Ninomiya Y, Urano Y, Yoshimoto K, Iwahana H, Sasaki S, Arase S, Itakura M
Department of Dermatology, School of Medicine, University of Tokushima, Japan.
J Dermatol Sci. 1997 Mar;14(3):173-8. doi: 10.1016/s0923-1811(96)00569-5.
In this and previous studies, we have shown p53 overexpression immunohistochemically in 14 of 17 porokeratotic specimens obtained from 14 lesions of nine cases, and in all six specimens of squamous cell carcinoma (SCC) arising on porokeratotic lesions of two cases. We screened mutations in exons 5 to 10 of the p53 gene in all these specimens by polymerase chain reaction-single strand conformation polymorphism analysis. Mutations of the p53 gene were detected in two of the six SCCs but not in any of the 17 porokeratotic specimens. These two mutations were C to T transitions at codons 146 and 175 in exon 5, which were a nonsense mutation at a dipyrimidine site and a missense mutation at a CG site, respectively. To our knowledge, neither of these mutations has been identified in skin cancers before. Our observations indicate that mutations of the p53 gene are not the major molecular etiology for porokeratosis, but are related to its skin carcinogenesis, and that p53 overexpression in porokeratosis is not due to p53 gene mutations.
在本研究及之前的研究中，我们通过免疫组织化学方法在取自9例患者14处皮损的17个汗孔角化病标本中的14个，以及2例汗孔角化病皮损处发生的6例鳞状细胞癌（SCC）的所有6个标本中均检测到p53过表达。我们通过聚合酶链反应-单链构象多态性分析对所有这些标本中p53基因的第5至10外显子进行了突变筛查。在6例SCC中的2例检测到p53基因突变，但在17个汗孔角化病标本中均未检测到。这两个突变分别是第5外显子密码子146和175处的C到T转换，分别为二嘧啶位点的无义突变和CG位点的错义突变。据我们所知，之前在皮肤癌中尚未发现这两种突变。我们的观察结果表明，p53基因突变不是汗孔角化病的主要分子病因，但与汗孔角化病的皮肤癌变有关，且汗孔角化病中p53过表达并非由p53基因突变所致。
