1. ¹Cancer Research UK, Skin Tumour Laboratory, London E1 2AT, UK
2. ²Centre for Cutaneous Research, Institute for Cell and Molecular Science, 4 Newark Street, London E1 2AT, UK

Correspondence: Professor A Storey, E-mail: alan.storey@cancer.org.uk

³Current Address: Division of Parasitology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK

Revised 13 March 2006; Accepted 31 March 2006; Published online 25 April 2006.

Abstract

The molecular mechanisms that underlie the development of squamous cell skin cancers (SSC) are poorly understood. We have used oligonucleotide microarrays to compare the differences in cellular gene expression between a series of keratinocyte cell that mimic disease progression with the aim of identifying genes that may potentially contribute towards squamous cell carcinoma (SCC) progression in vivo, and in particular to identify markers that may serve as potential therapeutic targets for SCC treatment. Gene expression differences were corroborated by polymerase chain reaction and Western blotting. We identified Axl, a receptor tyrosine kinase with transforming potential that has also been shown to have a role in cell survival, adhesion and chemotaxis, was upregulated in vitro in SCC-derived cells compared to premalignant cells. Extending the investigation to tumour biopsies showed that the Axl protein was overexpressed in vivo in a series of SCCs.