Mutations within the kinase domain and truncations of the epidermal growth factor receptor are rare events in bladder cancer: Implications for therapy
Mutations within the kinase domain and truncations of the epidermal growth factor receptor are rare events in bladder cancer: Implications for therapy
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DOI：
10.1158/1078-0432.ccr-06-0407
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发表时间：
2006-08-01
影响因子：
11.5
通讯作者：
Bar-Eli, Menashe
中科院分区：
文献类型：
--
作者：
Blehm, Kelly N.;Spiess, Philippe E.;Bar-Eli, Menashe
目的：先前已报道，患者对吉非替尼的反应取决于表皮生长因子受体（EGFR）激酶结构域内突变的存在或其截短形式EGFR变体III（EGFRvIII）的表达。本研究的重点是确定这些改变是否存在于酪氨酸激酶和EGFR的配体结合域inurothelial carcinoma.Experimental Design：激酶域内发现的EGFR从11膀胱癌细胞系和75例肿瘤的外显子18至21进行自动测序。EGFRvIII的表达通过免疫组化测定使用尿路上皮癌组织芯片，其表达随后通过逆转录PCR，实时PCR和Western印迹分析验证，使用EGFRvIII转染的胶质母细胞瘤细胞系和胶质母细胞瘤肿瘤作为阳性controls.Results：我们的分析未能检测到EGFR的酪氨酸激酶结构域内的突变在11个细胞系和75例患者测试。通过免疫组织化学对EGFRvIII表达的初步分析显示，至少50%的患者肿瘤在尿路上皮癌组织微阵列中表达EGFRvIII。然而，由于抗体的特异性和使用的方法，关于组织中EGFRvIII表达的程度存在令人怀疑的报道。因此，我们试图通过逆转录PCR、实时PCR和Western印迹分析来验证这一观察结果。在这些试验中，没有一个样品是阳性的EGFRvIII除了对照转染和glioblastomas.Conclusions：当我们的结果被放在一起，我们得出结论，酪氨酸激酶结构域和表达的EGFRvIII的改变是罕见的事件在膀胱癌。本研究对选择酪氨酸激酶抑制剂治疗尿路上皮癌具有临床意义。
Purpose: It has previously been reported that the patient response to gefitinib depends on the presence of mutations within the kinase domain of epidermal growth factor receptor (EGFR) or the expression of its truncated form, EGFR variant III (EGFRvIII). The focus of this study was to determine if these alterations are present within the tyrosine kinase and ligand-binding domain of EGFR in urothelial carcinoma.Experimental Design: The kinase domain found within exons 18 to 21 of the EGFR from 11 bladder cancer cell lines and 75 patient tumors were subjected to automated sequencing. EGFRvIII expression was determined by immunohistochemistry using a urothelial carcinoma tissue microarray, and its expression was subsequently verified by reverse transcription PCR, real-time PCR, and Western blot analysis, using an EGFRvIII-transfected glioblastoma cell line and glioblastoma tumors as positive controls.Results: Our analysis failed to detect mutations within the tyrosine kinase domain of EGFR in the 11 cell lines and 75 patients tested. The initial analysis of EGFRvIII expression by immunohistochemistry revealed that at least 50% of the patient tumors expressed EGFRvIII in a urothelial carcinoma tissue microarray. Conflicting reports exist, however, regarding the extent of EGFRvIII expression in tissues owing to the specificity of the antibodies and the methodologies used. Therefore, we sought to validate this observation by reverse transcription PCR, real-time PCR, and Western blot analysis. In these assays, none of the samples were positive for EGFRvIII except for control transfectants and glioblastomas.Conclusions: When our results are taken together, we conclude that alterations within the tyrosine kinase domain and expression of EGFRvIII are rare events in bladder cancer. The present study has clinical implications in selecting tyrosine kinase inhibitors for the therapy of urothelial carcinoma.