骨肉瘤组织中p16 基因的缺失突变及CDK4 基因的扩增(英文)

Deletion,mutation of p16 gene and CDK4 gene amplification in osteosarcoma

目的 确定在原发性骨肉瘤中是否有ｐ１６ 基因的异常及ｐ１６ 基因异常与ＣＤＫ 基因扩增之间的关系。方法 应用定量Ｓｏｕｔｈｅｒｎ ｂｌｏｔ 方法分析确定ｐ１６ 基因的缺失及ＣＤＫ 基因的扩增。用ＰＣＲＳＳＣＰ（ｐｏｌｙｍｅｒａｓｅｃｈａｉｎ ｒｅａｃｔｉｏｎ ａｎｄｓｉｎｇｌｅｓｔｒａｎｄ ｃｏｎｆｏｒｍａｔｉｏｎ ｐｏｌｙｍｏｒｐｈｉｓｍ） 方法检测ｐ１６ 基因突变。结果 在６０ 例分析ｐ１６ 基因的标本中有５ 例（９％ ）存在ｐ１６ 基因的重排或缺失。均发生于原发肿瘤。在６７ 例分析ＣＤＫ４ 基因的标本中，有６ 例（９％ ）存在ＣＤＫ４ 基因的扩增，包括３ 例原发及３ 例转移的骨肉瘤标本。ｐ１６ 基因异常及ＣＤＫ４ 基因的扩增发生于不同的骨肉瘤标本中，未见相互重叠。在４６ 例同时进行ｐ１６ 及ＣＤＫ４ 基因分析的标本中，２２ ％ 的标本有二者其一的的异常。结论 结合以前的报道，７５ ％ 的骨肉瘤有Ｒｂ 基因的异常提示细胞周期中Ｇ１ 到Ｓ期的异常是骨肉瘤发病机制的特征。

Objective To examine INK4A gene alterations in uncultured samples of osteosarcoma and the relationship between INK4A and CDK4 alterations, INK4A and CDK4 genes were analysed in 87 specimens. Methods INK4A deletion and CDK4 gene amplification were determined by quantitative Southern blot analysis. INK4A exon 2 was screened for mutation by polymerase chain reaction and single strand conformation polymorphism analysis. Results INK4A deletion(4/60) or rearrangement (1/60) was found in 5 of 60 cases(9%), all in primary tumors. CDK4 gene amplification was found in 6 of 67 samples(9%),including 3 primary and 3 metastatic tumors, all from different patients, but not in tumors with INK4A alteration. Of 46 patients studied for both INK4A alterations and CDK4 amplification,the tumors in 22% contained one or the other. Conclusion The prevalence of these alterations, in combination with the reported inactivation of Rb in up to 75% of cases suggests that genetic lesions deregulating the G1 to S cell cycle checkpoint may be the feature in the pathogenesis of osteosarcoma.