We have established and characterized the first human adrenocortical cell line (H-295) that expresses multiple pathways of steroid biosynthesis and is capable of growth in defined media. Growth, cytogenetic and ultrastructural features of this line have been defined. The steroids secreted by this line include pregnenolone, 17-hydroxypregnenolone, DHA, aldosterone and 11-deoxycortisol. In addition, we have characterized the expression of a variety of proto-- oncogenes and growth factors by this cell line as well as in the poorly differentiated adrenocortical cell line SW-13 and a battery of adrenal cancer tumor specimens. Of note is the presence of elevated levels of insulin like growth factor 2 (IGF-2) mRNA found in this line and absence of detectable basic FGF transcripts. The presence of elevated levels of IGF-2 message were detected in the four adrenocortical carcinoma tumor specimens. In light of our ongoing clinical protocol evaluating the efficacy of suramin in patients with a variety of malignancies including adrenal cancer, these two adrenocortical carcinoma cell lines have been tested for their sensitivity to this agent. By clonagenic assay, the LD50 for suramin appears to be above 400 micrograms/ml in both lines, which implies minimal antitumor effect at clinically achievable levels (up to 300 micrograms/ml). However, in the case of H-295, steroid biosynthesis can be effectively blocked at suramin concentrations as low as 100 micrograms/ml.
