Inhibition of in vivo angiogenesis by N-beta-alanyl-5-S-glutathionyl-3,4-dihydroxyphenylalanine.
ABSTRACT N-beta-alanyl-5-S-glutathionyl-3,4-dihydroxyphenylalanine (5-S-GAD), an antibacterial substance isolated from the flesh fly, inhibits human tumor growth in the nude mice model; however, the mechanism of its action is unclear. The in vivo antitumor effect includes the inhibition of tumor cell proliferation and suppression of angiogenesis. Angiogenesis is essential for tumor growth in vivo. In this study, we examined whether 5-S-GAD inhibits tumor cell-induced angiogenesis by performing the mouse dorsal air sac assay. We found that intraperitoneal administration of 5-S-GAD inhibited the angiogenesis induced by S180 mouse sarcoma cells. Furthermore, 5-S-GAD also inhibited vascular endothelial growth factor-induced angiogenesis in the Matrigel plug assay and embryonic angiogenesis in the chick embryo chorioallantoic membrane assay. However, 5-S-GAD did not show any effect on the proliferation, migration, and tube formation of vascular endothelial cells. These results provide the first evidence that a bioactive substance derived from the flesh fly has antiangiogenic activity in vivo, although the mechanisms involved could not be explained.
- SourceAvailable from: Xing-Bin Hu[Show abstract] [Hide abstract]
ABSTRACT: It has been reported that blocking Notch signaling in tumor-bearing mice results in abortive angiogenesis and tumor regression. However, given that Notch signaling influences numerous cellular processes in vivo, a comprehensive evaluation of the effect of Notch inactivation on tumor growth would be favorable. In this study, we inoculated four cancer cell lines in mice with the conditional inactivation of recombination signal-binding protein-Jkappa (RBP-J), which mediates signaling from all four mammalian Notch receptors. We found that whereas three tumors including hepatocarcinoma, lung cancer, and osteogenic sarcoma grew slower in the RBP-J-deficient mice, at least a melanoma, B16, grew significantly faster in the RBP-J-deficient mice than in the controls, suggesting that the RBP-J-deficient hosts could provide permissive cues for tumor growth. All these tumors showed increased microvessels and up-regulated hypoxia-inducible factor 1alpha, suggesting that whereas defective angiogenesis resulted in hypoxia, different tumors might grow differentially in the RBP-J-deleted mice. Similarly, increased infiltration of Gr1(+)/Mac1(+) cells were noticed in tumors grown in the RBP-J-inactivated mice. Moreover, we found that when inoculated in the RBP-J knockout hosts, the H22 hepatoma cells had a high frequency of metastasis and lethality, suggesting that at least for H22, deficiency of environmental Notch signaling favored tumor metastasis. Our findings suggested that the general blockade of Notch signaling in tumor-bearing mice could lead to defective angiogenesis in tumors, but depending on tumor cell types, general inhibition of Notch signaling might result in tumor regression, progression, or metastasis.Neoplasia (New York, N.Y.) 02/2009; 11(1):32-8. · 5.48 Impact Factor
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ABSTRACT: Pricking the body wall of Sarcophaga peregrina (flesh fly) larvae with a needle activated the immune system of this insect and induced various immune molecules, including antibacterial proteins, in the hemolymph. In this review, I summarize and discuss the functions of these immune molecules, with particular emphasis on the dual roles of some of these molecules in defense and development.Proceedings of the Japan Academy Ser B Physical and Biological Sciences 01/2010; 86(10):927-38. · 2.77 Impact Factor
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ABSTRACT: 5-S-Glutathionyl-N-beta-alanyl-3,4-dihydroxyphenylalanine (5-S-GAD) is a novel antibacterial substance purified from Sarcophaga peregrina (flesh fly) that has both a radical scavenging activity and antioxidative activity. This is a report of an investigation of the effect of 5-S-GAD (eyedrops) on UVB-induced cataracts in rats. Brown Norway male rats (n = 32; 7 weeks old) were treated with either 5-S-GAD 0.1%, 5-SGAD 1%, astaxanthin (AST) 0.1% suspension eyedrops or the vehicle alone (the solution without 5-S-GAD) three times a day (three doses at 5-min intervals each time). The treatment was scheduled 2 days before UV-B exposure and 2 days after UV-B exposure. Exposure to 100-200 mJ/cm(2) UV-B was performed once a week between drug treatments for 9 consecutive weeks, with a total dose of 1200 mJ/cm(2) UV-B. Ocular penetration of 5-S-GAD was analyzed using high-pressure liquid chromatography (HPLC). Cataract formation was documented by an anterior eye segment analysis system once a week under mydriasis. The light-scattering intensity (LSI) of the anterior superficial cortex region was measured. In the eighth to ninth week after the start of UV-B exposure, the LSI of anterior subcapsular lenses of 5-S-GAD-treated groups, as detected by HPLC, was significantly lower (P < 0.05) than that of the control, whereas no such difference was found in the AST-treated group. 5-S-GAD eyedrop application may delay the progression of UV-B-induced cataract in rats.Japanese Journal of Ophthalmology 09/2009; 53(5):531-5. · 1.27 Impact Factor