Molecular superfamily causes melanoma spread

May 13 2009

Molecular superfamily causes melanoma spread A superfamily of molecules holds the secret to the development and spread of melanoma - the deadliest form of skin cancer, revealed a study published in the British Journal of Cancer*.

A superfamily of molecules holds the secret to the development and spread of melanoma - the deadliest form of skin cancer, revealed a study published in the British Journal of Cancer* today (Wednesday).

Scientists based at the University of Nebraska Medical Centre investigated the roles of a superfamily of molecules called 'chemokines' and their receptor 'partner molecules' in melanoma development. The scientists 'turned up' the normal activity of two receptor molecules called CXCR1 and CXCR2 inside human melanoma cell lines and studied the effect on tumour growth in mice.

Their results suggested that CXCR1 and CXCR2 play key roles in the development and spread of melanoma. The scientists found that the molecules helped tumour cells to grow. And when they 'turned up' the activity of CXCR1 and CXCR2 in healthy cells it triggered tumour formation.

'Chemokines' together with their receptor 'partner molecules' control the movement of many types of cells in the body. Scientists already knew that some molecules from this superfamily regulated the movement of certain types of healthy cells in the body's lymphoid system and thought that chemokines might also control the migration of tumour cells in the body. Several studies have implicated CXCR1 and CXCR2 as important players in tumour progression.**

Malignant melanoma*** incidence rates in Britain have quadrupled since the 1970s killing more than 1,800 each year.It is a malignant tumour that originates in melanocytes, the cells which produce the pigment melanin that colours our skin, hair, and eyes and is the most serious form of skin cancer. If detected and treated early, it is easy to treat. But if it is ignored the cancer can advance and spread to other parts of the body, where it becomes hard to treat and can be fatal.

Professor Rakesh Singh, lead author, said: "These results suggest that a superfamily of molecules controls whether a melanoma advances and spreads to other parts of the body - when it becomes difficult to treat. There is a possibility these molecules could be used in future therapy for melanoma - something that doesn't exist at the moment."

Dr Lesley Walker, director of cancer information at Cancer Research UK, said: "This important research helps us understand how malignant melanoma progresses and spreads.

"Malignant melanoma is the most deadly form of skin cancer and a life threatening disease which could be prevented if people protect themselves in the sun with at least factor 15 sun cream, covering up, wearing sunglasses and staying in the shade between 11 and three when the sun is hottest. Sun beds are just as dangerous as staying out too long in the sun."

*CXCR1 and CXCr2 enhances human melanoma tumourigenesis, growth and invasion. RK Singh et al. British Journal of Cancer 12 May 2009.

**CXCL-8, a member of the CXC chemokine family, was known to trigger migration, stimulate blood vessel formation, and promote tumour cell growth in melanoma and other malignancies in previous studies. CXCL-8 binds to two 'partner' receptor molecules called CXCR1 and CXCR2.

***By the year 2024 Cancer Research UK statisticians predict that malignant melanoma will be the fourth most common cancer for men and for women - of all ages - rising from around 9,000 cases diagnosed each year now to more than 15,500.

There are two main types of skin cancer: non-melanoma skin cancer, which is very common, and malignant melanoma which is less common but more serious. Registration of non-melanoma skin cancer is incomplete. More than 76,000 cases of non-melanoma skin cancer were registered in 2005 but it is estimated that the actual number is at least 100,000 cases in the UK each year.

More than 9,500 cases of malignant melanoma were diagnosed in the UK in 2005.