EMT-activated secretory and endocytic vesicular trafficking programs underlie a vulnerability to PI4K2A antagonism in lung cancer
Xiaochao Tan, … , Chad J. Creighton, Jonathan M. Kurie
Xiaochao Tan, … , Chad J. Creighton, Jonathan M. Kurie
Published February 9, 2023
Citation Information: J Clin Invest. 2023;133(7):e165863. https://doi.org/10.1172/JCI165863.
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Research Article Cell biology Oncology

EMT-activated secretory and endocytic vesicular trafficking programs underlie a vulnerability to PI4K2A antagonism in lung cancer

Abstract

Hypersecretory malignant cells underlie therapeutic resistance, metastasis, and poor clinical outcomes. However, the molecular basis for malignant hypersecretion remains obscure. Here, we showed that epithelial-mesenchymal transition (EMT) initiates exocytic and endocytic vesicular trafficking programs in lung cancer. The EMT-activating transcription factor zinc finger E-box–binding homeobox 1 (ZEB1) executed a PI4KIIIβ-to-PI4KIIα (PI4K2A) dependency switch that drove PI4P synthesis in the Golgi and endosomes. EMT enhanced the vulnerability of lung cancer cells to PI4K2A small-molecule antagonists. PI4K2A formed a MYOIIA-containing protein complex that facilitated secretory vesicle biogenesis in the Golgi, thereby establishing a hypersecretory state involving osteopontin (SPP1) and other prometastatic ligands. In the endosomal compartment, PI4K2A accelerated recycling of SPP1 receptors to complete an SPP1-dependent autocrine loop and interacted with HSP90 to prevent lysosomal degradation of AXL receptor tyrosine kinase, a driver of cell migration. These results show that EMT coordinates exocytic and endocytic vesicular trafficking to establish a therapeutically actionable hypersecretory state that drives lung cancer progression.

Authors

Xiaochao Tan, Guan-Yu Xiao, Shike Wang, Lei Shi, Yanbin Zhao, Xin Liu, Jiang Yu, William K. Russell, Chad J. Creighton, Jonathan M. Kurie

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Figure 2

ZEB1 executes a PI4K2B-to-PI4K2A enzymatic switch.

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ZEB1 executes a PI4K2B-to-PI4K2A enzymatic switch. (A) qPCR analysis of ...
(A) qPCR analysis of ACBD3 mRNA levels in the cell lines (dots) described in Figure 1B. (B and C) WB analysis of ACBD3 protein levels in epithelial (B) and mesenchymal (C) cells subjected to ZEB1 gain or loss of function, respectively. (D and E) PI4P ELISA in mesenchymal (D) and epithelial (E) cells subjected to ACBD3 gain or loss of function, respectively. (F) Schema showing constructs containing MS2 binding sites (12X) fused downstream of a WT or mutant (MT) ACBD3 3′-UTR lacking the miR-34a–binding site (BS). (G) MS2-based RIP. MS2-UTR–associated miR-34a was quantified as fold enrichment values relative to MS2. miR-200b was included as a negative control. (H and I) WB analysis of ACBD3 and ZFP36L1 levels in cells transfected with miR mimics (H) or siRNAs (I). (J and K) WB analysis of ZFP36L1 levels in cell lysates (input), an MS2-based RIP complex (GFP), or a negative control IP (IgG). (L) Schema of the working model. ZEB1 executes a PI4KB-to-PI4K2A dependency switch by silencing miR-34a and miR-182/-183. Data indicate the mean ± SD from a single experiment incorporating biological replicate samples (n = 3, unless otherwise indicated) and are representative of at least 2 independent experiments. P values were determined by 2-tailed Student’s t test for 2-group comparisons (A, D, and E); 1-way ANOVA test for multiple comparisons.