Matrix stiffness-sensitive long noncoding RNA NEAT1 seeded paraspeckles in cancer cells

Mol Biol Cell. 2020 Jul 21;31(16):1654-1662. doi: 10.1091/mbc.E20-02-0097. Epub 2020 Apr 15.

Abstract

Cancer progression is influenced by changes in the tumor microenvironment, such as the stiffening of the extracellular matrix. Yet our understanding of how cancer cells sense and convert mechanical stimuli into biochemical signals and physiological responses is still limited. The long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1), which forms the backbone of subnuclear "paraspeckle" bodies, has been identified as a key genetic regulator in numerous cancers. Here, we investigated whether paraspeckles, as defined by NEAT1 localization, are mechanosensitive. Using tunable polyacrylamide hydrogels of extreme stiffnesses, we measured paraspeckle parameters in several cancer cell lines and observed an increase in paraspeckles in cells cultured on soft (3 kPa) hydrogels compared with stiffer (40 kPa) hydrogels. This response to soft substrate is erased when cells are first conditioned on stiff substrate, and then transferred onto soft hydrogels, suggestive of mechanomemory upstream of paraspeckle regulation. We also examined some well-characterized mechanosensitive markers, but found that lamin A expression, as well as YAP and MRTF-A nuclear translocation did not show consistent trends between stiffnesses, despite all cell types having increased migration, nuclear, and cell area on stiffer hydrogels. We thus propose that paraspeckles may prove of use as mechanosensors in cancer mechanobiology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism
  • Biomechanical Phenomena
  • Breast Neoplasms / pathology
  • Cell Line, Tumor
  • Cell Movement
  • Cell Nucleus / metabolism
  • Cell Shape
  • Extracellular Matrix / metabolism*
  • Female
  • Humans
  • Lamin Type A / metabolism
  • Mechanotransduction, Cellular
  • Myosin Type II / metabolism
  • Neoplasm Metastasis
  • Neoplasms / metabolism*
  • Neoplasms / pathology
  • RNA, Long Noncoding / genetics
  • RNA, Long Noncoding / metabolism*
  • Trans-Activators / metabolism
  • Transcription Factors / metabolism
  • YAP-Signaling Proteins

Substances

  • Adaptor Proteins, Signal Transducing
  • Lamin Type A
  • MRTFA protein, human
  • NEAT1 long non-coding RNA, human
  • RNA, Long Noncoding
  • Trans-Activators
  • Transcription Factors
  • YAP-Signaling Proteins
  • YAP1 protein, human
  • Myosin Type II