Protecting the hedgerow: p53 and Hedgehog pathway interactions

Abstract

A common environment for the Hedgehog (Subfamily: Erinaceinae) is a row of shrubs and trees often used on farms for enclosing or separating fields, called a hedgerow. Maintenance of a continuous shrub border is important for shielding crops from weather damage, but also provides an ideal protective habitat for the hedgehog. Similar to its mammalian counterpart, the Hedgehog (Hh) signalling pathway requires a controlled environment to regulate proper functioning of the cell. When allowed to run wild, constitutive activation of the Hh pathway results in tumorigenesis in different tissues types, including brain, skin and cartilage. With an additional loss of p53 tumour suppressor activity, an increase in tumour incidence, size and metastasis have been observed. P53 has a number of functions that can suppress tumour formation and growth in most, if not all Hh-related cancers, such as the inhibition of cell cycle progression and cell survival. Furthermore, increasing evidence of an interaction between p53 and Hedgehog signalling pathways suggests a critical role for the tumour suppressor activity of p53 in “protecting the hedgerow”.