Over 1.7 million new cancer cases and more than 600,000 cancer deaths are projected to occur in the United States in 2018. Could that number be reduced if microbes were used to treat cancer?
Katherine Broadway, a Virginia Tech graduate student in the Department of Biological Sciences is researching a cutting-edge, microbe-based cancer therapy as her dissertation project.
Proposed model of how the modified Salmonella Typhimurium strain VNP20009 colonizes a tumor. Image credit: Katherine Broadway.
Broadway is optimizing a tumor-targeting microbe that can be injected into the bloodstream. This microbe attaches to cancerous tissue, avoiding healthy tissue. When the microbe colonizes the tumor, it attracts the immune system, which then destroys the tumor.
“We hope our research will provide new avenues to treat cancer. This targeted, microbe-based therapy may be a better alternative to chemotherapy, which harms healthy cells,” said Broadway, a graduate student in the lab of Birgit Scharf, an associate professor of biological sciences in the College of Science and an affiliate of the Fralin Life Science Institute.
The microbe that Broadway is researching is Salmonella Typhimuriumstrain VNP20009. To most people, Salmonella are known as bacteria that make people sick when found in raw chicken or eggs. This particular strain, however, has been genetically engineered and tested to be safely used in the human body.
Broadway and Scharf discovered previously uncharacterized traits of VNP20009, including a chemotaxis, or sensing and movement, defect. Because of this, VNP20009 is unable to coordinate the sensing of chemicals in its environment and effective movement toward or away from those chemicals. It’s akin to a person running without being able to see and control where he is going. Broadway restored chemotaxis in VNP20009 and has successfully tested the modified strain in several cancer models within mice, including mammary carcinoma, inflammation driven colorectal cancer, and melanoma.
“Katherine’s research crosses different fields, from molecular genetics to cell biology, including animal models. She works with an interdisciplinary team of microbiologists, immunologists, and engineers, transforming engineering concepts into biological systems that can treat cancer. I am impressed with her drive, determination, and tenacity to achieve her research goals,” said Scharf.
This research was born from a collaboration with Bahareh Behkam, an associate professor of mechanical engineering in the College of Engineering, and Irving Coy Allen, an assistant professor of biomedical sciences and pathobiology in the Virginia-Maryland College of Veterinary Medicine at Virginia Tech.
Broadway has made remarkable progress in her graduate career. She has published four first-author manuscripts, three in the Journal of Biotechnology that characterized the genetics and characteristics of VNP20009, and one in Oncotarget that analyzed the effect of VNP20009 in mammary carcinomas.
She is currently wrapping up a completely novel dual-RNA sequencing project, which analyzes VNP20009 in a mouse melanoma cancer model. Funding for this project is supported by the College of Science Dean’s Discovery fund, awarded to Scharf and Liwu Li, a professor of immunology in the Department of Biological Sciences in the College of Science.
The next steps will be to optimize the tumor-targeting ability of VNP20009 and engineer it to carry drug-delivering nanoparticles, which will help attack tumors. This project holds great promise for using alternative medicinal approaches to fight cancer.
Source: VirginiaTech