Cancer suicide gene therapy with TK.007: superior killing efficiency and bystander effect
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Suicide gene therapy is a promising concept in oncology. We have recently introduced a novel suicide gene, TK.007, which was shown to excel established herpes simplex virus thymidine kinase (HSVtk) variants when used for donor-lymphocyte modification in adoptive immunotherapy models. Here, the potential of TK.007 in killing cancer cells was studied. Initially, we transduced tumour cell lines derived from different neoplasias (glioblastoma, melanoma, lung cancer, colon cancer) with lentiviral LeGO vectors encoding TK.007 or the splice-corrected (sc)HSVtk together with an eGFP/Neo-marker. Based on direct in vitro comparison, we found that TK.007 facilitates more efficient tumour cell killing at significantly lower ganciclovir doses in all tumour cell lines tested. Also, using different readout systems, we found a significantly stronger bystander effect of TK.007 as compared to scHSVtk. Importantly, in vitro data were confirmed in vivo using a subcutaneous G62 glioblastoma model in NOD/SCID mice. In mice transplanted with scHSVtk-positive tumours, treatment with low (10 mg/kg) or standard (50 mg/kg) ganciclovir doses resulted only in short-term growth inhibition or transient tumour remission, respectively. In striking contrast, in the TK.007 group, all animals achieved continuous complete remission after both standard and low-dose ganciclovir. Finally, a substantial bystander effect for TK.007 was also confirmed with the G62 model in vivo, where significantly prolonged survival for mice bearing tumours containing only 10% or 50% TK.007-expressing cells was observed. In summary, our data indicate strongly improved anti-tumour activity of TK.007 as compared to conventional HSVtk. We therefore suppose that TK.007 is an excellent candidate for cancer suicide gene therapy.
KeywordsSuicide gene HSVtk Cancer gene therapy Bystander effect
The authors wish to thank Daniela Brücher for expert technical assistance and Dr. Sebastian Newrzela for helpful support. We are indebted to Dr. Boris Brill and Ute Burkhardt for assistance with animal experiments. dsRed-positive G62 cells were kindly provided by Yvonne Heidemarie Fischer (Georg-Speyer-Haus Frankfurt am Main, Germany). This work was partially supported by the DFG (FE568/11-1) and the Frankfurter Stiftung für krebskranke Kinder.
- 2.Ostermann N, Lavie A, Padiyar S, Brundiers R, Veit T, Reinstein J, Goody RS, Konrad M, Schlichting I (2000) Potentiating AZT activation: structures of wild-type and mutant human thymidylate kinase suggest reasons for the mutants' improved kinetics with the HIV prodrug metabolite AZTMP. J Mol Biol 304:43–53PubMedCrossRefGoogle Scholar
- 5.Introna M, Barbui AM, Bambacioni F, Casati C, Gaipa G, Borleri G, Bernasconi S, Barbui T, Golay J, Biondi A, Rambaldi A (2000) Genetic modification of human T cells with CD20: a strategy to purify and lyse transduced cells with anti-CD20 antibodies. Hum Gene Ther 11:611–620PubMedCrossRefGoogle Scholar
- 14.Kuriyama S, Mitoro A, Yamazaki M, Tsujinoue H, Nakatani T, Akahane T, Toyokawa Y, Kojima H, Okamoto S, Fukui H (1999) Comparison of gene therapy with the herpes simplex virus thymidine kinase gene and the bacterial cytosine deaminase gene for the treatment of hepatocellular carcinoma. Scand J Gastroenterol 34:1033–1041PubMedCrossRefGoogle Scholar
- 15.Balzarini J, Liekens S, Solaroli N, El Omari K, Stammers DK, Karlsson A (2006) Engineering of a single conserved amino acid residue of herpes simplex virus type 1 thymidine kinase allows a predominant shift from pyrimidine to purine nucleoside phosphorylation. J Biol Chem 281:19273–19279PubMedCrossRefGoogle Scholar
- 27.Tiberghien P, Ferrand C, Lioure B, Milpied N, Angonin R, Deconinck E, Certoux JM, Robinet E, Saas P, Petracca B, Juttner C, Reynolds CW, Longo DL, Herve P, Cahn JY (2001) Administration of herpes simplex-thymidine kinase-expressing donor T cells with a T-cell-depleted allogeneic marrow graft. Blood 97:63–72PubMedCrossRefGoogle Scholar
- 34.Uckert W, Kammertons T, Haack K, Qin Z, Gebert J, Schendel DJ, Blankenstein T (1998) Double suicide gene (cytosine deaminase and herpes simplex virus thymidine kinase) but not single gene transfer allows reliable elimination of tumor cells in vivo. Hum Gene Ther 9:855–865PubMedCrossRefGoogle Scholar
- 36.Sandmair AM, Loimas S, Puranen P, Immonen A, Kossila M, Puranen M, Hurskainen H, Tyynela K, Turunen M, Vanninen R, Lehtolainen P, Paljarvi L, Johansson R, Vapalahti M, Yla-Herttuala S (2000) Thymidine kinase gene therapy for human malignant glioma, using replication-deficient retroviruses or adenoviruses. Hum Gene Ther 11:2197–2205PubMedCrossRefGoogle Scholar