Effect of DAPT, a gamma secretase inhibitor, on tumor angiogenesis in control mice

Authors

1 Department of Physiology, Students Research Center, Faculty of Medicine, Isfahan, Iran

2 Department of Anatomy, Isfahan University of Medical Sciences, Isfahan, Iran

3 Physiology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran

Abstract

Background: Notch signaling is a key factor for angiogenesis in physiological and pathological condition and γ-secretase is the regulator of Notch signaling. The main goal of this study was to assess the effect of (N-[N-(3,5-Diflurophenaacetyl-L-alanyl)]-S-phenylglycine t-Butyl Ester) DAPT, a γ-secretase inhibitor, on serum angiogenic biomarkers, and tumor angiogenesis in control mice.
Materials and Methods: Tumor was induced by inoculation of colon adenocarcinoma cells (CT26) in 12 male Balb/C mice. When tumors size is reached to a 350 ± 50 mm 3 , the animals were randomly divided into two groups: control and DAPT (n = 6/group). DAPT was injected subcutaneously 10 mg/kg/day. After 14 days, blood samples were taken and the tumors were harvested for immunohistochemical staining.
Results: Administration of DAPT significantly increased serum nitric oxide concentration and reduced vascular endothelial growth factor receptors-1 (VEGFR1) concentration without changes on serum VEGF concentration. DAPT reduced tumor vascular density in control mice (280.6 ± 81 vs. 386 ± 59.9 CD31 positive cells/mm 2 ), although, it was not statistically significant.
Conclusion: It seems that γ-secretase inhibitors can be considered for treatment of disorders with abnormal angiogenesis such as tumor angiogenesis.

Keywords

1. Carmeliet P. VEGF gene therapy: Stimulating angiogenesis or angioma-genesis? Nat Med 2000;6:1102-3.  Back to cited text no. 1
[PUBMED]    
2. Ferrara N. The role of VEGF in the regulation of physiological and pathological angiogenesis. EXS 2005;94:209-31.  Back to cited text no. 2
[PUBMED]    
3. Rahimi N. Vascular endothelial growth factor receptors: Molecular mechanisms of activation and therapeutic potentials. Exp Eye Res 2006;83:1005-16.  Back to cited text no. 3
[PUBMED]    
4. Olsson AK, Dimberg A, Kreuger J, Claesson-Welsh L. VEGF receptor signalling-in control of vascular function. Nat Rev Mol Cell Biol 2006;7:359-71.  Back to cited text no. 4
[PUBMED]    
5. Fong GH, Rossant J, Gertsenstein M, Breitman ML. Role of the Flt-1 receptor tyrosine kinase in regulating the assembly of vascular endothelium. Nature 1995;376:66-70.  Back to cited text no. 5
[PUBMED]    
6. Zhang Z, Neiva KG, Lingen MW, Ellis LM, Nör JE. VEGF-dependent tumor angiogenesis requires inverse and reciprocal regulation of VEGFR1 and VEGFR2. Cell Death Differ 2010;17:499-512.  Back to cited text no. 6
    
7. Cooke JP, Losordo DW. Nitric oxide and angiogenesis. Circulation 2002;105:2133-5.  Back to cited text no. 7
[PUBMED]    
8. Mailhos C, Modlich U, Lewis J, Harris A, Bicknell R, Ish-Horowicz D. Delta4, an endothelial specific notch ligand expressed at sites of physiological and tumor angiogenesis. Differentiation 2001;69:135-44.  Back to cited text no. 8
[PUBMED]    
9. Rehman AO, Wang CY. Notch signaling in the regulation of tumor angiogenesis. Trends Cell Biol 2006;16:293-300.  Back to cited text no. 9
[PUBMED]    
10. Ellisen LW, Bird J, West DC, Soreng AL, Reynolds TC, Smith SD, et al. TAN-1, the human homolog of the Drosophila notch gene, is broken by chromosomal translocations in T lymphoblastic neoplasms. Cell 1991;66:649-61.  Back to cited text no. 10
[PUBMED]    
11. Paris D, Quadros A, Patel N, Delle Donne A, Humphrey J, Mullan M. Inhibition of angiogenesis and tumor growth by beta and gamma-secretase inhibitors. Eur J Pharmacol 2005;514:1-15.  Back to cited text no. 11
    
12. Dovey HF, John V, Anderson JP, Chen LZ, de Saint Andrieu P, Fang LY, et al. Functional gamma-secretase inhibitors reduce beta-amyloid peptide levels in brain. J Neurochem 2001;76:173-81.  Back to cited text no. 12
[PUBMED]    
13. Masuda S, Kumano K, Suzuki T, Tomita T, Iwatsubo T, Natsugari H, et al. Dual antitumor mechanisms of signaling inhibitor in a T-cell acute lymphoblastic leukemia xenograft model. Cancer Sci 2009;100:2444-50.  Back to cited text no. 13
[PUBMED]    
14. Noguera-Troise I, Daly C, Papadopoulos NJ, Coetzee S, Boland P, Gale NW, et al. Blockade of Dll4 inhibits tumour growth by promoting non-productive angiogenesis. Nature 2006;444:1032-7.  Back to cited text no. 14
[PUBMED]    
15. Nakajima M, Yuasa S, Ueno M, Takakura N, Koseki H, Shirasawa T. Abnormal blood vessel development in mice lacking presenilin-1. Mech Dev 2003;120:657-67.  Back to cited text no. 15
[PUBMED]    
16. Zou YH, Cao YQ, Wang LX, Zhang YH, Yue ZJ, Liu JM. γ-secretase inhibitor up-regulates vascular endothelial growth factor receptor-2 and endothelial nitric oxide synthase. Exp Ther Med 2011;2:725-729.  Back to cited text no. 16
[PUBMED]    
17. Zou Y, Cao Y, Yue Z, Liu J. Gamma-secretase inhibitor DAPT suppresses glioblastoma growth via uncoupling of tumor vessel density from vessel function. Clin Exp Med 2012; [Epub ahead of print].  Back to cited text no. 17