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Abstract：
Epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase that is frequently modified by glycosylation post-translationally. In cancer, EGFR amplifications and hotspot mutations such as L858R that promote proliferation have been detected in a significant fraction of non-small cell lung carcinomas and breast adenocarcinomas. Molecular dynamic simulations suggested that glycosylation at asparagine residue 361 (N361) promotes dimerization and ligand binding. We stably expressed glycosylation-deficient mutant EGFR N361A, with or without the oncogenic mutation L858R. Immunofluorescence and flow cytometry demonstrated that the mutants were each well expressed at the cell membrane. N361A decreased proliferation relative to wild-type EGFR as well as decreased sensitivity to ligands. Proximity ligation assays measuring co-localization of EGFR with its binding partner HER2 in cells revealed that N361A mutations increased co-localization. N361A, located near the binding interface for the EGFR inhibitor necitumumab, desensitized cells expressing the oncogenic EGFR L858R to antibody-based inhibition. These findings underline the critical relevance of post-translational modifications on oncogene function.
摘要：
表皮生长因子受体（EGFR）是一种跨膜酪氨酸激酶，通常通过翻译后糖基化进行修饰。在癌症中，在很大一部分非小细胞肺癌和乳腺腺癌中检测到EGFR扩增和促进增殖的热点突变如L858R。分子动力学模拟表明,天冬酰胺残基361(N361)处的糖基化促进二聚化和配体结合。我们稳定表达糖基化缺陷突变EGFRN361A，有或没有致癌突变L858R。免疫荧光和流式细胞术证明突变体各自在细胞膜上良好表达。相对于野生型EGFR,N361A降低增殖以及对配体的敏感性降低。测量EGFR与其结合配偶体HER2在细胞中的共定位的邻近连接测定揭示N361A突变增加共定位。N361A,位于EGFR抑制剂necitumumab的结合界面附近，表达致癌EGFRL858R的脱敏细胞对基于抗体的抑制。这些发现强调了翻译后修饰对癌基因功能的关键相关性。
结论：EGFR将生长因子的信号传导到细胞增殖中，并且在肿瘤中经常被过度激活。N361的EGFR糖基化调节EGFR二聚化，增殖信号的生长因子刺激，和对靶向抑制的敏感性。对EGFR糖基化的见解可能会扩大治疗机会，使癌症患者受益。
结论：EGFR将生长因子的信号传导到细胞增殖中，并且在肿瘤中经常被过度激活。N361的EGFR糖基化调节EGFR二聚化，增殖信号的生长因子刺激，和对靶向抑制的敏感性。对EGFR糖基化的见解可能会扩大治疗机会，使癌症患者受益。
