Related Experiment Video

Updated: Jun 9, 2026

Analysis of Cell Cycle Position in Mammalian Cells
12:19

Analysis of Cell Cycle Position in Mammalian Cells

Published on: January 21, 2012

Cyclin D1 blocks the anti-proliferative function of RUNX3 by interfering with RUNX3-p300 interaction

Kazunori Iwatani1, Tetsuhiro Fujimoto, Takaaki Ito

  • 1Division of Pathology and Experimental Medicine, Graduate School of Life Sciences, Kumamoto University, Honjo 1-1-1, Kumamoto-shi 861-8556, Japan.

Biochemical and Biophysical Research Communications
|August 31, 2010
PubMed

Insights

Cyclin D1 protein suppresses RUNX3

Area of Science:

  • Molecular Biology
  • Cancer Research
  • Cell Biology

Background:

  • Deregulation of cyclin D1 is common in human cancers.
  • Cyclin D1's transcriptional functions are implicated in cancer development.
  • RUNX3 acts as a tumor suppressor in various cancers.

Purpose of the Study:

  • To investigate the non-canonical transcriptional role of cyclin D1 in lung cancer.
  • To elucidate the mechanism by which cyclin D1 affects RUNX3 activity.
  • To determine if cyclin D1's function is kinase-dependent.

Main Methods:

  • Investigated protein-protein interactions between cyclin D1 and RUNX3.
  • Assessed the impact of cyclin D1 on RUNX3 acetylation.
  • Monitored the expression of cyclin-dependent kinase (cdk) inhibitor p21.
  • Examined the role of cdk4/6 kinase activity.

Main Results:

  • Cyclin D1 directly binds to RUNX3, inhibiting its activity.
  • Cyclin D1 interferes with RUNX3's interaction with p300.
  • p300-dependent RUNX3 acetylation is inhibited by cyclin D1.
  • Cyclin D1 negatively regulates p21 expression independently of cdk4/6 kinase activity.

Conclusions:

  • Cyclin D1 acts as a transcriptional switch, repressing RUNX3 tumor suppressor activity in cancer cells.
  • This non-canonical function of cyclin D1 may be crucial for epithelial cell neoplastic transformation.
  • Understanding this mechanism offers potential therapeutic targets for cancers where RUNX3 is important.

More Related Videos

A Quantitative Assay to Study Protein:DNA Interactions, Discover Transcriptional Regulators of Gene Expression, and Identify Novel Anti-tumor Agents06:43

A Quantitative Assay to Study Protein:DNA Interactions, Discover Transcriptional Regulators of Gene Expression, and Identify Novel Anti-tumor Agents

Published on: August 31, 2013

Effect of Anti-c-fms Antibody on Osteoclast Formation and Proliferation of Osteoclast Precursor In Vitro07:51

Effect of Anti-c-fms Antibody on Osteoclast Formation and Proliferation of Osteoclast Precursor In Vitro

Published on: March 18, 2019

Related Concept Videos

Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Inhibition of CDK Activity02:34

Inhibition of CDK Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Negative Regulator Molecules01:23

Negative Regulator Molecules

Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
Positive Regulator Molecules02:39

Positive Regulator Molecules

Mitotic cell division results in daughter cells that exactly resemble the parent cell. However, errors in the DNA replication or distribution of genetic material may lead to genetic mutations that may be passed down to every new cell formed from the resulting abnormal cell. Propagation of such mutant cells is restricted through checkpoint mechanisms present at different stages of the cell cycle. These checkpoints involve regulator molecules that either promote or demote cell cycle events.
Positive Regulator Molecules01:45

Positive Regulator Molecules

To consistently produce healthy cells, the cell cycle—the process that generates daughter cells—must be precisely regulated.
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...