title: Zinc finger E-box binding homeobox-1 (Zeb1) drives anterograde lysosome trafficking and tumor cell invasion via upregulation of Na+/H+ Exchanger-1 (NHE1).
abstract: Tumor cell invasion through the extracellular matrix is facilitated by the secretion of lysosome-associated proteases. As a common mechanism for secretion, lysosomes must first traffic to the cell periphery (anterograde trafficking), consistent with invasive cells often containing lysosomes closer to the plasma membrane compared to non-invasive cells. Epithelial to mesenchymal transition (EMT) is a transcriptionally driven program that promotes an invasive phenotype, and Zeb1 is one transcription factor that activates the mesenchymal gene expression program. The role of lysosome trafficking in EMT-driven invasion has not been previously investigated. We found that cells with increased levels of Zeb1 displayed lysosomes located closer to the cell periphery and demonstrated increased protease secretion and invasion in 3-dimensional (3D) cultures compared to their epithelial counterparts. Additionally, preventing anterograde lysosome trafficking via pharmacological inhibition of Na+/H+ exchanger 1 (NHE1) or shRNA depletion of ADP-ribosylation like protein 8b (Arl8b) reversed the invasive phenotype of mesenchymal cells, thus supporting a role for lysosome positioning in EMT-mediated tumor cell invasion. Immunoblot revealed that expression of Na+/H+ exchanger 1 correlated with Zeb1 expression. Furthermore, we found that the transcription factor Zeb1 binds to the Na+/H+ exchanger 1 promoter, suggesting that Zeb1 directly controls Na+/H+ transcription. Collectively, these results provide insight into a novel mechanism regulating Na+/H+ exchanger 1 expression and support a role for anterograde lysosome trafficking in Zeb1-driven cancer progression. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Microbiology and Immunology, Louisiana State University Health Science Center - Shreveport, Shreveport, Louisiana.|Feist Weiller Cancer Center, Louisiana State University Health Science Center - Shreveport, Shreveport, Louisiana.
authors.forename: Samantha S
authors.initials: SS
authors.lastname: Dykes
authors.affiliation: Laboratory of Molecular Oncology, Van Andel Research Institute, Grand Rapids, Michigan.
authors.forename: ChongFeng
authors.initials: C
authors.lastname: Gao
authors.affiliation: Department of Microbiology and Immunology, Louisiana State University Health Science Center - Shreveport, Shreveport, Louisiana.|Feist Weiller Cancer Center, Louisiana State University Health Science Center - Shreveport, Shreveport, Louisiana.
authors.forename: William K
authors.initials: WK
authors.lastname: Songock
authors.affiliation: Department of Microbiology and Immunology, Louisiana State University Health Science Center - Shreveport, Shreveport, Louisiana.|Feist Weiller Cancer Center, Louisiana State University Health Science Center - Shreveport, Shreveport, Louisiana.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Bigelow
authors.affiliation: Laboratory of Molecular Oncology, Van Andel Research Institute, Grand Rapids, Michigan.
authors.forename: George Vande
authors.initials: GV
authors.lastname: Woude
authors.affiliation: Department of Microbiology and Immunology, Louisiana State University Health Science Center - Shreveport, Shreveport, Louisiana.|Feist Weiller Cancer Center, Louisiana State University Health Science Center - Shreveport, Shreveport, Louisiana.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Bodily
authors.affiliation: Department of Microbiology and Immunology, Louisiana State University Health Science Center - Shreveport, Shreveport, Louisiana.|Feist Weiller Cancer Center, Louisiana State University Health Science Center - Shreveport, Shreveport, Louisiana.
authors.forename: James A
authors.initials: JA
authors.lastname: Cardelli
mesh_terms: D027682:Cation Transport Proteins / Q000235:genetics*; D045744:Cell Line, Tumor; D002465:Cell Movement; D058750:Epithelial-Mesenchymal Transition; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008247:Lysosomes / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008297:Male; D009361:Neoplasm Invasiveness / Q000235:genetics* / Q000473:pathology; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000074082:Sodium-Hydrogen Exchanger 1; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics*; D015533:Transcriptional Activation; D015854:Up-Regulation; D000071799:Zinc Finger E-box-Binding Homeobox 1 / Q000235:genetics / Q000378:metabolism*
chemical_list: D027682:Cation Transport Proteins; C490998:SLC9A1 protein, human; D000074082:Sodium-Hydrogen Exchanger 1; D017923:Sodium-Hydrogen Exchangers; D000071799:Zinc Finger E-box-Binding Homeobox 1
keywords: NHE1; Zeb1; epithelial to mesenchymal transition; invasion; lysosome movement