Lymphoma Protein Studied in DNA Damage

Jun 11, 11:28 AM

Current Headlines: A U.S. study suggested a protein associated with B cell lymphomas suppresses elimination of useful B cells that otherwise harbor damaged DNA.

In most cells, DNA damage triggers sensors that halt cellular activity until the damage is repaired. Now Ari Melnick and colleagues at Albert Einstein University determined the protein Bcl-6 prevents the production of the DNA damage sensor called ATR in a select group of B cells called germinal center, or GC, cells, which produce antibodies.

The researchers say Bcl-6 is beneficial to B cells that encounter foreign antigen and then undergo highly focused DNA mutations in antibody-encoding genes -- a process normally required to generate highly effective antibodies. However, such DNA mutations can lead to germinal center cell death, potentially reducing the production of useful antibodies.

Melnick's group said the finding shows Bcl-6 can suppress ATR gene activity, which effectively turns off the DNA damage sensor and leaves the mutated B cells less prone to DNA damage-induced death.

The study, which suggests manipulating Bcl-6 in lymphoma cells might render them more sensitive to irradiation, appears in this week's online issue of the journal Nature Immunology.