Menu

Manipulative Microbiomes

Gut bacteria control tumor growth via the mammalian immune system.

Apr 1, 2015
Jenny Rood

CANCER COMMAND: The microbiome (as puppeteer) affects the immune system’s influence on tumor growth, in tandem with inflammatory cytokines (dogs).ILLUSTRATION BY MELANIE R. RUTKOWSKI AND GRAPHIC DESIGN BY SUBTERRANEAN GRAFIX

EDITOR'S CHOICE IN CELL & MOLECULAR BIOLOGY

The paper
M.R. Rutkowski et al., “Microbially driven TLR5-dependent signaling governs distal malignant progression through tumor-promoting inflammation,” Cancer Cell, 27:27-40, 2015.

The polymorphism
The gut microbiome influences nonintestinal cancer progression, but the role of toll-like receptor 5 (TLR5), an immune system protein that recognizes commensal bacteria, was a mystery. As more than seven percent of people have nonfunctional TLR5, José Conejo-Garcia of the Wistar Institute in Philadelphia and colleagues explored how TLR5 impacts tumor growth.

The controller
In a mouse model of sarcoma, the researchers found that tumors grew much faster in wild-type mice than in TLR5-deficient ones. Wiping out the mice’s microbiomes diminished the disparity, indicating that TLR5’s tumor-promoting effects are driven by commensal bacteria. TLR5-dependent signaling triggered the production of inflammatory interleukin 6 (IL-6), which in turn activated an immunosuppressive cascade—not switched on in TLR5-deficient animals—that promoted tumor growth.

The twist
In human breast cancers or mouse mammary carcinomas, where IL-6 levels are much lower, TLR5 had the opposite effect. Tumors in TLR5-deficient mice grew better, due to the upregulation of IL-17, a different inflammatory cytokine. As in the sarcoma model, any differences between TLR5-deficient and wild-type mice disappeared upon antibiotic treatment. “Cancer is a systemic disease that is very dramatically influenced by commensal bacteria,” Conejo-Garcia says.

The manipulation
“It’s very exciting to see this kind of progress,” says Susan Erdman of MIT. She says looking into the effects of human polymorphisms such as TLR5 “really contributes to the concept of personalized medicine in cancer therapy.” As a first step toward future treatments, study coauthor Melanie Rutkowski is exploring how manipulating the microbiome could inhibit tumor growth.

September 2018

The Muscle Issue

The dynamic tissue reveals its secrets

Marketplace

Sponsored Product Updates

Horizon Discovery introduces Myeloid DNA Reference Standard to support genetic testing of leukemia

Horizon Discovery introduces Myeloid DNA Reference Standard to support genetic testing of leukemia

Horizon Discovery Group plc, a global leader in gene editing and gene modulation technologies, today announced the launch of its Myeloid DNA Reference Standard. The first-to-market large cell-line derived myeloid cancer reference standard designed enables faster, more reliable and more cost-effective assay validation, to support the market in bringing routine testing into practice.

StemExpress LeukopakâNow Available in Frozen Format

StemExpress LeukopakâNow Available in Frozen Format

StemExpress, a Folsom, California based leading supplier of human biospecimens, announces the release of frozen Peripheral Blood Leukopaks. Leukopaks provide an enriched source of peripheral blood mononuclear cells (PBMCs) with low granulocyte and red blood cells that can be used in a variety of downstream cell-based applications.

New Antifade Mounting Media from Vector Laboratories Enhances Immunofluorescence Applications

New Antifade Mounting Media from Vector Laboratories Enhances Immunofluorescence Applications

Vector Laboratories, a leader in the development and manufacture of labeling and detection reagents for biomedical research, introduces VECTASHIELD® Vibrance™ – antifade mounting media that delivers significant improvements to the immunofluorescence workflow.

Best Practices for Sample Preparation and Lipid Extraction from Various Samples

Best Practices for Sample Preparation and Lipid Extraction from Various Samples

Download this white paper from Bertin Technologies to learn how to extract and analyze lipid samples from various models!