We transfected a Chinese hamster ovary cell line, CHO-K1, with the gene of the Escherichia coli beta-galactosidase (beta-Gal) or the firefly luciferase (Luc) gene together with neo(R) gene, and isolated the stable transfectants, designated as CHO-Z/neo and CHO-L/neo, respectively. When these cells were incubated for 24 to 72 h with 1.0 mu g/ml TEI-3313, a Delta(7)-prostaglandin A(1) analogue, the total and the specific activities of beta-Gal and Luc were enhanced severalfold. It was confirmed by immunotitration experiments that the enhancement of beta-Gal activity was due to an increase in the level of enzyme protein. Northern blot analysis revealed that this compound augmented the level of beta-Gal mRNA. On the other hand, it did not significantly affect the expression of an endogenous gene such as that encoding lactate dehydrogenase or beta-actin.