p53 Autoantibodies and Cancer: Specificity, Diagnosis and Monitoring

Publisher Summary p53 is called the guardian of the genome . Its protein participates in the regulation of the cell-cycle, acts as transcriptional transactivator/repressor, helps in DNA repair, suppresses cell growth, induces apoptosis, and functions in numerous other ways. During carcigenosis, there is loss of normal p53 functions. This is because of missense point mutation of p53 gene with dominant-negative effects; and nonmutational mechanisms that include complex formation with viral oncoproteins in virus-induced carcinogenesis, overexpression of the mdm2 protein in sarcoma, and inactivation of the dislocated nuclear p53 protein in the cytoplasm. This chapter describes the anti-humoral immune response and clinical significance of p53 autoantibodies. p53AAb are found to be associated mainly with solid tumors of the epithelias (carcinoma), or at reduced frequencies with the lymphatic system. p53 autoantibodies predates the diagnosis of cancer by months or years. These are detected in individuals at high risk of cancer and represent a very early marker for tumorigenesis. The chapter describes the use of p53 autoantibodies in the monitoring of cancer patients.