2014-01-08

Eric Green: Reading Cancer's Genetic Signature


source: Big Think 2014年01月08日
"Cancer death rates in the United States continue to decline." Despite this conclusion, from the recent Report to the Nation on the Status of Cancer, we are still thought to be losing the war against cancer. Why is this? For one thing, cancer may soon overtake heart disease as the #1 cause of death.

But this is an unfair comparison, writes George Johnson in The New York Times. "Heart disease and cancer are primarily diseases of aging," Johnson observes, adding that we are really talking about a zero-sum game: "Fewer people succumbing to one means more people living long enough to die from the other...Though not exactly consoling, the fact that we have reached this standoff is a kind of success."

Moreover, in measuring progress in this war, we need to appreciate the approach that researchers have adopted, of "fighting and even winning smaller battles," as Johnson puts it. That means reducing and sometimes preventing cancer that occurs in childhood or in the prime of someone's life. Eventually, we all will get it, unless something else gets us first. Cancer, after all, is a condition "deeply ingrained in the nature of evolution and multicellular life." In other words, cancer is fundamentally a disease of the genome.

Over the past 10 years we have learned to read out that genome, explains Eric Green, director of the National Human Genome Research Institute. Studying the sequence of a tumor's DNA allows us to "gain insights from that tumor with respect to the DNA changes that have led to those cells becoming a cancer," Green tells Big Think.

This is one of the most notable achievements of The Human Genome Project, Green argues, as the genomes of tumors can be analyzed, providing "a much better way of deciding what types of treatments to pursue."

The National Human Genome Research Institute, in partnership with the National Museum of Natural History at the Smithsonian, has launched an exhibition called "Genome: Unlocking Life's Code."

This multimedia exhibition—on view at the National Museum of Natural History through Sept. 1, 2014—is designed to provide the general public with the most cutting edge information on genomic research and how it impacts human health.

Transcript - So cancer is fundamentally a disease of the genome. I mean the reason a tumor grows is because the cells in that tumor have picked up glitches. They picked up mutations. They picked up changes in the DNA that make those cells grow out of control. It's like pressing an accelerator in a car and just keep it going. It just grows and grows and grows and grows. And the reason why is because something's broken in the genome. And so what's happened in the past ten years in particular since the end of the Human Genome Project is the recognition that we can read out the genome, the sequence of the tumor's DNA and gain insights from that tumor with respect to what had been the DNA changes that have led to those cells becoming a cancer.

And that is being done on a very large scale in many countries around the world and here including the United States where literally very defined cancers are being studied. Hundreds of specimens are being collected from people and those genomes of those tumors are being read out and have all that data be put on the Internet for scientists to be able to collect it all and analyze it. And we are learning a tremendous amount about cancer in many very interesting and surprising ways. And among the many things that are happening is it's giving us insights about how to better classify different types of cancer and different subtypes of cancer. And I often make the point that some of the earliest implementation of genomics in the medical situation is gonna be with cancer.

And it's already happening now and I think it's gonna grow considerably. Where I think standard of care for many types of cancer are gonna be get that tumor, read out it's DNA, sequence it's genome and based on what you've seen what's wrong with that tumor, not by looking at it under a microscope only or by looking at it in a sort of a gross fashion but actually looking inside it's blueprint, you will be able to have a much better way of deciding what types of treatments to pursue and have a much better idea about what's wrong in that kind of tumor. And some of those things will also be very helpful for leading to possibly new developments of therapies.

Directed / Produced by Jonathan Fowler and Dillon Fitton