Splicing function of mitotic regulators links R-loop-mediated DNA damage to tumor cell killing

J Cell Biol. 2015 Apr 27;209(2):235-46. doi: 10.1083/jcb.201409073.


Although studies suggest that perturbing mitotic progression leads to DNA damage and p53 activation, which in turn lead to either cell apoptosis or senescence, it remains unclear how mitotic defects trigger p53 activation. We show that BuGZ and Bub3, which are two mitotic regulators localized in the interphase nucleus, interact with the splicing machinery and are required for pre-mRNA splicing. Similar to inhibition of RNA splicing by pladienolide B, depletion of either BuGZ or Bub3 led to increased formation of RNA-DNA hybrids (R-loops), which led to DNA damage and p53 activation in both human tumor cells and primary cells. Thus, R-loop-mediated DNA damage and p53 activation offer a mechanistic explanation for apoptosis of cancer cells and senescence of primary cells upon disruption of the dual-function mitotic regulators. This demonstrates the importance of understanding the full range of functions of mitotic regulators to develop antitumor drugs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis*
  • Biomarkers / analysis
  • Blotting, Western
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cellular Senescence
  • DNA Damage*
  • Drosophila melanogaster / metabolism
  • Fibroblasts / cytology
  • Fibroblasts / metabolism
  • Fluorescent Antibody Technique
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Immunoprecipitation
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Mitosis / physiology
  • Neoplasms / genetics
  • Neoplasms / metabolism
  • Neoplasms / pathology*
  • Poly-ADP-Ribose Binding Proteins
  • RNA Splicing*
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tumor Cells, Cultured
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism*


  • BUB3 protein, human
  • Biomarkers
  • Cell Cycle Proteins
  • Microtubule-Associated Proteins
  • Poly-ADP-Ribose Binding Proteins
  • RNA, Messenger
  • TP53 protein, human
  • Tumor Suppressor Protein p53
  • ZNF207 protein, human