Scientists are using bacteria to treat cancer. These genetically modified bacteria grow in the low-oxygen center of the tumor and destroy it. ‘Quorum sensing’ technology helps them work even in the presence of oxygen.
Scientists are adopting a completely new approach to fighting cancer. In this, the tumor will be destroyed from within by using bacteria. This method works on those microbes which thrive in places without oxygen. The interior of many solid tumors is a similar place, which creates a good environment for these bacteria.
In this research mainly clostridium sporogenes A bacteria named (Clostridium sporogenes) is being used. It is a bacteria found in soil that can survive only in an oxygen-free environment. Inside the tumor, its core (center) is made up of dead cells and has very little oxygen. This gives the bacteria a chance to grow and spread, where they feed on nutrients and slowly begin to break down the tumor.
This research has been published in the journal ACS Synthetic Biology.
changes made in bacteria
However, there is a challenge. As the bacteria move toward the outer parts of the tumor, they become exposed to oxygen and begin to die. This reduces their ability to completely eliminate cancer. To deal with this difficulty, scientists removed a gene from another bacteria and added it to it, which can withstand oxygen better. Due to this change, the modified bacteria are able to survive longer even near the outer edges of the tumor.
quorum sensing technology
Now the question was when should the bacteria be given the strength to withstand oxygen. To control this, researchers used a natural communication system of bacteria, which is called ‘quorum sensing’. As the number of bacteria increases, they release chemical signals. Only when the number of bacteria inside the tumor reaches a certain level is this signal strong enough to activate oxygen-tolerance genes. This ensures that the bacteria work only where they are needed, and do not harm healthy body tissue.
dna circuit
In earlier experiments, bacteria were successfully reprogrammed to survive in the presence of oxygen. The timing of the quorum-sensing system was accurately set using a fluorescent marker (glowing marker). Researchers describe this entire process as creating a ‘DNA circuit’, just like an electrical system, where each part has a specific function to make the system work reliably. The next phase of research is to combine the oxygen-tolerance gene and the quorum-sensing system in a single bacteria and then test it in pre-clinical trials.