Endostatina

Endostatina, also known as endostatin, is a 20-kilodalton anti-angiogenic protein fragment derived from the C-terminal NC1 domain of type XVIII collagen. It is produced by proteolytic processing of collagen XVIII in basement membranes and extracellular matrix. In vitro and in vivo studies show that endostatina inhibits the formation of new blood vessels, which underpins its potential to slow tumor growth and metastasis.

Its anti-angiogenic effects are multifaceted. Endostatina can suppress endothelial cell proliferation, migration, and tube formation, and may induce endothelial cell apoptosis. Mechanistic data indicate interference with vascular endothelial growth factor (VEGF) signaling and modulation of matrix metalloproteinases, as well as interactions with cell-surface receptors such as integrins including α5β1 and αvβ3. The result is reduced angiogenesis and altered tumor vasculature.

Endostatina has been developed as a cancer therapeutic in preclinical studies and clinical trials. A recombinant form is marketed in China under the name Endostar for non-small cell lung cancer in combination with chemotherapy, reflecting regulatory approval in at least some jurisdictions. Global clinical trials have yielded mixed outcomes, with some reporting modest improvements in progression-free survival but no consistent overall survival benefit. Limitations include pharmacokinetics, delivery, and patient selection, and current research is focused on optimizing combination regimens and identifying predictive biomarkers.