American Association for Cancer Research
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Supplementary Data from Etk Interaction with PFKFB4 Modulates Chemoresistance of Small-cell Lung Cancer by Regulating Autophagy

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journal contribution
posted on 2023-03-31, 19:41 authored by Qiongyao Wang, Fanrui Zeng, Yanqin Sun, Qianqian Qiu, Jian Zhang, Weimei Huang, Jie Huang, Xiaomin Huang, Linlang Guo

Supplementary Data of Figure.S1-S4 and Table S1-S5 Table S1. The expression of PFKFB4 and Etk and their relationships with the clinicopathological characteristics in SCLC patients Table S2. Univariate and multivariate analyses of potential prognostic factors associated with overall survival of SCLC patients Table S3. The clinicopathological characteristics of the patient that donated SCLC specimen to perform PDX experiment. Table S4. Sequences of siRNA. Table S5. qRT-PCR primers


Guangdong Provincial Key Laboratory of Malignant Tumor Epigenitic and Gene Regulation

Sun Yat-Sen Memorial Hospital

Sun Yat-Sen University

Associations Enfants et Santé

National Natural Science Foundation of China

Clinical Research Initiative Project of Southern Medical University

Guangdong Natural Science Foundation



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.