The minimal active domain of endostatin is a heparin-binding motif that mediates inhibition of tumor vascularization.
نویسندگان
چکیده
Endostatin constitutes the COOH-terminal 20,000 Da proteolytic fragment of collagen XVIII and has been shown to possess antiangiogenic and antitumorigenic properties. In the present study, we have investigated the role of the heparin-binding sites in the in vivo mechanism of action of endostatin. The majority of the heparin binding is mediated by arginines 155/158/184/270 in endostatin, but there is also a minor site constituted by arginines 193/194. Using endostatin mutants lacking either of these two sites, we show that inhibition of fibroblast growth factor-2-induced angiogenesis in the chicken chorioallantoic membrane requires both heparin-binding sites. In contrast, inhibition of vascular endothelial growth factor-A-induced chorioallantoic membrane angiogenesis by endostatin was only dependent on the minor heparin-binding site (R193/194). These arginines were also required for endostatin to inhibit fibroblast growth factor-2- and vascular endothelial growth factor-A-induced chemotaxis of primary endothelial cells. Moreover, we show that a synthetic peptide corresponding to amino acids 180-199 of human endostatin (which covers the minor heparin-binding site) inhibits endothelial cell chemotaxis and reduces tumor vascularization in vivo. Substitution of arginine residues 193/194 for alanine attenuates the antiangiogenic effects of the peptide. These data show an essential role for heparin binding in the antiangiogenic action of endostatin.
منابع مشابه
Immunogenicity of heparin-binding hemagglutinin expressed by Pichia pastoris GS115 strain
Objective(s): Heparin-binding hemagglutinin (HBHA), a mycobacterial cell surface protein, mediates adhesion to nonphagocytic cells and the dissemination of Mycobacterium tuberculosis (M. tuberculosis) from the site of primary infection. Superior expression systems are required to obtain abundant M. tuberculosis proteins for the purpose of diagnosing M. tuberculosis infection or for the immuniza...
متن کاملStructural basis and potential role of heparin/heparan sulfate binding to the angiogenesis inhibitor endostatin.
Recombinant mouse endostatin produced by mammalian cells was shown to bind to heparin with a K(d) of 0.3 microM, suggesting that this interaction may play a role in its anti-angiogenic activity. Alanine mutagenesis demonstrated that a major site of four clustered arginines (positions 155, 158, 184 and 270) and a second site (R193, R194) are essential for binding. The same epitopes also particip...
متن کاملPolyclonal Antibody against Different Extracellular Subdomains of HER2 Induces Tumor Growth Inhibition in vitro
Background: Human epidermal growth factor receptor 2 (HER2) has a crucial role in several malignancies. The extracellular domain of HER2 (HER2-ECD) has been extensively employed as an important target in passive and active immunotherapy. Isolated recombinant prokaryotic HER2-ECD subdomains were previously found to be ineffective in inducing anti-tumor antibody response. Objective: To employ rec...
متن کاملBlockade of Hypoxia: The Impact on Tumor Growth in an Experimental Tumor Model
Background: Tumor microenvironment is an active factor participating in immunoregulation, thereby preventing immunosurveillance and limiting the efficacy of anticancer therapies. Hypoxia as a major characteristic of solid tumors causes the expression of Hypoxia-Inducible Factor-1α (HIF-1α). This is a transcription factor that mediates hypoxic responses of tumor cells and involves in the express...
متن کاملApplication of FITC for detecting the binding of antiangiogenic peptide to HUVECs
Angiogenesis is the generation of new blood vessels from the existing vasculature. The angiogenic programme requires the degradation of the basement membrane, endothelial cell migration and invasion of the extracellular matrix, with endothelial cell proliferation and capillary lumen formation before maturation and stabilization of the new vasculature. Angiogenesis is dependent on a delicate equ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Cancer research
دوره 64 24 شماره
صفحات -
تاریخ انتشار 2004