Genome Study Brings Blood Cancer Into Sharp Focus

24.03.2011 -

Scientists have mapped out the full genetic code of 38 people with multiple myeloma, uncovering never-before suspected genes that play a role in the blood cancer and showing that a promising new drug might help.

Studying the genetic blueprint of so many people with this cancer allows researchers to have a much more comprehensive picture of what drives the cancer, and it gives drug companies much better clues about how to shut down the disease.

"If we compare the tumor genome to the normal genome, that gives us great clues about what makes a normal cell into a cancer cell," said Todd Golub of the Broad Institute and the Dana-Farber Cancer Institute, who helped lead the study published on Wednesday in the journal Nature.

Golub said the findings revealed many new avenues for future treatments for the cancer, including several genes that have never before been implicated in any cancer.

"We have a number of examples of genes that were not thought to play a role, but they must be important," Golub said in a telephone interview.

"It sends the field in a new direction that they couldn't have anticipated before."

Most immediately, the results suggest that about 4% of patients with multiple myeloma have mutations in the BRAF gene - the same type of mutations found in some people with the skin cancer melanoma.

So far, melanoma patients with this mutation have shown a strong response to an experimental drug being developed by Roche and Daiichi Sankyo's newly acquired  Plexxikon, and the hope is the drug or others like it might also help a small subset of multiple myeloma patients.

"An important next phase will be to explore that hypothesis in a clinical trial," Golub said.

The Multiple Myeloma Research Foundation hailed the study as "a major step forward" in efforts take a personalized medicine approach in multiple myeloma, a cancer that starts in bone marrow cells and has a five-year survival rate of less than 40%.

Golub said the study showcases the power of new gene-sequencing technology that allows researchers to look at the whole genetic makeup of a cancer, something that was not possible even five years ago.

"This has been made possible not by our brilliance but by advances in new gene sequencing technology," said Golub, who is an investigator at Howard Hughes Medical Institute, and professor of pediatrics at Harvard Medical School.

The latest machines from companies like Illumina and Life Technologies can map out a patient's whole DNA code in just a few weeks for as little as $5,000, a far cry from 13 years and $3 billion it took to get the first human genome a decade ago. Golub said the study signals a new approach that is coming in cancer research.

"It is a very positive development that will enable the field to see things that were previously not imaginable," he said. "Five years from now, we will have the genetic landscape of all common human cancers mapped out."