Bacteria favored microorganisms scientists for several centuries, studied along and across. However, molecular biologists, biotechnologists and geneticists bacteria become and excellent tool for the production of programmed proteins. A few years ago, scientists using bacteria to diagnose cancer. The next goal of treatment. How does it happen?
Her Majesty Escherichia coli
Escherichia coli is the most studied of all bacteria. It has become a popular tool for biologists involved in cloning genes. Exactly E. coli is often used as a factory for the production of those proteins, whose genes are inserted into E. coli. How does it happen?
It’s very simple, at least for scientists You need to obtain a large amount of insulin? Not a problem. Take with genes encoding the peptide chain of insulin, insert them into the circular DNA of bacteria (plasmids), and all are now our bacteria, in addition to production of its own proteins to produce insulin. Moreover, scientists can insert foreign genes so that bacteria will produce the desired protein in abundance is much more than their own proteins.
This is a simple genetic engineering technology, which is currently used as for producing large quantities of desired protein (same insulin) and scientific purposes to study the properties of certain proteins or genes. Methods of cutting the desired gene and insert them into bacteria is also quite simple. In the laboratory you only need to mix a few reagents, and your bacterium turns into a mutant who starts to frantically multiply (new bacteria are formed also with the inserted gene) and produce a protein that you need.
You probably already wondered, where is the cancer treatment? A bit of patience. This is the first block of information needed to understand a very beautiful and interesting experiment.
Quorum sensing bacteria
People relatively recently learned to make collective decisions, while bacteria have been doing this for millions of years. Scientists have found that bacteria can communicate with each other. And for this they use specific signal substances. Surprisingly, when the number of bacteria becomes critical in a particular habitat, organisms behave differently. They become more aggressive or start to perform functions previously performed. This phenomenon has been called quorum sensing.
Quorum sensing can be explained by the fact that infectious disease in the body begins only after achieving a certain critical amount of pathogenic or opportunistic bacteria. When bacteria becomes a lot, they close, and they go to attack master new territories, acting ka as real invaders.
It turned out that the quorum sensing E. coli can be controlled. For example, can be programmed bacteria so that when quorum is achieved, they began to allocate to the environment, we need protein.
A group of scientists under the leadership of Tala Danino decided to program the bacterial cell so that when quorum is achieved, they began to produce a glowing protein. The experiment was successful colony of bacteria grew, and at some point there was a flash, which scientists have nicknamed Supernova by analogy with a radical increase in the brightness of stars. That is, scientists inserted the DNA of the bacterium the gene for a glowing protein, and made it so that this same protein was produced only when it reaches a quorum of bacteria.
As bacteria used for cancer diagnosis
The picture above illustration is an amazing experiment, which was conducted in 2015 by a group of scientists under the leadership of Tala Danino. This is a story about how using bacteria can be used to diagnose cancer and even cure it, but first a little entertaining information.
After a successful experiment with the outbreak, scientists came up with a brilliant idea. What if quorum sensing is to use for cancer diagnosis? It is known that bacteria are very fond of the tumor, because there they are protected from the immune system which notices of cancerous tumors. So, if the bacteria in the body reach a quorum, so they found him a cushy job – a tumor where they proliferate, and the immune system at all does not see.
Scientists have programmed probiotic bacteria in such a way that upon reaching a quorum, they start to secrete a protein that the urine color in a different color. This protein is a special cutting enzyme that breaks down one of the hardest substances on the dye molecule and the residual reaction product. Then the dye gets into the bloodstream, where upon reaching the kidney safely penetrates into the urine.
Probiotics were fed laboratory animals with liver cancer. As expected, scientists, bacteria hiding in the tumor and began to multiply. And upon reaching a critical number, they began to produce the enzyme, giving a dye, coloring the urine a different color. Thus, by means of such here simple procedure to diagnose liver cancer disease that is difficult to diagnose in the early stages.
However, scientists have gone further, and are now working on an experiment that will allow you to use the quorum sensing of bacteria to treat cancer. After all, bacteria can be programmed so that upon reaching a critical mass, they began to form inside of a tumor toxic to cancer cells drug.
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