Related Experiment Video

Updated: Jul 7, 2026

A Bilingual Computational Workflow for Identifying Potential PLK1 Inhibitors in American Sign Language and English
14:34

A Bilingual Computational Workflow for Identifying Potential PLK1 Inhibitors in American Sign Language and English

Published on: April 3, 2026

Plk1 depletion in nontransformed diploid cells activates the DNA-damage checkpoint

M Lei1, R L Erikson

  • 1Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA. minglei@fas.harvard.edu

Oncogene
|February 26, 2008
PubMed

Insights

Cancer cells require polo-like kinase 1 (Plk1) more than normal cells. Plk1 depletion causes cell cycle arrest and apoptosis in cancer cells but not in most normal cells.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Cancer Research

Background:

  • Polo-like kinase 1 (Plk1) is crucial for mitosis.
  • Previous studies showed Plk1 depletion causes mitotic arrest and apoptosis in cancer cells.
  • Normal diploid cell lines (hTERT-RPE1, MCF10A) tolerate Plk1 depletion better than cancer cells.

Purpose of the Study:

  • To investigate the long-term effects of Plk1 depletion in normal cell lines.
  • To generate and analyze Plk1-depleted clones of hTERT-RPE1 and MCF10A cells.
  • To compare the cellular response to Plk1 depletion in normal versus cancer cells.

Main Methods:

  • Lentivirus-based RNA interference for Plk1 depletion.
  • Generation of single-cell-derived clones of Plk1-depleted hTERT-RPE1 and MCF10A cells.
  • Cell proliferation assays, cell-cycle analysis, morphological assessment, and DNA-damage checkpoint activation analysis.

Main Results:

  • Long-term Plk1 depletion slowed hTERT-RPE1 cell proliferation and altered morphology.
  • Mild Plk1 depletion in MCF10A cells showed no obvious phenotype or cell-cycle arrest.
  • Severe Plk1 depletion in one MCF10A clone led to sporadic G2/M arrest and apoptosis, with DNA-damage checkpoint activation in both cell types.

Conclusions:

  • Normal diploid cells have a lower requirement for Plk1 compared to cancer cells.
  • Plk1 depletion elicits distinct responses in different normal cell lines.
  • Data reinforce the critical role of Plk1 in cancer cell viability.

More Related Videos

Detection and Visualization of DNA Damage-induced Protein Complexes in Suspension Cell Cultures Using the Proximity Ligation Assay13:10

Detection and Visualization of DNA Damage-induced Protein Complexes in Suspension Cell Cultures Using the Proximity Ligation Assay

Published on: June 9, 2017

Study of the DNA Damage Checkpoint using Xenopus Egg Extracts10:55

Study of the DNA Damage Checkpoint using Xenopus Egg Extracts

Published on: November 5, 2012

Related Concept Videos

DNA Damage Can Stall the Cell Cycle02:36

DNA 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...
DNA Damage can Stall the Cell Cycle02:36

DNA 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...
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.
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...
M-Cdk Drives Transition Into Mitosis02:15

M-Cdk Drives Transition Into Mitosis

Checkpoints throughout the cell cycle serve as safeguards and gatekeepers, allowing the cell cycle to progress in favorable conditions and slow or halt it in problematic ones. This regulation is known as the cell cycle control system.
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...