Effects of dibutyryl adenosine 3',5'-cyclic monophosphate on erythropoietin production in human renal carcinoma cell cultures

A human renal carcinoma from a patient with erythrocytosis, serially transplanted into athymic nude mice, was grown in primary monolayer cell cultures. After reaching confluency, the cultured cells formed multicellular hemicysts (domes), which became more abundant as the cultures approached saturation density. Erythropoietin (Ep) production by this renal carcinoma in culture was only slightly increased at the time of semiconfluency but showed a marked increase after the cultures reached confluency, in parallel with dome formation. Dibutyryl adenosine 3',5'-cyclic monophosphate significantly (P less than .01) stimulated Ep production and dome formation in the semiconfluent and confluent cultures of the renal carcinoma.