The immune response against p53 protein in cancer patients /

• Main Author: Naor, Naftaly
• Format: Others
• Language: en
• Published: McGill University 1993
• Subjects: Immune response.; Phosphoproteins.; Cancer > Genetic aspects.
• Online Access: http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69652

Mutations in the p53 gene are known to be associated with a wide range of human tumors. In some primary tumors and established cell lines, stable mutant p53 protein is expressed at high levels, whereas, in normal cells unstable wild-type p53 protein is expressed at very low levels. Sera from some patients with breast and colon tumors contain anti-p53 antibodies. It is unclear whether changes in p53 structure, or its increased level in tumors, causes p53 to become antigenic. In our study we tested sera from patients with various types of cancer for anti-p53 antibodies. Examination of the sera was made by Western blot, and the results were confirmed by rescreening sera with immunoprecipitation. Both techniques revealed the presence of anti-p53 antibodies in some sera from lung and ovary cancer patients, as well as in the sera from patients with breast or colon cancers. Clearly, patients with various cancer tumors are able to produce anti-p53 antibodies. It was unclear whether this humoral immune response is against mutant or wild type p53. To provide a better definition of this immune response, we have examined the anti-p53 response from cancer patients against mutant and wild type p53 in the native and denaturated state. Western blot and Immunoprecipitation analysis showed that the anti-p53 sera recognise both wild type and mutant p53 conformational and denaturation resistant epitopes. Taken together, these data demonstrate that the mutant p53 is not more antigenic than the wild type p53. This provides strong evidence that the antibody response is not directed solely against the altered conformation in mutant p53.