Original story published by the University of California, San Francisco March 12 2009: http://news.ucsf.edu/releases/scientists-create-mouse-model-of-melanoma-that-generates-hope-for-the-use-o/
In Australia our most common form of cancer is skin cancer, causing in excess of 1600 deaths every year. Although non-melanoma skin cancer is the most common form, Melanoma is by far the most life threatening in addition to being the most common form of cancer found in Australia's young people aged 15-24yo. Globally Australia and New Zealand have the highest incidence and mortality rates of Melanoma.
Melanoma is the uncontrolled cancerous growth of Melanocytes, the pigment cells most people will be familiar with as the sun-induced moles that appear on your skin. In most cases these moles are benign and never develop beyond this to become malignant, however mutations in various genes can cause the cell cycle to malfunction resulting in a cancerous Melanoma.
In about 30% of all Melanoma cases two of the genes found to be mutated are the BRAF genes and the PTEN gene. BRAF is responsible for making the B-RAF protein which has a function related to cell growth and PTEN is responsible for making the phosphatase enzyme which plays in role in stopping cells from growing and dividing too rapidly so it is seen to have a 'tumor preventing' role.
In a recent study at the University of California, scientist have been able to engineer mice with mutations to both of these genes. While mice with both un-mutated genes functioning normally where seen to develop skin lesions similar to those sun-induced moles found in humans, mice with the mutation in both genes very quickly developed many cancerous Melanoma.
With these genes successfully manipulated in the mice the study was then able to observe the effect of two separate drug therapies which each targeted different parts of the cell cycle. One related to the BRAF gene mutation and the other related to the PTEN gene mutation. Used individually the treatments could prevent the onset of Melanoma, but used together the drugs where actually found to cause a small amount of regression in the cancerous cells.
So what does this study mean for the future research of targeted gene therapies? Well this study was focused mainly on two very specific gene mutations which do not always occur in incidences of Melanoma. Also the development of Melanoma in humans is likely to be different and perhaps more complex that that induced in the mice. However the study does show a successful model, the 'Mouse Model', which may be further adapted and adopted to testing the success of various other future and currently being developed gene therapies. With hope this can lead to improved treatments and reduced mortality rates for not only one of Australia's most common forms of cancer, but cancer patients in general.
References
Actual Story - http://news.ucsf.edu
Statistics - http://www.skincancer.gov.au
General Information - http://en.wikipedia.org/wiki/Melanoma, http://en.wikipedia.org/wiki/BRAF_(gene), http://en.wikipedia.org/wiki/PTEN_(gene)
Medical Treatments - http://www.smu.org.au
Images - http://www.clearscience.info
Paul Moore
