blockade of vascular endothelial growth factor (VEGF) signaling with bevacizumab, a humanized anti-VEGF monoclonal antibody (mAb), or with receptor tyrosine kinase inhibitors, has improved progression-free survival and, in some indications, overall survival across several types of cancers by interrupting tumor angiogenesis. However, the clinical benefit conferred by these therapies is variable, and tumors from treated patients eventually reinitiate growth. Previously we demonstrated, in mouse tumor models, that galectin-1 (Gal1), an endogenous glycan-binding protein, preserves angiogenesis in anti-VEGF-resistant tumors by co-opting the VEGF receptor (VEGFR)2 signaling pathway in the absence of VEGF. However, the relevance of these findings in clinical settings is uncertain. Here, we explored, in a cohort of melanoma patients from AVAST-M, a multicenter, open-label, randomized controlled phase 3 trial of adjuvant bevacizumab versus standard surveillance, the role of circulating plasma Gal1 as part of a compensatory mechanism that orchestrates endothelial cell programs in bevacizumab-treated melanoma patients. We found that increasing Gal1 levels over time in patients in the bevacizumab arm, but not in the observation arm, significantly increased their risks of recurrence and death. Remarkably, plasma Gal1 was functionally active as it was able to reprogram endothelial cell biology, promoting migration, tubulogenesis, and VEGFR2 phosphorylation. These effects were prevented by blockade of Gal1 using a newly developed fully human anti-Gal1 neutralizing mAb. Thus, using samples from a large-scale clinical trial from stage II and III melanoma patients, we validated the clinical relevance of Gal1 as a potential mechanism of resistance to bevacizumab treatment.

Antitumor effect of isoquercetin on tissue vasohibin expression and colon cancer vasculature.

Tumor cells trigger angiogenesis through the expression of angiogenic factors. Vasohibins (VASHs) are a family of peptides that regulate angiogenesis. Flavonoids have antiproliferative antitumor properties; however, few studies have highlighted their antiangiogenic potential. This study evaluated the flavonoid isoquercetin (Q3G) as an antitumor compound related to colon cancer vascularization and regulation of VASH1 and 2. Mice bearing xenogeneic colon cancer (n = 15) were divided into 3 groups: Q3G-treated (gavage, daily over a week), bevacizumab-treated (intraperitoneal, single dose), or untreated animals. Tumor growth, histological characteristics, blood vessel volume, and VASH1 and 2 expressions were analyzed. Q3G impaired tumor growth and vascularization, upregulated VASH1, and downregulated VASH2 in comparison to untreated animals. Mice treated with Q3G showed approximately 65% fewer blood vessels than untreated animals and 50% fewer blood vessels than mice treated with bevacizumab. Thus, we show that Q3G has antitumor activity, impairs vascularization, and differentially modulates VASH1 and 2 expressions in colon cancer.

Organic Nanocarriers for Bevacizumab Delivery: An Overview of Development, Characterization and Applications.

Bevacizumab (BCZ) is a recombinant humanized monoclonal antibody against the vascular endothelial growth factor, which is involved in the angiogenesis process. Pathologic angiogenesis is observed in several diseases including ophthalmic disorders and cancer. The multiple administrations of BCZ can cause adverse effects. In this way, the development of controlled release systems for BCZ delivery can promote the modification of drug pharmacokinetics and, consequently, decrease the dose, toxicity, and cost due to improved efficacy. This review highlights BCZ formulated in organic nanoparticles providing an overview of the physicochemical characterization and in vitro and in vivo biological evaluations. Moreover, the main advantages and limitations of the different approaches are discussed. Despite difficulties in working with antibodies, those nanocarriers provided advantages in BCZ protection against degradation guaranteeing bioactivity maintenance.

A Critical Review of Biological Properties, Delivery Systems and Analytical/Bioanalytical Methods for Determination of Bevacizumab.

Bevacizumab is a chimeric monoclonal human-murine antibody originated from murine monoclonal antibody (muMAb A4.6.1) with the human immunoglobulin IgG1. BVZ binds the extracellular portion of vascular endothelial growth factor receptors (VEGFR), which have tyrosine kinase activity. The mechanism of action of BVZ involves binding to VEGFR, Flt-1 (VEGFR-1) and KDR/Flk-1 (VEGFR-2), inducing homodimerization of two receptor subunits, and, consequently, autophosphorylation of their tyrosine kinase domains located inside the cytoplasm. With the advent of nanostructured systems it is increasingly necessary to look for safe analytical methods, ensuring the reliability of the results obtained by them, becoming essential to ensure the quality of medicines. In this work, the incorporation of bevacizumab in to different drug delivery systems was presented. Moreover, detailed investigation was performed about methods for qualitative and quantitative analyses of bevacizumab, including, biological fluids, and drug delivery systems, were investigated. Most recently high performance liquid chromatography coupled with various detectors, liquid chromatography, mass spectrometry and ELISA were used for this purpose. Thus, this review was performed to evaluate the benefits of bevacizumab carried by nanostructured systems and the analytical methods available for detection and quantification of these drugs.

Relevance of angiogenesis in autoimmune testis inflammation.

Experimental autoimmune orchitis (EAO) is a useful model to study organ-specific autoimmunity and chronic testicular inflammation. This model reflects testicular pathological changes reported in immunological infertility in men. Progression of EAO in rodents is associated with a significantly increased percentage of testicular endothelial cells and interstitial testicular blood vessels, indicating an ongoing angiogenic process. Vascular endothelial growth factor A (VEGFA), the main regulator of physiological and pathological angiogenesis, can stimulate endothelial cell proliferation, chemotaxis and vascular permeability. The aim of this study was to explore the role of VEGFA in the pathogenesis of testicular inflammation. Our results found VEGFA expression in Leydig cells, endothelial cells and macrophages in testis of rats with autoimmune orchitis. VEGFA level was significantly higher in testicular fluid and serum of rats at the end of the immunization period, preceding testicular damage. VEGF receptor (VEGFR) 1 is expressed mainly in testicular endothelial cells, whereas VEGFR2 was detected in germ cells and vascular smooth muscle cells. Both receptors were expressed in testicular interstitial cells. VEGFR2 increased after the immunization period in the testicular interstitium and VEGFR1 was downregulated in EAO testis. In-vivo-specific VEGFA inhibition by Bevacizumab prevented the increase in blood vessel number and reduced EAO incidence and severity. Our results unveil relevance of VEGFA-VEGFR axis during orchitis development, suggesting that VEGFA might be an early marker of testicular inflammation and Bevacizumab a therapeutic tool for treatment of testicular inflammation associated with subfertility and infertility.

Bevacizumab-Conjugated Quantum Dots: In Vitro Antiangiogenic Potential and Biosafety in Rat Retina.

Purpose: Disturbances that affect the inside of the eyeball tend to be highly harmful since they compromise the homeostasis of this organ. Alongside this, the eyeball has several anatomical barriers that prevent the entry of substances. This way, diseases that affect the retina are among those that present greater difficulty in the treatment. In many cases, abnormal proliferation of blood vessels (neovascularization) occurs from the lower layers of the retina. This process damages its structure physiologically and anatomically, causing the rapid and irreversible loss of visual capacity. This work aims to develop nanosuspensions of quantum dots (QDs) conjugated to bevacizumab. Methods: Two types of QDs were produced by aqueous route, stabilized with chitosan conjugated to bevacizumab. The antiangiogenic activity was evaluated in the chorioallantoic membrane model, in which results indicated discrete activity at the doses tested. Samples were assessed for their biosafety in animals, after intravitreal administration, by means of electroretinography (ERG), intraocular pressure (IOP) measurement, histological, morphometric, and immunohistochemical evaluation. Results: No significant alterations were detected in ERG that suggests damage to retinal function by the samples. No significant changes in IOP were also detected. The histological sections did not show signs of acute inflammation, although there was evidence of late retinal damage. The immunohistochemical analysis did not detect any apoptotic bodies. Conclusion: Preliminary results suggest that QDs present potential applicability in ocular therapy, and it is necessary to better characterize their in vivo behavior and to optimize their dosage.

Impact of Bevacizumab on Experimentally Induced Endometriotic Lesions: Angiogenesis, Invasion, Apoptosis, and Cell Proliferation.

Endometriosis is responsible for pain symptoms with great impact on the patient's quality of life. Several medication lines have been studied aiming at its definitive treatment. Among them, angiogenesis inhibitor factors may be effective given that angiogenesis has fundamental role in the establishment and growth of endometriotic lesions. In this study, we investigated the influence of bevacizumab, anti-factor drug of endothelial growth (anti-VEGF), used at two different dosages, in experimental endometriosis induced in rats. After the induction of endometriosis lesions in rats, they were divided in 3 groups: control group, no treatment, and two other groups were treated with different dosages of the same medication for 4 weeks. At the end of the treatment, endometriotic lesions were removed and evaluated regarding area of lesions, presence of endometrial tissue in microscopy, positivity for anti-VEGF antibody in immunohistochemistry, and gene expression of Pcna, Mmp9, Tp63, and Vegfa. Bevacizumab acted by reducing the area of lesions in the groups that received medication (p = 0.002) and reducing gene expression to Tp63 in lesions (p = 0.04). There was no significant result in other evaluations. We observed that there was significant reduction of the area of lesions among groups, suggesting that bevacizumab has a positive effect on disease control. The gene expression of Tp63 was significantly lower in the group that received high dose of the drug when compared with the other two groups; therefore, we concluded that bevacizumab acts by reducing cell proliferation and differentiation in lesions, constituting a real option for treating endometriosis.

Comparing The Efficacy Of An Anti-Human VEGF-A Neutralizing Antibody Versus Bevacizumab On A Laser-Induced Choroidal Neovascularization (CNV) Rhesus Monkey Model.

PURPOSE: To evaluate the efficacy of a therapy on improving characteristics of laser-induced choroidal neovascularization (CNV) via single intravitreal injection of a humanized anti-human VEGF monoclonal antibody (PRO-169) versus bevacizumab in a rhesus monkey model. METHODS: To induce experimental CNV, small high-energy laser spots were used to treat several areas, around the macula in the retinas of monkeys at Day -21. Eighteen rhesus monkeys were used for CNV induction. The efficacy endpoints were fluorescein leakage by FFA and retinal thickness by OCT. FFA examinations were performed 19 days after induction. Appropriate animals were enrolled for treatment and randomly divided into 3 groups: bevacizumab (n=5, 7 eyes), PRO-169 (n=5, 7 eyes), and vehicle controls (n=4, 7 eyes). RESULTS: In 25 of 36 (69.4%) eyes, CNV lesions were identified. The average percent change of retinal thickness in the eyes of bevacizumab group was -159.3±62.2% and -154.0±45.1% (p<0.01 vs Vehicle) at Day 14 and Day 28, respectively; in the eyes of PRO-169 group it was -131.6±68.7% and -131.5±63.8% (p<0.01 vs Vehicle), respectively. The average percent change of leakage area in the eyes of bevacizumab group was -75.3±49.4% and -78.0±42.6% (p<0.01 vs Vehicle) at Day 14 and Day 28, respectively; in the eyes of PRO-169 group it was -82.0±19.3% and -81.4±21.0% (p<0.01 vs Vehicle), respectively. There were no abnormalities found in behavior, skin and hair, excretion and overall eye appearance before and after treatment in all groups. CONCLUSION: After photocoagulation, the eyes enrolled in this studio showed CNV related characteristics including increased retinal thickness, and fluorescein leakage at laser spots. PRO-169 (1.25 mg per eye) can reduce the retinal thickness and fluorescein leakage area after treatment for 14 and 28 days in this rhesus monkeys model, without toxic effect or adverse events. These findings suggested that PRO-169 can inhibit CNV.

The Effect of Single-Dose Intraperitoneal Bevacizumab on Peritoneal Adhesion Formation.

BACKGROUND: Intra-abdominal adhesions and their complications following abdominal surgery are serious problems, with an incidence of 67-93%. Prevention of peritoneal adhesion formation may eliminate the need for surgical intervention, decreasing complications, morbidity, and cost. Bevacizumab is a recombinant monoclonal antibody which specifically binds vascular endothelial growth factor, an important cytokine in adhesion formation, and neutralizes its biological activity. We developed an experimental model in rats to determine the effect of bevacizumab in preventing adhesion formation and analyzed its effect both micro- and macroscopically. METHODS: We used 32. Wistar rats randomly divided into two groups: Group A (control) and Group B (bevacizumab), with 16 rats each. A modified cecum abrasion model was developed; 0.9% NaCl solution was administered intraperitoneally to Group A and bevacizumab to Group B. On day 15, adhesion formation was evaluated both macro- and microscopically. RESULTS: Both micro- and macroscopic adhesion grades in Group B were significantly lower than those of control Group A; macroscopic grades were 2.69 ± 0.95 and 0.69 ± 0.8, and microscopic grades were 2.25 ± 1.06 and 0.5 ± 0.52 for Groups A and B, respectively. CONCLUSIONS: Bevacizumab was effective in preventing intraperitoneal adhesion formation in our study; however, its inhibitory effects on embryogenesis and the hematopoietic, endocrine, and immune systems may limit its clinical use.

Corneal Neovascularization: A Combined Approach of Bevacizumab and Suramin Showed Increased Antiangiogenic Effect Through Downregulation of BFGF and P2X2.

PURPOSE: The objective is to analyze the antiangiogenic mechanism of suramab, a pharmaceutical compound of bevacizumab and suramin, in a rabbit model of corneal angiogenesis. MATERIAL AND METHODS: Corneal neovascularization was induced in four groups of six New Zealand White rabbits by applying a filter paper disk soaked in 1 M Na (OH) on the central cornea. Group one was treated after injury with intravenous suramab at a dose equivalent to 3 mg/kg of bevacizumab and 10 mg/kg of suramin. Group two was treated with intravenous bevacizumab (5 mg/kg). Group three was treated with 10 mg/kg of suramin while the control group received no treatment. Digital photographs were taken at days 9, 15, 21, and 35. Neovessel formation was quantified giving a 0-4 score to each quadrant according to the centripetal growth of the longest vessel (neovessel index, NVI). Animals were sacrificed at day 35. Corneas were processed for histology, immunohistochemistry, and Western-blot using primary antibodies against P2X2, basic fibroblast growth factor (bFGF), LYVE-1, PECAM-1, and vascular endothelial growth factor-A (VEGF-A). RESULTS: Suramab significantly reduced neovessel growth (mean NVI: 4.2) compared to bevacizumab (8.4), suramin (7.22), and control animals (12.2) at 35 days post-injury (p < 0.01). A lower protein expression of P2X2, bFGF, LYVE-1, PECAM-1, and VEGF-A was found in the cornea of suramab animals than in the other groups of animals. CONCLUSIONS: Joint downregulation of bFGF, P2X2, bFGF, and LYVE-1 constitutes a mechanism that induces greater and longer inhibition of corneal angiogenesis. Results might be relevant to ophthalmic care. Ocular administration of suramab is currently being investigated.

Bevacizumab as a treatment for hereditary hemorrhagic telangiectasia in children: a case report.

CASE DESCRIPTION: Five-year-old female patient with hereditary hemorrhagic telangiectasia. CLINICAL FINDINGS: Deterioration of cardiopulmonary function with higher oxygen requirements secondary to pulmonary arteriovenous shunts, epistaxis. TREATMENT AND OUTCOME: The patient was treated with the monoclonal antibody bevacizumab, which inhibits the vascular endothelial growth factor, with good clinical outcome. CLINICAL RELEVANCE: Hereditary hemorrhagic telangiectasia is an autosomal dominant disorder characterized by arteriovenous malformations in different organs, making its clinical presentations varied. Systemic therapeutic options for a generalized disease are limited. The monoclonal antibody bevacizumab, seems to be a good option in this disorder. Although reported as successful in adult population, its use in pediatric population has not yet been reported. Here we report the use of bevacizumab in a 5-year-old female patient with hereditary hemorrhagic telangiectasia, showing clinical benefits and good outcome.

DESCRIPCIÓN DEL CASO: Paciente de cinco años de sexo femenino con telangiectasia hemorrágica hereditaria. HALLAZGOS CLÍNICOS: Deterioro de la función cardiopulmonar con mayores requerimientos de oxígeno secundario a shunt pulmonar arteriovenoso, epistaxis. TRATAMIENTO Y RESULTADO: La paciente fue tratada con el anticuerpo monoclonal bevacizumab, que inhibe el factor de crecimiento endotelial vascular, con buen resultado clínico. RELEVANCIA CLÍNICA: La telangiectasia hemorrágica hereditaria es un trastorno autosómico dominante caracterizado por malformaciones arteriovenosas en diferentes órganos, lo que hace que sus presentaciones clínicas varíen. Las opciones terapéuticas sistémicas para la enfermedad generalizada son limitadas. El anticuerpo monoclonal bevacizumab, parece ser una buena opción en este trastorno. Aunque se ha reportado como exitoso en la población adulta, su uso en población pediátrica aún no ha sido reportado. Aquí se informa el uso de bevacizumab en una paciente de 5 años de edad con telangiectasia hemorrágica hereditaria, mostrando beneficios clínicos y buen resultado.

Alginate hydrogel improves anti-angiogenic bevacizumab activity in cancer therapy.

Anti-vascular endothelial growth factor (anti-VEGF) therapy applied to solid tumors is a promising strategy, yet, the challenge to deliver these agents at high drug concentrations together with the maintenance of therapeutic doses locally, at the tumor site, minimizes its benefits. To overcome these obstacles, we propose the development of a bevacizumab-loaded alginate hydrogel by electrostatic interactions to design a delivery system for controlled and anti-angiogenic therapy under tumor microenvironmental conditions. The tridimensional hydrogel structure produced provides drug stability and a system able to be introduced as a flowable solution, stablishing a depot after local administration. Biological performance by the chick embryo chorioallantoic membrane (CAM) assay indicated a pH-independent improved anti-angiogenic activity (∼50%) compared to commercial available anti-VEGF drug. Moreover, there was a considerable regression in tumor size when treated with this system. Immunohistochemistry highlighted a reduced number and disorganization of microscopic blood vessels resulting from applied therapy. These results suggest that the developed hydrogel is a promising approach to create an innovative delivery system that offers the possibility to treat different solid tumors by intratumoral administration.

Bevacizumab as a treatment for hereditary hemorrhagic telangiectasia in children: a case report / Bevacizumab como tratamiento para telangiectasia hemorrágica hereditaria en niños: Reporte de caso

Abstract Case description: Five-year-old female patient with hereditary hemorrhagic telangiectasia. Clinical Findings: Deterioration of cardiopulmonary function with higher oxygen requirements secondary to pulmonary arteriovenous shunts, epistaxis. Treatment and Outcome: The patient was treated with the monoclonal antibody bevacizumab, which inhibits the vascular endothelial growth factor, with good clinical outcome. Clinical Relevance: Hereditary hemorrhagic telangiectasia is an autosomal dominant disorder characterized by arteriovenous malformations in different organs, making its clinical presentations varied. Systemic therapeutic options for a generalized disease are limited. The monoclonal antibody bevacizumab, seems to be a good option in this disorder. Although reported as successful in adult population, its use in pediatric population has not yet been reported. Here we report the use of bevacizumab in a 5-year-old female patient with hereditary hemorrhagic telangiectasia, showing clinical benefits and good outcome.

Resumen Descripción del caso: Paciente de cinco años de sexo femenino con telangiectasia hemorrágica hereditaria. Hallazgos Clínicos: Deterioro de la función cardiopulmonar con mayores requerimientos de oxígeno secundario a shunt pulmonar arteriovenoso, epistaxis. Tratamiento y resultado: La paciente fue tratada con el anticuerpo monoclonal bevacizumab, que inhibe el factor de crecimiento endotelial vascular, con buen resultado clínico. Relevancia clínica: La telangiectasia hemorrágica hereditaria es un trastorno autosómico dominante caracterizado por malformaciones arteriovenosas en diferentes órganos, lo que hace que sus presentaciones clínicas varíen. Las opciones terapéuticas sistémicas para la enfermedad generalizada son limitadas. El anticuerpo monoclonal bevacizumab, parece ser una buena opción en este trastorno. Aunque se ha reportado como exitoso en la población adulta, su uso en población pediátrica aún no ha sido reportado. Aquí se informa el uso de bevacizumab en una paciente de 5 años de edad con telangiectasia hemorrágica hereditaria, mostrando beneficios clínicos y buen resultado.

Cellular stress response in human Müller cells (MIO-M1) after bevacizumab treatment.

Bevacizumab, an anti-vascular endothelial growth factor (VEGF) agent, is widely used in the treatment of retinal vascular diseases. However, due to the essential role Müller cell derived-VEGF plays in the maintenance of retinal neurons and glial cells, cell viability is likely to be affected by VEGF inhibition. We therefore evaluated the effect of bevacizumab-induced VEGF inhibition on Müller cells (MIO-M1) in vitro. MIO-M1 cells were cultured for 12 or 24 h in media containing bevacizumab at 0.25 or 0.5 mg/mL. Controls were cultured in medium only. Cell viability was determined with the trypan blue exclusion test and MTT assay. Caspase-3, beclin-1, glial fibrillary acidic protein (GFAP) and vimentin content were quantified by immunohistochemistry. Gene expression was evaluated by real-time quantitative PCR. Treatment with bevacizumab did not reduce MIO-M1 cell viability, but increased metabolic activity at 24 h (0.5 mg/mL) and induced apoptosis and autophagy, as shown by the increased caspase-3 levels at 12 h (0.25 and 0.5 mg/mL) and the increased beclin levels at 24 h (0.5 mg/mL). Caspase-3 mRNA was upregulated at 12 h and downregulated at 24 h in cells treated with bevacizumab at 0.25 mg/mL. Bevacizumab treatment was also associated with structural protein abnormalities, with decreased GFAP and vimentin content and upregulated GFAP and vimentin mRNA expression. Although bevacizumab did not significantly affect MIO-M1 cell viability, it led to metabolic and molecular changes (apoptosis, autophagy and structural abnormalities) suggestive of significant cellular toxicity.

Targeted multidrug delivery system to overcome chemoresistance in breast cancer.

Chemotherapy has been widely used in breast cancer patients to reduce tumor size. However, most anticancer agents cannot differentiate between cancerous and normal cells, resulting in severe systemic toxicity. In addition, acquired drug resistance during the chemotherapy treatment further decreases treatment efficacy. With the proper treatment strategy, nanodrug carriers, such as liposomes/immunoliposomes, may be able to reduce undesired side effects of chemotherapy, to overcome the acquired multidrug resistance, and to further improve the treatment efficacy. In this study, a novel combinational targeted drug delivery system was developed by encapsulating antiangiogenesis drug bevacizumab into liposomes and encapsulating chemotherapy drug doxorubicin (DOX) into immunoliposomes where the human epidermal growth factor receptor 2 (HER2) antibody was used as a targeting ligand. This novel combinational system was tested in vitro using a HER2 positive and multidrug resistant breast cancer cell line (BT-474/MDR), and in vivo using a xenograft mouse tumor model. In vitro cell culture experiments show that immunoliposome delivery led to a high cell nucleus accumulation of DOX, whereas free DOX was observed mostly near the cell membrane and in cytoplasm due to the action of P-gp. Combining liposomal bevacizumab with immunoliposomal DOX achieved the best tumor growth inhibition and the lowest toxicity. Tumor size decreased steadily within a 60-day observation period indicating a potential synergistic effect between DOX and bevacizumab through the targeted delivery. Our findings clearly indicate that tumor growth was significantly delayed in the combinational liposomal drug delivery group. This novel combinational therapy has great potential for the treatment of patients with HER2/MDR double positive breast cancer.