The use of the glial fibrillary acidic protein (GFAP) biomarker as an early detection model of chemically induced cancer.

Due to the massive industrial development during recent decades, the general population today is exposed to numerous environmental chemicals not only through occupational exposure but also through the daily handling and consumption of products. In our study, we developed a carcinogenesis bioassay for industrial solvents and other pollutants by measuring the gliosis produced by these toxins. We investigated the morphological changes produced by some pollutants in astroglial rat cultures and the increase in GFAP-positive cells. Astroglial primary cultures were obtained from the cerebral hemispheres of neonatal rats. The nutrient medium consisted of Waymouth's medium supplemented with 20% fetal calf serum and antibiotics. The cultures were incubated at 37 degrees C in a humidified particle-filtered room containing an atmosphere of 5% CO2 in air. After being cultured for 22 days, toluene and a mixture of solvents (toluene, carbon tetrachloride, and 1,1,1-trichloroethylene) were applied in concentrations between 10(-4) M and 10(-6) M. Immunofluorescence staining for glial fibrillary acidic protein (GFAP), a specific marker for fibrillary astrocytes, was only occasionally positive in the monolayer of the control cultures; however, it was markedly positive in most cells maintained for 3 or 9 days and exposed to toluene and mixed solvents. This study provides a rapid in vitro assay by which cells exposed to chemicals can be examined.