The genetic code of two of the most deadly cancers has been cracked by British scientists in a world first that opens up a whole new era in the treatment for the disease.
All the mutations that turn healthy cells cancerous in both lung and skin tumours have been identified in what researchers described as a "transforming moment" in the search for preventions, treatments and cures for both terminal illnesses.
Eventually a simple blood test will lead to accurate "made to measure" treatments that can identify, attack and kill the causes of each patient's own individual cancer, they claim.
All cancers are caused by damage or mutations to the DNA of formerly healthy cells acquired during a person's lifetime.
This damage causes them to grow into abnormal lumps or tumours and spread around the body disrupting its normal processes and eventually--if unchecked--causing death.
In lung cancer the damage is almost entirely caused by smoking and in skin cancer or malignant melanoma by ultra violent sunlight.
The Sanger Institute studies used powerful new DNA sequencing technologies to decode completely the genome of both tumour tissue and normal tissue from a lung cancer and a malignant melanoma patient.
They then compared and contrasted the two to discover the differences and see what damage has occurred to cause the disease.
The lung cancer genome, which kills 34,500 people a year, contained more than 23,000 mutations, the melanoma, which kills 2,000 people a year, more than 33,000.
Most of these mutations are known as "passengers" and cause damage but not cancer. However a small number are called "drivers" and these lead to the disease.
By sequencing many more cancer patients over the next few years, the researchers hope to distil down the mix until they have a handful of targets to hit with treatments such as chemotherapy and radiotherapy.
It is eventually believed that a simple blood test will mean every patient will be given their own cancer chart so their treatment can be tailor made.
Already the lung cancer genome is yielding useful information. As the average victim has smoked 18,000 packets of cigarettes, the researchers have concluded that a mutation is caused roughly every 15 cigarettes.
The research, published in the journal Nature, was hailed as groundbreaking by fellow researchers.
Professor Carlos Caldas, a cancer expert from Cancer Research UK's Cambridge Research Institute, said: "This is groundbreaking research."
"By repeating and refining this technique with other forms of cancer, and comparing the results to data from the Human Genome Project, the hope and excitement for the future is that we'll eventually have a detailed picture of how different cancers develop, and ultimately how better to treat and prevent them."
Dr Elizabeth Rapley, of The Institute of Cancer Research, added: "These are exciting studies that show us a great deal about how cancer is triggered and driven by mutations in DNA. "
"This is the first time that a complete cancer genome has been sequenced and similar insights into other cancer genomes are likely to follow. "
"As more cancer genomes are revealed by this technique, we will gain a greater understanding of how cancer is caused and develops, improving our ability to prevent, treat and cure cancer."
2010-08-05 23:18 编辑：kuaileyingyu