University of Minnesota cancer researchers have discovered that an inherited mutation in a DNA replication gene may increase breast cancer risk.
The gene, Mcm4, encodes one of six related Mcm proteins whose purpose in the body is copying or replicating DNA. The identified genetic abnormality appears to impair the DNA replication processes. When studying female mice that had the mutation, nearly all formed breast tumors.
Mcm proteins are already extensively studied as a cancer marker, because cancer cells retain a higher level of Mcm proteins than normal cells.
"Our discovery demonstrates for the first time a link between an inherited mutation in a Mcm gene and breast cancer predisposition," Dr. Naoko Shima said, adding, "This discovery may provide an important clue to understanding the genetic mechanism of developing breast cancer, because Mcm genes have not previously been linked with breast cancer. What our discovery potentially means is that women who are found to have a similar abnormal genetic change in Mcm genes may also be predisposed to getting breast cancer."
Dr. Naoko Shima is an assistant professor and researcher with the University of Minnesota Medical School and Cancer Center.
Her team's findings are published in the Dec. 27, 2006, issue of the journal Nature Genetics.
The next steps in the research will include investigating the reasons why mice with mutant Mcm4 genes are prone to developing mammary tumors and then corroborating those laboratory finding in humans.