骨肉瘤中Rb、p16、CDK4、cyclinD1蛋白的表达及其意义

目的 探讨骨肉瘤中Ｒｂ、ｐ１６、ＣＤＫ４、ｃｙｃｌｉｎＤ１的蛋白表达、相互关系及其意义。方法 应用免疫组化方法对４０例骨肉瘤组织中Ｒｂ、ｐ１６、ＣＤＫ、ｃｙｃｌｉｎＤ１的蛋白表达状况进行检测。结果 ４０例骨肉瘤Ｒｂ、ｐ１６蛋白表达缺失分别为７２．５％（２９／４０和）２２．５％（９／４０）;１１例ｐＲｂ阳性的骨肉瘤中的８例ｐ１６阴性,２９例ｐＲｂ阴性的骨肉瘤中２８例ｐ１６阳性;５２．５％（２１／４０

Significance of Rb,p16,CDK4 and cyclinD1 expression in osteosarcomas

Objective: To evaluate the significance of Rb, pl6, CDK_4 and cyclinD_1 protein expression in osteosarcomas and the relationship among these proteins. Methods: A total of 40 cases of osteosarcomas were examined for pRb, pl6, CDK_4 and cyclinD_1 expression using immunohistochemistry. Results: There were 29 (72. 5% ) and 9 (22.5% ) cases lack of pRb and pl6 expression, respectively. In 11 pRb positive cases, 8 were negative for pl6. In contrast, in 29 pRb negative samples, 28 were positive for p16. CDK4 overexpression was observed in 52.5% (21/40) osteosarcoma specimens. Of the 11 pRb positive osteosarcomas, CDK_4 overexpression was appeared in 8 cases although 3 cases were faintly positive. Overexpression of CDK_4 was also observed in 3 cases of osteosarcomas which were both pRb and p16 positive. The percentage of total abnormality for pRb, pl6 and CAK_4 expression in our 40 osteosarcomas was 100%. Overexpression of cyclinD_1 was not observed in these osteosarcomas. Conclusions: (1) Loss of pRb and overexpression of CDK_4 are common molecular events in osteosarcoma. (2)There is a negative correlation between pl6 and pRb protein expression in osteosarcoma. (3)In pRb positive osteosarcomas, loss of pl6 and /or overexpression of CDK_4 may play a critical role in the hyperphosphorylation of pRb resulting in uncontrolled cell proliferation. (4)The abnormality of p16-CDK_4-pRb pathway is highly related to the pathogenesis of osteosarcoma.