Too much of a good thing can be bad, even when it comes to a tumor-suppressing gene. Researchers report that mice with an overactive gene for a protein called p53, which checks inappropriate cell division and helps prevent cancer, prematurely suffer age-related conditions such as osteoporosis and die earlier than normal. This raises the prospect that there's a trade-off between tumor suppression and a long lifespan.
Lawrence A. Donehower of the Baylor College of Medicine in Houston and his colleagues were trying to produce mice with a disabled p53 gene when they accidentally created a mouse strain in which the gene is overactive. Mice lacking the p53 gene are cancer-prone, so it isn't surprising that the new mutant strain is much less likely than normal to develop tumors.