About This Project

Cancer claims 10 million lives annually and even our best treatments can fail due to side effects, tumor resistance, and failure to concentrate where they’re needed. I aim to modify a safe, well-studied probiotic (B. longum 105-A) to activate a powerful chemotherapy drug only where it matters most. Through gene engineering, B105-A produces the enzyme CYP102A1 to selectively activate the chemo drug cyclophosphamide in the tumor.

Ask the Scientists

What is the context of this research?

I love sci-fi and was inspired by the concept of medical nanobots. I approached this idea through genetic modification of bacteria for the treatment/diagnosis of cancer. Current treatments face obstacles such as drug toxicity, difficulty penetrating the tumor microenvironment (TME), and resistance to treatment. Literature describes different solutions such as the application of Salmonella sp., Listeria sp., and Bifidobacterium sp.. These species are capable of targeting and proliferating inside the hypoxic and acidic environment of the TME, where they can serve as vehicles for delivering drugs, photosensitizers, nanoparticles, etc. However, significant concerns and limiting factors for progress in this field include safety, possibility of bacteremia, and occurrence of revertants in attenuated pathogens.

What is the significance of this project?

As previously described, current modalities of cancer treatment face the obstacles of side effects, dosage limits, difficulty of localization/penetration, resistance, and resurgence. This project is an attempt at further exploring a unique approach to cancer treatment and diagnostics. Instead of developing drugs and diagnostic compounds why not develop a vehicle instead? Literature already describes different bacterial species that have been developed for the mentioned purposes, with some even entering clinical trials. It would be an immense boon to the scientific community if we could further expand upon this particular approach through the use of a safe species that addresses safety concerns while also possessing traits that make it a top tier candidate for genetic modification. This study aims to do just that by developing B. longum 105-A into a flexible GMO that can activate the versatile chemodrug called Cyclophosphamide.

What are the goals of the project?

The first goal of this experiment is to successfully "transform" B105-A. This means inserting a specially designed piece of DNA called a plasmid, that contains the gene of interest. This specific gene is called CYP102A1 and it encodes an enzyme of the same name that is highly efficient at activating Cyclophosphamide.

Next, the actual process of gene editing has the end goal of combining the gene insert on the plasmid with the actual genome of B105-A for permanent effectiveness.

Lastly, the effectiveness of the gene editing will be indirectly observed through the MTT assay, which looks at how toxic cell free extracts are (thus giving an idea of how much activated cyclophosphamide was produced)