Low levels of urokinase plasminogen activator components in basal cell carcinoma of the skin

Basal cell carcinoma of the skin (BCC) is the most common cancer worldwide. Unlike most other human malignancies, BCCs rarely metastasise. In this inv estigation, we show that the serine protease urokinase plasminogen activato r (u-PA), which is causally involved in metastasis, is expressed at lower l evels in BCCs compared to other skin cancers, such as squamous-cell carcino mas (SCCs) or malignant melanomas, Similarly, the u-PA receptor as well as the inhibitor PAI-1 were present at lower levels in BCCs relative to both S CCs and melanomas. In contrast to u-PA, tissue-plasminogen activator, which is not thought to be involved in metastasis, was present at similar levels in the different types of skin lesion investigated. We conclude that the f ailure of BCCs to metastasise may at least be partially related to low expr ession of components of the u-PA system. Int. J. Cancer 85:457-459, 2000, ( C) 2000 Wiley-Liss, Inc.