Genetically Modified Salmonella typhimurium: A Trojan Horse Strategy for Targeted Cancer Therapy

Salmonella typhimurium, typically known for causing typhoid fever, has emerged as an effective agent in cancer therapy. Significant advancements in microbial biotechnology have demonstrated that disarmed strains of S. typhimurium possess considerable potential for targeting tumors, making them promising vehicles for anticancer treatment. Relevant peer-reviewed preclinical and clinical studies on genetically modified S. typhimurium for cancer therapy were identified through searches in PubMed, Embase, Medline, and Google Scholar using specific keywords. Non-relevant reviews, editorials, and non-experimental articles were excluded from this review. S. typhimurium tends to accumulate in tumor microenvironments, where it can induce processes such as apoptosis and necrosis to eliminate cancer cells. Research indicates that Salmonella can downregulate specific immunosuppressive molecules, such as IDO (Indoleamine 2,3-dioxygenase), while also enhancing the secretion of pro-inflammatory cytokines. This change transforms the tumor microenvironment from immunosuppressive to immunogenic. The ability of Salmonella to deliver selective therapeutic agents has been confirmed by clinical trials and supported by studies showing tumor regression in murine models. This review article will explore various aspects of disarmed S. typhimurium-mediated drug delivery, including strategies, mechanisms, prospects, and potential drawbacks.