Scientists at the University of Waterloo (Canada) are programming for genetically modified bacteria to penetrate deep into a solid tumor to consume nutrients. Because the core of the tumor is often oxygen-deprived, this is an ideal environment for anaerobic microorganisms to develop.
By genetic intervention, the team of experts created a meticulous biological attack, opening up new hope for the cancer treatment path, according to Science Daily on February 23.
The focus of the study is Clostridium sporogenes, a type of bacteria commonly found in soil. The natural characteristic of this species is that it only exists in completely anaerobic environments. Meanwhile, the centers of specific tumors are made up of dead and oxygen-deficient cells, creating perfect conditions for bacterial cloning.
Bacterial spores enter the tumor, finding a nutrient-rich and oxygen-free environment. Here, they begin to consume nutrients and grow" - Dr. Marc Aucoin, Professor at the University of Waterloo said. "We allow bacteria to settle in that space and basically, they will help the body remove tumors.
The biggest challenge is that when bacteria spread to the edge of the tumor - where there is oxygen - they will die before they can kill all cancer cells. To overcome this, scientists inserted an oxygen-tolerant gene from a related bacterial species into the genetic code of Clostridium sporogenes. However, if this gene is activated too early, the bacteria may develop in the bloodstream, causing danger.
To solve the problem, the research team used the "density sensing" mechanism. Bacteria will continuously secrete chemical signals; only when the bacterial density reaches a large enough level inside the tumor, does the system activate the antioxidant gene. This mechanism ensures that bacteria only activate their ability to survive when really necessary.
The research team applied integrated biology to design bacteria that operate accurately like a circuit board. "We built a structure similar to an electrical circuit, but instead of wires, we used DNA segments. Each DNA segment takes on a separate task, helping the system operate stably" - Dr. Brian Ingalls, Professor of Applied Mathematics at the University of Waterloo shared.
After successfully testing the ability to fluoride to confirm the time of gene activation, the next step of the project is to combine the entire control system into a single bacteria for evaluation in preclinical trials.
The research is the result of a multi-disciplinary collaboration at the University of Waterloo and the Toronto Environmental Microbiology Research Center (Canada), aiming to transform scientific discoveries into practical medical solutions for humans.
If successful, this method could open up a new approach to cancer treatment: using precisely programmed microorganisms to attack tumors from within - where traditional methods are often difficult to access.
