• Engineering Bacillus anthracis Protective Antigen for Targeted Cancer Therapy via Urokinase Plasminogen Activator Modulation
  • Mohammad Abootaleb,1,* Narjes Mohammadi Bandaria,2
    1. Agricultural Biotechnology Research Institute of Iran-North Branch (ABRII), Raika Gene Pharmed Technology Unit (company), Rasht, Gilan Province, Iran
    2. Agricultural Biotechnology Research Institute of Iran-North Branch (ABRII), Raika Gene Pharmed Technology Unit (company), Rasht, Gilan Province, Iran


  • Introduction: The challenge of cancer therapy is targeting malignant cells without harming normal tissues. The unique expression of uPA on cancer cells provides an opportunity to use bacterial proteins as precision therapeutic agents. Bacillus anthracis's protective antigen (PA) is crucial in anthrax pathogenesis, and its modifications could enhance selectivity towards these uPA-expressing cancer cells.
  • Methods: Bioinformatics tools were used to identify potential mutation sites within the PA gene to improve its affinity for uPA receptors. After introducing mutations via Overlap Extension PCR, plasmid construction included verification steps to ensure the accuracy of the insert. The TA-vector system was utilized for efficient cloning, and electroporation facilitated transformation into competent WB600 cells, optimized for protein expression.
  • Results: Subsequent analyses, including Sanger sequencing, confirmed the successful incorporation of mutations. Advances in protein expression were monitored through SDS-PAGE and Western blotting, demonstrating increased levels of modified PA proteins. Binding assays showed the enhanced affinity of mutated PA towards uPA receptors, a significant improvement over wild-type PA.
  • Conclusion: The implications of these findings are profound, as the engineered PA proteins may act as vehicle-cytotoxin conjugates, selectively delivering toxic agents to cancer cells. Utilizing high-affinity binding between the modified PA and uPA could facilitate targeted therapy, reducing systemic side effects. Further preclinical studies are needed to evaluate the therapeutic efficacy and safety profile of these novel constructs in vivo. This study contributes to ongoing research in targeted cancer therapies, demonstrating the potential of bacterial proteins in clinical applications. The engineered PA proteins not only provide insight into novel treatment strategies but also pave the way for future explorations into receptor-mediated targeting mechanisms in oncology.
  • Keywords: Targeted cancer therapy, Bacillus anthracis, Protective antigen, Urokinase Plasminogen Activator, Ge