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.
View: Text | PDF
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

×

Figure 1

ZEB1 executes a PI4KB-to-PI4K2A enzymatic switch.

Options: View larger image (or click on image) Download as PowerPoint
ZEB1 executes a PI4KB-to-PI4K2A enzymatic switch. (A) Heatmap illustrati...
(A) Heatmap illustration of mRNA expression levels in TCGA LUAD and LUSC cohorts (n = 1,016 tumors). An EMT score calculated for each tumor, as described previously (65), was correlated with each PI4K family member or, as a comparison, with the EMT-activating transcription factor using Pearson’s coefficient (r value). (B) qPCR analysis of PI4K2A and PI4KB mRNA levels in human lung cancer cell lines classified as epithelial (E) or mesenchymal (M). (C and D) WB analysis of PI4K2A, PI4KB, and ZEB1 levels in epithelial (C) or mesenchymal (D) cells subjected to ZEB1 gain or loss of function, respectively. Relative densitometric values are shown under the gel lanes. α-Tubulin was used as a loading control. Empty vector (Vec), scrambled control (siCTL), and ZEB1 (siZEB1) siRNAs were used. (E) WB analysis of PI4K2A in cells transfected with miR mimics. (F) PI4K2A 3′-UTR reporter assays. H1299 cells were cotransfected with miR mimics and reporters containing WT or miR-182/-183 binding site mutant 3′-UTRs (n = 4 replicates per condition). (G–I) PI4P ELISA in siRNA-transfected H1299 (G), H441 (H), and HCC827 (I) cells. 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 < 0.05, **P < 0.01, and ***P < 0.001, by 2-tailed Student’s t test for 2-group comparisons (B); 1-way ANOVA test for multiple comparisons (F–I). miR-NC, negative control mimic.