Protein kinase CK2 is involved in G2 arrest and apoptosis following spindle damage in epithelial cells

Oncogene. 2001 Oct 25;20(48):6994-7005. doi: 10.1038/sj.onc.1204894.


p53 undergoes phosphorylation on several residues in response to cellular stresses that include UV and ionizing radiation, however the influence of spindle damage on this parameter is relatively unclear. Consequently, the effect of nocodazole on serine 392 phosphorylation was examined in two epithelial cell lines. We show that this process is dependent upon the stepwise activation of p38 mitogen-activated protein kinase (p38 MAPK) and protein kinase casein kinase 2 (CK2). Furthermore, this activation correlated with the biochemical regulation of the maturation-promoting factor (MPF, cdc2/cyclin B), as both DRB and antisense depletion of CK2, as well as SB203580 were associated with an inhibition of its activation in response to nocodazole. Strikingly, when the cell cycle characteristics of nocodazole treated cells were examined, we observed that depletion or inhibition of the catalytic subunit of CK2, in the presence of microtubule inhibitors, resulted in a compromise of the G2 arrest (spindle checkpoint). Furthermore, CK2-depleted, nocodazole treated cells demonstrated a dramatic reduction in the apoptotic cell fraction, confirming that these cells had been endowed with oncogenic properties. These changes were observed in both HeLa cells and HCT116 cells. We also show that this effect is dependent on the presence of functional wild-type p53, as this phenomenon is not apparent in HCT116 p53(-/-) cells. Collectively, our results indicate two novel roles for CK2 in the spindle checkpoint arrest, in concert with p53. Firstly, to maintain increased cyclinB/cdc2 kinase activity, as a component of G2 arrest, and secondly, a role in p53-mediated apoptosis. These findings may have implications for an improved understanding of abnormalities of the spindle checkpoint in human cancers, which is a prerequisite for defining future therapies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / physiology*
  • Casein Kinase II
  • Cell Line
  • Colonic Neoplasms / pathology
  • Cyclin B / physiology
  • Enzyme Activation / drug effects
  • Enzyme Inhibitors / pharmacology
  • Epithelial Cells / cytology
  • Epithelial Cells / enzymology*
  • G2 Phase / physiology*
  • Genes, cdc*
  • Genes, p53
  • HeLa Cells / drug effects
  • HeLa Cells / enzymology
  • Humans
  • Imidazoles / pharmacology
  • MAP Kinase Signaling System
  • Mitogen-Activated Protein Kinases / physiology
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / physiology
  • Nocodazole / pharmacology
  • Oligodeoxyribonucleotides, Antisense / genetics
  • Phosphorylation / drug effects
  • Protein Processing, Post-Translational / drug effects
  • Protein-Serine-Threonine Kinases / physiology*
  • Pyridines / pharmacology
  • Recombinant Fusion Proteins / physiology
  • Spindle Apparatus / drug effects
  • Spindle Apparatus / physiology
  • Stress, Physiological / enzymology
  • Transfection
  • Tumor Cells, Cultured / drug effects
  • Tumor Cells, Cultured / enzymology
  • Tumor Suppressor Protein p53 / deficiency
  • Tumor Suppressor Protein p53 / physiology*
  • p38 Mitogen-Activated Protein Kinases


  • Cyclin B
  • Enzyme Inhibitors
  • Imidazoles
  • Neoplasm Proteins
  • Oligodeoxyribonucleotides, Antisense
  • Pyridines
  • Recombinant Fusion Proteins
  • Tumor Suppressor Protein p53
  • Casein Kinase II
  • Protein-Serine-Threonine Kinases
  • Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases
  • SB 203580
  • Nocodazole