Department of Thoracic Surgery, Tongji University School of Medicine, Shanghai, PR China.
Department of Pathology, Tongji University School of Medicine, Shanghai, PR China.
Biomed Pharmacother. 2019 Sep;117:109185. doi: 10.1016/j.biopha.2019.109185. Epub 2019 Jul 9.
Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is the first-line treatment in non-resectable non-small lung cancer (NSCLC) with EGFR mutation. However, EGFR-TIKs resistance would inevitably develop within 9-14 months after treatment. And, chemotherapy is the main treatment for EGFR-TKIs resistant patients. WEE1 kinase, a G2/M checkpoint regulator, was recently considered as a putative biomarker for the platinum-based chemo-response. The aim of this study is to clarify the relationship between WEE1 kinase and chemosensitivity in EGFR-TKIs resistant NSCLC. WEE1 expression was tested in EGFR-TKIs resistant cell lines (H1299, PC9/G2) and patients' specimens by western blot, qPCR and immunohistochemistry (IHC). In in vitro experiment, WEE1 expression was higher in EGFR-TKIs resistant than EGFR-TKIs sensitive cell lines and was gradually increased following cisplatin or gemcitabine treatment with the enrichment of G2/M cell cycle phase. And, for patients with acquired Icotinib/Gefitinib resistance, 58.4% (7/12) had increased WEE1 expression compared to its initial expression level. In order to explore the impact of WEE1 on chemo-response, WEE1 knockdown was conducted in EGFR-TKIs resistant H1299 and PC9/G2 cells. MTT and colony formation assay showed that the efficacy of cisplatin and gemcitabine was enhanced in the two cell lines after WEE1 knockdown. And, the IC50 value of cisplatin decreased from 8.64 μg/ml to 3.10 μg/ml or 2.38 μg/ml in H1299 and from 3.66 μg/ml to 0.97 μg/ml or 1.18 μg/ml in PC9/G2 after WEE1 knockdown with two specific shRNAs. This study revealed that WEE1 expression was increased after EGFR-TKIs resistance, and WEE1 knockdown could enhance chemosensitivity in EGFR-TKIs resistant NSCLC. It is suggested the combination of WEE1 inhibitor and chemotherapy might improve the clinical outcome of NSCLC patients with acquired EGFR-TKIs resistance.
表皮生长因子受体 (EGFR) 酪氨酸激酶抑制剂 (TKIs) 是具有 EGFR 突变的不可切除性非小细胞肺癌 (NSCLC) 的一线治疗药物。然而，EGFR-TKIs 耐药性在治疗后 9-14 个月内不可避免地会发生。并且，化疗是 EGFR-TKIs 耐药患者的主要治疗方法。WEE1 激酶，一种 G2/M 检查点调节剂，最近被认为是铂类化疗反应的潜在生物标志物。本研究旨在阐明 WEE1 激酶与 EGFR-TKIs 耐药 NSCLC 化疗敏感性之间的关系。通过 Western blot、qPCR 和免疫组织化学 (IHC) 检测 EGFR-TKIs 耐药细胞系 (H1299、PC9/G2) 和患者标本中的 WEE1 激酶表达。在体外实验中，EGFR-TKIs 耐药细胞系中的 WEE1 表达高于 EGFR-TKIs 敏感细胞系，并且随着顺铂或吉西他滨治疗，G2/M 细胞周期期逐渐增加，WEE1 表达也逐渐增加。并且，对于获得性伊可替尼/吉非替尼耐药的患者，与初始表达水平相比，有 58.4%（7/12）的患者 WEE1 表达增加。为了探讨 WEE1 对化疗反应的影响，在 EGFR-TKIs 耐药的 H1299 和 PC9/G2 细胞中进行了 WEE1 敲低。MTT 和集落形成实验表明，在两种细胞系中，WEE1 敲低后顺铂和吉西他滨的疗效增强。并且，用两种特异性 shRNA 敲低 WEE1 后，H1299 中的顺铂 IC50 值从 8.64μg/ml 降低至 3.10μg/ml 或 2.38μg/ml，PC9/G2 中的顺铂 IC50 值从 3.66μg/ml 降低至 0.97μg/ml 或 1.18μg/ml。本研究表明，EGFR-TKIs 耐药后 WEE1 表达增加，WEE1 敲低可增强 EGFR-TKIs 耐药 NSCLC 的化疗敏感性。提示 WEE1 抑制剂联合化疗可能改善获得性 EGFR-TKIs 耐药 NSCLC 患者的临床预后。
