Transferrin receptor expression in normal skin and in various cutaneous tumors.

In the majority of human cells the transferrin receptor (TFR) plays an important role by mediating the cellular iron uptake. The TFR is especially expressed by proliferating cells and has been found in high amounts in malignant tumors. The distribution of the TFR in frozen sections of 89 skin biopsies of normal skin and of various cutaneous tumors was investigated using an anti-TFR monoclonal antibody (OKT9) and a 3-step immunoperoxidase method. Our results indicate that in normal human skin the TFR shows a characteristic microanatomical distribution in the basal cell layer correlated to the architectural pattern of the dermal-epidermal interface. In cutaneous lymphomas of high grade malignancy the TFR was expressed in virtually all cells compared to only 25-75% in low grade lymphomas. Malignant melanomas were strongly positive in the whole tumor tissue, whereas benign melanocytic nevi were largely negative. Obviously the immunohistochemical demonstration of the TFR may serve as prognostic indicator or diagnostic aid, respectively.