| IntroductionOsteosarcoma is a Commonly encountered disease. Its incidence rate was possible in 20% of osteoma. Os s cell - differentiation is poor and the post - operation survival rate is low. However, the mechanism underlying the development and progression of Os is not fully understood. Caspase - 3 is a member of ICE family. It plays an important role in the programmed cell death.Bcl - 2 is the Cancer gene of follicular B - cell lymphoma. The [ Bcl - 2 ] can stop releasion of cytochrome C and restrict the activity of cpp - 32. Then restrain pro grammed cell death. In some studies, the expression of Bcl - 2 and Caspase -3 is abnormal at the gastric Carcinoma, bladder Carcinoma and so on. There is relationship between their expression. But there is no resemble study in Os. In this study, immunohisto chemistry was used to detected the expression of Bcl - 2 and caspase - 3 in Osteosarcoma and osteochondroma. We analyse the relationship between the expression level and clinical data for the purpose to understand the role of Bcl - 2 and Caspase - 3 in the Occurrence and development of Osteosarcoma.Materials and MethodsTo collect 41 specimens of Os, 13 specimens of Oc placed on the file. For the Os, there were 23 women and 18 men, with a mean age of 25 (range from 11 to 50). There were 15 better differentiated Os and 26 poor differentiated Os.Four - micrometer - thick sections were cut from formalin - fixed paraffin -embedded tissue blocked and mounted on polylysine - coated glass sliders. Thepositive controls were sections of Lymph node ( Bel - 2 ) and tonsillar tissue ( Caspase - 3 ). Negative controls were sections stained without the primary antibody. Plasma that has immuno reactivity is yellow or brown. For each section, 10 high -power ( 400) microscopic fields were examined for 1000 cells. Bel -2/ Caspase -3: greater than 10% of cells showed immunoreactivity( + ) ; Bel -2/Caspase -3( - ) ;less than 10% of cells showed no immunoreactivity. The data were processed with the SPSS software applying chi - square test.ResultsFor the osteochondromas, 13 showed normal Caspase -3 expression. None showed normal Bel -2 expression. For the 41 Os, 19 showed normal Caspase -3 expression(46. 3% ). The rate of positive expression was significantly lower than that of Oc ( P <0.01). For the 41 Os, 14 showed normal Bel -2 expression (34.1% ). And the positive rate was significantly lower than that of osteochondromas.For the 41 Os, 19 showed normal Caspase -3 expression (46. 3% ). The positive rate was significantly higher in better - differentiated Os than that in lower - diff erentiated cases( P < 0. 05 ). The rate of normal expression was not associated with gender, age.There was significant association between the level of Bel - 2 expression and differentiation.For the 14 Os that expressed normal Bel - 2 level, 13 showed normal Caspase -3 expression (92.9% ); For the 27 OS that expressed decreased Bel -2 level, 22 showed decreased Caspase -3 expression(81.5% ). The correlation was found between the Caspase -3 and the Bel -2.DiscussionOver expression of Bel - 2 protein can restrict programmed cell death, then improve occurrence and development of tumor. In this study, We found that the positive rate of better - differentiated was significantly higher than that of lower-differentiated OS(P<0.01). In osteosarcomas, the positive rate of Bel -2 was significantly higher than that in osetochondromas. So we can conclude that Bel -2 plays an important role in occurrence of Os. Because the positive rate in better - differentiated was significantly higher than that in poor - differentiated, expression of Bel -2 is closely associated with the biological behavior of Os.Caspase -3 is an enzyme. It has two types:enzyme and pro - enzyme. Only enzyme can take effect to programmed cell death. Bel -2 can strict it& activity. In this study, we measured expression of caspase -3 and Bel -2 to detect their relationship and significance in Os.Some studies showed that Bel - 2 can restrict Caspase - 3, and the activated Caspase - 3 can reduce Bel - 2 protein as well. So the level of Bel - 2 expression can suggest the activity of caspase - 3. In this study, we founded that Caspase - 3 and Bel - 2 were co - expressed in Os and their expression in better — differentiated was stronger than that in lower - differentiated. This suggests that, in Os, programmed cell death is restrictedConclusionExpression of Bel - 2 in OC and better - differentiated OS is significantly high. This suggests that Bel - 2 restricts programmed cell death on early stage in Os, and closely associated with occurrence of Os. The down - regulation of Caspase -3 expression is a common event in Os. So it is associated with occurrence and development of Os. Caspase - 3 and Bel - 2 were co - expressed in Os. This suggests that, In Os, the programmed cell death s restriction is a result of their mutual action.
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