| PREFACEBurnet and Thomas proposed immune surveillance theory in 50 s and 60 s this century. Immune system could recognize and kill tumor cells by immune effective cells such as TIL, LAK, and NK. Furthermore , escape from the immune surveillance may play an important role in tumor outgrowth and metastasis in some cases.Osteosarcoma is the commonest primary malignant tumor of bone. Osteosarcoma is highly malignant with bad prognosis that lacks effective therapy to date. The five - year - survival rate of osteosarcoma is only 17% ~ 20%. The morbidity of giant cell tumor of bone is only minor to osteochondroma in China. It is a low malignant or potential malignant tumor. There are no effective items for diagnosis, pathological grades, therapy and prognosis judgement of these two bone tumors till now.MATERIALSAll cases were from Department of Pathology, China Medical University, and from 1989 - 1999, including 30 osteosarcoma, 47 giant cell tumor of bone and comparied to 24 osteochondroma. Giant tumor of bone was divided into two groups by Jaffe grading, including 38 grade I , E and 9 grade HI of giant cell tumor of bone. Tumor tissue was resected at the same time SJJLHI section and S - P method used. A-gents in this experiment, Fas/FasL polyclonal antibodies were from Santa Cruz company U.S.A. and S - P was from Zymed company U.S.A.METHODSThe samples were fixed with 10% formalin in for 48 hours, embedded with paraffin wax, sectioned for 5|xm, and heat repaired for immunohistochemistry stain ( SP method). PBS instead of the first antibody was applied as negative control. 200 cells were counted in HPF. 4 HPFs should be available. The positive expression was the cell in which brown - yellow particles scattered within cytoplasm, cell membraneor cell nucleus. The degree of positive was reflected by the percentage of positive cells. We applied x test to analysis the correlation between Fas, FasL and osteosarcoma, giant cell tumor of bone. The correlation of them was analyzed to explore their roles in occurring and development of bone tumors.RESULTSThe positive rate of Fas in 30 osteosarcoma in this study was 40. 0% , and 72.3% in giant cell tumor of bone. It was 62.5% expressed in 24 osteochondroma. No significant differences could be seen between osteosarcoma and osteochondroma and between osteochon -droma and giant cell tumor of bone. The positive rate of Fas in grade I , fl of giant cell tumor of bone was 78. 9% , and 44. 4% in grade III. There was statistic difference between giant cell tumor of bone . The positive rate of FasL in 30 osteosarcoma was 90. 0% , 55. 3% in giant cell tumor of bone, and 50. 0% in osteochondroma. There was statistic difference between osteosarcoma and osteochondroma, and nostatistic difference between giant cell tumor of bone and osteochondro-ma. The positive rate of FasL in grade I , H of giant cell tumor of bone was 47.4% , and 88. 9% in grade HI. The difference between them was prominent.DISCUSSIONResults from some studies have recently revealed that the Fas/ FasL system has been identified as a key regulator of apoptosis in some normal tissues. The dynamic balance between the proliferation and death is important for normal cell life cycle. Fas protein is known to induce cell death by apoptosis in susceptible cells. Apoptosis induced by Fas ligation is frequendy lost during tumor progression. Dysfunction of the interaction between Fas and FasL may contribute to development and progression of autoimmune diseases and neoplasms. Human Fas gene lies in 10q24.1, about 70kb. Its product, Fas protein is a kind of I type transmembrane protein composed of 335 aminoacids and a-bout 40kda. Fas is a kind of signal receptor of cell apoptosis. Human FasL gene lies in 1 chromosome about 45 kda. Its product, Fas ligand distributes among activated T cell membrane and has the same amino-acid sequence as II type transmembrane glycoprotein. Ligation of Fas and FasL could induce the apoptosis of susceptible cells. Despite being infiltrated by TIL, these TIL are un... |
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