Radiotherapy combined with an engineered Salmonella typhimurium inhibits tumor growth in a mouse model of colon cancer.

The engineered Salmonella typhimurium ΔppGpp (S.t ΔppGpp) has been studied in terms of its ability to carry imaging probes (bacterial luciferase, Lux) for tumor imaging or carry therapeutic molecules (Cytolysin A) to kill cancer cells. To establish a novel cancer therapy, bacterial therapy was combined with radiotherapy using the attenuated strain S.t ΔppGpp/pBAD-ClyA. Radiotherapy (21Gy) contributed to S. typhimurium colonization in a colon tumor (CT26) model of BALB/c mice. The combination of bacterial therapy and radiotherapy treatments reduced tumor growth compared with only bacterial therapy.