Transforming growth factor-beta expression in human testicular neoplasms.

OBJECTIVE: To investigate the localization of transforming growth factors (TGF-beta 1, -beta 2 and -beta 3) and their receptors (TGF-beta RI and RII). STUDY DESIGN: The study included 26 paraffin-embedded tissues from human testicular neoplasms: 15 seminomas, 2 embryonal carcinomas, 1 immature teratoma, 4 immature teratomas with embryonal carcinoma, 1 immature teratoma with seminoma, 1 seminoma with embryonal carcinoma and 2 gonadal stromal tumors (Leydig cell tumors). RESULTS: TGF-beta 1 immunoreactivity was cytoplasmic and was expressed in 22 (84.6%), TGF-beta 2 in 20 (77%), TGF-beta 3 in 11 (42.3%), TGF-beta-RI in 21 (80.8%) and TGF-beta-RII in 18 (69.2%) of the 26 neoplasms. The percentage of positive immunostained cells and the intensity of staining were significantly higher in tumor than in peritumor nonneoplastic testis. In the peritumor nonneoplastic testis, Leydig, Sertoli and germ cells coexpressed both the three TGF-beta isoforms and TGF-beta-RI and RII. The myoepithelial cells of the seminiferous tubules showed immunoreactivity for TGF-beta RI and RII but not for TGF-beta s. In tumor testis areas the pattern of TGF-beta and TGF-beta receptor expression and distribution varied according to the histologic type of testicular tumor. Seminomas showed a diffuse pattern of TGF-beta immunoreactivity, whereas immature teratomas had focal and patchy distribution. In teratomas, differentiated structures contained more TGF-beta s than undifferentiated structures.