Discover magazine reports:

Millions of years ago, our ancestors, like us today, had to contend with viruses. No doubt the infections were unpleasant for them at the time, but their suffering wasn’t for naught — some of those viruses left traces in our DNA.

And, according to scientists at the Francis Crick Institute, these remnants may aid the body’s immune response to cancer today.

While studying lung cancer in mice and in human tumor samples, the team found that immunotherapy treatment seemed to work better when B cells (which produce antibodies that fend off foreign substances in the body) were present near a tumor. In a study published in Nature earlier this year, they reported that the antibodies were targeting proteins expressed by those viral remnants, known as endogenous retroviruses, or ERVs.

It seems like a strange alliance — an old disease, which may originally have caused cancer itself, helping us fight cancer in the present. But there’s a logic here, according to George Kassiotis, lead author and head of the institute’s Retroviral Immunology Laboratory.

“Cancer is a disease of the DNA,” he says, “and there are no parasites of our DNA that have been more successful than endogenous retroviruses.” [Continue reading…]