Runnebaum I B, Nagarajan M, Bowman M, Soto D, Sukumar S
Molecular Biology of Breast Cancer Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037.
Proc Natl Acad Sci U S A. 1991 Dec 1;88(23):10657-61. doi: 10.1073/pnas.88.23.10657.
Based on the high incidence of loss of heterozygosity for loci on chromosome 17p in the vicinity of the p53 locus in human breast tumors, we investigated the frequency and effects of mutations in the p53 tumor suppressor gene in mammary neoplasia. We examined the p53 gene in 20 breast cancer cell lines and 59 primary breast tumors. Northern blot analysis, immunoprecipitation, and nucleotide sequencing analysis revealed aberrant mRNA expression, over-expression of protein, and point mutations in the p53 gene in 50% of the cell lines tested. A multiplex PCR assay was developed to search for deletions in the p53 genomic locus. Multiplex PCR of genomic DNA showed that up to 36% of primary tumors contained aberrations in the p53 locus. Mutations in exons 5-9 of the p53 gene were found in 10 out of 59 (17%) of the primary tumors studies by single-stranded conformation polymorphism analysis. We conclude that, compared to amplification of HER2/NEU, MYC, or INT2 oncogene loci, p53 gene mutations and deletions are the most frequently observed genetic change in breast cancer related to a single gene. Correlated to disease status, p53 gene mutations could prove to be a valuable marker for diagnosis and/or prognosis of breast neoplasia.
基于人类乳腺肿瘤中17号染色体短臂上p53基因座附近杂合性缺失的高发生率，我们研究了乳腺肿瘤中p53肿瘤抑制基因突变的频率和影响。我们检测了20个乳腺癌细胞系和59个原发性乳腺肿瘤中的p53基因。Northern印迹分析、免疫沉淀和核苷酸测序分析显示，在所检测的50%的细胞系中，p53基因存在异常mRNA表达、蛋白过度表达和点突变。我们开发了一种多重PCR检测方法来寻找p53基因座的缺失。基因组DNA的多重PCR显示，高达36%的原发性肿瘤在p53基因座存在畸变。通过单链构象多态性分析，在59个原发性肿瘤中有10个（17%）发现了p53基因第5至9外显子的突变。我们得出结论，与HER2/NEU、MYC或INT2癌基因座的扩增相比，p53基因突变和缺失是乳腺癌中与单个基因相关的最常见遗传改变。与疾病状态相关，p53基因突变可能被证明是乳腺肿瘤诊断和/或预后的一个有价值的标志物。
