Introduction and Objectives: Osteosarcomas are the most frequent malignant primitive bone tumors. Since 1980, the management of osteosarcomas has changed due to the introduction of neoadjuvant chemotherapy which allows limb salvage surgery to be performed. Nur77 is a transcription factor (nuclear receptor superfamily), when it migrates from the nucleus to the mitochondria and interacts with molecule Bcl2, it converts it into a pro-apoptotic substance that mediates the apoptotic effects of certain chemotherapeutic agents. In our study we quantify, in a relative way, the expression of the gene Nur77 in osteogenic osteosarcomas. Procedures that increase its expression and induce its translocation could increase the efficacy of chemotherapeutic agents.

Materials and Methods: We took 10 frozen samples (6 osteogenic osteosarcomas, 2 metastases, 2 normal tissues) and reviewed the patient’s clinical history (age, diagnosis, treatment, evolution and degree of tumor necrosis). After extracting total RNA and synthesizing cDNA from each sample, we quantified the level of expression of the gene Nur77 by means of real-time PCR.

Results: We analyzed the results using the delta-delta Ct method approximation analysis and analysis relative to normal data.

Discussion and Conclusions: We observed heterogeneous behavior with reference to gene Nur77 expression. Those tumors that had Nur77 expression values lower than that of normal tissue seemed to respond worse to chemotherapy. This suggests, preliminarily, an association between the expression of Nur77 and the response to chemotherapy.