What is the microsatellite instability?

Listen to pronunciation. (MY-kroh-SA-teh-lite in-stuh-BIH-lih-tee) A change that occurs in certain cells (such as cancer cells) in which the number of repeated DNA bases in a microsatellite (a short, repeated sequence of DNA) is different from what it was when the microsatellite was inherited.

What is microsatellite instability and how can it drive cancer?

Microsatellite instability-high cancer cells may have a defect in the ability to correct mistakes that occur when DNA is copied in the cell. Microsatellite instability is found most often in colorectal cancer, gastric cancer, and endometrial cancer, but it may also be found in many other types of cancer.

How do you identify microsatellite instability?

Microsatellite instability testing is used to identify tumors caused by defective MMR by comparing the number of nucleotide repeats in a panel of microsatellite markers in normal tissue with the number from tumor tissue from the same individual.

How does microsatellite instability cause cancer?

These data suggest that H. pylori impairs central DNA repair mechanisms, inducing a transient mutator phenotype, which renders gastric epithelial cells vulnerable to the accumulation of genetic instability, thus contributing to gastric carcinogenesis in infected individuals[29].

What does it mean to have microsatellite instability?

Microsatellite instability (MSI) is the condition of genetic hypermutability (predisposition to mutation) that results from impaired DNA mismatch repair (MMR). The presence of MSI represents phenotypic evidence that MMR is not functioning normally.

What is the H & E stain for microsatellite instability?

H&E stain. Microsatellite instability ( MSI) is the condition of genetic hypermutability (predisposition to mutation) that results from impaired DNA mismatch repair (MMR). The presence of MSI represents phenotypic evidence that MMR is not functioning normally.

How is microsatellite instability related to dMMR?

The repetitive nature of these regions makes them particularly sensitive to mismatch errors that in case of dMMR result in the accumulation of mutations of repeat length alterations, defined as microsatellite instability (MSI), which is easily uncovered by the analysis of polyA microsatellites.

How is microsatellite instability a hypermutable phenotype?

Microsatellite instability (MSI) is a hypermutable phenotype caused by the loss of DNA mismatch repair activity.