What is a microsatellite instability?

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.

Is MSI-H good or bad?

The poor differentiation, advanced T stage, early N stage and low LNR were associated with MSI-H. Among these factors, poor differentiation, and advanced T stage were associated with a poor prognosis, and the other factors correlated with MSI-H were associated with a good prognosis.

Is MSI the same as MMR?

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 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.

Are there immunotherapy options for microsatellite instability?

With the recent development of MSI detection technology and immunosuppressant in tumor therapy, researchers found that MSI-H tumors respond well to immunotherapy. FDA approved PD-L1 (programed cell death ligand 1) blockade Keytruda to treat MSI-H/MMR patients.

How is loss of heterozygosity / microsatellite instability detected?

PCR–Based Detection: Loss of Heterozygosity/Microsatellite Instability. Polymerase chain reaction (PCR) is used to amplify a sequence with known MSI. Typically, the alteration is detected by standard DNA gel electrophoresis, and the difference in the length of the MSI is seen as difference in migration of the band.