Genetic Instability Markers in Cancer

Area of Science:

• Oncology
• Immunology
• Genetics

Background:

• High mutation frequency correlates with neoepitope formation and tumor immunogenicity.
• Somatic hypermutation status may predict response to immune checkpoint inhibitors.
• Defects in DNA mismatch repair can lead to microsatellite instability (MSI).

Purpose of the Study:

• To describe methods for investigating the MSI phenotype in cancer.
• To link MSI to mutation load, neoantigen expression, and tumor immunogenicity.
• To evaluate MSI as a predictive biomarker for immunotherapy.

Main Methods:

• Utilizing molecular approaches on paraffin-embedded cancer tissues.
• Assessing genetic instability and microsatellite instability.
• Combining multiple strategies to detect the MSI phenotype.

Main Results:

• MSI is associated with increased mutation load and neoantigen expression.
• A hypermutated status, potentially driven by MSI, can enhance tumor immunogenicity.
• Methodological strategies were developed to investigate MSI in clinical samples.

Conclusions:

• MSI is a key factor in tumor immunogenicity and a potential biomarker for immunotherapy.
• Investigating MSI phenotype is essential for predicting treatment response.
• Molecular analysis of MSI in paraffin-embedded tissues offers a viable diagnostic approach.