Microsatellite and Microsatellite Instability

Microsatellites, also known as short tandem repeats, consist of repeated sequences of 1–6 nucleotides. They are highly polymorphic in their lengths due to variability in repeat numbers. This has led them to be widely used as genetic markers in various research areas. Researchers also found that microsatellites contributed more on de novo mutations, regulate gene expression, maintain DNA structure such as G-quadruplex, and so on. Microsatellite instability (MSI) is a situation in which hypermutation occurs in microsatellite region of malignancies due to a deficient DNA mismatch repair system. Recently, MSI has been reported in diverse cancer types including colorectal cancer, endometrial, ovarian, gastric, and prostate cancer, glioblastoma etc. And the fact that microsatellite instability tumors respond well to immunotherapy makes the study and application of microsatellite and microsatellite instability extremely popular.

This Research Topic focuses on the germline and somatic variant detection, mechanism, and application of microsatellite and microsatellite instability in cancer. We welcome novel experimental and computational methods to accurately detect microsatellite mutation and microsatellite instability based on high-throughput sequencing, particularly in the situation of low allele fractions. With the accurate profiling of millions of microsatellites in tumor individuals, we hope to clarify the mechanism of microsatellite in tumorigenesis and tumor therapy. Moreover, we want to apply the biomarkers of microsatellite instability to early screening and diagnosis of cancer and explore more biomarkers for microsatellite stable cancers. We believe that some new technologies such as target gene sequencing, Pacbio HiFi sequencing, single cell sequencing etc. will help to achieve the goal of this research topic. 

This Research Topic aims to provide a comprehensive overview on recent progress in microsatellite and microsatellite instability. We welcome the submission of Review, Methods, Original Research, and Clinical Trial articles covering, but not limited to, the following topics:

1) Novel detection methods for microsatellite mutations and microsatellite instability

2) Mechanism of microsatellite and microsatellite instability in tumorigenesis

3) The influence of microsatellite instability on gene expression and epigenetics

4) Difference of microsatellite instability and tumor mutation burden in tumor therapy

5) Difference of tumor evolution between microsatellite instable tumor and microsatellite stable tumor

6) New biomarkers or therapeutic strategies for microsatellite stable tumors