DNA mismatch repair and cancer
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Updated: Oct 9, 2026
Visualizing and Quantifying Endonuclease-Based Site-Specific DNA Damage
Published on: August 21, 2021
1Division of Human Cancer Genetics, Comprehensive Cancer Center, The Ohio State University, 690 Medical Research Facility, 420 W. 12th Avenue, Columbus, OH 43210, USA. peltomaki-1@medctr.osu.edu
Abstract:
Five human DNA mismatch repair genes have been identified that, when mutated, cause susceptibility to hereditary nonpolyposis colorectal cancer (HNPCC). Mutational inactivation of both copies of a DNA mismatch repair gene results in a profound repair defect and progressive accumulation of mutations throughout the genome. Some of the mutations confer selective advantage on the cells, giving rise to cancer. Recent discoveries suggest that apart from postreplication repair, DNA mismatch repair proteins have several other functions that are highly relevant to carcinogenesis. These include DNA damage surveillance, prevention of recombination between nonidentical sequences and participation in meiotic processes (chromosome pairing). A brief overview of these different features of the human DNA mismatch repair system will be provided, with the emphasis in their implications in cancer development.
Insights
Mutations in DNA mismatch repair genes increase cancer risk by causing widespread genetic errors. These genes also play roles in DNA surveillance and cell division, impacting cancer development.
Area of Science:
- Genetics
- Molecular Biology
- Oncology
Background:
- Five human DNA mismatch repair (MMR) genes are linked to hereditary nonpolyposis colorectal cancer (HNPCC).
- Inactivation of MMR genes leads to a significant repair defect, causing mutations to accumulate across the genome.
- Accumulated mutations can provide a selective advantage, driving cancer formation.
Purpose of the Study:
- To provide an overview of the functions of human DNA mismatch repair proteins.
- To emphasize the implications of these functions in cancer development.
- To explore roles beyond post-replication repair, including DNA damage surveillance, recombination prevention, and meiotic processes.
Main Methods:
- Review of existing literature on DNA mismatch repair genes and their functions.
- Analysis of the role of MMR proteins in carcinogenesis.
- Discussion of implications in cancer development.
Main Results:
- Mutational inactivation of MMR genes results in a profound repair defect and genomic instability.
- MMR proteins are involved in critical cellular processes relevant to cancer, such as DNA damage surveillance and meiosis.
- These additional functions highlight the multifaceted role of MMR in preventing or promoting cancer.
Conclusions:
- The human DNA mismatch repair system is crucial for maintaining genomic integrity.
- Dysfunctional MMR contributes to cancer susceptibility and progression through various mechanisms.
- Understanding the diverse roles of MMR proteins offers insights into cancer prevention and treatment strategies.
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