Maspin is a
serine protease inhibitor with
tumor suppressor activity.
Maspin can suppress
tumor growth and
metastasis in vivo and
tumor cell motility and invasion in vitro.
Maspin also modulates apoptosis of
tumor cells, possibly by modulating the expression of the B-cell lymphoma-2 family member. p53 regulates the expression of the tumor suppressor gene
maspin.
Breast cancer is known for its propensity to recur even after decades. The biology behind this phenomenon of
tumor dormancy is poorly understood. This study was conducted to clarify the role of
maspin and B-cell lymphoma-2 in early and late recurring
breast cancer. The expression of
maspin, B-cell lymphoma-2, p53, and
estrogen receptor was studied by immunohistochemistry in 73 primary breast
cancers and in their metastatic relapses detected within 2 years, or 5 or 10 years after primary surgery. The cytoplasmic expression of
maspin was significantly higher in the primary
tumors of the early metastasizing breast
cancers (first
tumor relapse within 2 years) and also in their
metastases compared to late metastasizing
cancers. An opposite activity was observed in the expression of B-cell lymphoma-2. The level of B-cell lymphoma-2 staining was lower in the early relapsing
cancers and significantly lower in their
metastases, compared to
tumors which metastasized 5 or 10 years after primary surgery. High cytoplasmic expression of
maspin and low expression of B-cell lymphoma-2 in primary
breast cancer predict early
tumor relapse.