Skilling J S, Sood A, Niemann T, Lager D J, Buller R E
Department of Obstetrics and Gynecology, University of Iowa Hospitals and Clinics, Iowa City, 52242, USA.
Oncogene. 1996 Jul 4;13(1):117-23.
Ovarian cancers from 64 midwestern US women were screened for p53 dysfunction both by immunohistochemical staining (IHCS) and single strand conformation polymorphism (SSCP) analysis of the entire open reading frame (ORF). Forty SSCP abnormalities in 39 tumors included nine deletion, one insertion, two splice junction, two nonsense, one silent and 25 missense mutations were confirmed by direct genomic sequencing. Eight of the insertion/deletion defects may have occurred due to slippage during the course of DNA replication. This observation suggests that genomic instability may play an important role in ovarian carcinogenesis. Fifteen percent of the mutations encountered were located outside exons 5-9 and four of these were null. The sensitivity of IHCS was 96% for missense mutations but only 14% for null mutations. This contrasted with 100% sensitivity of the SSCP screening methodology. The 21% overall incidence of null mutations in the present study far exceeds the reported 6.8% incidence in the world literature (P=0.0003). Explanations for this difference include: (1) our complete analysis of the entire ORF of the p53 gene; (2) the tendency of others to rely upon IHCS to screen tumors prior to mutation analysis; and (3) environmental or endogenous genetic influences.
对来自美国中西部64名女性的卵巢癌进行了p53功能障碍筛查，采用免疫组织化学染色（IHCS）和对整个开放阅读框（ORF）进行单链构象多态性（SSCP）分析的方法。39个肿瘤中的40个SSCP异常包括9个缺失、1个插入、2个剪接位点、2个无义、1个沉默和25个错义突变，经直接基因组测序得以证实。8个插入/缺失缺陷可能是由于DNA复制过程中的滑动所致。这一观察结果表明，基因组不稳定性可能在卵巢癌发生过程中起重要作用。所遇到的突变中有15%位于外显子5 - 9之外，其中4个为无效突变。IHCS对错义突变的敏感性为96%，但对无效突变仅为14%。这与SSCP筛查方法100%的敏感性形成对比。本研究中无效突变的总体发生率为21%，远远超过世界文献报道的6.8%的发生率（P = 0.0003）。造成这种差异的原因包括：（1）我们对p53基因整个ORF的完整分析；（2）其他人在进行突变分析之前倾向于依靠IHCS来筛查肿瘤；以及（3）环境或内源性遗传影响。
