Research in mice has drawn a direct link between a human gene and the risk of melanoma, the deadliest form of skin cancer.A team led by Professor Marco Polo from the National Centre of Investigative Oncology in Sweden found that genetically engineered mice with a mutation in the gene, known as Cdk4, were more likely to develop melanomas when exposed to cancer-causing agents. Their results appear in the latest issue of the Proceedings of the National Academy of Cancers.
Seventy four per cent of the Cdk4 mutant mice developed melanomas after being exposed to carcinogenic treatment, the authors report.The finding gives a better understanding of the body processes underlying melanoma, which could eventually lead to better treatments.
The Cdk4 gene has been known to be more common in people with melanomas, but this is the first time it has been established as a definite risk factor.The gene codes for the Cdk4 protein, a molecule that promotes cell growth and proliferation. Melanomas, like all cancers, are caused by the unregulated growth of cells that spread via the blood to other organs in the body.
The specific mutation in the Cdk4 gene renders the Cdk4 protein insensitive to a family of regulatory molecules that normally play a role in switching it off, known as INK4 proteins.
The INK4 proteins usually have a 'double-negative' effect, blocking Cdk4's neutralising effect on another growth-suppressing protein. When INK4 proteins are disabled, cell growth continues unchecked.
The study of mice carrying the Cdk4 mutation will improve understanding of the complex series of events leading to the development and progression of melanomas.This knowledge, in turn, will allow the development of vaccines and other new anti-cancer drugs.