Gastric cancer cell line Hs746T harbors a splice site mutation of c-Met causing juxtamembrane domain deletion
Gastric cancer cell line Hs746T harbors a splice site mutation of c-Met causing juxtamembrane domain deletion
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DOI：
10.1016/j.bbrc.2010.03.120
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发表时间：
2010-04-16
影响因子：
3.1
通讯作者：
Koike, Kazuhiko
中科院分区：
文献类型：
--
作者：
Asaoka, Yoshinari;Tada, Motohisa;Koike, Kazuhiko
受体酪氨酸激酶（RTK）参与许多癌症的肿瘤发生和疾病进展。针对它们的抑制剂被大力开发，其中一些在临床环境中进行了测试。某些RTK（c-Met，FGFR 2和ErbB 2）的扩增与人类胃癌进展相关。根据我们使用高密度单核苷酸多态性基因分型芯片对34个胃癌细胞系的遗传病变进行全基因组扫描，我们证实了c-met位点在4个胃癌细胞系（Hs 746 T，MKN 45，NUGC 4和SNU 5）中扩增。据报道，在基因扩增的某种类型癌症的肿瘤样品中偶尔检测到体细胞突变。既往研究发现胃癌中存在FGFR 2和ErbB 2基因突变，但c-Met致癌突变未见报道。我们使用胃癌细胞系的基因组DNA对c-Met的胞质结构域进行突变分析，发现H5746 T细胞具有外显子14的剪接位点突变。通过cDNA序列测定和Western blotting分析，我们发现该突变导致了质膜结构域的缺失。以前，这种突变仅在肺癌标本中检测到，这种缺失导致Cbl E3-连接酶结合的丧失，导致泛素化降低和下调延迟。结果表明，4株胃癌细胞株均存在c-met基因扩增，其中H5746 T存在扩增的致癌突变。这些信息将有助于筛选针对胃癌c-Met畸变的抑制剂。(C)2010年爱思唯尔公司All rights reserved.
Receptor tyrosine kinases (RTKs) are involved in oncogenesis and disease progression for many cancers. Inhibitors targeting them are vigorously developed and some of them are tested in the clinical setting. Amplifications of certain RTKs (c-Met, FGFR2 and ErbB2) have been associated with human gastric cancer progression. According to our genome-wide scans of genetic lesions in 34 gastric cancer cell lines using high-density single-nucleotide polymorphism genotyping microarrays, we confirmed that the c-met locus was amplified in four gastric cancer cell lines (Hs746T, MKN45, NUGC4 and SNU5). It was reported that somatic mutation is occasionally detected in tumor samples of a certain type of cancer with gene amplification. Previous reports showed gastric cancers harbored mutations of FGFR2 and ErbB2, but c-Met oncogenic mutation had not yet been reported. We performed mutational analysis of the cytoplasmic domains of c-Met using the genome DNA of the gastric cancer cell lines, and found that H5746T cells had a splice site mutation of exon 14. By cDNA sequencing and Western blotting, we showed that the mutation caused juxtamembrane domain deletion. Previously, this mutation had been detected only in lung cancer specimens and this deletion resulted in the loss of Cbl E3-ligase binding causing decreased ubiquitination and delayed down-regulation. In conclusion, four gastric cancer cell lines harbored amplification of c-met locus, and among them, H5746T had a putative oncogenic mutation with amplification. This information will be useful for screening of inhibitors targeting gastric cancer with c-Met aberration. (C) 2010 Elsevier Inc. All rights reserved.