Rab13 regulates sEV secretion in mutant KRAS colorectal cancer cells

Sci Rep. 2020 Sep 25;10(1):15804. doi: 10.1038/s41598-020-72503-8.

Abstract

Small extracellular vesicles (sEVs), 50-150 nm in diameter, have been proposed to mediate cell-cell communication with important implications in tumor microenvironment interactions, tumor growth, and metastasis. We previously showed that mutant KRAS colorectal cancer (CRC) cells release sEVs containing Rab13 protein and mRNA. Previous work had shown that disruption of intracellular Rab13 trafficking inhibits epithelial cell proliferation and invasiveness. Here, we show that Rab13 additionally regulates the secretion of sEVs corresponding to both traditional exosomes and a novel subset of vesicles containing both β1-integrin and Rab13. We find that exposure of recipient cells to sEVs from KRAS mutant donor cells increases proliferation and tumorigenesis and that knockdown of Rab13 blocks these effects. Thus, Rab13 serves as both a cargo protein and as a regulator of sEV secretion. Our data support a model whereby Rab13 can mediate its effects on cell proliferation and invasiveness via autocrine and paracrine signaling.

Publication types

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

MeSH terms

  • Cell Communication
  • Cell Movement
  • Cell Proliferation
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / metabolism
  • Colorectal Neoplasms / pathology*
  • Exosomes / metabolism*
  • Extracellular Vesicles / metabolism*
  • Humans
  • Integrin beta1 / genetics
  • Integrin beta1 / metabolism*
  • Mutation*
  • Proto-Oncogene Proteins p21(ras) / genetics
  • Proto-Oncogene Proteins p21(ras) / metabolism*
  • Tumor Cells, Cultured
  • Tumor Microenvironment
  • rab GTP-Binding Proteins / genetics
  • rab GTP-Binding Proteins / metabolism*

Substances

  • Integrin beta1
  • KRAS protein, human
  • RAB13 protein, human
  • Proto-Oncogene Proteins p21(ras)
  • rab GTP-Binding Proteins