Scientists Engineer Bacteria to Eat Cancer Tumors From the Inside Out

Researchers at the University of Waterloo are pioneering a novel cancer treatment that utilizes engineered bacteria to selectively target and consume tumors from within. This innovative approach leverages the unique characteristics of Clostridium sporogenes, a bacterium commonly found in soil, to infiltrate and destroy cancerous growths.

How It Works: Targeting the Oxygen-Deprived Tumor Core

Solid tumors often develop a core region devoid of oxygen, creating an ideal environment for anaerobic bacteria like Clostridium sporogenes to thrive. These bacteria naturally prefer environments lacking oxygen and abundant in nutrients – conditions precisely found within the tumor core. “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,” explains Dr. Marc Aucoin, a chemical engineering professor at Waterloo .

The engineered bacteria essentially colonize the central space of the tumor, consuming it from the inside and effectively “ridding the body of the tumor.”

Overcoming the Oxygen Barrier with Genetic Engineering

While Clostridium sporogenes excels in oxygen-free environments, a challenge arises as the bacteria approach the oxygen-exposed edges of the tumor. To address this, researchers have incorporated a genetic modification that enhances bacterial survival near these oxygenated areas, but only when a sufficient population density is reached. This carefully programmed biological attack ensures a coordinated and effective destruction of the tumor.

Quorum Sensing and Bacterial Communication

The engineering process involves integrating the Staphylococcus aureus agr-QS system into Clostridium sporogenes. This system enables density-dependent gene regulation, allowing the bacteria to communicate and coordinate their actions. Researchers confirmed the production of autoinducing peptides in the engineered strain using LC-MS/MS , demonstrating successful integration of the quorum sensing system. This means the bacteria can sense their population size and activate gene expression accordingly, optimizing their tumor-destroying capabilities.

Expanding the Synthetic Biology Toolkit

This research represents a significant advancement in synthetic biology, marking the first successful engineering of the agr quorum sensing system in an obligate anaerobe. This achievement expands the possibilities for developing bacterial therapies and metabolic engineering applications. The ability to control bacterial behavior through genetic circuits opens fresh avenues for targeted drug delivery and personalized medicine.

Future Implications

This innovative approach holds promise as a potential new way to destroy cancer. While still in the early stages of development, the engineered bacteria offer a targeted and potentially effective treatment option, particularly for solid tumors. Further research and clinical trials will be necessary to fully evaluate the safety and efficacy of this groundbreaking therapy.