Hedgehogs: la dolce vita

Abstract

This European Molecular Biology Organization workshop on Hedgehog‐Gli Signaling in Cancer and Stem Cells took place between 30 September and 4 October 2006 in Rome, Italy, and was organized by A. Gulino, H. Hahn, A. Ruiz i Altaba, R. Toftgard, F. Watt, P. Therond and I. Guerrero. ![][1] During a wonderfully seasonal autumn, researchers from around the world gathered in Rome, the soul of Italy, for an EMBO workshop on Hedgehog (Hh) signalling in cancer and stem cells. The focus of this workshop was timely, as this area of research is responsible for the exponential growth—and increased research diversity—in the Hh field. Hh was first identified in a screen for genes required for Drosophila embryonic patterning (Nusslein‐Volhard & Wieschaus, 1980). Subsequent isolation of the affected hh gene and its encoded protein revealed a unique signalling molecule with related orthologues in vertebrates (Ingham & McMahon, 2001). Since its original description, the Hh pathway has received increasing attention, not only because of its involvement as a crucial regulator of embryonic organogenesis but also as an oncogenic pathway that has been implicated in several human tumours (Beachy et al , 2004; Pasca di Magliano & Hebrok, 2003; Robbins et al , 2005; Ruiz i Altaba et al , 2002). Despite extensive studies addressing the regulation and function of the pathway in different organs, the exact mechanisms by which Hh signals are transmitted and how they elicit diverse activities in a cell‐specific manner remain obscure. Here, we review some of the recent advances in the Hh field that were discussed at this workshop and highlight some of the questions that remain. Hh is translated into an approximately 47 kDa protein, which subsequently undergoes an intramolecular cleavage reaction that produces two discrete smaller proteins (Singh et al , 2006; Ingham & McMahon, 2001). The amino‐terminal product … [1]: /embed/graphic-1.gif