2023 World Conference on Lung Cancer (Posters)-EP02.03. Defining Genetic Instability at Tetranucleotide Repeats (EMAST) In a Non-small Cell Lung Cancer

EP02.03. Defining Genetic Instability at Tetranucleotide Repeats (EMAST) In a Non-small Cell Lung Cancer - PDF(Abstract)

Back to course

Pdf Summary

This presentation at the WCLC 2023 conference discusses the identification of genetic instability at tetranucleotide repeats in non-small cell lung cancer (NSCLC). The study focuses on the microsatellite alterations at selected tetranucleotide repeats (EMAST), a form of microsatellite instability that has been associated with MSH3 protein deficiency in colorectal cancer. However, its significance in lung cancer is poorly understood.<br /><br />The researchers developed PCR-based tests and immunohistochemistry to identify MSH3 dysfunction and EMAST in lung cancer. They analyzed a cohort of 219 patients with matched normal and tumor tissue/DNA. Three multiplex PCR protocols were developed for a panel of 10 EMAST markers, and PCR products were separated using capillary electrophoresis.<br /><br />The results showed that tetranucleotide repeat instability was present in 30% of lung cancers, with majority exhibiting EMAST in the L17686 marker and at least one other marker. Squamous cell carcinoma had the highest prevalence of EMAST, followed by adenocarcinoma. Immunohistochemical staining revealed patchy loss of nuclear MSH3 expression and increased cytoplasmic expression in these cancers.<br /><br />The researchers suggest that EMAST may be more frequent in lung cancer than the known frequency of MSH3 coding sequence alterations. They propose that detecting MSH3 protein dysfunction through PCR or immunohistochemistry may help identify lung cancers responsive to treatments targeting DNA repair defects.<br /><br />Overall, this study highlights the presence of genetic instability at tetranucleotide repeats in NSCLC and suggests that EMAST could be a potential biomarker for targeted lung cancer treatment.

Asset Subtitle

Hannah Parker

Meta Tag

Speaker Hannah Parker

Topic Tumor Biology: Preclinical Biology - Regulatory Mechanisms

Keywords

genetic instability

tetranucleotide repeats

non-small cell lung cancer

EMAST

MSH3 protein deficiency

PCR-based tests

immunohistochemistry

squamous cell carcinoma

adenocarcinoma

biomarker