CHARACTERIZATION AND CLINICOPATHOLOGICAL CORRELATES OF SERUM ANTI-P53ANTIBODIES IN BREAST AND COLON-CANCER

The humoral immune response to p53 was determined in 54 individuals wi th colon or breast cancer and 50 healthy subjects, in an attempt to be tter understand the origin and significance of anti-p53 serum antibodi es. The presence of anti-p53 antibodies in serum was determined by enz yme-linked immunosorbent assay using purified recombinant human p53, a nd results were validated by immunoprecipitation of radiolabelled p53. Immunohistochemical analysis of 28 tumours was performed to detect th e accumulation of p53 protein. Antibodies against p53 were significant ly more common in patients with colorectal (10 of 42) and breast (2 of 12) cancer than in healthy individuals (2 of 50). They were of both t he IgM (7 of 11) and IgG (4 of 11) isotypes. There was no significant difference in prevalence of serum antibodies against p53 with respect to the p53 immunohistochemical status of the tumour or to other pathol ogical features, including the presence of lymph node and distant meta stases. These findings provide indirect evidence that, rather than ari sing as a result of a specific immune response, anti-p53 antibodies in individuals with cancer may represent elevated levels of naturally oc curring polyreactive antibodies.