Once Good, Now Bad

cancerDarian Naill (11 AM Micro) found an article from Science Daily which describes a role that bacteria normally found in the digestive tract may play in the formation of certain cancers. As we begin chapter 15 in Bauman in another week or so, we will begin to talk about the process of inflammation, which can have profound effects in a localized region and throughout the body. The normal microbiota, even in the absence of disease, can act as triggers and modulators of inflammation, and as Darian describes, this can have some surprising effects on other diseases. Here is Darian’s summary:

Normal microbiota are important microorganisms that live on or within the human body. These microorganisms live on the skin, in mucous membranes, in the digestive tract, and other places of the body as well. These microbiota are acquired at birth in order to help protect against transient microbiota. These microbiota may be protective, however, recent research has found that such normal microbiota may be influencing growth of cancerous tumors.

In an experiment done by Frank Rauscher at The Wistar Institute, he and his colleagues were able to look in depth at how some normal microbiota may be harmful to the human body. He and his colleagues studied the bacteria growing in the colon. Our colons are a portion of the intestinal tract that house lots and lots of microbiota. These microbiota in the colon are not necessarily doing good. In research, Rauscher found bacteria to be altering genetics which allows for tumor growth. The bacteria in our colon may just be an instigator of colon cancer.

Through Rauscher’s research he injected an enzyme called NLEE into human colon cells. This protein is relevant to the regulation of inflammation of the human gut. The protein they injected, NLEE, targets TAB2. By targeting TAB2, NLEE inactivates inflammatory responses in the stomach thus allowing inflammation to occur. (Science Daily). Once Rauscher realized NLEE targets proteins, he thought to himself what other types of proteins might also be affected, and his research continued. Rauscher found that the enzyme NLEE was shutting off proteins. One of the proteins, was known as ZRNAB3. This specific protein is essential for DNA repair. (Science Daily). The compound NLEE was invading cells of the colon and disrupting their DNA and their ability to repair themselves. Rauscher and his colleagues concluded that if the cells of our colon are no longer able to repair themselves, they have become susceptible to mutation, allowing the growth of tumors to occur. (Science Daily). The microbiota which are supposed to be doing our body good, and protecting us, are not doing their job; they are increasing disease in our body.

Rauscher and his colleagues were then concerned how NLEE was doing such thing to human bodies. Feng Shao, Ph.D., at the National Institute of Biological Sciences in Beijing, China, came along to help in the research of this cancerous ordeal. Through their research they found the exact components NLEE was attacking. NLEE attacked TAB2 and ZRANB3 and then underwent methylation (adding a single methyl molecule) which then caused the DNA to be disrupted. (Science Daily). The NLEE was like a key to unlock the door allowing it go in and affect the zinc finger. The zinc finger is a very important piece to a protein which allows a shorter version (less amino acids) to be made, but still be as useful as a larger protein. (Protein Data Bank). Rauscher noted through his experiment that this zinc finger pattern was a common component found in repair enzymes. (Science Daily). Therefore, in recognition of what the zinc finger was associated for, and the cause which affected it; he concluded that without the ability of DNA to repair itself, it allowed for tumor growth. If further research could be conducted we could hope to identify a specific bacteria in our colon allowing for the mutation of the DNA. By doing so, we could potentially limit the amount of such bacteria as a way to prevent tumor growth. Rauscher’s research may be a start to the limitation of cancerous growth, or even better a total prevention plan.


About ycpmicro

My name is David Singleton, and I am an Associate Professor of Microbiology at York College of Pennsylvania. My main course is BIO230, a course taken by allied-health students at YCP. Views on this site are my own.

Posted on November 10, 2014, in Guest Post. Bookmark the permalink. 2 Comments.

  1. I find it troubling that this is happening in our bodies. I wonder if this has always been happening or if we have just noticed that there is bacteria causing tumors in our colon due to advanced technology that we now have. Also, maybe our diets are affecting the bacteria and this could potentially be stopped through different diets. Maybe this could be stopped by genetic modification.

  2. I don’t think there will ever be a total prevention plan. As one cancer causing agent may be cured another one will pop up. I feel a lot of our problem is based on our diet and the preservatives that are used in foods.

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