Molecular analysis of mutations in thyroid tumors with TGGE

Immunohistochemical demonstration of overexpression of the p53 protein indicates a mutational alteration of the gene. Our own investigations of 59 differentiated thyroid carcinomas revealed an overexpression in 15% of the tumors. A correlation to unfavourable tumor prognosis was found (stage I and II: 0/11 (0%); stage III: 4/26 (14%); stage IV: 5/22 (23%)). For screening of one out of more than 300 possible mutations temperature gradient gel electrophoresis was employed. Analysis of the highly-conserved regions of the p53 gene (exon 5 to 8) could demonstrate a mutation in only 1 out of 31 differentiated thyroid carcinomas. The question arises whether accumulation of the protein is due to a mutational event or rather other molecular mechanisms.