Quantitative Morphometry Of Respiratory Tract Epithelial Cells As A Tool For Testing Chemopreventive Agent Efficacy

Previously, we developed a 30-day transformation assay (focus inhibition, FIA) of rat tracheal epithelial (RTE) cells to identify cancer preventive agents. This study reports nuclear density (ND) as a morphometric biomarker for efficacy evaluation of at an early stage before transformed foci appear. Positive (oltipraz, D-carvone, fumaric acid, and 2-amino-4-methylpyridine or 2-A-MPR) and negative agents (myristoleic acid, anethole trithione, hydrocortisone, and 3'-hydro-xyflavanone), identified from FIA, were tested for their effect on ND. RTE cells plated for 24 h were treated with a carcinogen, benzo[a] pyrene (B[c]P) or plus a test agent. The data based on the number of nuclei in agent-treated and control cells at day 14 showed that all FIA-positive agents inhibited ND from 23-66% at 0.3-1000.0 mu M and except for myristoleic acid, all of the FIA-negative compounds were also negative in the morphometty assay. As there is strong correlation between the FIA and morphometry data, morphometry analysis is useful for rapid screening of potential chemopreventive agents.