Chronic and low-level inflammation associated with persistent bacterial infections or associated with colonic tumors, however, the effects of transientty and self-limiting infections in colon tumors driven by bacteria are unclear.

Recently, a research report published in International Journal of Cancer Discovery is "bacterial gnotoxin accelerates transient infection-driven murine colon tumorigenesis", scientists from John Hopkins University and other institutions have found that common food poisoning Symptomatic bacteria may produce special toxins that damage the intestinal cell DNA, thereby potentially inducing colon cancer. This research has discovered that there may be a possibility that there are approximately 2 million colon cancer cases in the world, and some patients have a problem of short-lived and seemingly gentle food poisoning events. At the same time, researchers also pointed out the future The possibility of developing new drugs is to prevent the occurrence of colorectal cancer by neutralizing this newly discovered toxin.

Image Source: Johns Hopkins University Bloomberg School of Public Health Health

Previous results showed that specific bacteria planted in the intestines may induce colorectal cancer by participating in persistent infections in chronic intestinal inflammation, and triggering short-term infections in food poisoning (including travelers diarrhea, patients usually in 1-2 days. It can be relieved) is often considered non-carcinogenic. Researcher Fengyi Wan said, we hope this paper or promote other scientists to conduct epidemiological studies to investigate the potential association between short diarrhea infections and colon cancer.

In this study, the researchers used citrate bacteria to infect mice to cause short-term diarrhea diseases, which was similar to the symptoms of human infections, and the results showed that citrate pylori infections were rapid. There are obvious signs of DNA injury in the intestinal wall of mice. The researchers noted that this damage relies on a mechanism called a Type III secretion system in the bacteria that enclosures such as citrate bacillus and diarrhea large intestinal dilution is used to inject in host cells. Protein, this mechanism is conducive to invading microbial growth and survival.

The final researchers locked a Type III secretion system injectable protein, which perhaps DNA injury, and it was found that the USHA protein produced by the Escherichiature of Escherichia, which is said to have a decomposed DNA enzyme. The researchers do not know the function of the DNA decomposition element in the life cycle of the citrate, which does not seem to damage the growth or survival of bacteria, but the researchers have found evidence in the model of mouse model, USHA may It will have a clear carcinogenic effect on the infected host.

Subsequent researchers use a genetic engineered mouse product that spontaneously forms colon tumor. It has been found that the mice infected with citrate bacillus containing USHA may significantly accelerate the formation of tumors in their body; The engineering citrogega infected with lacking the USHA gene may have no effect on accelerating the progression of tumors. In addition, researchers have also found that mutations in colon tumors acrunge citric acid are similar to the mutant type in human colonic tumors, which may once again emphasize the potential correlation between human health.

Image Source: https://cancerdiscovery.aacrjournalrS.org/content/12/1/236#

Such a powerful confirmation of this association may not be easily realized, as a short infection may have disappeared as defined, and the colon tumor may have developed many years before being detected, before being detected. It is necessary to establish a large number of epidemiological studies of microorganisms and human colorectal cancers carrying USHA, and these research may be performed in Africa, Sahara, because in these areas, laxative bacterial infections and Normal colon cancer is very common. At present, researchers are jointly studying to develop inhibitors for USHA toxins. In principle, researchers can give such inhibitors that have existing diarrhea diseases to protect them against cancer DNA damage.

In summary, the research results show that USHA may serve as a bacterial III secretion system dependent gene toxin, which may play a key role in the process of accelerating colon tumors in promotion of short and non-invasive bacterial infections.

Original source:

Yue Liu, Kai Fu, Eric M. Wier, et al. Bacterial Genotoxin Accelerates Transient Infection-Driven Murine Colon Tumorigenesis, Cancer Discovery (2022). Doi: 10.1158 / 2159-8290.CD-21-0912