Fusobacterium nucleatum Potentiates Intestinal Tumorigenesis in Mice via a Toll-Like Receptor 4/p21-Activated Kinase 1 Cascade.

Abstract

BACKGROUND:

The underlying pathogenic mechanism of Fusobacterium nucleatum in the carcinogenesis of colorectal cancer has been poorly understood.

METHODS:

Using C57BL/6-ApcMin/+ mice, we investigated gut microbial structures with F. nucleatum, antibiotics, and Toll-like receptor 4 (TLR4) antagonist TAK-242 treatment. In addition, we measured intestinal tumor formation and the expression of TLR4, p21-activated kinase 1 (PAK1), phosphorylated-PAK1 (p-PAK1), phosphorylated-β-catenin S675 (p-β-catenin S675), and cyclin D1 in mice with different treatments.

RESULTS:

Fusobacterium nucleatum and antibiotics treatment altered gut microbial structures in mice. In addition, F. nucleatum invaded into the intestinal mucosa in large amounts but were less abundant in the feces of F. nucleatum-fed mice. The average number and size of intestinal tumors in F. nucleatum groups was significantly increased compared to control groups in ApcMin/+ mice (P < 0.05). The expression of TLR4, PAK1, p-PAK1, p-β-catenin S675, and cyclin D1 was significantly increased in F. nucleatum groups compared to the control groups (P < 0.05). Moreover, TAK-242 significantly decreased the average number and size of intestinal tumors compared to F. nucleatum groups (P < 0.05). The expression of p-PAK1, p-β-catenin S675, and cyclin D1 was also significantly decreased in the TAK-242-treated group compared to F. nucleatum groups (P < 0.05).

CONCLUSIONS:

Fusobacterium nucleatum potentiates intestinal tumorigenesis in ApcMin/+ mice via a TLR4/p-PAK1/p-β-catenin S675 cascade. Fusobacterium nucleatum-induced intestinal tumorigenesis can be inhibited by TAK-242, implicating TLR4 as a potential target for the prevention and therapy of F. nucleatum-related colorectal cancer.

• Authors: Yaxin Wu, Jiao Wu, Ting Chen, Qing Li, Wei Peng, Huan Li, Xiaowei Tang, Xiangsheng Fu
• Journal: Digestive diseases and sciences (Dig Dis Sci) Vol. 63 Issue 5 Pg. 1210-1218 (05 2018) ISSN: 1573-2568 [Electronic] United States
• PMID: 29508166 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Bacterial Agents
• Biomarkers
• Tlr4 protein, mouse
• Toll-Like Receptor 4
• beta Catenin
• Pak1 protein, mouse
• p21-Activated Kinases

Topics

• Animals
• Anti-Bacterial Agents (pharmacology)
• Biomarkers (metabolism)
• Blotting, Western
• Colorectal Neoplasms (metabolism, microbiology, pathology)
• Feces (microbiology)
• Fusobacterium nucleatum
• Gastrointestinal Microbiome (drug effects)
• Immunohistochemistry
• In Situ Hybridization, Fluorescence
• Intestinal Mucosa (drug effects, metabolism, microbiology, pathology)
• Male
• Mice
• Mice, Inbred C57BL
• Random Allocation
• Signal Transduction
• Toll-Like Receptor 4 (metabolism)
• beta Catenin (metabolism)
• p21-Activated Kinases (metabolism)