Konitsiotis, Antonios D3; Chang, Shu-Chun3; Jovanović, Biljana3; Ciepla, Paulina4; Masumoto, Naoko4; Palmer, Christopher P5; Tate, Edward W4; Couchman, John Robert8; Magee, Anthony I7
1 Section of Molecular Pathology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, Københavns Universitet2 Couchman Group, BRIC Research Groups, BRIC, Københavns Universitet3 Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, London, United Kingdom.4 Department of Chemistry, Imperial College London, London, United Kingdom; Institute of Chemical Biology, Imperial College London, London, United Kingdom.5 Institute for Health Research and Policy, London Metropolitan University, London, United Kingdom.6 Couchman Group, BRIC, Faculty of Health and Medical Sciences, Københavns Universitet7 Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, London, United Kingdom; Institute of Chemical Biology, Imperial College London, London, United Kingdom.8 Couchman Group, BRIC, Faculty of Health and Medical Sciences, Københavns Universitet
Overexpression of Hedgehog family proteins contributes to the aetiology of many cancers. To be highly active, Hedgehog proteins must be palmitoylated at their N-terminus by the MBOAT family multispanning membrane enzyme Hedgehog acyltransferase (Hhat). In a pancreatic ductal adenocarcinoma (PDAC) cell line PANC-1 and transfected HEK293a cells Hhat localized to the endoplasmic reticulum. siRNA knockdown showed that Hhat is required for Sonic hedgehog (Shh) palmitoylation, for its assembly into high molecular weight extracellular complexes and for functional activity. Hhat knockdown inhibited Hh autocrine and juxtacrine signaling, and inhibited PDAC cell growth and invasiveness in vitro. In addition, Hhat knockdown in a HEK293a cell line constitutively expressing Shh and A549 human non-small cell lung cancer cells inhibited their ability to signal in a juxtacrine/paracrine fashion to the reporter cell lines C3H10T1/2 and Shh-Light2. Our data identify Hhat as a key player in Hh-dependent signaling and tumour cell transformed behaviour.