BD Pharmingen™ Purified Mouse Anti-Human Maspin

Maspin is a 42 kDa protein that may play a role in human breast cancer by functioning as a tumor suppressor.  Maspin is expressed in normal mammary epithelial cells, but there is a loss of expression in invasive breast cancer including lymph node and distant metastases. Further, maspin is not expressed in most mammary carcinoma cell lines. Mammary carcinoma cells transfected with recombinant maspin have a reduced ability to migrate through reconstituted basement membrane and lose their ability to form tumors in nude mice, providing support for maspin as a tumor suppressor protein. Maspin has homology to members of the serpin family of protease inhibitors, some of which have been implicated in the regulation of invasion and metastasis. Yet protease inhibitory activity has not been detected using recombinant maspin.  It has been suggested that maspin, unlike most serpins, may be a ligand-binding serpin rather than a protease inhibitor. However, the question of whether or not maspin has protease inhibitor activity remains to be determined. G167-70 is specific for human maspin. It detects maspin as a 42 kD protein in western blots of normal human mammary epithelial cells. Many mammary tumor cell lines including MDA-MB-231 (ATCC HTB 26) and MDA-MB-435S (ATCC HTB 129) lack maspin expression and are suitable as negative controls. Purified recombinant human maspin from a yeast expression system was used as immunogen.