Maspin is a multifunctional tumor- suppressing serpin

Maspin (MAmmary SerPIN) is a member of the family of SERine Protease INhibitors or serpins. It is non-inhibitory and is grouped in the ovalbumin serpin (ov-serpin) subfamily because it exhibits significant sequence similarity to chicken ovalbumin. Initially identified from human normal mammary epithelial cells, maspin was named after its source of identification (mammary epithelia). Subsequent studies by our laboratory and many colleagues concluded that maspin is not only expressed in mammary epithelial cells but also in many other tissues and cell types. Functionally, maspin was first reported to be a breast tumorsuppressing serpin. Maspin has been shown to be a potent metastasis inhibitor in breast and prostate cancers by numerous groups in the last 20 years. In addition, maspin possesses multiple functions in other cancers, vascular diseases, and physiological processes. Numerous mouse models have been developed to determine its role in normal biology and disease development. In this review, we intend to summarize some of the key findings of maspin research in the last two decades. These studies offer great potential for developing maspin-based therapeutics against cancer and other diseases. We focus discussion on maspin’s biological functions, gene regulation, and animal models of maspin research.