Molecular Pathologic Researches Of Gene Changes In Giant Cell Tumor Of Bone

Giant cell tumor of bone (GCT) is a potential malignant, primary bone neoplasm that constitutes 15% of all primary bone tumors in China. It is often difficult for pathologic diagnosis and treatment because of its unpredictable pattern of biologic aggressiveness. GCT has a high rate of chromosome aberration and the aberration frequently involves chromosomes 9-22 in which there are many important loci of oncogenes such as p53, bcl-2, c-Abl, c-fos, nm23, and MDM2 which were respectively localized in 17pl3, 18q21, 9, 14, 17q and 12ql3-14. It has not been reported about the expression condition and relationship among these genes, and whether these oncogenes are to be influenced in the aberration of chromosomes in GCT. Therefore, to investigate the molecular markers which is closely related to tumor phenotype and to detect the effects of oncogene changes in tumorigenesis are very significant in theory and practice.The expression of those gene products and mRNA levels were examined by immunohistochemical method and in situ hybridization technique. The primary culture was established and the growth character in vitro, cell types, DNA flow cytometry and ultrastructure of tumor cells were also observed. Meanwhile, the tissue origin of the tumor was discussed, and the cytogenetic changes were further investigated. The localization of p53, bcl-2, c-fos, nm23 and MDM2 oncogenes in aberrant chromosomes was detected by FISH and PRINS technique. The results show:1. The positive expression of all genes was observed in GCT and the expression level was different. The level was lower in p53 and c-fos, moderate in bcl-2 and nm23, and high in MDM2 and c-Abl. The results suggest that all these oncogenes were involved in oncogenesis and development of GCT but with different biological effects. The p53 and c-fos may have the loss of gene phenotype in GCT. The high level expression of MDM2 and c-Abl may be related to oncogenesis because MDM2...