Procathepsin D in cancer development

Over thirty years of research showed that procathepsin D is overexpressed and secreted by cells of several tumor types including lung, breast and prostate cancer. After secretion, it exhibits growth factor –like mitogenic activity. Subsequent in vivo and in vitro studies strongly support the hypothesis that the mitogenic effects are mediated via its activation peptide. Another potential cancer-related role of procathepsin D is the effect on resistance of cancer cell to chemotherapeutic drugs. The purpose of this review is to summarize the two major roles of procathepsin D in cancer development.