Related Experiment Video

Updated: Oct 5, 2026

Characterization at the Molecular Level using Robust Biochemical Approaches of a New Kinase Protein
11:23

Characterization at the Molecular Level using Robust Biochemical Approaches of a New Kinase Protein

Published on: June 30, 2019

Reduced expression and impaired kinase activity of a Chk2 mutant identified in human lung cancer

S Matsuoka1, T Nakagawa, A Masuda

  • 1Howard Hughes Medical Institute, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA. matsuoka@bcm.tmc.edu

Cancer Research
|July 17, 2001
PubMed

Insights

Checkpoint kinase 2 (Chk2) mutations in lung cancer reduce its stability and expression, inactivating DNA damage repair pathways. This study confirms Chk2 pathway inactivation contributes to lung cancer development.

Area of Science:

  • Molecular Biology
  • Oncology
  • Genetics

Background:

  • Checkpoint kinase 2 (Chk2) is crucial for DNA damage response.
  • Somatic mutations in CHK2 have been identified in human lung cancer.
  • The functional impact of these mutations on Chk2 activity and stability is not fully understood.

Purpose of the Study:

  • To investigate the functional consequences of a CHK2 mutation found in lung cancer.
  • To determine the effect of the mutation on Chk2 kinase activity, phosphorylation, and protein stability.
  • To assess the role of Chk2 inactivation in lung cancer development.

Main Methods:

  • In vitro kinase assays to compare wild-type and mutant Chk2 activity.
  • Analysis of Chk2 phosphorylation and activation after ionizing radiation.
  • Western blot analysis to determine protein expression levels and stability in various cell types.

Main Results:

  • The CHK2 mutant showed modestly reduced in vitro kinase activity compared to wild type.
  • Mutant Chk2 was normally phosphorylated and activated by ionizing radiation.
  • Mutant Chk2 protein exhibited reduced stability, leading to significantly lower expression levels (20% of wild type).

Conclusions:

  • The DNA damage checkpoint pathway involving Chk2 is inactivated in human lung cancer.
  • Reduced Chk2 expression, due to decreased protein stability, is a significant mechanism contributing to lung cancer development.
  • These findings highlight the importance of Chk2 in maintaining genomic stability and preventing lung tumorigenesis.

More Related Videos

Utilizing 18F-FDG PET/CT Imaging and Quantitative Histology to Measure Dynamic Changes in the Glucose Metabolism in Mouse Models of Lung Cancer06:51

Utilizing 18F-FDG PET/CT Imaging and Quantitative Histology to Measure Dynamic Changes in the Glucose Metabolism in Mouse Models of Lung Cancer

Published on: July 21, 2018

Characterize Disease-related Mutants of RAF Family Kinases by Using a Set of Practical and Feasible Methods07:49

Characterize Disease-related Mutants of RAF Family Kinases by Using a Set of Practical and Feasible Methods

Published on: July 17, 2019

Related Concept Videos

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...
Loss of Tumor Suppressor Gene Functions01:12

Loss of Tumor Suppressor Gene Functions

Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
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...
The Retinoblastoma Gene01:20

The Retinoblastoma Gene

Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
Cancer-Critical Genes II: Tumor Suppressor Genes01:05

Cancer-Critical Genes II: Tumor Suppressor Genes

Genes usually encode proteins necessary for the proper functioning of a healthy cell. Mutations can often cause changes to the gene expression pattern, thereby altering the phenotype.
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...