COX-2 dependent regulation of mechanotransduction in human breast cancer cells

A. Rum Yoon, Ioannis Stasinopoulos, Jae Hun Kim, Hwan Mee Yong, Onur Kilic, Denis Wirtz, Zaver M. Bhujwalla, Steven S. An

Research output: Contribution to journalArticle

Abstract

The ability of living cells to exert physical forces upon their surrounding is a necessary prerequisite for diverse biological processes, such as local cellular migrations in wound healing to metastatic-invasion of cancer. How forces are coopted in metastasis has remained unclear, however, because the mechanical interplay between cancer cells and the various stromal components has not been experimentally accessible. Current dogma implicates inflammation in these mechanical processes. Using Fourier transform traction microscopy, we measured the force-generating capacity of human breast cancer cells occupying a spectrum of invasiveness as well as basal and inducible COX-2 expression (MCF-7<SUM-149<MDA-MB- 231). Compared with non-invasive MCF-7 and moderately-invasive SUM-149, poorly-differentiated MDA-MB-231 cells showed increased cellular dispersion on collagen matrix that was accompanied by emergent distribution of contractile stresses at the interface between the adherent cell and its substrate, defined herein as the traction field. In metastatic MDA-MB-231 cells, the local tractions were precisely tuned to the surrounding matrix rigidity in a physiologic range with the concomitant expression of mechanosensitive integrin β1. These discrete responses at the single-cell resolution were correlated with PGE2 secretion and were ablated by shRNA-mediated knockdown of COX-2. Both COX-2-silenced and COX-2-expressing cells expressed EP2 and EP4 receptors, but not EP1 and EP3. Exogenous addition of PGE2 increased cell tractions and stiffened the underlying cytoskeletal network. To our knowledge this is the first report linking the expression of COX-2 with mechanotransduction of human breast cancer cells, and the regulation of COX-2-PGE2-EP signaling with physical properties of the tumor microenvironment. Drug treatments aimed at reducing this mechanical interplay may have therapeutic potential in the treatment of breast cancer.

Original languageEnglish (US)
Pages (from-to)430-437
Number of pages8
JournalCancer Biology and Therapy
Volume16
Issue number3
DOIs
StatePublished - Mar 1 2015

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Keywords

  • Breast cancer
  • COX-2
  • Cellular motions
  • Mechanobiology
  • Prostaglandin E

ASJC Scopus subject areas

  • Molecular Medicine
  • Oncology
  • Pharmacology
  • Cancer Research

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