Bone
metastasis is a frequent occurrence in
prostate cancer patients and often is lethal.
Zoledronic acid (ZOL) is often used for bone
metastasis with limited efficacy. More effective models and treatment methods are required to improve the outcome of
prostate cancer patients. In the present study, the effects of
tumor-targeting Salmonella typhimurium A1-R were analyzed in vitro and in vivo on
prostate cancer cells and experimental bone
metastasis. Both ZOL and S. typhimurium A1-R inhibited the growth of PC-3 cells expressing red fluorescent protien in vitro. To investigate the efficacy of S. typhimurium A1-R on
prostate cancer experimental bone
metastasis, we established models of both early and advanced stage bone
metastasis. The mice were treated with ZOL, S. typhimurium A1-R, and combination
therapy of both ZOL and S. typhimurium A1-R. ZOL and S. typhimurium A1-R inhibited the growth of solitary bone
metastases. S. typhimurium A1-R treatment significantly decreased bone
metastasis and delayed the appearance of PC-3 bone
metastases of multiple mouse models. Additionally, S. typhimurium A1-R treatment significantly improved the overall survival of the mice with multiple bone
metastases. The results of the present study indicate that S. typhimurium A1-R is useful to prevent and inhibit
prostate cancer bone
metastasis and has potential for future clinical use in the adjuvant setting.