Dr. Sheng and colleagues.

Maspin, a novel serine proteinase inhibitor, is giving a Wayne State pathology researcher something to get excited about. Based on an inverse correlation between maspin expression and breast cancer tumor progression, Shijie Sheng, PhD, believes that maspin is a potential molecular marker to predict cancer prognosis. But that is not all. It can also act as a tumor suppressor, inhibiting tumor invasion and metastasis of breast cancer.

Dr. Sheng, assistant professor of pathology, has received a United States Department of Defense grant to continue studying maspin and its mechanisms. "Tumor invasion and metastasis are facilitated by an imbalance between proteases and their inhibitors," said Dr. Sheng. "An uncontrolled elevation of proteolysis destroys the host environment and promotes tumor dissemination. However, maspin acts as an inhibitor of this destructive proteolytic process, thus blocking tumor progression."

Sensitive to the possible pharmacological uncertainties of maspin, including dosage, toxicity, and immune responses, Dr. Sheng is generating and characterizing six derivatives of maspin to adequately test it as a potential cancer suppressive agent.

"A better understanding of maspin’s effect on the growth, invasion and metastasis of breast cancer may lead to other translational discoveries," she said. "For instance, we have already seen similar suppressive effects on prostate cancer cells, too."

If positive results are found in this three-year study, Dr. Sheng hopes to extend the studies to evaluate maspin in animal models.