Navone N M, Labate M E, Troncoso P, Pisters L L, Conti C J, von Eschenbach A C, Logothetis C J
Department of Genitourinary Medical Oncology, The University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
J Urol. 1999 Jan;161(1):304-8.
This study was undertaken to establish the pattern of specific p53 gene mutations in prostate cancer within primary tumors and distant metastases.
We performed polymerase chain reaction-single-strand conformation polymorphism and sequencing analyses of p53 exons 5-8 in DNA extracted from 22 formalin-fixed, paraffin-embedded tissues from 17 patients. Samples from three patients included specimens from primary and metastatic sites (paired specimens).
G:C-to-A:T transitions were the most common point mutations (64%). Six (55%) of 11 G:C-to-A:T transitions occurred at CpG dinucleotides in five hot-spot codons (175, 245, 248, 273, and 282). Sequencing analysis of the paired samples revealed that two of the three pairs had the same mutation in both. Sequencing analysis of DNA from a different area of one of the primary tumors revealed a different mutation in the p53 gene.
Our results suggest that specific p53 mutations participate in the progression of human prostate cancer. These findings support those of others that indicate that the primary cancer is heterogeneous and clonal expansion occurs during the progression of clinically detectable prostate cancer. Our data also imply that p53 mutations at the primary site may be predictive of metastases.
本研究旨在确定原发性肿瘤和远处转移灶中前列腺癌特定p53基因突变模式。
我们对17例患者的22份福尔马林固定、石蜡包埋组织提取的DNA进行了p53基因第5至8外显子的聚合酶链反应-单链构象多态性及测序分析。3例患者的样本包括来自原发部位和转移部位的标本(配对标本)。
G:C到A:T的转换是最常见的点突变(64%)。11个G:C到A:T的转换中有6个(55%)发生在5个热点密码子(175、245、248、273和282)的CpG二核苷酸处。配对样本的测序分析显示,3对中有2对在两个部位均有相同突变。对其中一个原发性肿瘤不同区域的DNA进行测序分析,发现p53基因存在不同突变。
我们的结果表明特定的p53突变参与了人类前列腺癌的进展。这些发现支持了其他人的研究结果,即原发性癌症具有异质性,且在临床可检测的前列腺癌进展过程中会发生克隆性扩增。我们的数据还表明,原发部位的p53突变可能预测转移。