Mutation and expression analyses of the MET and CDKN2A genes in rhabdomyosarcoma with emphasis on MET overexpression
Mutation and expression analyses of the MET and CDKN2A genes in rhabdomyosarcoma with emphasis on MET overexpression
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DOI：
10.1002/gcc.20416
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发表时间：
2007-04-01
影响因子：
3.7
通讯作者：
Hayashi, Yasuhide
中科院分区：
文献类型：
--
作者：
Chen, Yuyan;Takita, Junko;Hayashi, Yasuhide
横纹肌肉瘤（RMS）是儿童最常见的软组织肉瘤。在转染肝细胞生长因子/散射因子（HGF/SF）的Ink4a/Arf（-/-）小鼠中，Ink4a/Arf功能的同时缺失以及Met信号通路的破坏会诱导出具有极高外显率和极短潜伏期的RMS。为了明确MET和CDKN2A（p16(INK4A)/p14(ARF)）在人类RMS中的作用，我们通过PCR - SSCR对39例RMS样本进行了突变分析。在MET基因的14 - 21号外显子中未检测到突变，而在一个肺泡型RMS细胞系中发现了p16(INK4A)第80位密码子的无义突变。我们还通过实时定量PCR对7个细胞系和17个新鲜肿瘤中这些基因的相对表达水平和DNA拷贝数进行了定量。在所有样本中都检测到了MET的表达；然而，尽管DNA拷贝数正常，但在表达水平较高或较低的样本中发现了超过10倍的差异。蛋白质表达水平与mRNA表达水平一致，并且在表达水平较高的细胞系中，MET被组成性激活。值得注意的是，MET的表达水平在死亡患者（P = 0.02）、IV期患者（P = 0.04）以及具有PAX3 - FKHR嵌合转录本的患者（P = 0.04）中显著更高。另一方面，p16(INK4A)和/或p14(ARF)表达降低或缺失与临床病理参数除诊断时年龄外无显著相关性。我们的数据表明MET在RMS的进展中起作用。（c）2007威利 - 利斯公司
Rhabdomyosarcoma (RIMS) is the most common soft-tissue sarcoma of childhood. The simultaneous loss of Ink4a/Arf function and disruption of Met signaling in lnk4a/Arf(-/-) mice transgenic for hepatocyte growth factor/scatter factor (HGF/SF) induces RMS with extremely high penetrance and short latency. To address the roles of MET and CDKN2A (p16(INK4A)/p14(ARF)) in human RMS, we performed mutational analyses in 39 samples of RMS by PCR-SSCR No mutations were detected in exons 14-21 of MET whereas a nonsense mutation at codon 80 of p16(INK4A) was identified in an alveolar RMS cell line. We also quantified the relative expression levels and DNA copy numbers of these genes in seven cell lines and 17 fresh tumors by real-time quantitative PCR. Expression of MET was detected in all samples; however, more than 10-fold difference was found in the samples with higher or lower expression level, despite a normal DNA copy number. The protein expression level was consistent with that of mRNA, and in cell lines with a higher expression level, MET was constitutively activated. Notably, the expression level of MET was significantly higher in patients who died (P = 0.02), in patients with stage IV (P = 0.04), as well as in patients with PAX3-FKHR chimeric transcript (P = 0.04). On the other hand, reduced or absent expression of p16(INK4A) and/or p14(ARF) showed no significant correlation with the clinicopathological parameters, except for the age at diagnosis. Our data suggest that MET plays a role in the progression of RMS. (c) 2007 Wiley-Liss, Inc.