The Hedgehog signalling pathway and cancer

The Hedgehog signalling pathway is important in embryological development a nd is highly conserved through evolution. Recently Patched, a member of the pathway, was found to be important in Gorlin's syndrome. Inherited Patched gene mutations underlie the syndrome, in which a key feature is multiple b asal cell carcinomas (BCCs). The gene is also mutated in sporadic BCCs as w ell as in sporadic occurrences of other tumours seen in Gorlin's syndrome. The precise mechanism whereby Patched gene mutation leads to tumour develop ment is not known, but BCC is characterized by relentless local invasion an d only rarely metastasizes. This suggests that abnormalities of the Hedgeho g pathway account for these features. This proposal is discussed in the con text of what is already known about the normal function of the Hedgehog pat hway and its deregulation in cancer. Copyright (C) 2000 John Wiley & Sons, Ltd.