A New in Vitro Screening Method for Teratogens Using Human Embryonic Palatal Mesenchymal Cells

Abstract In order to establish an in vitro screening assay system for cleft palate-inducing teratogens, we tested 31 teratogenic and 10 tionteratogenic compounds using human embryonic cultured cells. We examined whether cleft palate-inducing ability can be detected by differential growth inhibition between human embryonic palatal mesenchymal (HEPM) cells and human embryonic fibroblasts (MRC-5). Thirty one compounds with proven cleft palate-inductive effects in vivo preferentially inhibited the proliferation of HEPM cells. The average of the relative resistant rates (rate of IC50 value for HEPM cells to MRC-5 cells) of teratogens was 0.53. In contrast, almost all nonterato-gens identically inhibited the proliferation of both cell lines and the average of the relative resistant rates was 1.01. These results show that teratogens which induce cleft palate in vivo preferentially inhibit the proliferation of embryonic palatal mesenchymal cells.
The data indicated that in vitro screening using HEPM and MRC-5 cells is useful for detecting the cleft palate-inducing ability of chemicals.