Characterization of choline kinase in human endothelial cells

NMR Biomed. 2013 Nov;26(11):1501-7. doi: 10.1002/nbm.2983. Epub 2013 Jun 18.


High choline kinase-α (Chk-α) expression is frequently observed in cancer cells, making it a novel target for pharmacological and molecular inhibition. As inhibiting agents are delivered systemically, it is important to determine Chk-α expression levels in endothelial cells that line both normal and tumor vasculature, and the effect of Chk-α downregulation on these cells. Here, we characterized Chk-α expression and the effect of its downregulation in human umbilical vein endothelial cells (HUVECs) relative to MDA-MB-231 human breast cancer cells. We used small interfering RNA (siRNA) to downregulate Chk-α expression. Basal mRNA levels of Chk-α were approximately three-fold lower in HUVECs relative to MDA-MB-231 breast cancer cells. Consistent with the differences in Chk-α protein levels, phosphocholine levels were approximately 10-fold lower in HUVECs relative to MDA-MB-231 cells. Transient transfection with siRNA-Chk resulted in comparable levels of mRNA and protein in MDA-MB-231 breast cancer cells and HUVECs. However, there was a significant reduction in proliferation in MDA-MB-231 cells, but not in HUVECs. No significant difference in CD31 immunostaining was observed in tumor sections obtained from mice injected with control luciferase-short hairpin (sh)RNA or Chk-shRNA lentivirus. These data suggest that systemically delivered agents that downregulate Chk-α in tumors will not affect endothelial cell proliferation during delivery, and further support the development of Chk-α downregulation as a cancer-specific treatment.

Keywords: MRS; angiogenesis; breast cancer; choline kinase; endothelial cells; phosphocholine; proliferation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cell Extracts
  • Cell Line, Tumor
  • Cell Proliferation
  • Cell Survival
  • Choline Kinase / genetics
  • Choline Kinase / metabolism*
  • Down-Regulation
  • Gene Expression Regulation, Enzymologic
  • Human Umbilical Vein Endothelial Cells / cytology
  • Human Umbilical Vein Endothelial Cells / enzymology*
  • Humans
  • Magnetic Resonance Spectroscopy
  • Mice
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / metabolism
  • Real-Time Polymerase Chain Reaction
  • Transfection


  • Cell Extracts
  • RNA, Messenger
  • RNA, Small Interfering
  • Choline Kinase