Immunohistochemical localization of transforming growth factor-α, epidermal growth factor receptor and c-erbB-2 protein in hyperplastic human prostates

Abstract

Transforming growth factor-α (TGF-α) is a potent mitogenic factor which acts by binding to the epidermal growth factor (EGF). c-erbB-2 is a member of the EGF receptor family and is known to be associated with cellular growth and differentiation. The roles played by these factors in benign prostatic hyperplasia (BPH) are not clearly known. In the present study, expression of these factors was investigated immunohistochemically in frozen and formalin fixed prostate tissues from subjects suffering from BPH. Intracytoplasmic localization of TGF-α was observed in the epithelium of nine out of 39 (23.07%) cases. Twenty-six out of 36 (72.22%) frozen BPH tissues exhibited moderate to strong staining for immunoreactive EGF-receptor in the cell membrane. c-erbB-2 oncoprotein was localized in 35 out of 39 cases (89.74%) with the intensity of staining being variable. All nine cases positive for TGF-α were also positive for both EGF-receptor and c-erbB-2 protein. Staining reaction had no correlation with the serum testosterone, prostate specific acid phosphatase and prostate specific antigen levels. Immunohistochemical studies indicate the expression of TGF-α, EGF receptor and c-erbB-2 protein in BPH tissues. Further study is required to elucidate the precise roles played by these factors in benign growth of prostates.