MUTATIONAL ACTIVATION OF N-RAS-12 GENE IS ABSENT IN PEDIATRIC OSTEOSARCOMA

Activation of ras oncogenes is found in human cancers, overall it is observed in 151 of all neoplasms. OBJECTIVE: The purpose of this study was to assess the extent of involment of ras oncogenes in osteosarcoma. STUDY DESIGN: Tumor samples from a series of 53 pediatric patients diagnosed of osteosarcoma and treated at our institution were evaluated. Parraffin-embedded tumor samples from diagnostic biopsies, from tissue of tumor en bloc resection after neoadjuvant chemotherapy, and samples from metastases were examined for point mutations at the N-ras-12 gene by means of polymerase chain reaction (PCR), slot-blotting, and radioactive labelled specific DNA probes. RESULTS: A total of 133 archival samples were studied. No point mutations activating the N-ras-12 gene were found. CONCLUSIONS: In order to exclude the potential role of the ras gene family in the development of ostesarcomas codon 61 of the N-ras gene and codons 12 and 61 of genes H-ras and K-ras must evaluated. These studies are been performed. Archival tumor samples are adequate for PCR amplification. PCR greatly facilitates the study of oncogene activation in tumor samples.