Salmonella Typhimurium as a potential anticancer agent: A Review

Bacteria mediated cancer therapy has not been used as much as other methods, despite being considered a potential adjunct in anticancer therapeutic strategy for decades. However, in recent years, there has been considerable interest in exploration of the option of bacteria mediated cancer immunotherapy. The conventional anticancer therapy does not eradicate cancer completely. It often fails and has several other limitations which can easily be overcome through the bacteria mediated approach as an adjunctive therapy.

Members of the genus Salmonella have the ability to colonize all forms of tumours and their metastasis much more efficiently than other bacteria. Salmonella has over 2500 serovars of which Salmonella Typhimurium, a non-typhoidal strain, is the most extensively studied for its anticancer activity. S. Typhimurium has the intrinsic attribute of being able to selectively colonize solid tumours and their metastasis.

S. Typhimurium is able to target and destroy tumours in three specific ways; inducing immune response to the presence of tumours, utilizing bacterial toxins to directly activate caspase-3, ( an important enzyme of the apoptotic pathway) and also as a vector in delivering of anti-cancer compounds to tumour sites. S. Typhimurium is currently considered as a bacterium with great potential in the field of cancer immunotherapy. In this review, the explanation of the mechanisms of anticancer activity of live attenuated and engineered S.  Typhimurium strains in vitro and in vivo is attempted.