Scientists Map Genetic Codes for Breast, Colon Cancers
and for some good news, this is very significant and will eventually lead to therapies and cures. we're getting closer.
Scientists Map Genetic Codes for Breast, Colon Cancers
21:33:54 EDT Sep 7, 2006
Canadian Press: E.J. MUNDELL /HEALTHDAY REPORTER
THURSDAY, Sept. 7 (HealthDay News) - In what experts are calling a milestone achievement, U.S. researchers have sequenced the genetic "blueprints" of two major cancer killers - breast and colon cancer.
Identifying nearly 200 genes thought responsible for these diseases, the work gives researchers new insight into these malignancies and lays the foundation for the gene-targeted therapies that may one day cure them.
"Only by understanding this blueprint of cancer will we be fully able to understand the mechanism of what makes a cancer a cancer and to think about strategies for diagnosis, prevention and therapy," explained Dr. Victor Velculescu, senior researcher on the project and an assistant professor of oncology at Johns Hopkins University's Kimmel Cancer Center.
Experts elsewhere were similarly optimistic. In a statement, Dr. Elias A. Zerhouni, director of the U.S. National Institutes of Health, which funded the project, described the new genetic maps as "groundbreaking work."
"This research approach holds great promise for providing an understanding of the genomic contributions to cancer," he said.
Velculescu's team outlined the findings in the Sept. 8 issue of the journal Science.
Just as the human body has its genetic code, so, too, do cancer cells.
"Work from the past two decades has shown us that cancer is a genetic disease," said Velculescu. He explained that a malignancy occurs when specific genes in healthy cells undergo unhealthy mutations.
"A mutation is really like a typo in a blueprint that's 3 billion letters long," he said, so spotting any one mutation has been like finding the proverbial needle in a haystack.
A new $100 million federal initiative, The Cancer Genome Atlas project, seeks to change all that by mapping the myriad genetic "typos" that cause specific tumor types to form. The project described in Science is the first major step in that effort.
In their research, Velculescu and his colleagues from across the United States focused on cracking the gene codes for breast and colon cancers, which together make up one-fifth of all cancer diagnoses worldwide. Other initiatives, focused on other tumor types, are currently under way.
The team analyzed more than 13,000 genes from tumor tissues taken from 11 patients with breast cancer and 11 patients with colorectal cancer.
What they found surprised them.
"Many of us might have expected that only a few of the 'building blocks' in a cell to be mutated, but we actually found quite a number of them," Velculescu said. "It looks like each cancer has about 100 different genes that are mutated, at least 20 of which are thought to be important for the tumor's progression."
The research also confirmed that there's no one disease called cancer.
"It looks like there are quite a bit of differences between the blueprint of different cancer types," the Johns Hopkins expert noted. "Colon and breast cancers are different, and, in addition, each individual's cancer is different. This, in part, may explain the differences that clinicians for a long time have seen among their cancer patients."
But the team also found "commonalities" between colon and breast cancers as well - mutations that affected similar cellular pathways. "As we learn more and more about how these genes interact, about pathways and how these genes control processes that occur inside cancer cells, we may be able to find simpler (treatment) targets," Velculescu said.
Another expert agreed. "This achievement is important because, to the degree that those genes are proven now to be related to the cancer process, they provide targets that can be potentially used either for diagnostic or treatment purposes," said Dr. Len Lichtenfeld, deputy chief medical officer at the American Cancer Society.
For example, doctors may someday use sensitive nanotechnology early detection tests to spot tiny amounts of cancer-linked proteins produced by these aberrant genes. "That would be a test that would enable you to diagnose a cancer long before you are actually able to see it," Lichtenfeld said.
In terms of treatments, drug developers can target specific genes and their proteins to create treatments that stop a cancer cold without harming the patient. Gleevec - the "wonder" drug now used to halt chronic myelogenous leukemia - is one such targeted therapy, Lichtenfeld said.
"So, this new achievement is a really important step and an important link between where we are today and where we have been talking that we will be in five, 10, 15 years," he said.
Velculescu said he shares that vision.
"We are predicting that cancer is an individualized disease, and there will come a day when people will go into the clinic and their tumor will be analyzed for specific mutations," he said. "Based on the combination of genes that are mutated, they will receive a particular combination of therapies that will treat the disease."
"We're not there yet, and there's still a long way to go," Velculescu said. "But without knowing what's broken inside a cancer cell, we have no hope of fixing it."
my aunt died of breast cancer last year,,she had it for a couple of years and it also came to a point that doctors have to remove her breasts,,they thought they removed all the cancer by removing her breasts but there were some left on her until it spread to other organs,,before we even found out it was too late...last time i saw her was 5yrs ago.........
.i dont know if they'll ever find a cure for cancer,,maybe they will, but it will be a long long time...........
RIP to my aunt and to all cancer victims
some cancers have already been "cured".
Originally Posted by flipKawiguy
if it's not cured, cancers will likely become manageable. the mapping of the genes allows us for the first time to really understand what is going on. with so many mutations discovered, each represents a potential for tailored drugs to disrupt cellular function either resulting in halting of growth or outright cell death.
and yet another approach that is in it's infancy. one more step.
Gene trial cures 2 of cancer
White blood cells converted to attack melanoma
Sept. 1, 2006 12:00 AM
WASHINGTON - Government scientists turned regular blood cells into tumor attackers that wiped out all signs of cancer in two men with advanced melanoma. The striking finding, unveiled Thursday, marks an important step in the quest for gene therapy for cancer.
But the genetically altered cells didn't help 15 other melanoma victims. So scientists are trying to strengthen the shots.
Still, the National Cancer Institute called its experiment the first real success in cancer gene therapy because it fought cancer's worst stage, when it has spread through the body, unlike earlier attempts that targeted single tumors.
The government hopes to soon begin testing the gene therapy in small numbers of patients dying of more common cancers, such as advanced breast or colon cancer.
The hope is that, one day, such treatment will provide long-lasting tumor suppression.
"It's not like chemotherapy or radiation where as soon as you're done, you're done," said Dr. Steven Rosenberg, lead researcher and the institute's surgery chief. "We're giving living cells, which continue to grow and function in the body."
The first two successful patients appear melanoma-free almost two years after infusions of tumor fighters made from their own blood. Doctors can't predict how the men will fare long-term. Melanoma, the most aggressive skin cancer and killer of almost 8,000 Americans a year, is notorious for returning years after patients think they've subdued it.
"I'm cured for now," is how a grateful Mark Origer, 53, of Watertown, Wis., put it after a checkup from institute doctors this week. "I know how fortunate I am to have gone through this and responded to this. Not everybody's that lucky."
Cancer specialists praised the work, published by the journal Science, but warned that years of additional research are needed.
"Clearly, this is a first step," cautioned Dr. Len Lichtenfeld of the American Cancer Society. "We have to be very cautious about not raising hopes too much."
But "it is exciting," he added. "It certainly is a proof of concept that this approach will work."
The institute's Rosenberg has long led a tantalizing research field: how to harness the body's immune system to fight cancer.
White blood cells called T-lymphocytes hunt down germs and other foreign tissue. But cancerous cells look a lot like healthy cells, making it hard for those T-cells to spot a problem.
By 2002, Rosenberg had made a breakthrough. He found small numbers of cancer-fighting T-cells inside some patients with advanced melanoma.
He literally pulled those cells out of their blood and grew billions more of them in laboratory dishes, enough to have a chance at overwhelming a tumor when they're pumped back into patients.
About half significantly improve after this so-called cell-transfer therapy.
But few melanoma patients make enough cancer-fighting T-cells naturally for scientists to spot in their bloodstream, and T-cells that attack other cancers are virtually impossible to find. So Rosenberg and colleagues set out to create those tumor fighters from scratch.
The scientists took normal lymphocytes, or ones that don't recognize cancer, out of 17 patients with advanced melanoma who had exhausted their treatment options.
They infected those cells with a virus carrying genes that create T-cell receptors, essentially homing devices for, in this case, melanoma. (Different genes create receptors for other cancers.)
"We can take a normal cell from you or me or any patient and ... convert that cell into a cell that recognizes the cancer," Rosenberg explained.
In 15 of the 17 patients who tried it, the newly armed cells took root and grew at low levels for a few months.
But only two saw their tumors gradually fade away: Origer and a 30-year-old whose T-cell levels remained superhigh for over a year.
Why did the genetically altered cells flourish in only two people?
"That's the critical question," said Dr. Patrick Hwu, melanoma chairman at the University of Texas M.D. Anderson Cancer Center, who once worked with the National Cancer Institute's team.
Picking the right lymphocyte to genetically alter isn't easy - there are many different kinds - or perhaps more precise T-cell receptors were needed, Hwu suggested.
"(But) these are all solvable issues," he stressed, calling the study "one of the first documented, effective cases of cancer gene therapy working."