Potential for estrogen synthesis and action in human normal and neoplastic thyroid tissues.

To investigate the potential of intracrine or paracrine estrogen synthesis and action in the human thyroid gland and thyroid tumors, the presence of the messenger ribonucleic acids (mRNAs) of both cytochrome P450 aromatase (P450arom) and estrogen receptor (ER) was investigated by RT-PCR with primers designed on the respective coding regions and Southern hybridization analysis with specific probes in neoplastic (n = 42), hyperplastic (n = 7), and adjacent histologically normal thyroid tissues (n = 33) obtained from 43 female and 7 male patients. Most thyroid tissues were positive for both mRNAs, but 2 normal and 3 neoplastic tissues were negative for P450arom mRNA only, 3 normal and 1 hyperplastic tissues were negative for ER mRNA only, and 2 normal tissues were double negative. In some patients, P450arom mRNA was absent in either the neoplastic tissue or the normal one. Single and double negative samples were relatively more frequent in men (n = 4) than in women (n = 7). All negative samples were positive...