Undergraduate Student Researcher University of Florida Orlando, Florida, United States
Introduction/Rationale: Salmonella, known for its facultative anaerobic nature to replicate in tumors and ability to deliver foreign genes into tumors, is a promising candidate for anticancer therapies. However, clinical trials showed that the targeting ability needs to be strengthened. This study focuses on testing the adhesion and invasion efficiency of tumor-targeting Salmonella vectors.
Methods: Engineered Salmonella vectors were designed to express tumor-targeting peptides along with a GFP reporter to study their interactions with cancer cells. Peptides were fused to the outer membrane protein A (OmpA). To determine optimal infection conditions, CT26 colorectal carcinoma cells were exposed to different multiplicities of infection (MOI 1, 10, and 100). After imaging with a fluorescence microscope, fluorescence analysis conducted in Fiji identified MOI 10 as the most effective condition for characterizing differences among peptides. Using this condition, CT26 cells were infected with four different Salmonella vectors carrying the wild-type ompA gene (ompAW) and genes encoding the peptides GE11, RKO, and TK.
Results: Colony-forming unit (CFU) data across three biological replicates revealed RKO showed potential for attachment. TK and RKO peptides are promising candidates for invasion. Although variability was observed across biological replicates, the overall trends were maintained, with RKO displaying the strongest performance and TK showing intermediate activity.
Conclusion: Overall, these findings identify peptides that can affect the Salmonella tumor-targeting abilities. Peptide candidates have the potential for further therapeutic development. Further replicates will be needed to validate potential peptide candidates. This research represents a novel approach to bacterial-mediated cancer therapy, offering potential breakthroughs in targeted treatment strategies.
