Drug Discovery and Development Division, Shizuoka Cancer Center Research Institute, 1007 Shimonagakubo Nagaizumi-cho Sunto-gun, Shizuoka, 411-8777, Japan.
Anticancer Res. 2013 Dec;33(12):5223-33.
BACKGROUND/AIM: Mechanisms of resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) are not fully-understood. In this study we aimed to elucidate remaining unknown mechanisms using erlotinib-resistant NSCLC cells.
We performed array comparative genomic hybridization (aCGH) to identify genomic aberrations associated with EGFR-TKI resistance in erlotinib-resistant PC-9ER cells. Real-time polymerase chain reaction (PCR) and immunoblot analyses were performed to confirm the results of aCGH.
Among the five regions with copy number gain detected in PC-9ER cells, we focused on 22q11.2-q12.1 including v-crk avian sarcoma virus CT10 oncogene homolog-like (CRKL), the overexpression of which seemed to be associated with EGFR-TKI resistance. Blockade of downstream phosphatidylinositol 3-kinase (PI3K)/v-akt murine thymoma viral oncogene homolog (AKT) signaling using NVP-BEZ235 suppressed the proliferation of PC-9ER cells, implying the involvement of acquired CRKL amplification in EGFR-TKI resistance.
Acquired CRKL amplification was identified as contributing to EGFR-TKI resistance; this cell line model can be utilized to study this resistance mechanism.
背景/目的：非小细胞肺癌（NSCLC）中表皮生长因子受体（EGFR）-酪氨酸激酶抑制剂（TKI）耐药的机制尚不完全清楚。在本研究中，我们旨在使用厄洛替尼耐药的 NSCLC 细胞阐明未知的耐药机制。
我们进行了 array 比较基因组杂交（aCGH），以鉴定与厄洛替尼耐药相关的 EGFR-TKI 耐药的基因组畸变。实时聚合酶链反应（PCR）和免疫印迹分析用于确认 aCGH 的结果。
在 PC-9ER 细胞中检测到的五个拷贝数增加的区域中，我们关注 22q11.2-q12.1 区域，包括 v-crk 禽肉瘤病毒 CT10 癌基因同源物样（CRKL），其过表达似乎与 EGFR-TKI 耐药有关。使用 NVP-BEZ235 阻断下游磷脂酰肌醇 3-激酶（PI3K）/v-akt 鼠胸腺瘤病毒癌基因同源物（AKT）信号通路抑制了 PC-9ER 细胞的增殖，这表明获得性 CRKL 扩增参与了 EGFR-TKI 耐药。
获得性 CRKL 扩增被确定为导致 EGFR-TKI 耐药的原因；这种细胞系模型可用于研究这种耐药机制。
