Carcinogenesis Advance Access originally published online on December 5, 2008
Carcinogenesis 2009 30(2):249-257; doi:10.1093/carcin/bgn278
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
A novel Src kinase inhibitor reduces tumour formation in a skin carcinogenesis model
Institute of Genetics and Molecular Medicine, Edinburgh Cancer Research Centre, University of Edinburgh, Crewe Road South, Edinburgh, EH4 2XR, UK
1 The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Bearsden, Glasgow, G61 1BD, UK
2 Institute of Comparative Medicine, University of Glasgow, Glasgow G61 1QH, UK
3 AstraZeneca, Alderley Park, Macclesfield, SK10 4TF, UK
4 Present address: ISTEM/CECS/INSERM/UEVE 861, 1 rue de l'internationale, BP 118, 91004 Evry Cedex, France
* To whom correspondence should be addressed. Tel: +44 131 777 3556; Fax: +44 131 777 3520; Email: v.brunton{at}ed.ac.uk
The Src family tyrosine kinases are key modulators of cancer cell invasion and metastasis and a number of Src kinase inhibitors are currently in clinical development for the treatment of solid tumours. However, there is growing evidence that Src is also upregulated at very early stages of epithelial cancer development. We have investigated the role of Src in mouse skin, which is one of the most tractable models of epithelial homoeostasis and tumorigenesis. We found that Src protein expression and activity was regulated during the normal hair cycle and was increased specifically during the proliferative anagen phase and also in response to the tumour promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). AZD0530, a selective Src inhibitor, prevented the TPA-induced proliferation of basal keratinocytes both in vivo and in vitro. Moreover, treatment with AZD0530 reduced papilloma formation following the well-established 7,12-dimethylbenz(a)anthracene/TPA skin carcinogenesis protocol but did not inhibit the subsequent proliferation of the papillomas. Furthermore, AZD0530 did not alter the malignant conversion of papillomas to squamous cell carcinoma suggesting a role for Src in early tumour development in the skin carcinogenesis model, rather than at later stages of tumour progression. Src expression and activity were also seen in human actinic keratoses that are hyperproliferative pre-malignant skin lesions, indicating that Src may also play a role in the early stages of human skin tumour development. Thus, Src inhibitors such as AZD0530 may therefore have chemopreventative properties in patients with hyperproliferative epidermal disorders.
Abbreviations: DMBA, 7,12-dimethylbenz(a)anthracene; PBS, phosphate-buffered saline; SFK, Src family kinase; TPA, 12-O-tetradecanoylphorbol-13-acetate
Received July 2, 2008; revised December 3, 2008; accepted December 3, 2008.