ULTRASENSITIVE DETECTION SYSTEM FOR LOW-LEVEL TOXICITY

THE LONG-TERM OBJECTIVE OF THIS PROJECT IS TO DEVELOP A LABORATORY TEST FOR MONITORING LOW-LEVEL TOXICITY FROM CHEMICAL EXPOSURE AT LEVELS THAT DO NOT PRODUCE ACUTE SYMPTOMS SUCH AS CYTOTOXICITY, BUT PRODUCE DETECTABLE DAMAGE LATER. THE SPECIFIC AIMS FOR THE PHASE I INVESTIGATIONS ARE TO: (1) DETERMINE THE SUBCYTOTOXIC LEVELS OF THREE ENVIRONMENTALAGENTS-A MYCOTOXIN, A POLYCYCLIC HYDROCARBON, AND AN AROMATIC AMINE; (2) SET UP A FAIRLY LONG-TERM (3 TO 4 MONTHS) BIOASSAY USING A WELL-CHARACTERIZED RAT LIVER EPITHELIAL CELL LINE, EXPOSED CHRONICALLY TO THE ABOVE SUBCYTOTOXIC DOSES OF CARCINOGENS; AND (3) MONITOR THE EMERGENCE OF A POPULATION OF CELLS CONTAINING MUTATED RAS ONCOGENE USING MOLECULAR BIOLOGICAL ENDPOINTS. THE TECHNICAL INNOVATIONS IN THESE STUDIES INCLUDE POLYMERASE CHAIN REACTION AMPLIFICATION OF LOW LEVELS OF CHEMICALLY INDUCED MUTATIONS IN AN ONCOGENE FROM MAMMALIAN CELLS AND THEIR MEASUREMENT AND DETECTION WITH A LIQUID HYBRIDIZATION/GEL RETARDATION ASSAY.