Description |
Angiostatin is a 38 kDa fragment of Plasmin, the active form of the zymogen Plasminogen (PLG) and includes three to five contiguous Kringle modules. It was observed initially as an angiogenesis inhibitor in serum/urine of mice bearing a Lewis lung carcinoma (3LL cells) and is produced by the protelytic cleavage of Plasminogen by different Metalloproteinases (MMPS), Elastase, Prostate-Specific Antigen (KLK3/PSA), and other serine proteases. The production of Angiostatin by Human pancreatic cancer cells can be inhibited by TGF beta 1 in participation with Plasminogen Activator Inhibitor 1 (SERPINE1/PAI1). Angiostatin specifically inhibits endothelial cell proliferation. In an animal tumor model the factor produced by the primary tumor suppresses the growth of its remote metastases, which neovascularize and grow after tumor removal. The Human Angiostatin ELISA is an, in vitro, enzyme-linked immunosorbent assay for the quantitative measurement of Human Angiostatin in serum, plasma, cell culture supernatants and urine. This assay employs an antibody specific for Human Angiostatin coated on a 96-well plate. Standards and samples are pipetted into the wells and Angiostatin present in a sample is bound to the wells by the immobilized antibody. The wells are washed and Biotinylated Anti-Human Angiostatin antibody is added. After washing away unbound Biotinylated antibody, HRP-Streptavidin is pipetted to the wells. The wells are again washed, a TMB substrate solution is added to the wells and color develops in proportion to the amount of Angiostatin bound. |