Genetically Modified Bacteria as Targeted Agent for Cancer

ABSTRACT

With the emergence of microbiome as a major player in many human diseases, bacteria as therapeutics are gaining significant interest. Whole bacteria or cytotoxic or immunogenic peptides carried by them exert potent anti-tumor effects in the experimental models of cancer. The use of attenuated microorganism (s) e.g., BCG to treat human urinary bladder cancer was found to be superior compared to standard chemotherapy. While bacteria alone may not offer full therapeutic benefits, modifying them with anti-tumor agents, anti-oncogenes or immunogenic antigens, either alone or in combination, will prove to be beneficial. Vectors for delivering shRNAs that target oncogenic products, express tumor suppressor genes and immunogenic proteins have been developed. These approaches have showed promising anti-tumor activity in mouse models against various tumors. These can be potential therapeutics for humans in the future and such therapeutics may become a future alternative or adjunct regimen along with conventional chemotherapy and radiotherapy. In this review, some conceptual and practical issues on how to improve these agents for human applications are discussed.