CHFR-associated early G2/M checkpoint defects in breast cancer cells.

Cell division is a highly regulated process. Checkpoints can halt cell-cycle progression due to adverse conditions such as misalignment of chromosomes to prevent missegregation. The search for new regulators of the cell cycle revealed the mitotic checkpoint gene CHFR (checkpoint with forkhead-associated and ring finger). CHFR coordinates an early mitotic phase by delaying chromosome condensation in response to a mitotic stress. Because aneuploidy and chromosome instability are common in malignant breast tumors, we screened 24 breast cancer cell lines for CHFR expression and demonstrated that 50% (12 of 24) of breast cancer cell lines had low CHFR levels. Expression of CHFR was reactivated with the demethylating agent 5-aza-2'-deoxycytidine (5-aza-dC) in two low-CHFR-expressing cell lines. Eleven of these 12 (92%) low-CHFR-expressing cell lines had an unusually high number of condensed chromosomes and high mitotic indices in response to nocodazole treatment. Transfection of CHFR in one of these cancer cell lines lowered the mitotic index after nocodazole treatment. In conclusion, our data suggested that low CHFR expression associated with high mitotic indices in response to nocodazole treatment were common in the breast cancer cell lines studied. Additional flow cytometry studies and analysis of a protein that interacts with CHFR in vitro, polo-like kinase 1 (PLK1), suggests that this CHFR-associated early G(2)/M checkpoint is complex, involving additional, as yet unidentified, proteins. Further analysis of CHFR in breast cancer cells will be important for understanding the complex mechanisms leading to aneuploidy and chromosomal instability observed in breast cancer.
AuthorsAyse E Erson, Elizabeth M Petty
JournalMolecular carcinogenesis (Mol Carcinog) Vol. 39 Issue 1 Pg. 26-33 (Jan 2004) ISSN: 0899-1987 [Print] United States
PMID14694445 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
CopyrightCopyright 2003 Wiley-Liss, Inc.
Chemical References
  • CHFR protein, human
  • Cell Cycle Proteins
  • Enzyme Inhibitors
  • Neoplasm Proteins
  • decitabine
  • Azacitidine
  • Azacitidine (analogs & derivatives, pharmacology)
  • Blotting, Western
  • Breast Neoplasms (genetics)
  • Cell Cycle Proteins (genetics, metabolism)
  • CpG Islands (genetics)
  • DNA Methylation
  • Enzyme Inhibitors (pharmacology)
  • Female
  • Flow Cytometry
  • G2 Phase (genetics)
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Mitosis (genetics)
  • Mitotic Index
  • Neoplasm Proteins (genetics, metabolism)
  • Tumor Cells, Cultured

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research network!

Choose Username:
Verify Password: