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Overexpression of DOC-1R inhibits cell cycle G1/S transition by repressing CDK2 expression and activation

Qi Liu1, Xing Liu, Jinlan Gao

  • 1The Research Center for Medical Genomics, MOH Key Laboratory of Cell Biology and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China.

International Journal of Biological Sciences
|June 20, 2013
PubMed

Insights

Deleted in oral cancer-1 related (DOC-1R) protein acts as a tumor suppressor by inhibiting cell cycle progression. DOC-1R overexpression halts DNA replication and suppresses CDK2 activation, crucial for cancer cell growth.

Area of Science:

  • Oncology
  • Molecular Biology
  • Cell Cycle Regulation

Background:

  • The deleted in oral cancer-1 related (DOC-1R) protein is a novel, putative tumor suppressor.
  • Understanding DOC-1R's role in cancer is crucial for developing targeted therapies.

Purpose of the Study:

  • To investigate the antitumor activity of DOC-1R.
  • To elucidate the molecular mechanisms underlying DOC-1R's tumor-suppressive functions.

Main Methods:

  • Overexpression of DOC-1R in HeLa cells.
  • Cell cycle analysis using flow cytometry and BrdU incorporation.
  • Assessment of CDK2 kinase activity.
  • Gene and protein expression analysis via RT-PCR and Western blotting.
  • Protein-protein interaction studies (GST pull-down, immunoprecipitation).

Main Results:

  • DOC-1R overexpression inhibited G1/S phase transition and DNA replication.
  • DOC-1R suppressed CDK2 activity, expression (mRNA and protein), and activation.
  • DOC-1R overexpression led to decreased levels of cyclin D1 and E, and increased levels of p21, p27, and p53.
  • DOC-1R directly associated with CDK2, hindering its interaction with cyclin E and A.

Conclusions:

  • DOC-1R exhibits antitumor effects by inhibiting cell cycle progression.
  • DOC-1R negatively regulates the G1 phase and G1/S transition by suppressing CDK2 expression and activation.
Keywords:
CDK2CKI.DOC-1RG1/S transitioncyclin Acyclin E

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