NUPR1 maintains autolysosomal efflux by activating SNAP25 transcription in cancer cells

Autophagy. 2018;14(4):654-670. doi: 10.1080/15548627.2017.1338556. Epub 2017 Dec 31.

Abstract

In the advanced stages of cancer, autophagy is thought to promote tumor progression through its ability to mitigate various cellular stresses. However, the details of how autophagy is homeostatically regulated in such tumors are unknown. Here, we report that NUPR1 (nuclear protein 1, transcriptional regulator), a transcriptional coregulator, is aberrantly expressed in a subset of cancer cells and predicts low overall survival rates for lung cancer patients. NUPR1 regulates the late stages of autolysosome processing through the induction of the SNARE protein SNAP25, which forms a complex with the lysosomal SNARE-associated protein VAMP8. NUPR1 depletion deregulates autophagic flux and impairs autolysosomal clearance, inducing massive cytoplasmic vacuolization and premature senescence in vitro and tumor suppression in vivo. Collectively, our data show that NUPR1 is a potent regulator of autolysosomal dynamics and is required for the progression of some epithelial cancers.

Keywords: NUPR1; SNAP25; autolysosomal efflux; premature senescence; transcriptional regulator.

Publication types

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

MeSH terms

  • Autophagy / physiology*
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Gene Expression Regulation, Neoplastic / genetics*
  • Humans
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / pathology
  • Lysosomes / metabolism
  • Neoplasm Proteins / metabolism*
  • Synaptosomal-Associated Protein 25 / metabolism*

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • NUPR1 protein, human
  • Neoplasm Proteins
  • SNAP25 protein, human
  • Synaptosomal-Associated Protein 25