- Fusobacterium nucleatum (F. nucleatum), the bacterium found in the mouth is known to cause periodontal disease.
- Study showed that F. nucleatum is present in cancer tissues of patients with esophageal cancer.
- The survival time of such patients who had F. nucleatum in their tisse was shorter.
Fusobacterium nucleatum (F. nucleatum), a type of bacterium usually found in the human mouth, has been found to be related to the prognosis of esophageal cancer in Japanese patients.
F. nucleatum in known to cause periodontal disease.
‘The oral cavity bacterium Fusobacterium nucleatum may be involved in the development and progression of esophageal cancer via chemokines.’
It has not been the focus of much research until recently when it was reported that F. nucleatum was frequently detected in colon cancer tissue, and that it may have an effect on the development of colorectal cancer.
There are hundreds of intestinal bacteria species in the human body and they play an important role in maintaining homeostasis.
The role of intestinal bacterial flora has been gaining the attention recently due to its association with various cancers, diabetes, obesity, inflammatory bowel disease, and nonalcoholic fatty liver disease.
Helicobacter pylori, a bacterium residing in the stomach, which has been linked to stomach cancer, is an example.
Role of F.nucleatum in Esophageal Cancer
Due to the proximity of the oral cavity to the esophagus, researchers suspect that F. nucleatum may also play an important role in esophageal cancer.
To test their hypothesis researchers used real-time PCR analysis, to assess DNA in the cancer tissue of 325 patients who had undergone surgical removal of esophageal cancer at Kumamoto University Hospital.
Researchers found that 74 out of 325 patients (nearly 23%) had F. nucleatum in their cancer tissues.
On comparing the after-surgery survival time between patients, researchers found that the group that tested positive with F. nucleatum in their cancer tissues had significantly shorter survival times.
The genes of patients with esophageal cancer were analyzed using RNA extracted from the tissues of F. nucleatum positive and negative esophageal cancers.
Patients with F. nucleatum positive esophageal cancer had a different set of genes related to inflammatory cytokines (proteins that promote inflammation).
Detailed analysis revealed that the number of genes of specific chemokines, which are proteins related to the transport of white blood cells, such as CCL20 and CXCL7 had increased.
"This study suggested that the oral cavity bacterium F. nucleatum may be involved in the development and progression of esophageal cancer via chemokines," said Professor Hideo Baba, who lead the research. "It should be noted that it is still unknown whether F. nucleatumitself causes esophageal cancer. Further analysis by more institutions, preferably world-wide, is desired since intestinal flora differs between individuals. In future research, after elucidating the role of F. nucleatum in esophageal cancer development in more detail, we should be able to develop new drugs to better treat this form of cancer."
The study was conducted by researchers from Kumamoto University, Japan and the findings were posted on line in Clinical Cancer Research
on October 21st, 2016.
- Hideo Baba et al. Human microbiome fusobacterium nucleatum in esophageal cancer tissue is associated with prognosis. Clinical Cancer Research ; (2016)