Scientists map breast cancer genomes faster and cheaper

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The 24 breast cancer genomes that researchers mapped in the journal Nature on Wednesday are just the first steps in a larger effort by the International Cancer Genome Consortium to map the genomes of 1,500 different breast cancers within the next five years.

That would be an expensive prospect, said study co-author Jorge Reis-Filho of the Institute of Cancer Research in London, if they were working with older technologies. Mapping one genome, the researcher said, can easily cost tens of thousands of dollars. But by using a new technique called massively parallel sequencing – in which millions of sequencing reactions can happen at the same time, using a small fraction of reactant– the same mapping could be done for a fraction of that cost.

That’s especially important for finding genomic rearrangements in breast cancer, Reis-Filho said. The more breast cancer genomes they map, the better an idea they have of the disease’s causes.

Usually strains of cancers such as myeloid leukemia all show the same type of genetic mistakes, the scientist pointed out.

But “in breast cancer, it’s a completely different picture,” Reis-Filho said in an interview. “We could not find any fusion gene that was recurrent. So each malignancy had a different rearrangement.”

Some of these mistakes are likely caused by faulty DNA repair functions, the researcher said, and new drug therapies could potentially overload those mechanisms and kill the cancer, leaving the normal, healthy cells intact.
But, Reis-Filho added, since breast cancer’s broken mechanisms don’t have just one cause, it will likely prove a much more complicated disease to target and kill.

-- Amina Khan