Inhibition of the V-ATPase by Archazolid A: A New Strategy to Inhibit EMT

Mol Cancer Ther. 2017 Nov;16(11):2329-2339. doi: 10.1158/1535-7163.MCT-17-0129. Epub 2017 Aug 3.

Abstract

Epithelial-mesenchymal transition (EMT) induces tumor-initiating cells (TIC), which account for tumor recurrence, metastasis, and therapeutic resistance. Strategies to interfere with EMT are rare but urgently needed to improve cancer therapy. By using the myxobacterial natural compound Archazolid A as a tool, we elucidate the V-ATPase, a multimeric proton pump that regulates lysosomal acidification, as a crucial player in EMT and identify the inhibition of V-ATPase by Archazolid A as a promising strategy to block EMT. Genetic knockdown and pharmacologic inhibition of the V-ATPase by Archazolid A interfere with the EMT process and inhibit TIC generation, as shown by a reduced formation of mammospheres and decreased cell motility. As an underlying mechanism, V-ATPase inhibition by Archazolid A disturbs the turnover of E-cadherin: Archazolid abrogates E-cadherin loss during EMT by interfering with its internalization and recycling. Our study elucidates V-ATPase as essential player in EMT by regulating E-cadherin turnover. Archazolid A is suggested as a promising therapeutic agent to block EMT and the generation of TICs. Mol Cancer Ther; 16(11); 2329-39. ©2017 AACR.

MeSH terms

  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / genetics
  • Breast Neoplasms / pathology
  • Cadherins / genetics
  • Cell Line, Tumor
  • Epithelial-Mesenchymal Transition / drug effects*
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Macrolides / administration & dosage*
  • Neoplasm Metastasis
  • Neoplastic Stem Cells / drug effects
  • Neoplastic Stem Cells / pathology
  • Thiazoles / administration & dosage*
  • Vacuolar Proton-Translocating ATPases / antagonists & inhibitors
  • Vacuolar Proton-Translocating ATPases / genetics*

Substances

  • Cadherins
  • Macrolides
  • Thiazoles
  • archazolid A
  • Vacuolar Proton-Translocating ATPases