Bookstein R, MacGrogan D, Hilsenbeck S G, Sharkey F, Allred D C
Department of Molecular Biology, Canji, Inc., San Diego, California 92121.
Cancer Res. 1993 Jul 15;53(14):3369-73.
Inactivation of p53, a tumor suppressor gene, contributes to the genesis and/or progression of a substantial fraction of all human cancers, including > or = 50% of breast, lung, and colon carcinomas. Mutated p53 alleles typically contain missense single-base substitutions within exons 5-8 and encode abnormally stable p53 proteins that accumulate to high levels in tumor cell nuclei. To evaluate the frequency, type, and clinical significance of p53 mutation in human prostate cancer, archival tumor material from 150 prostate cancer patients was examined by immunohistochemistry (IHC) with anti-p53 antibodies. Abnormal nuclear p53 accumulation (IHC) was observed in 19 tumors (12.7%) and was strongly related to disease stage (23% of 69 stage III or IV tumors were IHC+ versus 4% of 74 stage 0-II tumors; P < 0.001, Fisher's exact test). The methods of polymerase chain reaction, single-strand conformational polymorphism, and direct sequencing were used to identify mutations, predominantly missense single-base substitutions in exons 5, 7, or 8 in 9 of 14 IHC+ cases but in none of 20 IHC- cases; 5 of these mutations were G:C-->A:T transitions at CpG dinucleotides. These data indicate that mutated p53 alleles are quite uncommon in early prostate cancers but are found in 20-25% of advanced cancers, suggesting a role for p53 mutation in the progression of at least a subset of prostate cancers.
肿瘤抑制基因p53的失活在所有人类癌症的很大一部分发生和/或进展过程中发挥作用,包括≥50%的乳腺癌、肺癌和结肠癌。突变的p53等位基因通常在外显子5 - 8内含有错义单碱基替换,并编码异常稳定的p53蛋白,这些蛋白在肿瘤细胞核中大量积累。为了评估人类前列腺癌中p53突变的频率、类型及临床意义,采用抗p53抗体免疫组化(IHC)方法检测了150例前列腺癌患者的存档肿瘤材料。在19个肿瘤(12.7%)中观察到异常的核p53积累(IHC),且与疾病分期密切相关(69例III期或IV期肿瘤中有23%为IHC阳性,而74例0 - II期肿瘤中只有4%;P<0.001,Fisher精确检验)。采用聚合酶链反应、单链构象多态性和直接测序方法来鉴定突变,在14例IHC阳性病例中的9例中主要发现外显子5、7或外显子8中的错义单碱基替换,但在20例IHC阴性病例中均未发现;这些突变中有5个是CpG二核苷酸处的G:C→A:T转换。这些数据表明,突变的p53等位基因在早期前列腺癌中相当罕见,但在20% - 25%的晚期癌症中存在,提示p53突变在至少一部分前列腺癌的进展中发挥作用。