Related Experiment Video
Updated: Jun 17, 2026
14:57
Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
p53 suppresses structural chromosome instability after mitotic arrest in human cells
1Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA.
Oncogene
|January 12, 2010
Summary
The tumor suppressor p53 prevents chromosome instability in polyploid cells after mitotic arrest. This finding reveals a new mechanism for p53 tumor suppression and its role in cancer therapy.
Area of Science:
- Cell biology
- Cancer research
- Genetics
Background:
- The tumor suppressor p53 inhibits proliferation following prolonged mitotic checkpoint activation.
- The precise function of this p53-mediated antiproliferative response remains unclear.
Purpose of the Study:
- To investigate the role of p53 in suppressing structural chromosome instability after mitotic arrest.
- To elucidate the function of p53 in polyploid cells resulting from mitotic arrest.
Main Methods:
- Utilized HCT116 colon cancer cells and normal human fibroblasts.
- Induced mitotic arrest and polyploidization.
- Performed DNA break analysis and time-lapse videomicroscopy.
- Assessed p53-dependent cell cycle arrest and chromosome instability.
Main Results:
- DNA breaks occurred during mitotic arrest independently of p53.
- p53 suppressed proliferation and structural chromosome instability in polyploid cells post-mitotic arrest.
- Polyploidization without mitotic arrest did not induce significant chromosome instability or p53-dependent arrest.
- p53 also reduced the frequency and instability of spontaneous polyploids.
- p53(-/-) cells exhibited polyploidization often accompanied by mitotic arrest.
Conclusions:
- p53's postmitotic response prevents structural chromosome instability following prolonged mitotic checkpoint activation.
- This study proposes a novel tumor suppression mechanism for p53.
- p53 may influence the efficacy of antimitotic chemotherapy.
Related Concept Videos
02:23Abnormal 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...
02:36DNA Damage can Stall the Cell Cycle
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
02:36DNA Damage Can Stall the Cell Cycle
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
01:23Negative 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.
02:34Inhibition 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...
02:17Separation of Sister Chromatids
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...