Estrogen metabolism and human papillomavirus-induced tumors of the larynx: chemo-prophylaxis with indole-3-carbinol.

A relationship was established between estradiol 16 alpha-hydroxylation, papillomavirus and its malignant sequelae. In this study, we determined that 16 alpha-hydroxylation was substantial in normal larynx and further increased in laryngeal papillomas. Estradiol or 16 alpha-hydroxyestrone stimulated proliferation in both kinds of cells while 2-hydroxyestrone was antiproliferative. Indole-3-carbinol, which induces 2-hydroxylation, abrogated the proliferative effects of estradiol. In immunocompromised mice, papilloma cysts formed in HPV-11 infected laryngeal tissue implanted under the renal capsules in 100% of control mice but only in 25% of mice fed indole-3-carbinol.