Related Experiment Video

Updated: May 31, 2026

Silencing of BRCA2 to Identify Novel BRCA2-regulated Biological Functions in Cultured Human Cells
09:24

Silencing of BRCA2 to Identify Novel BRCA2-regulated Biological Functions in Cultured Human Cells

Published on: August 12, 2015

Compromised CDK1 activity sensitizes BRCA-proficient cancers to PARP inhibition

Neil Johnson1, Yu-Chen Li, Zandra E Walton

  • 1Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts, USA.

Nature Medicine
|June 28, 2011
PubMed

Insights

Inhibiting cyclin-dependent kinase 1 (Cdk1) impairs homologous recombination repair, making BRCA-proficient cancers sensitive to PARP inhibitors. This expands potential therapeutic strategies beyond BRCA-deficient tumors.

Area of Science:

  • Molecular oncology
  • DNA repair mechanisms
  • Cancer therapeutics

Background:

  • Homologous recombination (HR) deficiency, seen in BRCA1/BRCA2 mutations, confers sensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors.
  • BRCA-deficient tumors are rare, limiting PARP inhibitor monotherapy's broad applicability.
  • Cyclin-dependent kinase 1 (Cdk1) phosphorylation of BRCA1 is crucial for DNA repair foci formation.

Purpose of the Study:

  • To investigate the role of Cdk1 in homologous recombination repair.
  • To evaluate the potential of combined Cdk1 and PARP inhibition in BRCA-proficient cancers.
  • To determine if Cdk1 inhibition sensitizes cancer cells to PARP inhibitors without affecting normal cells.

Main Methods:

  • Depletion or inhibition of Cdk1 in cancer cell lines.
  • Assessment of DNA repair by homologous recombination.
  • Combination therapy studies involving Cdk1 and PARP inhibitors in BRCA-wild-type cancer cells and tumor xenograft models.

Main Results:

  • Cdk1 inhibition compromised homologous recombination repair.
  • Combined Cdk1 and PARP inhibition reduced colony formation and delayed tumor xenograft growth in BRCA-wild-type cancer cells.
  • Tumor regression and prolonged survival were observed in a lung adenocarcinoma mouse model treated with combined inhibitors.
  • Cdk1 inhibition did not sensitize normal cells or tissues to PARP inhibition.

Conclusions:

  • Reduced Cdk1 activity impairs BRCA1 function and homologous recombination repair.
  • Cdk1 inhibition is a viable strategy to sensitize BRCA-proficient cancers to PARP inhibitors.
  • This approach broadens the therapeutic potential of PARP inhibitors to a wider range of cancer patients.

More Related Videos

Assessment of Global DNA Double-Strand End Resection using BrdU-DNA Labeling coupled with Cell Cycle Discrimination Imaging06:44

Assessment of Global DNA Double-Strand End Resection using BrdU-DNA Labeling coupled with Cell Cycle Discrimination Imaging

Published on: April 28, 2021

Laser Microirradiation to Study In Vivo Cellular Responses to Simple and Complex DNA Damage10:44

Laser Microirradiation to Study In Vivo Cellular Responses to Simple and Complex DNA Damage

Published on: January 31, 2018

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...
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...
Targeted Cancer Therapies02:57

Targeted Cancer Therapies

The targeted cancer therapies, also known as “molecular targeted therapies,” take advantage of the molecular and genetic differences between the cancer cells and the normal cells. It needs a thorough understanding of the cancer cells to develop drugs that can target specific molecular aspects that drive the growth, progression, and spread of cancer cells without affecting the growth and survival of other normal cells in the body.
There are several types of targeted therapies against specific...
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.