Hypoxia regulates global membrane protein endocytosis through caveolin-1 in cancer cells

Nat Commun. 2016 Apr 20:7:11371. doi: 10.1038/ncomms11371.

Abstract

Hypoxia promotes tumour aggressiveness and resistance of cancers to oncological treatment. The identification of cancer cell internalizing antigens for drug targeting to the hypoxic tumour niche remains a challenge of high clinical relevance. Here we show that hypoxia down-regulates the surface proteome at the global level and, more specifically, membrane proteome internalization. We find that hypoxic down-regulation of constitutive endocytosis is HIF-independent, and involves caveolin-1-mediated inhibition of dynamin-dependent, membrane raft endocytosis. Caveolin-1 overexpression inhibits protein internalization, suggesting a general negative regulatory role of caveolin-1 in endocytosis. In contrast to this global inhibitory effect, we identify several proteins that can override caveolin-1 negative regulation, exhibiting increased internalization at hypoxia. We demonstrate antibody-mediated cytotoxin delivery and killing specifically of hypoxic cells through one of these proteins, carbonic anhydrase IX. Our data reveal that caveolin-1 modulates cell-surface proteome turnover at hypoxia with potential implications for specific targeting of the hypoxic tumour microenvironment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies / chemistry
  • Antibodies / pharmacology
  • Antigens, Neoplasm / genetics*
  • Antigens, Neoplasm / metabolism
  • Carbonic Anhydrase IX
  • Carbonic Anhydrases / genetics*
  • Carbonic Anhydrases / metabolism
  • Caveolae / drug effects
  • Caveolin 1 / genetics*
  • Caveolin 1 / metabolism
  • Cell Hypoxia
  • Cell Line, Tumor
  • Cholera Toxin / chemistry
  • Cholera Toxin / pharmacology
  • Dynamins / genetics*
  • Dynamins / metabolism
  • Fibroblasts / cytology
  • Fibroblasts / metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Immunoconjugates / chemistry
  • Immunoconjugates / pharmacology
  • Mice
  • Protein Transport / drug effects
  • Proteome / genetics
  • Proteome / metabolism
  • Signal Transduction

Substances

  • Antibodies
  • Antigens, Neoplasm
  • CAV1 protein, human
  • Caveolin 1
  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Immunoconjugates
  • Proteome
  • Cholera Toxin
  • Dynamins
  • CA9 protein, human
  • Carbonic Anhydrase IX
  • Carbonic Anhydrases