Attenuation of LDHA expression in cancer cells leads to redox-dependent alterations in cytoskeletal structure and cell migration

Cancer Lett. 2013 Sep 28;338(2):255-66. doi: 10.1016/j.canlet.2013.03.034. Epub 2013 Apr 11.

Abstract

Aerobic glycolysis, the preferential use of glycolysis even in the presence of oxygen to meet cellular metabolic demands, is a near universal feature of cancer. This unique type of metabolism is thought to protect cancer cells from damaging reactive oxygen species (ROS) produced in the mitochondria. Using the cancer cell line MDA-MB-435 it is shown that shRNA mediated knockdown of lactate dehydrogenase A (LDHA), a key mediator of aerobic glycolysis, results in elevated mitochondrial ROS production and a concomitant decrease in cell proliferation and motility. Redox-sensitive proteins affected by oxidative stress associated with LDHA knockdown were identified by Redox 2D-PAGE and mass spectrometry. In particular, tropomyosin (Tm) isoforms Tm4, Tm5NM1 and Tm5NM5, proteins involved in cell migration and cytoskeletal dynamics, exhibited changes in disulfide bonding and co-localized with peri-nuclear actin aggregates in LDHA knockdown cells. In contrast, treatment with the thiol-based antioxidant N-acetylcysteine promoted the relocalization of Tms to cortical actin microfilaments and partially rescued the migration defects associated with attenuated LDHA expression. These results suggest that aerobic glycolysis and reduced mitochondrial ROS production create an environment conducive to cytoskeletal remodeling; key events linked to the high cell motility associated with cancer.

Keywords: Actin; Cell motility; Lactate dehydrogenase A; Redox regulation; Tropomyosin-3; Warburg effect.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms / enzymology*
  • Breast Neoplasms / pathology*
  • Cell Growth Processes / physiology
  • Cell Line, Tumor
  • Cell Movement / physiology*
  • Cytoskeleton / enzymology
  • Cytoskeleton / metabolism*
  • Cytoskeleton / pathology*
  • Female
  • Gene Knockdown Techniques
  • Humans
  • Isoenzymes / biosynthesis
  • Isoenzymes / deficiency
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • L-Lactate Dehydrogenase / biosynthesis*
  • L-Lactate Dehydrogenase / deficiency
  • L-Lactate Dehydrogenase / genetics
  • L-Lactate Dehydrogenase / metabolism
  • Lactate Dehydrogenase 5
  • MCF-7 Cells
  • Mitochondria / enzymology
  • Mitochondria / metabolism
  • Oxidation-Reduction
  • Reactive Oxygen Species / metabolism

Substances

  • Isoenzymes
  • Reactive Oxygen Species
  • L-Lactate Dehydrogenase
  • Lactate Dehydrogenase 5