# The role of Fusobacterium nucleatum in the tumour microenvironment and carcinogenesis of oral and colonic malignancies

## TL;DR

This paper reviews how Fusobacterium nucleatum may contribute to the development and progression of oral and colorectal cancers by affecting the tumor environment and immune response.

## Contribution

The paper synthesizes current evidence on F. nucleatum's role in carcinogenesis and highlights its potential as a target for cancer prevention and treatment.

## Key findings

- Fusobacterium nucleatum is associated with DNA damage and increased cellular proliferation in oral and colorectal tumors.
- The bacterium promotes tumor growth by inducing chronic inflammation and impairing immune cell function.
- F. nucleatum infection is linked to epithelial-to-mesenchymal transition and worse cancer prognosis.

## Abstract

The intra-tumoural microbiome is an increasing area of research with potential benefits in cancer diagnostics and treatment development. Numerous studies have implicated Fusobacterium nucleatum, a member of the oral microbiota, in the development, immune evasion, and dissemination of oral and colorectal tumours. Although F. nucleatum is yet to be classified as a cause or consequence of cancer, reports indicate the microorganism’s involvement in DNA damage, pathologic glucose uptake, and cellular proliferation. This accumulation of genetic instability is consistent with the multistep nature of malignant neoplasm progression. Virulence factors of F. nucleatum were shown to maintain an unresolved inflammatory state and impair the normal function of immune cells. The accompanying pro-inflammatory conditions facilitate vasculature remodelling, expediting tumour expansion, through a range of mechanisms. Pro-metastatic epithelial-to-mesenchymal transition and changes in gene expression have been observed in cancer cells upon F. nucleatum infection, suggesting an association with poorer prognosis. As a frequently encountered microorganism in the oral and colorectal intra-tumoural microbiome, F. nucleatum represents an intriguing, yet cautious research prospect with opportunities for novel prevention and therapeutic strategies. The objective of this work is to review the relevant evidence, taking into account the complexity of the tumour microenvironment.

Review and synthesis of the role in malignancies, genomic analysis, and therapeutic potential of a Gram-negative oral pathogen, Fusobacterium nucleatum.