Androgen receptors, androgen-dependent proliferation, and 5 alpha-reductase activity of small-cell lung cancer cell lines.

We investigated the influence of testosterone on binding to established small-cell lung cancer (SCLC) cell lines and were able to show specific high-affinity and low-capacity binding sites in some cell lines with a typical receptor size, using sucrose density gradient centrifugation. In addition, we demonstrated marked growth stimulation with testosterone and dehydrotestosterone using different androgen-receptor-positive small-cell lung cancer cell lines. This growth stimulation could be counteracted by the addition of anti-androgens like cyproterone acetate or flutamide. The presence of 5 alpha-reductase activity, 17 beta-hydroxysteroid-dehydrogenase and 3 alpha-hydroxysteroid-dehydrogenase activities could be demonstrated, suggesting testosterone metabolism of small-cell lung cancer cell lines.