HRAS-driven cancer cells are vulnerable to TRPML1 inhibition

EMBO Rep. 2019 Apr;20(4):e46685. doi: 10.15252/embr.201846685. Epub 2019 Feb 20.


By serving as intermediaries between cellular metabolism and the bioenergetic demands of proliferation, endolysosomes allow cancer cells to thrive under normally detrimental conditions. Here, we show that an endolysosomal TRP channel, TRPML1, is necessary for the proliferation of cancer cells that bear activating mutations in HRAS Expression of MCOLN1, which encodes TRPML1, is significantly elevated in HRAS-positive tumors and inversely correlated with patient prognosis. Concordantly, MCOLN1 knockdown or TRPML1 inhibition selectively reduces the proliferation of cancer cells that express oncogenic, but not wild-type, HRAS Mechanistically, TRPML1 maintains oncogenic HRAS in signaling-competent nanoclusters at the plasma membrane by mediating cholesterol de-esterification and transport. TRPML1 inhibition disrupts the distribution and levels of cholesterol and thereby attenuates HRAS nanoclustering and plasma membrane abundance, ERK phosphorylation, and cell proliferation. These findings reveal a selective vulnerability of HRAS-driven cancers to TRPML1 inhibition, which may be leveraged as an actionable therapeutic strategy.

Keywords: HRAS; TRPML1; cancer; cholesterol; endolysosomes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism
  • Calcium Signaling
  • Cell Membrane / metabolism
  • Cell Proliferation
  • Drosophila
  • Endosomes / metabolism
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Gene Expression
  • Gene Regulatory Networks
  • Humans
  • Lysosomes / metabolism
  • Models, Biological
  • Mutation
  • Neoplasms / genetics
  • Neoplasms / metabolism
  • Neoplasms / mortality
  • Neoplasms / pathology
  • Phosphorylation
  • Prognosis
  • Proto-Oncogene Proteins p21(ras) / genetics*
  • Proto-Oncogene Proteins p21(ras) / metabolism*
  • Signal Transduction
  • Transcriptome
  • Transient Receptor Potential Channels / antagonists & inhibitors*
  • Transient Receptor Potential Channels / genetics*
  • Transient Receptor Potential Channels / metabolism


  • MCOLN1 protein, human
  • Transient Receptor Potential Channels
  • Extracellular Signal-Regulated MAP Kinases
  • HRAS protein, human
  • Proto-Oncogene Proteins p21(ras)
  • Calcium