Tamoxifen Induces Heparanase Expression in Estrogen Receptor–Positive Breast Cancer

Abstract
Purpose: Mammalian heparanase degrades heparan sulfate, the main polysaccharide of the basement membrane. Heparanase is an important determinant in cancer progression, acting via the breakdown of extracellular barriers for invasion, as well as release of heparan sulfate–bound angiogenic and growth-promoting factors. The present study was undertaken to elucidate molecular mechanisms responsible for heparanase overexpression in breast cancer.