Detection of p73 antibodies in patients with various types of cancer: immunological characterization

• Published in: British journal of cancer Vol. 84; no. 1; pp. 57 - 63
• Main Authors: TOMINAGA, O, UNSAL, K, ZALCMAN, G, SOUSSI, T
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing Group 05-01-2001
• Subjects: Antibodies; Antibodies, Neoplasm - analysis; Biological and medical sciences; Breast Neoplasms - blood; Breast Neoplasms - immunology; Cancer research; Case-Control Studies; Cross Reactions - immunology; DNA-Binding Proteins - immunology; Epitope Mapping - methods; Follow-Up Studies; Genes, Tumor Suppressor; Head and Neck Neoplasms - blood; Head and Neck Neoplasms - immunology; Host-tumor relations. Immunology. Biological markers; Humans; Immunology; Lung Neoplasms - blood; Lung Neoplasms - immunology; Medical research; Medical sciences; Membrane Proteins; Mutation; Neoplasms - blood; Neoplasms - immunology; Nuclear Proteins - immunology; p73 protein; Phosphoproteins - immunology; Proteins; Regular; Trans-Activators; Transcription Factors; Tumor Protein p73; Tumor Suppressor Protein p53 - immunology; Tumor Suppressor Proteins; Tumors; Human; TP53 Gene; Immune response; Antibody; Gene product; Homology; Malignant tumor; Humoral immunity; Tumor suppressor gene
• ISSN: 0007-0920; 1532-1827; 1532-1827
• DOI: 10.1054/bjoc.2000.1542

p53 antibodies have been found in the sera of patients with various types of cancer. The presence of these antibodies is generally associated with p53 accumulation in the tumour that is believed to trigger this humoral response. The recent discovery of 2 new members of the p53 family, p73 and p63, led us to study the specificity of this immune response towards the 3 proteins. Serum samples from 148 patients with various types of cancer were tested for antibodies against p73 and p63 using immunoprecipitation. 72 patients were previously shown to have p53 antibodies whereas 76 were negative. The control group consisted of 50 blood donors. p73 were detected in 22/148 (14.9%) of the cancer patients (11/72 in the group with p53-antibodies and 11/76 in the negative group). Only two sera from the control (4%) were positive. p63 antibodies were detected in only 4/148 (2.7%) of the cancer patients. Epitope mappings were performed and demonstrate that p73 antibodies are directed toward the central region of the p73 protein whereas p53 antibodies react predominantly toward the amino- and the carboxy-terminus of p53. Our results indicate that there is a specific immune response toward the p73 protein in cancer patients, a finding supported by an increasing number of publications describing p73 accumulation in tumoral cells.