Tumor-targeting Salmonella typhimurium, a natural tool for activation of prodrug 6MePdR and their combination therapy in murine melanoma model
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The PNP/6-methylpurine 2′-deoxyriboside (6MePdR) system is an efficient gene-directed enzyme prodrug therapy system with significant antitumor activities. In this system, Escherichia coli purine nucleoside phosphorylase (ePNP) activates nontoxic 6MePdR into potent antitumor drug 6-methylpurine (6MeP). The Salmonella typhimurium PNP (sPNP) gene has a 96-% sequence homology in comparison with ePNP and also has the ability to convert 6MePdR to 6MeP. In this study, we used tumor-targeting S. typhimurium VNP20009 expressing endogenous PNP gene constitutively to activate 6MePdR and a combination treatment of bacteria and prodrug in B16F10 melanoma model. The conversion of 6MePdR to 6MeP by S. typhimurium was analyzed by HPLC and the enzyme activity of sPNP was confirmed by in vitro (tetrazolium-based colorimetric assay) MTT cytotoxicity assay. After systemic administration of VNP20009 to mice, the bacteria largely accumulated and specifically delivered endogenous sPNP in the tumor. In comparison with VNP20009 or 6MePdR treatment alone, combined administration of VNP20009 followed by 6MePdR treatment significantly delayed the growth of B16F10 tumor and increased the CD8+ T-cell infiltration. In summary, our results demonstrated that the combination therapy of S. typhimurium and prodrug 6MePdR is a promising strategy for cancer therapy.
KeywordsSalmonella typhimurium Tumor therapy Purine nucleoside phosphorylase Bacteria/prodrug therapy system
The authors are grateful to grants from: the Doctoral Station Science Foundation from the Chinese Ministry of Education (200802840023), the National Key Basic Research Program from Ministry of Science and Technology (2011CB933502), the Jiangsu Provincial Nature Science Foundation (BK2010046, BZ2010074, BK2011228, BZ2011048), the Chinese National Nature Sciences Foundation (30821006, 50973046, 31071196, 30730030), Bureau of Science and Technology of Changzhou (CN20100016, CZ20100008, CJ20115006, CE20115034, CZ20110028), and the Department of Science and Technology of Wujin District, Changzhou (WS201004).
The authors have no conflicts of interest.
- Bharara S, Sorscher EJ, Gillespie GY, Lindsey JR, Hong JS, Curlee KV, Allan PW, Gadi VK, Alexander SA, Secrist JA 3rd, Parker WB, Waud WR (2005) Antibiotic-mediated chemoprotection enhances adaptation of E. coli PNP for herpes simplex virus-based glioma therapy. Hum Gene Ther 16:339–347CrossRefGoogle Scholar
- Friedlos F, Lehouritis P, Ogilvie L, Hedley D, Davies L, Bermudes D, King I, Martin J, Marais R, Springer CJ (2008) Attenuated Salmonella targets prodrug activating enzyme carboxypeptidase G2 to mouse melanoma and human breast and colon carcinomas for effective suicide gene therapy. Clin Cancer Res 14:4259–4266CrossRefGoogle Scholar
- Hughes BW, Wells AH, Bebok Z, Gadi VK, Garver RI Jr, Parker WB, Sorscher EJ (1995) Bystander killing of melanoma cells using the human tyrosinase promoter to express the Escherichia coli purine nucleoside phosphorylase gene. Cancer Res 55:3339–3345Google Scholar
- Kikuchi E, Menendez S, Ozu C, Ohori M, Cordon-Cardo C, Logg CR, Kasahara N, Bochner BH (2007) Delivery of replication-competent retrovirus expressing Escherichia coli purine nucleoside phosphorylase increases the metabolism of the prodrug, fludarabine phosphate and suppresses the growth of bladder tumor xenografts. Cancer Gene Ther 14:279–286CrossRefGoogle Scholar
- Low KB, Ittensohn M, Luo X, Zheng LM, King I, Pawelek JM, Bermudes D (2004) Construction of VNP20009: a novel, genetically stable antibiotic-sensitive strain of tumor-targeting Salmonella for parenteral administration in humans. Methods Mol Med 90:47–60Google Scholar
- Nowak AK, Lake RA, Marzo AL, Scott B, Heath WR, Collins EJ, Frelinger JA, Robinson BW (2003) Induction of tumor cell apoptosis in vivo increases tumor antigen cross-presentation, cross-priming rather than cross-tolerizing host tumor-specific CD8 T cells. J Immunol 170:4905–4913Google Scholar
- Pawelek JM, Low KB, Bermudes D (1997) Tumor-targeted Salmonella as a novel anticancer vector. Cancer Res 57:4537–4544Google Scholar
- Robertson BC, Hoffee PA (1973) Purification and properties of purine nucleoside phosphorylase from Salmonella typhimurium. J Biol Chem 248:2040–2043Google Scholar
- Sorscher EJ, Peng S, Bebok Z, Allan PW, Bennett LL Jr, Parker WB (1994) Tumor cell bystander killing in colonic carcinoma utilizing the Escherichia coli DeoD gene to generate toxic purines. Gene Ther 1:233–238Google Scholar
- Toso JF, Gill VJ, Hwu P, Marincola FM, Restifo NP, Schwartzentruber DJ, Sherry RM, Topalian SL, Yang JC, Stock F, Freezer LJ, Morton KE, Seipp C, Haworth L, Mavroukakis S, White D, MacDonald S, Mao J, Sznol M, Rosenberg SA (2002) Phase I study of the intravenous administration of attenuated Salmonella typhimurium to patients with metastatic melanoma. J Clin Oncol 20:142–152CrossRefGoogle Scholar
- Yagil E, Beacham IR (1975) Uptake of adenosine 5′-monophosphate by Escherichia coli. J Bacteriol 121:401–405Google Scholar
- Zhang L, Gao L, Zhao L, Guo B, Ji K, Tian Y, Wang J, Yu H, Hu J, Kalvakolanu DV, Kopecko DJ, Zhao X, Xu DQ (2007) Intratumoral delivery and suppression of prostate tumor growth by attenuated Salmonella enterica serovar typhimurium carrying plasmid-based small interfering RNAs. Cancer Res 67:5859–5864CrossRefGoogle Scholar
- Zhou JH, Tang B, Liu XL, He DW, Yang DT (2007) hTERT-targeted E. coli purine nucleoside phosphorylase gene/6-methylpurine deoxyribose therapy for pancreatic cancer. Chin Med J (Engl) 120:1348–1352Google Scholar