These data suggest that mutational inactivation of the p53 gene occurs in a minority (20%) of sporadic adrenocortical carcinomas and that these mutations constitute a late event in the multi-step process of malignant transformation.
Allelic losses at the p53 and RB loci were detected in all tumor samples, suggesting that the p53 and RB genes are involved in the tumorigenesis of adrenocortical carcinoma.
There were marked organ-specific differences in the mean age at which carriers of p53 germline mutations present with neoplastic disease: 5 years for adrenocortical carcinomas, 16 years for sarcomas, 25 years for brain tumors, 37 years for breast cancer, and almost 50 years for lung cancer.
Germline p53 mutations carry an increased risk of development of breast cancer, soft tissue and osteosarcomas, brain tumors, leukemia and adrenocortical carcinomas.
Oncogenes and tumour-suppressor genes involved in adrenal carcinomas include mutations in the p53 tumour-suppressor gene and rearrangements of the chromosomal locus 11p15.5 associated with IGF II hyperexpression.
pH-sensitive molecular defect of p53 (R337H) suggests that pH-dependent p53 dysfunction is the molecular basis for cases of adrenocortical carcinoma in Brazilian children
Germline mutations of the p53 coding region are present in approximately 50-70% of patients with Li-Fraumeni Syndrome (LFS), a rare hereditary disorder of familial and intraindividual clustering of different malignancies such as sarcoma (index tumor), breast cancer, brain tumors, leukemias, and adrenocortical carcinomas, the latter usually in young children.
The tetramerization domain for wild-type p53 (p53tet-wt) and a p53 mutant, R337H (p53tet-R337H), associated with adrenocortical carcinoma (ACC) in children, can be converted from the soluble native state to amyloid-like fibrils under certain conditions.
Recently, a characteristic TP53 mutation at codon 337 (R337H) has been identified in the germline of children with adrenocortical carcinoma in Southern Brazil.