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Purpose: To report the estimated incidence, probability, risk factors, and 1-year outcomes of rhegmatogenous retinal detachment (RRD) in eyes receiving intravitreal injections (IVTs) of VEGF inhibitors for various retinal conditions in routine clinical practice. Design: Retrospective analysis of data from a prospectively designed observational outcomes registry: the Fight Retinal Blindness! Participants: Eyes of patients starting IVTs of VEGF inhibitors (ranibizumab, aflibercept, or bevacizumab) for neovascular age-related macular degeneration, diabetic macular edema, or retinal vein occlusion from January 1, 2006, to December 31, 2020. All eyes that developed RRD within 90 days of IVTs were defined as cases with RRD and were matched with control eyes. Methods: Estimated incidence, probability, and hazard ratios (HRs) of RRD were measured using Poisson regression, Kaplan-Meier survival curve, and Cox proportional hazards models. Locally weighted scatterplot smoothing curves were used to compare visual acuity (VA) between cases and matched controls. Main outcome measures: Estimated incidence of RRD. Results: We identified 16 915 eyes of 13 792 patients who collectively received 265 781 IVTs over 14 years. Thirty-six eyes were reported to develop RRD over the study period. The estimated incidence (95% confidence interval [CI]) per year per 1000 patients and per 10 000 injections was 0.77 (0.54-1.07) and 1.36 (0.95-1.89), respectively. The probability of RRD did not significantly increase at each successive injection (P = 0.95) with the time of follow-up. Older patients (HR [95% CI] = 1.81 [1.21-3.62] for every decade increase in age, P < 0.01) were at a higher risk of RRD, whereas patients with good presenting VA (HR [95% CI] = 0.85 [0.70-0.98] for every 10-letter increase in VA, P = 0.02) were at a lower risk. Neither the type of retinal disease (P = 0.52) nor the VEGF inhibitor (P = 0.09) was significantly associated with RRD risk. Cases with RRD lost 3 lines of vision on average compared with the prior RRD VA and had significantly fewer injections than matched controls over the year after the RRD. Conclusions: Rhegmatogenous retinal detachment is a rare complication of VEGF inhibitor IVT in routine clinical practice with poor visual outcomes at 1 year.

Purpose: To report the 24-month outcomes of vascular endothelial growth factor (VEGF) inhibitors for myopic choroidal neovascularization (mCNV) in predominantly Caucasian eyes in routine clinical practice. Methods: Retrospective analysis of treatment-na¿ıve eyes starting intravitreal injection of VEGF inhibitors of either bevacizumab (1.25 mg) or ranibizumab (0.5 mg) for mCNV from 1 January 2006 to 31 May 2018 that were tracked in the Fight Retinal Blindness! registry. Results: We identified 203 eyes (bevacizumab-85 and ranibizumab-118) of 189 patients. The estimated mean (95% CI) change in VA over 24 months for all eyes using longitudinal models was +8 (5, 11) letters with a median (Q1, Q3) of 3 (2, 5) injections given mostly during the first year. The estimated mean change in VA at 24 months was similar between bevacizumab and ranibizumab [+9 (5, 13) letters for bevacizumab versus +9 (6, 13) letters for ranibizumab; p = 0.37]. Both agents were also similar in the mCNV activity outcomes, treatment frequency and visit frequency. Conclusions: The 24-month treatment outcomes of VEGF inhibitors for mCNV were favourable in this largest series yet reported of predominantly Caucasian eyes in routine clinical practice,with approximately two lines of visual gain and amedian of three injections given mostly during the first year. These outcomes are similar to those reported for predominantly Asian eyes.Bevacizumab appeared to be as safeandeffective as ranibizumab. Key words: anti-VEGF therapy - Caucasian - high myopia - myopia - myopic choroidal neovascularization - optical coherence tomography - pathologic myopia - VEGF inhibitors

[eng] Our knowledge on the molecular basis behind physiological angiogenesis has significantly expanded in the last two decades. This progress also led to improvement in understanding of many vascular-related diseases in which angiogenesis is pathologically altered. Among many molecular regulators of angiogenesis, a family of lipid kinases called phosphatidylinositol 3-kinases (PI3Ks) occupies an important position in controlling endothelial cell functions. Indeed, numerous studies showed that endothelial cells are highly sensitive to fluctuations in the levels of phospholipids generated by these enzymes. Although highly conservative, the eight PI3K isoforms can produce three different types of phospholipids and this phenomenon formed the basis of the division into three different classes. Two members, ass I PI3Kα and ass II PI3K-C2α, are essential for proper vascular development. Moreover, somatic activating mutations in the gene encoding PI3Kα (PIK3CA) were found to cause 25% of venous malformations – a non-malignant, painful and mainly pediatric vascular disease for which the treatment options are limited. The vascular function of other isoforms, in particular class II PI3K-C2β, remains enigmatic. This is surprising given that this isoform is also express in cultured endothelial cells. This thesis is composed of two principal objectives objectives which together have been conceived to increase our knowledge on PI3K signaling in the endothelium. In the first part I evaluated the therapeutic efficacy of pan-AKT inhibitor, miransertib, in Pik3ca-driven vascular malformations using a preclinical mouse model. I showed that miransertib significantly prevents and reverts Pik3ca associated vascular hyperplasia through inhibition of endothelial cell proliferation. My results provide rationale for the therapeutic intervention of miransertib in treating patients with vascular malformations. The second part of the thesis studies the impact of PI3K-C2β isoform on blood vessel expansion and endothelial cell biology. Using both in vivo and in vitro models, I demonstrated for the first time that PI3K-C2β regulates retinal vascularity and vessel width, most likely as result of elevated vascular mTORC1 activity. Moreover, PI3K-C2β kinase inactivation led to increased collagen IV deposition and more stable vascular connections. In parallel, we showed that blood vessel-associated pericytes express high levels of PI3K-C2β and that its loss of function alters their morphology. Finally, we addressed the role of PI3K-C2β in the pathological neoangiogenesis associated with oxygen-induced retinopathy.

Diabetic retinopathy causes vascular damage to retinal neurons, presenting characteristics of chronic inflammation. The development of new therapies capable of combating vision loss involves knowledge of inflammatory retinal changes. Studies in animal models and patients with diabetes have shown a high expression of the inflammatory molecules that are involved in the progression of diabetic retinopathy. Uveal melanoma is an eye tumour that remains highly deadly, because despite the correct treatment, it still causes metastasis in about 50% of patients. This type of tumour has the ability to produce and store melanin, which may result in resistance to therapy. Over time there has been development of new therapies for this disease, such as radiotherapy and surgical resection. In this review, we discuss diabetic retinopathy and ocular melanoma, their relationship with angiogenesis and the current anti-angiogenic therapies for their treatment., The authors acknowledge the financial support received from the Portuguese Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) under the project references M-ERANET/0004/2015-PAIRED, UIDB/04469/2020 (strategic fund) and UID/AGR/04033/2019 (CITAB), co-financed by FEDER, under the Partnership Agreement PT2020. The authors also acknowledge the support of the research project: Nutraceutica come supporto nutrizionale nel paziente oncologico, CUP: B83D18000140007., info:eu-repo/semantics/publishedVersion

VEGFR-2/Notch signalling regulates angiogenesis in part by driving the remodelling of endothelial cell junctions and by inducing cell migration. Here, we show that VEGF-induced polarized cell elongation increases cell perimeter and decreases the relative VE-cadherin concentration at junctions, triggering polarized formation of actin-driven junction-associated intermittent lamellipodia (JAIL) under control of the WASP/WAVE/ARP2/3 complex. JAIL allow formation of new VE-cadherin adhesion sites that are critical for cell migration and monolayer integrity. Whereas at the leading edge of the cell, large JAIL drive cell migration with supportive contraction, lateral junctions show small JAIL that allow relative cell movement. VEGFR-2 activation initiates cell elongation through dephosphorylation of junctional myosin light chain II, which leads to a local loss of tension to induce JAIL-mediated junctional remodelling. These events require both microtubules and polarized Rac activity. Together, we propose a model where polarized JAIL formation drives directed cell migration and junctional remodelling during sprouting angiogenesis., The formation of new blood vessels requires both polarized cell migration and coordinated control of endothelial cell contacts. Here, Cao and colleagues describe at the sub-cellular level the cytoskeletal and cell junction dynamics regulating these processes upon VEGF-induced cell elongation.

Purpose: To examine vision-related quality of life in patients with diabetic macular edema (DME) treated with intravitreal aflibercept (EYLEA, Regeneron Pharmaceuticals, Inc, Tarrytown, NY). Design: AQUA was a multicenter, open-label, single-arm, phase 4 study. Participants: Adults 18 years of age or older with type 1 or 2 diabetes mellitus and DME. Methods: Patients received intravitreal aflibercept 2 mg every 8 weeks for 52 weeks, after 5 initial doses every 4 weeks. Main outcome measures: The primary outcome was the change in 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) total score from baseline to week 52. Secondary outcomes included the change in NEI VFQ-25 near and distant activities subscale scores, best-corrected visual acuity (BCVA; Early Treatment Diabetic Retinopathy Study [ETDRS] letters), and central retinal thickness (CRT) from baseline to week 52. Change in NEI VFQ-25 score at week 52 for better-seeing eyes (BSEs) and worse-seeing eyes (WSEs) also was evaluated. Results: A total of 553 patients comprised the full analysis set, and 560 patients comprised the safety analysis set. At baseline, the mean NEI VFQ-25 total score was 70.12, mean BCVA was 61.5 ETDRS letters, and mean CRT was 464.81 μm. A mean of 8.8 injections were administered over 52 weeks. At week 52, the mean improvement from baseline in the NEI VFQ-25 total score was +6.11 (standard deviation [SD], 11.46); the corresponding improvements in near and distant activities were +11.37 (SD, 18.01) and +7.33 (SD, 17.32), respectively. Similarly, improvements in patients whose BSE and WSE were treated were 7.74 (SD, 13.59) and 5.48 (SD, 9.70), respectively. At week 52, mean change in BCVA was +10.0 ETDRS letters (SD, 8.0 ETDRS letters), and mean change in CRT was -175.38 μm (SD, 132.62 μm). Overall, 53.6% of patients reported treatment-emergent adverse events (TEAEs), of whom 26.8% experienced an ocular TEAE in the study eye. The most common serious ocular TEAE was endophthalmitis (0.5% [n = 3]). Five deaths (0.9%) were reported, but were not considered treatment related. Conclusions: Intravitreal aflibercept was associated with clinically meaningful improvements in NEI VFQ-25 total score over 52 weeks in patients with DME; these were even more pronounced for near than for distant activities. Adverse events were consistent with the known safety profile of intravitreal aflibercept.

Vascular endothelial growth factor receptor‐3 (VEGFR3) signalling promotes lymphangiogenesis. While there are many reported mechanisms of VEGFR3 activation, there is little understanding of how VEGFR3 signalling is attenuated to prevent lymphatic vascular overgrowth and ensure proper lymph vessel development. Here, we show that endothelial cell‐specific depletion of integrin‐linked kinase (ILK) in mouse embryos hyper‐activates VEGFR3 signalling and leads to overgrowth of the jugular lymph sacs/primordial thoracic ducts, oedema and embryonic lethality. Lymphatic endothelial cell (LEC)‐specific deletion of Ilk in adult mice initiates lymphatic vascular expansion in different organs, including cornea, skin and myocardium. Knockdown of ILK in human LECs triggers VEGFR3 tyrosine phosphorylation and proliferation. ILK is further found to impede interactions between VEGFR3 and β1 integrin in vitro and in vivo, and endothelial cell‐specific deletion of an Itgb1 allele rescues the excessive lymphatic vascular growth observed upon ILK depletion. Finally, mechanical stimulation disrupts the assembly of ILK and β1 integrin, releasing the integrin to enable its interaction with VEGFR3. Our data suggest that ILK facilitates mechanically regulated VEGFR3 signalling via controlling its interaction with β1 integrin and thus ensures proper development of lymphatic vessels.

Growth factors promote plasticity in injured brain and improve impaired functions. For clinical application, efficient approaches for growth factor delivery into the brain are necessary. Poly(ester amide) (PEA)-derived microspheres (MS) could serve as vehicles due to their thermal and mechanical properties, biocompatibility and biodegradability. Vascular endothelial growth factor (VEGF) exerts both vascular and neuronal actions, making it suitable to stimulate post-stroke recovery. Here, PEA (composed of adipic acid, L-phenyl-alanine and 1,4-butanediol) MS were loaded with VEGF and injected intracerebrally in mice subjected to cortical stroke. Loaded MS provided sustained release of VEGF in vitro and, after injection, biologically active VEGF was released long-term, as evidenced by high VEGF immunoreactivity, increased VEGF tissue levels, and higher vessel density and more NG2+ cells in injured hemisphere of animals with VEGF-loaded as compared to non-loaded MS. Loaded MS gave rise to more rapid recovery of neurological score. Both loaded and non-loaded MS induced improvement in neurological score and adhesive removal test, probably due to anti-inflammatory action. In summary, grafted PEA MS can act as efficient vehicles, with anti-inflammatory action, for long-term delivery of growth factors into injured brain. Our data suggest PEA MS as a new tool for neurorestorative approaches with therapeutic potential.

Background: Systemic lupus erythematosus (SLE) is a genetically complex rheumatic disease characterized by heterogeneous clinical manifestations of unknown etiology. Recent studies have suggested the existence of a genetic basis for SLE heterogeneity. The objective of the present study was to identify new genetic variation associated with the clinically relevant phenotypes in SLE. Methods: A two-stage pathway-based approach was used to identify the genetic variation associated with the main clinical phenotypes in SLE. In the discovery stage, 482 SLE patients were genotyped using Illumina Human Quad610 microarrays. Association between 798 reference genetic pathways from the Molecular Signatures Database and 11 SLE phenotypes was tested using the set-based method implemented in PLINK software. Pathways significantly associated after multiple test correction were subsequently tested for replication in an independent cohort of 425 SLE patients. Using an in silico approach, we analyzed the functional effects of common SLE therapies on the replicated genetic pathways. The association of known SLE risk variants with the development of the clinical phenotypes was also analyzed. Results: In the discovery stage, we found a significant association between the vascular endothelial growth factor (VEGF) pathway and oral ulceration (P value for false discovery rate (P FDR ) < 0.05), and between the negative regulation signaling pathway of retinoic acid inducible gene-I/melanoma differentiation associated gene 5 and the production of antinuclear antibodies (P FDR < 0.05). In the replication stage, we validated the association between the VEGF pathway and oral ulceration. Therapies commonly used to treat mucocutaneous phenotypes in SLE were found to strongly influence VEGF pathway gene expression (P = 4.60e-4 to 5.38e-14). Analysis of known SLE risk loci identified a strong association between PTPN22 and the risk of hematologic disorder and with the development of antinuclear antibodies. Conclusions: The present study has identified VEGF genetic pathway association with the risk of oral ulceration in SLE. New therapies targeting the VEGF pathway could be more effective in reducing the severity of this phenotype. These findings represent a first step towards the understanding of the genetic basis of phenotype heterogeneity in SLE, This study was funded by the Spanish Ministry of Economy and Competitiveness (grant numbers: PSE-010000-2006-6 and IPT-010000-2010-36 and by the “Agència de Gestió d’Ajuts Universitaris i de Recerca” (AGAUR, Generalitat de Catalunya, FI-DGR 2016, grant number: 00587)

During immune surveillance and inflammation, leukocytes exit the vasculature through transient openings in the endothelium without causing plasma leakage. However, the exact mechanisms behind this intriguing phenomenon are still unknown. Here we report that maintenance of endothelial barrier integrity during leukocyte diapedesis requires local endothelial RhoA cycling. Endothelial RhoA depletion in vitro or Rho inhibition in vivo provokes neutrophil-induced vascular leakage that manifests during the physical movement of neutrophils through the endothelial layer. Local RhoA activation initiates the formation of contractile F-actin structures that surround emigrating neutrophils. These structures that surround neutrophil-induced endothelial pores prevent plasma leakage through actomyosin-based pore confinement. Mechanistically, we found that the initiation of RhoA activity involves ICAM-1 and the Rho GEFs Ect2 and LARG. In addition, regulation of actomyosin-based endothelial pore confinement involves ROCK2b, but not ROCK1. Thus, endothelial cells assemble RhoA-controlled contractile F-actin structures around endothelial pores that prevent vascular leakage during leukocyte extravasation., Endothelial cells can support leukocyte extravasation without causing vascular leakage, but the exact mechanism underlying this process has not been fully elucidated. Here the authors show that it is regulated through actomyosin-based endothelial pore confinement, which requires local endothelial RhoA activation.

This randomized phase II study evaluated two schedules of the marine compound Plitidepsin with or without co-administration of L-carnitine in patients with renal cell carcinoma. Patients had adequate performance status and organ function. The primary endpoint was the rate of disease control ( no progression) at 12 weeks (RECIST). Other endpoints included the response rate and time dependent efficacy measures. The trial also assessed the efficacy of L-carnitine to prevent Plitidepsin-related toxicity. The two regimes given as 24 hour infusion every two weeks showed hints of antitumoral activity. Disease control at 12 weeks was 15.8% in Arm A (5mg/m2, no L-carnitine) and 11,1% in Arm B (7mg/m2 with L-carnitine). Two partial responses were observed in Arm A ( 19 patients), none in Arm B ( 20 patients). Both schedules had the same progression-free interval (2.1 months). The median overall survival was 7.0 and 7.6 months. The safety profile was similar in both arms of the trial and adverse events were mainly mild to moderate (NCI CTC version 2.0). Increasing the dose to 7mg/m2 did not increase the treatment efficacy but the incidence of transaminase and CPK elevations and serious AEs. Coadministration of L-carnitine did not prevent muscular toxicity or CPK-elevation associated with Plitidepsin.

Background and aims: The extent and molecular mechanisms governing plasma extravasation and formation of ascites in cirrhosis are unknown. Vascular endothelial growth factor-A (VEGF-A) and angiopoietin-2 (Ang-2) are endogenous substances with powerful vascular permeability effects. We assessed regional blood flow, vascular leakage, mRNA and tissular expression of VEGF-A and Ang-2 and vascular permeability following VEGF receptor 2 blockade in control and cirrhotic rats to define the vascular territories showing altered vascular permeability in cirrhosis and to determine whether VEGF-A and Ang-2 are involved in this phenomenon. Methods: Arterial blood flow was analysed with the coloured microsphere method. Vascular leakage was measured and visualised with the dye Evan¿s Blue and colloidal carbon techniques, respectively. VEGF-A and Ang-2 expression were determined by real-time polymerase chain reaction (RT-PCR), immunohistochemistry and western blot. The effect on vascular permeability induced by VEGFR2 blockade was assessed by administration of the receptor inhibitor SU11248. Results: Arterial blood flow was increased in the mesentery, pancreas and small intestine but not in the kidney and spleen of cirrhotic rats as compared to controls. Increased vascular leakage was observed in the mesentery and liver, where colloidal carbon spread from microvessels to the adjacent fibrotic tracts. Increased hepatic and mesenteric expression of VEGF-A and Ang-2 was found in cirrhotic rats as compared to controls. Blockade of VEGFR2 markedly reduced hepatic and mesenteric vascular leakage in cirrhotic rats. Conclusions: Enhanced endothelial permeability is restricted to the hepatic and mesenteric vascular beds in cirrhotic rats with ascites and VEGF-A and Ang-2 are key factors in the signalling pathways regulating this dysfunction.

HIPÒTESI DE TREBALL. L'angiogènesi al melanoma maligne està influenciada per factors autocrins i paracrins, entre els que es troba el VEGF. La influència del VEGF és especialment significativa a les primeres fases del desenvolupament tumoral.La modificació de l'equilibri angiogènic actuant sobre el VEGF podria condicionar un canvi significatiu al creixement tumoral i la seva capacitat metastàtica.OBJECTIUS.1.- Valorar l'expressió de VEGF en una sèrie de melanomes malignes primaris cutanis humans de baix risc.2.- Valorar el creixement tumoral i l'angiogènesi als tumors desenvolupats en ratolins atímics inoculats ortotòpicament amb les línies de melanoma humà A375P i A375MM, coinjectades o no amb Matrigel. 3.- Avaluar la influència de la modificació genètica de l'expressió de VEGF, mitjançant la transfecció del cDNA del VEGF en sentit i antisentit a les línies de melanoma humà A375P i A375MM, als tumors desenvolupats a ratolins atímics a partir de la injecció ortotòpica d'ambdues línies així modificades.MÈTODES.1.- Melanomes humans: 53 melanomes malignes cutanis primaris. Angiogènesi: tinció amb Ulex Europaeus I. Expressió VEGF: anàlisi immunohistoquímica.2.- Expressió de VEGF a línies de melanoma humà xenoempeltades a ratolins immunodeprimits: Inoculació ortotòpica a ratolins Balb/c nude de les línies A375P i A375MM, la meitat coinjectades amb Matrigel. Angiogènesi: tinció immunohistoquímica amb Ac anti-factor VIII. Expressió VEGF: anàlisi immunohistoquímica.3.- Modificació de l'expressió de VEGF a línies de melanoma humà xenoempeltades a ratolins immunodeprimits: Construcció del cDNA del VEGF en sentit i antisentit en un vector d'expressió (pRC/CMV), transfecció mitjançant liposomes a les línies A375P i A375MM, selecció dels transfectants i inoculació ortotòpica a ratolins atímics. Extirpació de la meitat dels tumors el més aviat possible (5-6 dies), per a avaluar la malaltia en les seves fases més precoces. Per a l'altra meitat, lliure creixement, calculant les corbes de creixement i extirpant els tumors a l'assolir un volum de 1·1 cm o equivalent. Seguiment de la supervivència dels ratolins. Angiogènesi: immunotinció amb Ac anti-factor VIII.RESULTATS.1.- Melanomes humans: El VEGF ha estat present al 84,9% de melanomes avaluats.Als melanomes en fase de creixement radial (in situ), a 7 de 29 s'ha observat un grau alt d'expressió de VEGF, front 12 de 16 a melanomes amb fase vertical (p=0,002). Una vegada el melanoma era ja invasor, no s'han trobat diferències entre el grau d'expressió de VEGF i el nivell de Breslow. No s'ha trobat relació entre angiogènesi i expressió de VEGF.2.- Expressió de VEGF als tumors desenvolupats als ratolins inoculats: S'ha demostrat una major expressió de VEGF en els estadis més temprans del desenvolupament tumoral, representats aquests per aquells tumors més petits (3.- Efecte de la modificació de l'expressió de VEGF sobre les dues línies A375P i A375MM xenoempeltades a ratolins atímics. Transfecció cDNA del VEGF en sentit: ha incrementat significativament el creixement dels tumors a les fases inicials del desenvolupament tumoral (4 clons de 4), a la corba de creixement (2 de 4), i a la supervivència (1 de 4). Transfecció cDNA VEGF en antisentit: cap diferència repecte al control, ni a fases inicials, ni a la corba de creixement, ni a la supervivència. Angiogènesi: no diferències en la densitat vascular entre els diferents clons.CONCLUSIÓ FINAL. El VEGF és determinant a les fases inicials del desenvolupament tumoral al melanoma maligne. Més endavant perd el seu paper protagonista. Igualment, la modificació genètica de la seva expressió en un model in vivo amb línies de melanoma humà xenoempeltades a ratolins atímics té efecte només als moments inicials del creixement tumoral, perdent tota la seva influència a les fases més tardanes del desenvolupament tumoral., We hypothesized that angiogenesis in melanoma is related to VEGF, and that the modification of the expression of VEGF could influence angiogenesis, tumour growth and metastatic capacity.First, we examined immunohistochemically the expression of VEGF in cutaneous primary melanoma. VEGF expression was graded in a scale from 0 to 3. Angiogenesis was measured with Ulex Europaeus I staining. 84,9% of tumours expressed VEGF. Vertical Growth Phase (VGP) was significatively associated with a higher intensity expression of VEGF when comparing to radial growth phase. However, once VGP had developed, there were no differences in VEGF expression between tumours. Surprisingly, VEGF expression was not related to angiogenesis.Second, in a model of human melanoma cell lines (A375P, A375MM) xenografted to nude mice, we evaluated the expression of VEGF. The most significant finding was a higher intensity expression of VEGF in tumours representing the first steps of tumour development: tumours lower than 0,5 cm in diameter and those extracted before day 9 post-inoculation demonstrated higher expression of VEGF when compared with the remainder.Third, VEGF sense and antisense cDNA were cloned to an expression vector (pRC/CMV) and transfected to A375P and A375MM melanoma cell lines with cationic liposomes; modified cell lines were xenografted to nude mice. To analyse first stages of tumour progression, half of the resultant tumours were extracted when they were minimally detectable. Growth curves of the rest of tumours were measured, and they were excised when reaching a volume of 0,4 cm3. Survival curves of mice were analysed afterwards. Angiogenesis was evaluated with Factor VIII staining.Sense VEGF transfection significatively enhanced tumour growth on initial stages of development (4 clones of 4), on growth curves (2 of 4) and on survival (1 of 4). Antisense VEGF transfection did not show any difference with control clones at any stage. Angiogenesis was not different between the clones.Conclusion: VEGF is decisive at first stages of development in melanoma. The modification of VEGF expression in an in vivo model of human melanoma cell lines xenografted to nude mice plays a role at initial stages of tumour development, losing its influence later.

[spa] El cáncer gástrico presenta, en el momento actual, un pronóstico desfavorable debido a su tendencia a la recidiva tras la cirugía realizada con intención curativa si no se diagnóstica en estadíos precoces. La instauración de terapias más agresivas en pacientes seleccionados podría mejorar la supervivencia. El pronóstico de estos pacientes se basa en el análisis de toda una serie de criterios clinicopatológicos clásicos, pero en el momento actual es de sumo interés el estudio de nuevos marcadores moleculares que permitan una mejor evaluación pronóstica y la identificación de aquellos pacientes con un elevado riesgo de desarrollar recidivas. La multiplicación celular es el factor más importante para que se produzca el crecimiento y progresión de los tumores. La proteína p53 es un elemento determinante en la regulación de la multiplicación celular, tanto por su capacidad para inducir la apoptosis como por el bloqueo que ejerce sobre el ciclo celular que impide la replicación. Por otro lado, dicha multiplicación y crecimiento tumoral, también dependen en alto grado de la angiogénesis, que está mediada por distintos factores angiogénicos, entre los que destaca el VEGF por ser uno de los más potentes y específicos. Nuestra hipótesis establece que el grado de angiogénesis valorado directamente mediante la densidad microvascular e indirectamente a través de la sobreexpressión de p53 y VEGF (ambos actuando como factores promotores de dicha angiogénesis), ejerce una influencia significativa sobre la agresividad clínica del cáncer gástrico. Hemos analizado la expresión de la p53, del VEGF y de la angiogénesis tumoral en 206 pacientes intervenidos quirúrgicamente por adenocarcinoma de estómago.

Introducción y objetivos: los autores presentan una serie de 18 pacientes con mielopatía en los que se diagnosticó una fístula dural arteriovenosa con drenaje venoso medular (FDdVM). El objetivo consistió en estudiar la efectividad inicial y a largo plazo de la embolización, como tratamiento inicial, utilizando partículas de polivinil-alcohol (PVA) y líquidos adhesivos, N-butil-cianoacrilato (NBCA). Material y métodos. Se obtuvieron imágenes de RM en todos los pacientes demostrando cambios en el parénquima medular compatibles con un proceso isquémico secundario a hipertensión venosa. Resultados: todos los pacientes mejoraron inicialmente de su sintomatología y en algunos casos se demostró la desaparición de las imágenes previas en las RM de control. Se presentó recurrencia de la sintomatología y de la FDdVM angiográficamente demostrada en 8 casos (todos tratados con PVA). Estos pacientes fueron tratados con éxito mediante nueva embolización con NBCA. La embolización con PVA es ineficaz a largo plazo y no está exenta de riesgos. El tratamiento endovascular es menos invasivo, con menor morbilidad y asegura una rehabilitación más precoz que la cirugía. Si la embolización fracasa todavía puede ser tratado quirúrgicamente. Conclusiones: recomendamos la embolización con NBCA como tratamiento inicial de elección en las FDdVM si contamos con una unidad de Neuroradiología intervencionista experimentada. Se precisa detenida evaluación clínica neurológica para establecer el diagnóstico de FDdVM. Finalmente recomendamos que los pacientes sean revisados estrecha y agresivamente. Son indispensables evaluaciones periódicas clínicas y radiológicas, incluyendo RM y angiografía medular para el tratamiento eficaz de estos pacientes

Vascular EndothelialGrowth Factor (VEGF) is a potent mitogen for vascular endothelial cells that has been implicated in tumor neovascularization. We show that, in hamster fibroblasts (CCL39 cells), VEGF mRNAs are expressed at low levels in serum-deprived or exponentially growing cells, whereas it is rapidly induced after stimulation of quiescent cells with serum. CCL39 derivatives, transformed with Polyoma virus or with active members of the p42/p44 mitogen-activated protein (MAP) kinase pathway, Gly/Val point mutant of Ras at position 12 (Ras-Val12), MKK1 in which Ser218 and Ser222 were mutated to Asp (MKK1-SS/DD)), express very high levels of VEGF mRNA. To analyze the contribution of the p42/p44MAP kinase in this induction, we used the CCL39-derived cell line (Raf-1:ER) expressing an estradiol-activable Raf-1. We show a time and an estradiol dose-dependent up-regulation of VEGF mRNA clearly detectable after 2 h of stimulation. The induction of VEGF mRNA in response to conditioned activation of Raf-1 is reverted by an inhibitor of MKK1, PD 098059, highlighting a specific role for the p42/p44 MAP kinase pathway in VEGF expression. Interestingly, hypoxia has an additive effect on VEGF induction in CCL39 cells stimulated by serum or in Raf-1:ER cells stimulated by estradiol. In contrast to VEGF, the isoforms VEGF-B and VEGF-C are poorly regulated by growth and oncogenic factors. We have identified a GC-rich region of the VEGF promoter between −88 and −66 base pairs which contains all the elements responsible of its up-regulation by constitutive active Ras or MKK1-SS/DD. By mutation of the putative binding sites and electrophoretic mobility supershift experiments, we showed that the GC-rich region constitutively binds Sp1 and AP-2 transcription factors. Furthermore, following activation of the p42/p44 MAP kinase module, the binding of Sp1 and AP-2 is increased in the complexes formed in this region of the promoter. Altogether, these data suggest that hypoxia and p42/p44 MAP kinase independently play a key role in the regulation of the VEGF expression.

Juan Carlos Mesa Gutiérrez, Luis Arias Barquet, Josep Maria Caminal Mitjana, Sergi Prades Almolda, Nùria Planas Domènech, Octavi Pujol Goita, Marc Rubio Caso, Jorge Arruga GinebredaDepartment of Ophthalmology, Hospital Universitari de Bellvitge, L’Hospitalet de Llobregat, Barcelona, SpainObjective: To evaluate efficacy and safety of intravitreal injections of bevacizumab in the treatment of macular edema secondary to retinal vein occlusion (RVO).Methods: Prospective study, noncomparative, interventional case series. Twelve consecutive patients (12 eyes) with macular edema associated with nonischemic retinal vein occlusion were treated with intravitreal bevacizumab (1.25 mg). All subjects underwent standardized ophthalmic evaluation at baseline and at weeks 1, 4, 12, and 24, consisting of visual acuity (VA) measurement using ETDRS charts, and imaging with ocular coherence tomography evaluating changes in foveal thickness (FT) and macular volume (MV).Results: The median age was 66 years (± 4.16), and the median duration of symptoms was 4 months (± 1.81). There were six cases of inferior branch vein occlusion and six cases of superior branch retinal vein occlusion. Mean VA improved from 1.32 ± 0.24 (logMAR values) at baseline to 0.8 ± 0.15 (p = 0.0003) at the 6-month follow-up. The macular edema responded promptly, and a trend to restoration of normal macular anatomy was observed at by the seventh day. Mean FT improved from 615.50 ± 116.29 microns to 420 ± 72.53 microns (p = 0.001), and the mean MV improved from 19.81 ± 2.31mm3 to 9.23 ± 1.38 (p = 0.0001) at the 6-month follow-up.Keywords: Bevacizumab, retinal vein occlusion, intravitreal injection, vascular endothelial growth factor

International audience; During angiogenic sprouting, endothelial tip cells emerge from existing vessels in a process that requires vascular basement membrane degradation. Here, we show that F-actin/cortactin/P-Src-based matrix-degrading microdomains called podosomes contribute to this step. In vitro, VEGF-A/Notch signaling regulates the formation of functional podosomes in endothelial cells. Using a retinal neovascularization model, we demonstrate that tip cells assemble podosomes during physiological angiogenesis in vivo. In the retina, podosomes are also part of an interconnected network that surrounds large microvessels and impinges on the underlying basement membrane. Consistently, collagen-IV is scarce in podosome areas. Moreover, Notch inhibition exacerbates podosome formation and collagen-IV loss. We propose that the localized proteolytic action of podosomes on basement membrane collagen-IV facilitates endothelial cell sprouting and anastomosis within the developing vasculature. The identification of podosomes as key components of the sprouting machinery provides another opportunity to target angiogenesis therapeutically.

Objective— ALK1 (activin-receptor like kinase 1) is an endothelial cell-restricted receptor with high affinity for BMP (bone morphogenetic protein) 9 TGF-β (transforming growth factor-β) family member. Loss-of-function mutations in ALK1 cause a subtype of hereditary hemorrhagic telangiectasia—a rare disease characterized by vasculature malformations. Therapeutic strategies are aimed at reducing potential complications because of vascular malformations, but currently, there is no curative treatment for hereditary hemorrhagic telangiectasia. Approach and Results— In this work, we report that a reduction in ALK1 gene dosage (heterozygous ALK1 +/ − mice) results in enhanced retinal endothelial cell proliferation and vascular hyperplasia at the sprouting front. We found that BMP9/ALK1 represses VEGF (vascular endothelial growth factor)-mediated PI3K (phosphatidylinositol 3-kinase) by promoting the activity of the PTEN (phosphatase and tensin homolog). Consequently, loss of ALK1 function in endothelial cells results in increased activity of the PI3K pathway. These results were confirmed in cutaneous telangiectasia biopsies of patients with hereditary hemorrhagic telangiectasia 2, in which we also detected an increase in endothelial cell proliferation linked to an increase on the PI3K pathway. In mice, genetic and pharmacological inhibition of PI3K is sufficient to abolish the vascular hyperplasia of ALK1 +/ − retinas and in turn normalize the vasculature. Conclusions— Overall, our results indicate that the BMP9/ALK1 hub critically mediates vascular quiescence by limiting PI3K signaling and suggest that PI3K inhibitors could be used as novel therapeutic agents to treat hereditary hemorrhagic telangiectasia.