In this study, 21 cases of low-grade central osteosarcoma were analyzed for mutations of the p53 gene, amplification of the MDM2 gene, and mutations of the H-ras gene using formalin-fixed, paraffin-embedded materials.
While p53 mutations and MDM2 amplification have been reported to occur in rhabdomyosarcoma and osteogenic sarcoma, the incidence of MDM2 in other pediatric solid tumors is not known.
We and others have previously described murine models of osteosarcoma based on osteoblast-restricted Cre:lox deletion of Trp53 (p53) and Rb1 (Rb), resulting in a phenotype most similar to fibroblastic osteosarcoma in humans.
Germline p53 mutations carry an increased risk of development of breast cancer, soft tissue and osteosarcomas, brain tumors, leukemia and adrenocortical carcinomas.
The current findings demonstrated compellingly that the TP53R337H mutation is associated not only with ACT but also with CPC and, to a lesser extent, with osteosarcoma, both of which are core-component tumors of the Li-Fraumeni syndrome.
To determine the relation between COPS3 amplification, P53 mutation, and patient outcome in osteosarcoma, tumors from a large cohort of patients with high-grade osteosarcoma and long-term clinical follow-up were examined.
This study warrants a future evaluation of this formulation for gene silencing efficiency of mutant p53 in tissue culture and animal models for the treatment of osteosarcoma.
A similar proportion of localized osteosarcomas had alterations of the p53 gene (55 of 247 specimens; 22.3%) compared with tumors from patients who had metastases at the time of diagnosis (5 of 25 specimens; 20%; P = 0.96).
Some of the genetic changes identified were in tumor suppressor genes previously identified as altered in osteosarcoma: p53 (arginine→histidine at codon 273 [R273H], R→cysteine at codon 723 [R273C], and tyrosine→C at codon 163 [Y163C]) and retinoblastoma 1 (RB1) (glutamic acid→* at codon 137 [E137*]).
This study found an association between alterations in the TP53 gene and the synergy score for combination treatment with doxorubicin and an Src kinase inhibitor using human osteosarcoma cell lines (MG63 and U2OS) and human colon cancer cell line.
By utilizing the clinical information in GSE21257, 10 critical genes associated with osteosarcoma prognosis were obtained, including CTP synthase 2 (CTPS2), tumor protein p53 inducible protein 3 (TP53I3) and solute carrier family 1 member 1 (SLC1A1).
The study provides evidence supporting the association of MDM2 SNP309 with high-grade osteosarcoma risk in females and shows that TP53Arg72Pro has a prognostic value for overall survival and EFS in osteosarcoma patients.
The data presented here demonstrate the importance of genetic and epigenetic alterations in the INK4a/ARF locus for the growth of osteosarcoma and thus will be useful to further understand the biologic behavior of osteosarcoma in association with the defects in the p53 and RB pathways.
In a survey of 134 human carcinomas, sarcomas, leukemias, and lymphomas obtained at surgery or from peripheral blood, we found rearrangements of the p53 gene only in osteogenic sarcomas (3 of 6 osteogenic sarcomas examined).
Overexpression of COPS3 has been linked to TP53 protein degradation and, being equivalent to TP53 mutation, the induction of genomic instability, which frequently occurs in high-grade osteosarcoma.
TP53 mutations were detected in 12 cases (five osteosarcomas, four MFHs, and three leiomyosarcomas), of which none showed amplification, but one had increased levels of MDM2 mRNA.