Alterations of the INK4a‐ARF gene locus in pleomorphic adenoma of the parotid gland
Alterations of the INK4a‐ARF gene locus in pleomorphic adenoma of the parotid gland
复制标题
DOI：
10.1002/path.1210
复制
发表时间：
2002-11
期刊：
影响因子：
--
通讯作者：
A. Weber;L. Langhanki;A. Schütz;C. Wittekind;F. Bootz;A. Tannapfel
中科院分区：
文献类型：
--
作者：
A. Weber;L. Langhanki;A. Schütz;C. Wittekind;F. Bootz;A. Tannapfel
腮腺多形性腺瘤是由上皮细胞和间叶细胞组成的良性肿瘤。染色体9 p21上的INK 4a-ARF（CDKN 2A）基因座编码两种肿瘤抑制蛋白，p16 INK 4a和p14 ARF，它们作为Rb-CDK 4和p53通路的上游调节剂。为了研究每个通路在多形性腺瘤中的作用，本研究分析了这些肿瘤中p14 ARF、p16 INK 4a、p53和pRb的改变。在显微解剖不同的组织学成分后，通过DNA序列分析、甲基化特异性PCR（MSP）、限制性酶相关聚合酶链反应（RE-PCR）、mRNA表达、微卫星分析和免疫组织化学分析42例腮腺多形性腺瘤的INK 4a-ARF失活。此外，通过差异PCR检测p14 ARF和p16 INK 4a的微缺失。采用直接测序和免疫组化方法检测p53和Rb的表达情况。使用显微解剖，有可能检查肿瘤成分，即上皮，间质和过渡，分别免疫组化鉴定后。42例多形性腺瘤中1例p14 ARF基因甲基化，12例p16 INK 4a基因改变，与mRNA转录丢失有关。未检测到任一外显子的微缺失或特异性突变。甲基化仅在上皮和移行成分中检测到，而不是在肿瘤的间质部分。在4/42个腺瘤中检测到p53突变，也仅发生在肿瘤的上皮成分中。pRb在42例腺瘤中有40例阳性。在正常腮腺组织中，未观察到p14 ARF、p16 INK 4a、p53和pRb的改变。观察到p14 ARF和p16 INK 4a的改变，以及p53突变，仅发生在多形性腺瘤的上皮和移行成分，支持了腺瘤中这些区域易于恶变为癌的理论。版权所有© 2002年约翰威利父子有限公司。
Pleomorphic adenomas of the parotid gland are benign tumours composed of epithelial and mesenchymal cells. The INK4a‐ARF (CDKN2A) locus on chromosome 9p21 encodes two tumour suppressor proteins, p16INK4a and p14ARF, which act as upstream regulators of the Rb‐CDK4 and p53 pathways. To study the contribution of each pathway in pleomorphic adenomas, this study analysed alterations of p14ARF, p16INK4a, p53, and pRb in these tumours. After microdissecting the different histological components, 42 pleomorphic adenomas of the parotid gland were analysed for INK4a‐ARF inactivation by DNA sequence analysis, methylation‐specific PCR (MSP), restriction enzyme‐related polymerase chain reaction (RE‐PCR), mRNA expression, microsatellite analysis, and immunohistochemistry. In addition, microdeletion of p14ARF and p16INK4a were assessed by differential PCR. The status of p53 and Rb was examined by direct sequencing and immunohistochemistry. Using microdissection, it was possible to examine the tumour components, i.e. epithelial, mesenchymal, and transitional, separately after immunohistochemical identification. Methylation of p14ARF was found in 1/42 cases and alterations of p16INK4a occurred in 12/42 of pleomorphic adenomas, which correlated with loss of mRNA transcription. Microdeletions or specific mutations of either exon were not detected. Methylation was detected exclusively in the epithelial and transitional components and not within the mesenchymal part of the tumour. p53 mutations were detected in 4/42 adenomas, also occurring solely in the epithelial components of the tumours. pRb was detected immunohistochemically in 40/42 adenomas. In normal, corresponding parotid tissue, p14ARF, p16INK4a, p53, and pRb alterations were not observed. The observation that alterations of p14ARF and p16INK4a, and also p53 mutations, occurred exclusively in the epithelial and transitional components of pleomorphic adenoma supports the theory that these areas are prone to malignant transformation to carcinoma in adenoma. Copyright © 2002 John Wiley & Sons, Ltd.