# DNA mismatch repair system expression in salivary gland tumors: A Systematic Review

## TL;DR

This review examines how DNA mismatch repair proteins are expressed in salivary gland tumors and finds reduced levels linked to tumor development.

## Contribution

The study systematically reviews MMR protein expression in salivary gland tumors, highlighting its potential role in oncogenesis.

## Key findings

- Reduced expression of MMR proteins like hMSH2, hMLH1, hMSH3, and hMSH6 was observed in salivary gland tumors.
- The reduction in MMR proteins correlates with both benign and malignant tumor development.
- Further research is needed to clarify the role of MMR protein expression as a biomarker.

## Abstract

The DNA mismatch repair (MMR) system serves as a sophisticated guardian of the precise functioning of the human genome. Dysregulation within this system is linked to the oncogenesis process. Reduced expression of MMR system proteins identified in salivary gland tumors (SGTs) suggests an increased risk of tumoral occurrence. This study aims to analyze the expression of MMR proteins in SGTs and discuss the relevance of this association to the development of these neoplasms.

This review was conducted following the PRISMA guidelines and was registered in PROSPERO (CRD42023465590). A comprehensive search of the PubMed/MEDLINE, Web of Science, Scopus, Embase, and ProQuest (non-peer reviewed platform) was performed to answer the question “Do DNA MMR system proteins exhibit expression in SGTs?”. The methodological quality of the selected studies was assessed using the JBI’s Critical Appraisal Tool.

A total of 142 patients with benign SGTs and 84 with malignant SGTs were included in this review. The literature analysis showed a noTable reduction in the expression of DNA MMR system proteins (hHMS2, hMLH1, hMSH3 and hMSH6) in the percentage of marked cells.

The reduction in the expression of the DNA MMR system proteins suggests an interesting correlation with the development of malignant and benign SGTs. Nevertheless, further investigations are warranted to better clarify the precision of measuring biomarker protein expression.

Key words:Salivary gland neoplasms, salivary gland cancer, DNA mismatch repair.