| Tumor has been regarded as one type of common disease that harm the human health and one main reason that lead to death. Bone tumors, especially invasive bone tumors, are always happening to young adults with active skeletal development. Invasive bone tumors are always highly malignant, which develop fast and have bad prognosis. The studying of the biological behavior and pathogenic mechanism of invasive bone tumors has much significance in reality.The most significant characteristic of tumor, especially malignant tumor, is the persistent abnormal proliferation of tumor cell which is incoordinate to that of the whole body. This kind of disease could be classified into cloning gene disease from molecular genetics. Why this kind of malignant tumor has the characteristic of unlimited growth lost controlling? The discovery and the research of telomerase (TLMA) in the recent years has given an reasonable explanation to it. This not only enriches our knowledge about the initiation and the development of tumors, but also provides new considerations and inspirations to the gene therapy of tumor. This also gives some hope for human beings of curing tumor at last.Telomearse is one kind of ribonucleoprotein DNA polymerase in charge of the synthesis of telomere. Telomere is the natural terminus of eukaryotic chromosome. It is composed of DNA and protein. The research of the relationship betweentelomere, telomerase and tumor has drawn much attention in the recent years. Tumor cells, especially malignant tumor cells, always obtain immortality, which lead to the capacity of unlimited proliferation. The ability of unlimited proliferation of tumor cells depened on the activation of telomerase. Lots of researches have shown that abnormal high level expression of telomerase could be found nearly in all kinds of malignant tumors. As the research of telomerase activity in bone tumors is concerned, there only has the report of Schwartz in telomerase detection from the cells of giant cell tumor of bone in 5 cases and that of Butler from the cells of chordoma in lumbarosarcral region in 2 cases. There still has no report of whether there is some certain connection between the overexpression of bcl-2 and bax, gene mutation of p53 and the activation of telomerase.In this research, telomerase activity was detected by TRAP silver staining method in osteogenic cells in vitro or in many kinds of invasive bone tumor tissues. Expression of bcl-2, bax and p53 were detected immunohistochemically. The following are the main results.1 .Telomerase activity in 75 frozen preserved bone tumor samples was detected by TRAP silver staining. The result showed that 62 (82.7%) cases were positively stained, in which 29 cases (80.6%) were osteosarcoma, 20 cases (85.7%) were chondrosarcoma, 2 cases (100%) were malignant fibrous histiocytoma, 2 cases (100%) were rhabdomyosarcoma and the left 3 cases (100%) were chordoma. Of the other 9 cases chondroma, only 1 (11.1%) case was positively detected. Telomerase activity in muscle tissues or soft tissues beside the invasive bone tumor tissues in 17 cases was also detected without any positive finding.2. Detection result of different grade telomerase activity in giant cell tumor of bone 25 cases of giant cell tumor of bone were divided into three grades according to thenumber of multinucleus giant cells and the form of mononucleus stromal cells, in which 8 cases were belong to grade I, 17 cases were belong to grade II-EEL The detection results of telomerase activities in different grade giant cell tumors of bone have no obvious difference statistically (p>0.05).3.Detection result of telomerase activity in osteogenic cells in vitro by TRAP silver staining. Telomerase activity was not detected in 3 normal periosteum cells, aneurismal bone cyst at 102 passages cultivated after treatment with carcinogen 4-NQO, and human osteosarcoma cell line (OS732). However, another human osteosarcoma cell line (HOS) expressed the activity of telomerase.4. Expression of bcl-2 and bax in osteosarc...
|
PDF Full Text Request