Related Experiment Video
Updated: Jul 29, 2026
Studying Cell Cycle-regulated Gene Expression by Two Complementary Cell Synchronization Protocols
Published on: June 6, 2017
Cell cycle checkpoint status in human malignant mesothelioma cell lines: response to gamma radiation
1INSERM EMI 9909, Faculté de Médecine, Université Paris XII, Creteil, France.
Abstract:
Knowledge of the function of the cell cycle checkpoints in tumour cells may be important to develop treatment strategies for human cancers. The protein p53 is an important factor that regulates cell cycle progression and apoptosis in response to drugs. In human malignant mesothelioma, p53 is generally not mutated, but may be inactivated by SV40 early region T antigen (SV40 Tag). However, the function of p53 has not been investigated in mesothelioma cells. Here, we investigated the function of the cell cycle checkpoints in six human mesothelioma cell lines (HMCLs) by studying the cell distribution in the different phases of the cell cycle by flow cytometry, and expression of cell cycle proteins, p53, p21(WAF1/CIP1) and p27(KIP1). In addition, we studied p53 gene mutations and expression of SV40 Tag. After exposure to gamma-radiation, HMCLs were arrested either in one or both phases of the cell cycle, demonstrating a heterogeneity in cell cycle control. G1 arrest was p21(WAF1/CIP1)- and p53-dependent. Lack of arrest in G1 was not related to p53 mutation or binding to SV40 Tag, except in one HMCL presenting a missense mutation at codon 248. These results may help us to understand mesothelioma and develop new treatments.
Insights
Investigating cell cycle checkpoints in mesothelioma cells revealed heterogeneity in response to radiation. G1 arrest was dependent on p53 and p21(WAF1/CIP1), offering insights for cancer treatment strategies.
Area of Science:
- Oncology
- Molecular Biology
- Cell Biology
Background:
- Cell cycle checkpoints are crucial for preventing cancer progression.
- The tumor suppressor protein p53 regulates cell cycle and apoptosis.
- In malignant mesothelioma, p53 is typically not mutated but can be inactivated by SV40 Tag.
Purpose of the Study:
- To investigate the function of cell cycle checkpoints in human mesothelioma cell lines (HMCLs).
- To analyze the role of p53, p21(WAF1/CIP1), and p27(KIP1) in cell cycle regulation within these cells.
- To examine p53 gene mutations and SV40 Tag expression in HMCLs.
Main Methods:
- Flow cytometry was used to analyze cell distribution across cell cycle phases.
- Expression levels of cell cycle proteins (p53, p21(WAF1/CIP1), p27(KIP1)) were measured.
- p53 gene mutations and SV40 Tag expression were assessed after gamma-radiation exposure.
Main Results:
- HMCLs exhibited heterogeneous cell cycle arrest (G1, G2/M) following gamma-radiation.
- G1 arrest was dependent on p53 and p21(WAF1/CIP1) expression.
- Lack of G1 arrest was not linked to p53 mutation or SV40 Tag binding, except in one cell line with a p53 mutation.
Conclusions:
- Mesothelioma cells display varied cell cycle control mechanisms.
- p53 and p21(WAF1/CIP1) play a significant role in mediating G1 arrest in response to DNA damage.
- Understanding these pathways can inform novel therapeutic approaches for mesothelioma.
Related Concept Videos
02:36DNA Damage can Stall the Cell Cycle
02:36DNA Damage Can Stall the Cell Cycle
01:28The Cell Cycle Control System
Cyclins and cyclin-dependent kinases (Cdks) are the primary cell cycle regulators and function at the cell...