Pharmacological Targeting of Vacuolar H+-ATPase via Subunit V1G Combats Multidrug-Resistant Cancer

Cell Chem Biol. 2020 Nov 19;27(11):1359-1370.e8. doi: 10.1016/j.chembiol.2020.06.011. Epub 2020 Jul 9.

Abstract

Multidrug resistance (MDR) in cancer remains a major challenge for the success of chemotherapy. Natural products have been a rich source for the discovery of drugs against MDR cancers. Here, we applied high-throughput cytotoxicity screening of an in-house natural product library against MDR SGC7901/VCR cells and identified that the cyclodepsipeptide verucopeptin demonstrated notable antitumor potency. Cytological profiling combined with click chemistry-based proteomics revealed that ATP6V1G directly interacted with verucopeptin. ATP6V1G, a subunit of the vacuolar H+-ATPase (v-ATPase) that has not been previously targeted, was essential for SGC7901/VCR cell growth. Verucopeptin exhibited strong inhibition of both v-ATPase activity and mTORC1 signaling, leading to substantial pharmacological efficacy against SGC7901/VCR cell proliferation and tumor growth in vivo. Our results demonstrate that targeting v-ATPase via its V1G subunit constitutes a unique approach for modulating v-ATPase and mTORC1 signaling with great potential for the development of therapeutics against MDR cancers.

Keywords: V-ATPase; mTORC1 pathway; natural product; target identification.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Biological Products / chemical synthesis
  • Biological Products / chemistry
  • Biological Products / pharmacology*
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Cells, Cultured
  • Depsipeptides / chemical synthesis
  • Depsipeptides / chemistry
  • Depsipeptides / pharmacology*
  • Drug Resistance, Multiple / drug effects*
  • Drug Resistance, Neoplasm / drug effects*
  • Drug Screening Assays, Antitumor
  • Female
  • Humans
  • Male
  • Mechanistic Target of Rapamycin Complex 1 / antagonists & inhibitors
  • Mechanistic Target of Rapamycin Complex 1 / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Neoplasms, Experimental / drug therapy
  • Neoplasms, Experimental / metabolism
  • Neoplasms, Experimental / pathology
  • Protein Subunits / drug effects
  • Proteomics
  • Vacuolar Proton-Translocating ATPases / antagonists & inhibitors*
  • Vacuolar Proton-Translocating ATPases / metabolism

Substances

  • Antineoplastic Agents
  • Biological Products
  • Depsipeptides
  • Protein Subunits
  • verucopeptin
  • Mechanistic Target of Rapamycin Complex 1
  • Vacuolar Proton-Translocating ATPases