C-MYC AND C-FOS IN HUMAN OSTEOSARCOMA - PROGNOSTIC VALUE OF MESSENGER-RNA AND PROTEIN EXPRESSION

The c-myc and c-fos proto-oncogenes have several putative functions, i ncluding regulation of cell growth. In many neoplasms c-myc overexpres sion has been linked to poor prognosis. In order to study the role of c-myc and c-fos expression on the tumorigenesis, and the metastatic sp read of osteosarcoma, frozen and paraffin-embedded tissue 38 primary o steosarcoma and 10 lung metastases were analyzed. The mRNA analysis wa s performed by quantitative reverse transcription-polymerase chain rea ction and in situ hybridization. The protein expression was studied by Western blot analysis and immunohistochemistry. C-myc and c-fos were found overexpressed in a high percentage of the relapsed tumors and of the metastases, and overexpression of both oncogenes in the same tumo r was strongly correlated to the development of metastases (p < 0.05), as 6 of the 7 primary turners overexpressing both the oncogenes gave metastases. In conclusion, both c-myc and c-fos are involved in the gr owth and spread of osteosarcoma and a synchronous overexpression of bo th oncogenes is highly significant for a metastatic potential of a pri mary tumor.