EVIDENCE FOR ANDROGEN RECEPTOR GENE-EXPRESSION IN HUMAN THYROID-CELLSAND TUMORS

Androgen-binding activity has been identified in normal and pathologic al thyroids, but evidence for the expression of the canonic androgen r eceptor (AR) in the thyroid has not been provided so far. In this stud y we have used reverse transcription (RT)-PCR to examine RNA expressio n of the canonic AR gene in human thyroid tissues, in primary cultures of human thyrocytes and in a variety of neoplastic thyroid cell lines (NPA, TPC and WRO). An AR cDNA fragment with the expected size of 262 bp was detected in normal tissues and cultured thyrocytes as well as in neoplastic cell lines, demonstrating that the gene for AR is indeed expressed in thyroid follicular cells. Immunocytochemical analysis re vealed the presence of the AR protein in cancer cell lines and androge n treatment increased nuclear positivity to AR. In a survey of 35 thyr oid tissues AR cDNA was detected in all the nonneoplastic samples (6 n ormal and 3 goitrous) and in 19 of 26 neoplastic samples. AR cDNA was not detected in 4 of the 9 follicular adenomas and in 3 of the 12 papi llary carcinomas. AR was revealed by immunohistochemistry in 1 of 2 no rmal thyroids, in 1 goiter and in 1 of 2 neoplastic thyroids. These fi ndings show the presence of the canonic AR in the human thyroid.