Genetic code of lethal skin and lung cancer sequenced

It is the first time that complete genetic codes of two deadly human cancers have been sequenced. Scientists are defining this success as a ‘transforming moment’ which could lead to a medical revolution wherein such terminal diseases could be contained.

“This is a fundamental moment in cancer research. From here on in we will think about cancers in a very different way," said Professor Mike Stratton who led the cancer genome project from UK.

"Today for the first time, in two individual cancers, a melanoma and a lung cancer, we have provided the complete list of abnormalities in DNA in each of those two cancers.

"We now see uncovered all the forces that have generated that cancer and we now see all the genes that are responsible for driving those two cancers," he added.

Cancers are generally caused by mutations or damage to the DNA of healthy cells which obstruct the normal functioning of these cells and eventually cause death.

These findings appear in the journal Nature.

Genetic code identified from DNA mutations in cancer patients
A team of scientists from Britain's Wellcome Trust Sanger Institute has uncovered this genetic code from the cancer tumors of two patients suffering from lung cancer and malignant melanoma, a deadly skin cancer.

For decoding the genome of both the cancer tissues, powerful new DNA sequencing technologies were used.

By comparing the cancer tissues with the healthy ones, scientists discovered 33,345 faulty mutations for melanoma and 22,910 damaged mutations for lung cancer, which they consider remarkable.

The DNA mutations in the melanoma patient were mainly caused by an extreme exposure to sun, while lung cancer tumors were developed due to excessive smoking.

Professor Peter Campbell, who led the lung cancer team, said, "These mutations are a bit like Russian roulette. Most of the time you will hit an empty chamber and cause a passenger mutation. But every now and again you will hit a bullet and cause a tumour."

They claim that with the cancer genome mapping, eventually a simple blood test will set the stage for accurate and early diagnosis and treatment of the disease. The cancer genome sequence will also pave the way for better understanding of the mechanisms of such illnesses.

Cataloguing of other types of cancers in future
To gain similar insights into other types of cancers, scientists from all across the world are working to decode the faulty cancerous genes.

For instance, UK is examining breast cancer tumors, Japan is looking at liver, India at mouth, China at stomach cancer, and US is studying cancers of brain, ovary and pancreas.

They say, it will take another five years and lot of funding to accomplish such a huge task. However, they are hopeful that once completed, many patients would benefit.

Prof Stratton said, "These catalogues are going to change the way we think about individual cancers. By identifying all the cancer genes we will be able to develop new drugs that target the specific mutated genes and work out which patients will benefit from these novel treatments.

"We can envisage a time when following the removal of a cancer cataloging it will become routine."