Human tumor suppressor p53 and DNA viruses.

Human tumor suppressor protein p53 plays a major role in the cell cycle, orchestrating a number of important genes involved in cell-cycle control and apoptosis, and seems to be one of the most important molecules protecting cells from malignant transformation. Mutations in the p53 gene are observed in about 50% of primary tumors, inducing defective p53 protein no longer capable of binding DNA and of activating transcription. Certain DNA viruses are thought to act in a similar way and may also contribute to the progression of invasive cancer in infected tissue. One of the most effective strategies employed by these viruses is the inhibition of p53 protein by interaction with viral oncoproteins, implying a direct but also an indirect role of these viruses in the impairment of p53 structure and function. This article provides a summary of current knowledge concerning p53 tumor suppressor protein and reviews the different mechanisms adopted by different DNA viruses in undermining p53 function.