Expression analysis of maspin in invasive ductal carcinoma of breast and modulation of its expression by curcumin in breast cancer cell lines

In breast cancer, maspin, a serine protease inhibitor, can suppress tumor growth and metastasis in vivo and tumor cell motility and invasion in vitro. The clinical significance of maspin expression in breast cancer, especially in the sequence of ductal carcinoma in situ (DCIS)–invasive cancer–lymph node metastasis is well known in the Western countries, but its status in the rapidly increasing breast cancers in India remains unknown.The present study was designed to determine the clinical significance of maspin expression in invasive ductal carcinomas of breast (IDCs) in North Indian population and modulation of its expression by curcumin. Immunohistochemical analysis of maspin showed loss or reduced cytoplasmic expression in 36 of 59 (61%) tumors. Furthermore, breast cancer cells (MCF-7 (wild type p53) and MDA-MB-231 (mutant p53)) were treated with curcumin and the effect on expression of maspin gene at transcription and translation levels was analyzed by RT-PCR, immunofluorescence and Western blotting. Maspin expression was also correlated with p53 and Bcl-2 levels. Curcumin inhibited cell growth, induced apoptosis and upregulated maspin gene expression in MCF-7 cells and these findings were further correlated with the upregulation of p53 protein and downregulation of Bcl-2, suggesting maspin mediated apoptosis in MCF-7 cells. To our knowledge this is the first report showing the upregulation of maspin expression by curcumin in breast cancer cells and taken together with the clinical data suggests a potential therapeutic role for curcumin in inducing maspin mediated inhibition of invasion of breast carcinoma cells.