Engineered Bacteria Shown to Consume Tumors in New Cancer Treatment | University of Waterloo Research
- Researchers at the University of Waterloo are pioneering a novel approach to cancer treatment, utilizing genetically engineered bacteria to directly consume tumors from the inside.
- The core of this innovative treatment lies in Clostridium sporogenes, a bacterium commonly found in soil.
- A significant challenge arises as the bacteria expand outward and encounter areas of the tumor with even small amounts of oxygen, leading to their demise before complete tumor...
Engineering Bacteria to Fight Cancer From Within
Researchers at the University of Waterloo are pioneering a novel approach to cancer treatment, utilizing genetically engineered bacteria to directly consume tumors from the inside. This strategy focuses on leveraging microbes that naturally thrive in the oxygen-deprived environment found within solid tumors, turning a weakness of cancer cells into a therapeutic advantage.
The core of this innovative treatment lies in Clostridium sporogenes, a bacterium commonly found in soil. Dr. Marc Aucoin, a chemical engineering professor at Waterloo, explains, “Bacteria spores enter the tumor, finding an environment where there are lots of nutrients and no oxygen, which this organism prefers, and so it starts eating those nutrients and growing in size. So, we are now colonizing that central space, and the bacterium is essentially ridding the body of the tumor.” The inner core of solid tumors, characterized by dead cells and a lack of oxygen, provides an ideal breeding ground for this microbe.
However, simply introducing the bacteria isn’t enough. A significant challenge arises as the bacteria expand outward and encounter areas of the tumor with even small amounts of oxygen, leading to their demise before complete tumor elimination. To overcome this obstacle, the research team has incorporated a gene from a related bacterium known for its greater oxygen tolerance.
Crucially, activating this oxygen-tolerance feature prematurely could pose risks, potentially allowing the bacteria to proliferate in oxygen-rich areas like the bloodstream. To prevent this, the researchers employed a sophisticated biological control mechanism called quorum sensing. This natural bacterial communication process relies on chemical signals released by the bacteria themselves. As their population density increases within the tumor, the signal strength grows. Only when a sufficient number of bacteria have accumulated does the signal reach a threshold that activates the oxygen-resistant gene, ensuring the survival mechanism is engaged only when and where it’s needed.
Synthetic Biology and DNA Circuits
The team’s work builds upon previous research demonstrating the genetic modifiability of Clostridium sporogenes to enhance its oxygen resistance. In a subsequent experiment, they validated their quorum sensing design by programming the bacteria to produce a green fluorescent protein, confirming that the system activated at the intended moment. This approach, described by Dr. Brian Ingalls, a professor of applied mathematics at Waterloo, as building “something like an electrical circuit, but instead of wires we used pieces of DNA,” highlights the power of synthetic biology in creating precisely controlled biological systems. “Each piece has its job. When assembled correctly, they form a system that works in a predictable way.”
The next phase of research involves combining both the oxygen-tolerance gene and the quorum-sensing control system into a single bacterium and rigorously evaluating its effectiveness against tumors in pre-clinical trials.
A Collaborative Effort
This groundbreaking research originated with the work of PhD student Bahram Zargar, under the guidance of Dr. Ingalls and Dr. Pu Chen, a retired professor of chemical engineering at Waterloo. The project exemplifies the University of Waterloo’s commitment to interdisciplinary health innovation, bringing together expertise from engineering, mathematics, and life sciences to translate scientific discoveries into tangible medical solutions.
The Waterloo team is actively collaborating with the Center for Research on Environmental Microbiology (CREM Co Labs), a Toronto-based company co-founded by Dr. Zargar. This partnership also includes Dr. Sara Sadr, a former Waterloo doctoral student who played a pivotal role in advancing the research. This collaborative spirit underscores the complex and multifaceted nature of modern cancer research.
While still in the pre-clinical stages, this research offers a promising new avenue for cancer treatment. The ability to harness the natural properties of bacteria and engineer them to selectively target and destroy tumor cells represents a significant step forward in the ongoing fight against cancer. Further research and clinical trials will be essential to determine the safety and efficacy of this approach in human patients.
The University of Waterloo continues to be at the forefront of scientific endeavor, conducting innovative research with global impact, as highlighted on their website. This work, alongside other advancements like the engineering of bacteria to consume tumors, demonstrates a dedication to fundamental science that could benefit generations to come.