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The p38 Mitogen-Activated Protein Kinase Pathway Links the DNA Mismatch Repair System to the G2 Checkpoint and to Resistance to Chemotherapeutic DNA-Methylating Agents
- Source :
- Molecular and Cellular Biology. 23:8306-8315
- Publication Year :
- 2003
- Publisher :
- Informa UK Limited, 2003.
-
Abstract
- Although human cells exposed to DNA-methylating agents undergo mismatch repair (MMR)-dependent G(2) arrest, the basis for the linkage between MMR and the G(2) checkpoint is unclear. We noted that mitogen-activated protein kinase p38alpha was activated in MMR-proficient human glioma cells exposed to the chemotherapeutic methylating agent temozolomide (TMZ) but not in paired cells made MMR deficient by expression of a short inhibitory RNA (siRNA) targeted to the MMR protein Mlh1. Furthermore, activation of p38alpha in MMR-proficient cells was associated with nuclear inactivation of the cell cycle regulator Cdc25C phosphatase and its downstream target Cdc2 and with activation of the G(2) checkpoint, actions which were suppressed by the p38alpha/beta inhibitors SB203580 and SB202590 or by expression of a p38alpha siRNA. Finally, pharmacologic or genetic inhibition of p38alpha increased the sensitivity of MMR-proficient cells to the cytotoxic actions of TMZ by increasing the percentage of cells that underwent mitotic catastrophe as a consequence of G(2) checkpoint bypass. These results suggest that p38alpha links DNA MMR to the G(2) checkpoint and to resistance to chemotherapeutic DNA-methylating agents. The p38 pathway may therefore represent a new target for the development of agents to sensitize tumor cells to chemotherapeutic methylating agents.
- Subjects :
- G2 Phase
DNA Repair
Base Pair Mismatch
Pyridines
DNA repair
Biology
p38 Mitogen-Activated Protein Kinases
Cell Line, Tumor
Temozolomide
Humans
Enzyme Inhibitors
Protein kinase A
Antineoplastic Agents, Alkylating
Cell Growth and Development
Molecular Biology
Mitotic catastrophe
Cyclin-dependent kinase 1
Base Sequence
Imidazoles
DNA, Neoplasm
Cell Biology
DNA Methylation
Cell cycle
G2-M DNA damage checkpoint
digestive system diseases
Dacarbazine
Enzyme Activation
Drug Resistance, Neoplasm
DNA methylation
Cancer research
DNA mismatch repair
Mitogen-Activated Protein Kinases
Subjects
Details
- ISSN :
- 10985549
- Volume :
- 23
- Database :
- OpenAIRE
- Journal :
- Molecular and Cellular Biology
- Accession number :
- edsair.doi.dedup.....b45cdac7b0c5e03ee78802f068e36570
- Full Text :
- https://doi.org/10.1128/mcb.23.22.8306-8315.2003