EFFECTS OF THE BOWMAN-BIRK PROTEASE INHIBITOR ON SURVIVAL OF FIBROBLASTS AND CANCER-CELLS EXPOSED TO RADIATION AND CISPLATINUM

The Bowman-Birk inhibitor (BBI) is a soybean-derived anticarcinogenic protease inhibitor with anti-inflammatory activity. To assess the poss ibility of utilizing BBI for alleviating the side effects associated w ith lung cancer radiation and chemotherapy, we have determined the eff ects of BBI and a soybean concentrate enriched in BBI (known as BBIC) on radiation- and cis-platinum-induced cytotoxicity in A549 human lung cancer cells. The results demonstrated that neither BBI nor BBIC prot ected A549 cells from radiation- and cis-platinum-induced cytotoxicity . In fact, BBI and BBIC potentiated the cell-killing effects induced b y cis-platinum alone, and BBIC treatment led to significantly enhanced cell killing by cis-platinum in combination with radiation treatment in the lung carcinoma cells. BBI conferred a significant protective ef fect onto mouse fibroblasts (10T1/2 cells) treated with cis-platinum i n combination with 6 Gy of X-ray irradiation. These results suggest th at BBI and BBIC, when given to lung cancer patients, are unlikely to i nterfere with cancer treatment utilizing radiation and cis-platinum.