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Cancer: Expert bets on genomics

In 1989, Dr Harold E. Varmus, received the Nobel Prize in Physiology or Medicine.

Bangalore: In 1989, Dr Harold E. Varmus, received the Nobel Prize in Physiology or Medicine, for his discovery of the cellular origin of retroviral oncogenes.

He delivered the centenary lecture at the Indian Institute of Science on Tuesday morning, discussing the new directions in cancer research.

Dr Varmus is the current Director of the National Cancer Institute U.S. and also serves on the President's Council of Advisors on Science and Technology.

He began his work on the oncogene (a gene that has the potential to cause cancer) in 1970 during his post-doctoral studies in Bishop's lab, University of California, San Francisco.

Most normal cells undergo a programmed form of death. However, an activated oncogene can cause those cells marked for this apoptosis to survive and proliferate. But how does an oncogene enter an organism? This is where Dr Varmus came in.

In his early reading on the subject, he came to understand that viruses might provide a relatively simple foray into the complex problem of cancers.

"Tobacco, UV rays, viruses, heredity and age are the main causes of cancer," explained Dr Varmus, whose talk was an elaboration of his Nobel Speech, with a somewhat vague outlining of the direction in which the research is heading. "While there is marked heterogeneity, the commonalities are what we hope to address."

Some cancers can be prevented with vaccines, he said, others with behavioural control.

"Some growths can be detected early, making for increased accuracy in diagnosis. Some can be cured and others controlled." So far, cancer research has been unable to prevent or screen most cancers and predict outcomes of those that are in the early stages.

"We also haven't been able to cure or chronically control what has spread or eliminate complications of therapy," he said.

Of course, the growing cost of cancer treatment is another worry. "Cancer genomics can increase precision," he said.

"In the 1960s and 70s, there wasn't much evidence at all. We knew vaguely the causes of cancer, but methods like genomics were very new."

In the late 70s, the three types of oncogenes were classified - proto oncogenes, tumor suppressor genes and genes governing DNA integrity. "How the genes contribute to the cancer causing process is still somewhat mysterious," he said.

The lecture was detailed, but contained very few deliverables. This was brought up by a PhD student in the audience, who said, "We have a lot of information, but where are we going with it?" Dr Varmus said, "What makes news today was discovered ten years ago. Although we haven't made as much progress as we would have wanted to, progress has been made, all the same."

Another member of the audience asked him about the use of alternate medicines, saying the use of turmeric has been recommended here, in India. “A lot of patients take drugs and treatments that are very harmful,” Dr Varmus said, at once.

“Can the immune system be manipulated into fighting cancer?” asked another audience member. “There is no proof that the immune system will respond to neo-anogens,” was his response.

Dr Varmus stressed on the need for international collaboration in cancer research and hopes India will have a significant role to play in this. Why does an oncogene have the effect it does? What can we do about prevention, suppression and treatment? The greatest scientific answers, however, require a touch of the imagination and these questions were, for the time being, left to ours.

( Source : dc )
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