Sloppy gene repairs: a cause of lymphoma?

The blood and lymphatic systems transport the immune system’s infection-fighting B cells throughout the body. During an immune response, random mutations are introduced in B cell genes by a process known as somatic hypermutation (SHM), which makes the cells more effective at fighting a variety of foreign invaders.

To keep harmful mutations at bay, B cells contain DNA repair enzymes that repair faulty genes created by SHM, but little is known about how effective these repair mechanisms are, or whether they might be related to the development of the cancerous B cells seen in lymphoma.

In the February 14 issue of Nature, a team led by David G. Schatz, Ph.D., professor of immunobiology and Howard Hughes Medical Institute investigator, found that almost 25 percent of B cell genes accumulated mutations, including genes that are strongly associated with human lymphomas.

“The implications of these findings are considerable,” Schatz says. “It now seems likely that anything that compromises the function of these DNA repair processes could lead to widespread mutations and an increased risk of cancer.”.