Higher Levels of c-Met Expression and Phosphorylation Identify Cell Lines With Increased Sensitivity to AMG-458, a Novel Selective c-Met Inhibitor With Radiosensitizing Effects
Higher Levels of c-Met Expression and Phosphorylation Identify Cell Lines With Increased Sensitivity to AMG-458, a Novel Selective c-Met Inhibitor With Radiosensitizing Effects
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DOI：
10.1016/j.ijrobp.2012.06.025
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发表时间：
2012-11-15
影响因子：
7
通讯作者：
Lu, Bo
中科院分区：
文献类型：
--
作者：
Li, Bo;Torossian, Artour;Lu, Bo
目的：c-Met在某些非小细胞肺癌（NSCLC）细胞系和组织中过表达。具有较高水平的c-Met表达和磷酸化的细胞系依赖于该受体存活。我们研究了AMG-458对2种NSCLC细胞系的作用。方法和材料：3-（4，5-二甲基噻唑-2-基）-5-（3-羧基甲氧基苯基）-2-（4-磺基苯基）-2H-四唑鎓试验评估了细胞对AMG-458的敏感性。克隆形成存活试验证明了AMG-458的放射增敏作用。Western印迹法检测caspase 3的裂解，检测细胞凋亡。采用免疫印迹法检测c-Met、磷酸化Met（p-Met）、Akt/p-Akt和Erk/p-Erk.Results：AMG-458增强H441细胞的放射敏感性，但对A549细胞无影响。H441显示c-Met的组成性磷酸化。A549表达低水平的c-Met，其仅在外源性肝细胞生长因子存在下被磷酸化。发现放射治疗和AMG-458联合治疗可协同增加H441细胞系的细胞凋亡，但在A549中不存在。发现放射治疗、AMG-458和联合治疗可降低H441中的p-Akt和p-Erk水平，但在A549中未降低。小干扰RNA敲低c-Met后，H441对AMG-458的敏感性降低; A549无变化。结论：AMG-458对c-Met/p-Met高表达的细胞更有效，表明NSCLC组织中c-Met和p-Met高表达可能是对针对该受体的分子治疗更敏感的肿瘤亚群。(C)2012 Elsevier Inc.
Purpose: c-Met is overexpressed in some non-small cell lung cancer (NSCLC) cell lines and tissues. Cell lines with higher levels of c-Met expression and phosphorylation depend on this receptor for survival. We studied the effects of AMG-458 on 2 NSCLC cell lines.Methods and Materials: 3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assays assessed the sensitivities of the cells to AMG-458. Clonogenic survival assays illustrated the radiosensitizing effects of AMG-458. Western blot for cleaved caspase 3 measured apoptosis. Immunoblotting for c-Met, phospho-Met (p-Met), Akt/p-Akt, and Erk/p-Erk was performed to observe downstream signaling.Results: AMG-458 enhanced radiosensitivity in H441 but not in A549. H441 showed constitutive phosphorylation of c-Met. A549 expressed low levels of c-Met, which were phosphorylated only in the presence of exogenous hepatocyte growth factor. The combination of radiation therapy and AMG-458 treatment was found to synergistically increase apoptosis in the H441 cell line but not in A549. Radiation therapy, AMG-458, and combination treatment were found to reduce p-Akt and p-Erk levels in H441 but not in A549. H441 became less sensitive to AMG-458 after small interfering RNA knockdown of c-Met; there was no change in A549. After overexpression of c-Met, A549 became more sensitive, while H441 became less sensitive to AMG-458.Conclusions: AMG-458 was more effective in cells that expressed higher levels of c-Met/p-Met, suggesting that higher levels of c-Met and p-Met in NSCLC tissue may classify a subset of tumors that are more sensitive to molecular therapies against this receptor. (C) 2012 Elsevier Inc.