Effects of steroidal and non steroidal drugs on the neovascularization response induced by tumoral TA3 supernatant on CAM from chick embryo.

Angiogenesis, the development of new blood vessels from the existing vascular network, may result as a consequence of the increase or decrease of proangiogenic or antiangiogenic factors, respectively. The tumor itself could up-regulate the production of angiogenic factors. Recently, we established that the steroidal drug betamethasone in low concentration inhibit the neovascularization promoted by TA3 Ts on CAM of chick embryos. We describe here the effects of the non-steroidal drug ketoprofen, alone or in association with betamethasone, on the angiogenesis promoted by TA3 Ts on CAM. The main finding reported here is that the formation of new blood vessels is strongly inhibited by low concentrations of ketoprofen. The association of both drugs produced a synergistic effect, significantly decreasing tumoral supernatant angiogenesis. It is known that steroidal anti-inflammatory drugs inhibit the enzymes required for the production of prostaglandins through a nuclear GR mediated mechanism. This may operate as a general mechanism in endothelial cells as well. Considering that the induction of COX 1 and COX2 are inhibited by ketoprofen, and that these enzymes are located in the stromal compartment of the CAM, we propose that its antiangiogenic effect may occur via inhibition of the two COX isoforms. In fact, we found that ketoprofen induced apoptosis in both the stromal fibroblast and endothelial cells. The potentiated effect of the combination of betamethasone and ketoprofen may have some therapeutic projections in the control of pathological angiogenesis.

Effects of steroidal and non steroidal drugs on the neovascularization response induced by tumoral TA3 supernatant on CAM from chick embryo

Angiogenesis, the development of new blood vessels from the existing vascular network, may result as a consequence of the increase or decrease of proangiogenic or antiangiogenic factors, respectively. The tumor itself could up-regulate the production of angiogenic factors. Recently, we established that the steroidal drug betamethasone in low concentration inhibit the neovascularization promoted by TA3 Ts on CAM of chick embryos. We describe here the effects of the non-steroidal drug ketoprofen, alone or in association with betamethasone, on the angiogenesis promoted by TA3 Ts on CAM. The main finding reported here is that the formation of new blood vessels is strongly inhibited by low concentrations of ketoprofen. The association of both drugs produced a synergistic effect, significantly decreasing tumoral supernatant angiogenesis. It is known that steroidal anti-inflammatory drugs inhibit the enzymes required for the production of prostaglandins through a nuclear GR mediated mechanism. This may operate as a general mechanism in endothelial cells as well. Considering that the induction of COX 1 and COX2 are inhibited by ketoprofen, and that these enzymes are located in the stromal compartment of the CAM, we propose that its antiangiogenic effect may occur via inhibition of the two COX isoforms. In fact, we found that ketoprofen induced apoptosis in both the stromal fibroblast and endothelial cells. The potentiated effect of the combination of betamethasone and ketoprofen may have some therapeutic projections in the control of pathological angiogenesis

Effects of betamethasone, sulindac and quinacrine drugs on the inflammatory neoangiogenesis response induced by polyurethane sponge implanted in mouse.

In this study, we showed the effect of the betamethasone, sulindac and quinacrine alone or combined, on the inflammatory angiogenesis promoted by polyurethane sponge on mice. The main finding reported here is that the formation of new blood vessels was strongly inhibited by low concentration of betamethasone, sulindac or quinacrine, whether alone or in combination. It is known that steroidal anti-inflammatory drugs inhibit the enzymes required for the production of prostaglandins through a nuclear glucocorticoid receptor (GR) mediated mechanism. This mechanism may occur in endothelial cells as well. Considering that activity of cyclo-oxigenases 1 and 2 is inhibited by sulindac, and that these enzymes are located in the stromal tissue, we propose that the anti-angiogenic effect of these agents may occur via inhibition of both COX isoforms. On the other hand, quinacrine inhibited PLA2 activity, and we propose here that the anti-angiogenic effect occurs via inhibition of the enzyme PLA2. The potentiated effect of the association of betamethasone, sulindac and quinacrine may have some therapeutic benefit in the control of pathological angiogenesis. Further studies are required to validate these propositions.

Inhibitory effect of vanillin-like compounds on respiration and growth of adenocarcinoma TA3 and its multiresistant variant TA3-MTX-R.

The effects of some imine and amine derivatives of vanillin on the respiration rate of mouse mammary adenocarcinoma TA3 line, its multiresistant variant TA3-MTX-R line and mouse hepatocytes, together with their respective mitochondrial fractions, are described. These derivatives inhibit respiration in both tumour cell lines more effectively than vanillin in the absence or presence of the uncoupler CCCP. Since both types of derivatives block the electron flow, mainly through the NADH-CoQ span, they behave as oxidative phosphorylation inhibitors. Thus, they prevent ATP synthesis and alter cellular processes requiring energy, which would lead to cellular death. Amine derivatives of vanillin present a similar effect on both tumour cell lines, being amine C the most efficient inhibitor. Moreover, mouse hepatocytes are about 4-fold less sensitive to amine C than tumour cells. These amine derivatives are better inhibitors than the corresponding imines; probably because they should interact better with the respiratory chain reaction site.

Effect of sulfated beta-cyclodextrin, a water soluble cycloamylose, on the promotion and/or inhibition of angiogenesis.

Previous studies have reported that sulfated b b-cyclodextrin, a naturally occurring cycloamylose built up from six to eight glucopyranose units, when administered alone promotes angiogenesis, but administered with an angiostatic steroid inhibits angiogenesis in the cick embryo bioassay. In our experiments sulfated b b-cyclodextrin has been shown to possess many properties unrelated to its classical functions in the promotion and inhibition of angiogenesis that were not previously described. We studied the angiogenic and angiostatic properties of b b-cyclodextrin in a subcutaneous plastic sponge model in mice. We realized two set of experiments. In each set mice were randomized into five groups (n= 5 mice). The first group was treated with sulfated b b-cyclodextrin (200 ng), the second group was treated with sulfated b b-cyclodextrin (2000 ng), the third group received unsubstituted b b-cyclodextrin (2000 ng), the fourth group was treated with sulfated b b-cyclodextrin (20000 ng) and the last group was used as a control group. In all groups compounds were administered intraperitoneally 4 days after subcutaneous implantation of a sterile polyvinyl sponge on day 0, controls were not treated. Cyclodextrin administered alone at low drug concentration (200 ng) promoted angiogenesis and increased the development of venules in the sponge matrix. However, cyclodextrin administered at high drug concentration (2000 and 20 000 ng) reduced the vessel index in the sponge and areas of microhemorrhages were observed. From our results we propose that b b-cyclodextrin contains both a promoter and an inhibitor of angiogenesis and that the activation of both is drug concentration dependent.

Effects of betamethasone, sulindac and quinacrine drugs on the inflammatory neoangiogenesis response induced by polyurethane sponge implanted in mouse

In this study, we showed the effect of the betamethasone, sulindac and quinacrine alone or combined, on the inflammatory angiogenesis promoted by polyurethane sponge on mice. The main finding reported here is that the formation of new blood vessels was strongly inhibited by low concentration of betamethasone, sulindac or quinacrine, whether alone or in combination. It is known that steroidal anti-inflammatory drugs inhibit the enzymes required for the production of prostaglandins through a nuclear glucocorticoid receptor (GR) mediated mechanism. This mechanism may occur in endothelial cells as well. Considering that activity of cyclo-oxigenases 1 and 2 is inhibited by sulindac, and that these enzymes are located in the stromal tissue, we propose that the anti-angiogenic effect of these agents may occur via inhibition of both COX isoforms. On the other hand, quinacrine inhibited PLA2 activity, and we propose here that the anti-angiogenic effect occurs via inhibition of the enzyme PLA2. The potentiated effect of the association of betamethasone, sulindac and quinacrine may have some therapeutic benefit in the control of pathological angiogenesis. Further studies are required to validate these propositions

Antiangiogenic effect of betamethasone on the chick cam stimulated by TA3 tumor supernatant

Tumor growth is the result of combined cell proliferation overwhelming cell death and neoangiogenesis. This report shows CAM angiogenesis promoted by TA3 tumor supernatant with or without low dosis of betamethasone (Minimal antiangiogenic concentration: beta-MAAC). Methylcellulose discs instilled with 10 microliters of beta-MAAC (0.08 microgram/ml), 10 microliters of tumor supernatant (TA3ts), 5 microliters beta-MAAC + 5 microliters TA3ts, and 10 microliters of PBS as control were implanted in host chick eggs. On day 12, the grafts were removed, photographed and fixed. Sections were stained in parallel, one and three with hematoxylin-eosin, and section two by the Tunel method. The number of vessels was evaluated in a microscopic field of the CAM (2250 micron 2). The results show that beta-MAAC produced a significant inhibition of neovascularization in comparison to that observed in controls (P < 0.0025; Student t-Test). Discs instilled with TA3ts produced an intense stimulation of angiogenesis in contrast, when discs were instilled with 5 microliters of beta-MAAC + 5 microliters of TA3ts the angiogenesis was significantly inhibited (P < 0.001). The results show that effective antiangiogenic doses of betamethasone are in the range of 10(-7) M, (probably a genomic mediated action) and that this effect of low concentration may have clinical applications.

Análisis citoquímico de células neoplásicas mediante lectinas conjugadas con peroxidasa de rábano / Cytochemical analysis of neoplastic cells by conjugated lectins with horseradish peroxidase

Se acepta que los receptores de adhesión: MAC, cadherinas, integrinas y selectinas intervendrían en el destino de células inmunes. Además, controlarían la diseminación de tumores sólidos. Mediante técnicas ad hoc es posible aisla células cancerosas y traspasarlas a receptores. Una herramienta impostante en oncología experimental es la identificación de residuos glicosídicos mediante lectinas. En este trabajo estudiamos el pérfil glicosídico de céluas de un tumos ascítico experimental, mediante lectinas conjugadas con peroxidasa de rábano (lectina-HRP). Utilizamos ratones AJ portadores de las líneas tumorales TA3MTXR (resistente a metotrexato) y TA3 de menor malignidad. Las células fueron inoculadas por vía intramuscular, en ratones sanos. Se obtuvieron biopsias de nódulos primarios a los 7 y 21 días y nódulos metastásicos en corazón y pulmón a los 21 días. Los cortes fueron fijados e incubados en Con A, DBA, PNA, WGA y RCA. Como controles utilizamos azúcares inhibitorios específicos. La mayor intensidad correspondió a PNA en tumores primarios y metastásicos. Con A, WGA y DBA reaccionaron con intensidad menor. Se registraron diferencias entre metástasis cardíacas y pulmonares, en relación a Con A. No hubo reacción frente a RCA. Estos resultados muestran algunas diferencias entre residuos glicosídicos presentes a metastásis cardíacas y pulmonares, específicamente con respecto a manosa y glucosa. Aparentemente, no existirían mayores diferencias entre tumores primarios y metastásicos, con respecto a galactosa, N-acetil glucosamina y ácido siálico