Two recently published studies by different research groups have provided new evidence that oral microbiota is associated with colorectal cancer. In particular, the studies demonstrated that fusobacteria stimulate negative immune responses and turn on cancer growth genes to form colorectal tumors. Until now, it was unknown whether these microbes contribute to the formation of tumors directly.
In the first study, which was conducted at the Case Western Reserve University School of Dental Medicine, researchers found that fusobacteria depend on a molecule called Fusobacterium adhesin A (FadA). It is found on the surface of these bacterial cells and helps fusobacteria to attach to and invade human colorectal cancer cells, where they induce oncogenic and inflammatory responses to promote tumor formation.
"This discovery creates the potential for new diagnostic tools and therapies to treat and prevent colorectal cancer," said Dr. Yiping W. Han, professor of periodontics at the university. "FadA can be used as a diagnostic marker for early detection of colon cancer. In addition, it can be used to determine whether a treatment works effectively at reducing fusobacteria load in the colon and the mouth."
Han and her team also identified a compound that can prevent FadA's effects on cancer cells.
In the first study, which was conducted at the Case Western Reserve University School of Dental Medicine, researchers found that fusobacteria depend on a molecule called Fusobacterium adhesin A (FadA). It is found on the surface of these bacterial cells and helps fusobacteria to attach to and invade human colorectal cancer cells, where they induce oncogenic and inflammatory responses to promote tumor formation.
"This discovery creates the potential for new diagnostic tools and therapies to treat and prevent colorectal cancer," said Dr. Yiping W. Han, professor of periodontics at the university. "FadA can be used as a diagnostic marker for early detection of colon cancer. In addition, it can be used to determine whether a treatment works effectively at reducing fusobacteria load in the colon and the mouth."
Han and her team also identified a compound that can prevent FadA's effects on cancer cells.
Another study conducted at different medical institutions in Boston found that fusobacteria are enriched in human colonic adenomas, benign tumors that can become malignant over time, suggesting that the microbes have an early role in tumorigenesis.
According to the Centers for Disease Control and Prevention, colorectal cancer is the second-leading cause of cancer-related death in the U.S. In 2009, 136,717 people were diagnosed with colorectal cancer and 51,848 people died from the disease.
The studies, titled "Fusobacterium nucleatum Promotes Colorectal Carcinogenesis by Modulating E-Cadherin/β-Catenin Signaling via its FadA Adhesin" and "Fusobacterium nucleatum Potentiates Intestinal Tumorigenesis and Modulates the Tumor-Immune Microenvironment," were published in the August issue of the Cell Host and Microbe journal.
No comments:
Post a Comment