Etk Interaction with PFKFB4 Modulates Chemoresistance of Small-cell Lung Cancer by Regulating Autophagy
Etk Interaction with PFKFB4 Modulates Chemoresistance of Small-cell Lung Cancer by Regulating Autophagy
复制标题
Etk 与 PFKFB4 的相互作用通过调节自噬调节小细胞肺癌的化疗耐药性
DOI：
10.1158/1078-0432.ccr-17-1475
复制
发表时间：
2018-02-15
影响因子：
11.5
通讯作者：
Guo, Linlang
中科院分区：
文献类型：
--
作者：
Wang, Qiongyao;Zeng, Fanrui;Guo, Linlang
目的：在我们的初步研究中发现上皮和内皮酪氨酸激酶（Etk），也称为骨髓X激酶（Bmx），在调节小细胞肺癌（SCLC）的化疗耐药中起关键作用。然而，Etk在SCLC化疗耐药中的分子机制仍然知之甚少。实验设计：我们确定Etk与SCLC自噬的相关性。并通过直接抑制自噬来验证其对化疗耐药的影响。在微阵列分析后，进行了共免疫沉淀（co-IP）和gst下拉实验来验证Etk和PFKFB4的相互作用。通过体外和体内功能获得或丧失分析和评估PFKFB4在SCLC标本中的表达，验证其在化疗耐药中的作用。使用包括PDX模型在内的临床前模型，在SCLC细胞中施用Ibrutinib以验证其与化疗的协同抗肿瘤作用。结果：下调Etk抑制SCLC耐药细胞的自噬，直接抑制自噬使细胞对化疗敏感。PFKFB4（6-磷酸果糖-2-激酶/果糖-2,6-双磷酸酶4）被确定为Etk的下游靶点和Etk相互作用蛋白，可促进SCLC的化疗耐药，并与不良的治疗反应和预后相关。此外，发现伊鲁替尼在靶向Etk的化疗中表现出协同抗肿瘤作用。结论：我们的研究结果首次证明了Etk与PFKFB4相互作用，通过调节自噬促进SCLC化疗耐药。异常的Etk和PFKFB4可能是SCLC化疗反应的预测因素，也是潜在的治疗靶点。临床癌症研究；24 (4);950 - 62。AACR©2017。
Purpose: Epithelial and endothelial tyrosine kinase (Etk), also known as bone marrow X kinase (Bmx), was found to be critical in modulating the chemoresistance of small-cell lung cancer (SCLC) in our preliminary study. However, the molecular mechanisms of Etk in SCLC chemoresistance remain poorly understood. Experimental Design: We determined correlation of Etk with autophagy in SCLC. And direct inhibition of autophagy was performed to validate its effect on chemoresistance. Coimmunoprecipitation (co-IP) and GST-pull down experiments were conducted to verify the interaction of Etk and PFKFB4, after a microarray analysis. In vitro and in vivo gain or loss-of-function analyses and evaluation of PFKFB4 expression in SCLC specimens, were done to validate its role in chemoresistance. Ibrutinib was administrated in SCLC cells to verify its synergistic anti-tumor effect with chemotherapy using preclinical models including a PDX model. Results: Downregulation of Etk suppressed autophagy in chemoresistant SCLC cells, and direct inhibition of autophagy sensitized cells to chemotherapy. PFKFB4 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 4) was identified as a downstream target of Etk and an Etk-interacting protein, which promoted chemoresistance in SCLC and was associated with poor therapeutic response and prognosis. Furthermore, ibrutinib was found to exhibit a synergistic anti-tumor effect with chemotherapy in targeting Etk. Conclusions: Our results demonstrated for the first time that Etk interacts with PFKFB4 to promote SCLC chemoresistance through regulation of autophagy. Aberrant Etk and PFKFB4 can be predictive factors for the chemotherapy response as well as potential therapeutic targets in SCLC. Clin Cancer Res; 24(4); 950–62. ©2017 AACR.