MSI in melanoma refers to microsatellite instability found in melanoma tumors. This instability is due to deficient DNA repair mechanisms. According to research, a MSI phenotype was found in up to 25% of malignant melanomas analyzed.
Understanding Microsatellite Instability (MSI)
Microsatellite instability (MSI) is a condition characterized by changes in the length of microsatellites (short, repetitive DNA sequences) within cells.
Causes of MSI
- Deficient DNA Repair: The primary cause of MSI is a defect in the DNA mismatch repair (MMR) system. This system normally corrects errors that occur during DNA replication. When the MMR system is not functioning properly, these errors accumulate, leading to MSI.
MSI in Melanoma
While MSI is well-known in other cancers like colorectal cancer, it also occurs in melanoma. The reference indicates that MSI can be found in a significant proportion of melanoma cases:
- Prevalence: Studies have shown that up to 25% of malignant melanomas exhibit an MSI phenotype.
Implications of MSI
- Tumor Development: MSI can lead to the accumulation of mutations in genes that control cell growth and division, contributing to the development and progression of cancer.
