Membrane androgen binding sites are preferentially expressed in human prostate carcinoma cells

Prostate cancer is one of the most frequent malignancies in males. Nevertheless, to this moment, there is no specific routine diagnostic marker to be used in clinical practice. Recently, the identification of a membrane testosterone binding site involved in the remodeling of actin cytoskeleton structures and PSA secretion, on LNCaP human prostate cancer cells has been reported. We have investigated whether this membrane testosterone binding component could be of value for the identification of prostate cancer.

Using a non-internalizable testosterone-BSA-FITC analog, proven to bind on membrane sites only in LNCaP cells, we have investigated the expression of membrane testosterone binding sites in a series of prostate carcinomas (n = 14), morphologically normal epithelia, taken from areas of the surgical specimens far from the location of the carcinomas (n = 8) and benign prostate hyperplasia epithelia (n = 10). Isolated epithelial cells were studied by flow cytometry, and touching preparations, after 10-min incubation. In addition, routine histological slides were assayed by confocal laser microscopy.

We show that membrane testosterone binding sites are preferentially expressed in prostate carcinoma cells, while BPH and non-malignant epithelial cells show a low or absent binding.

Our results indicate that membrane testosterone receptors might be of use for the rapid routine identification of prostate cancer, representing a new diagnostic marker of the disease.