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An evaluation of thymidine phosphorylase as a means of preventing thymidine rescue from the thymidylate synthase inhibitor raltitrexed

Abstract

The antitumour effect of thymidylate synthase inhibitors such as raltitrexed (RTX) may be reversed by salvage of thymidine (Thd). Since thymidine phosphorylase (TP) depletes Thd, the potential for tumour-selective depletion of Thd using antibody-mediated delivery of TP to tumours was investigated. In vitro studies demonstrated that 25 × 10−3 units/ml TP depleted extracellular Thd (3 μM) and restored sensitivity to the growth inhibitory effects of RTX in Lovo and HT29 cell lines. Thymidine concentrations in xenograft tumours were inversely proportional to the activity of TP in the tumour, and the presence of a subcutaneous Lovo xenograft reduced plasma Thd concentrations from 0.92 ± 0.07 to 0.37 ± 0.04 μM. Intravenous administration of native TP enzyme depleted plasma Thd to 5 nM, but following rapid elimination of TP, plasma Thd returned to pretreatment values. There was no effect on tumour TP or Thd. Conjugation of TP to the A5B7 F(ab)2 antibody fragment, which targets carcinoembryonic antigen (CEA) expressed on colorectal cell-lines such as Lovo, did result in selective accumulation of TP in the tumour. However, there was no tumour-selective depletion of Thd and there did not appear to be any potential benefit of combining antibody-targeted TP with RTX.

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References

  1. Bagshawe KD, Sharma SK, Springer CJ, Antoniw P (1995) Antibody directed enzyme prodrug therapy (ADEPT): a pilot scale clinical therapy. Tumor Target 1:17–29

    Google Scholar 

  2. Blakey D, Davies D, Dowell R, East S, Burke P, Sharma S, Springer C, Mauger A, Melton R (1995) Anti-tumour effects of an antibody-carboxypeptidase G2 conjugate in combination with phenol mustard prodrugs. Br J Cancer 72:1083–1088

    PubMed  CAS  Google Scholar 

  3. Blakey DC, Burke PJ, Davies DH, Dowell RI, East SJ, Eckersley KP, Fitton JE, McDaid J, Melton RG, NiculescuDuvaz IA, Pinder PE, Sharma SK, Wright AF, Springer CJ (1996) ZD2767, an improved system for antibody-directed enzyme prodrug therapy that results in tumor regressions in colorectal tumor xenografts. Cancer Res 56(14):3287–3292

    PubMed  CAS  Google Scholar 

  4. Fox SB, Engels K, Comley M, Whitehouse RM, Turley H, Gatter KC, Harris AL (1997) Relationship of elevated tumour thymidine phosphorylase in node-positive breast carcinomas to the effects of adjuvant CMF. Ann Oncol 8(3):271–275

    Article  PubMed  CAS  Google Scholar 

  5. Iltzsch M, Kouni ME, Cha S (1985) Kinetic studies of thymidine phosphorylase from mouse liver. Biochemistry 24:2871–2875

    Article  Google Scholar 

  6. Jackman AL, Calvert AH (1995) Folate-based thymidylate synthase inhibitors as anticancer agents. Ann Oncol 6:871–881

    PubMed  CAS  Google Scholar 

  7. Jackman AL, Taylor GA, Calvert AH, Harrap KR (1984) Modulation of anti-metabolite effects; effects of thymidine on the efficacy of the quinazoline based thymidylate synthetase inhibitor CB3717. Biochem Pharmacol 33(20):3269–3275

    PubMed  CAS  Article  Google Scholar 

  8. Jackman AL, Taylor GA, Gibson W, Kimbell R, Brown M, Calvert AH, Judson IR, Hughes LR (1991) ICI D1694, a quinazoline antifolate thymidylate sythase inhibitor that is a potent inhibitor of L1210 tumor cell growth in vitro and in vivo: a new agent for clinical study. Cancer Res 51:5579–5586

    PubMed  CAS  Google Scholar 

  9. Jackman A, Farrugia D, Gibson W, Kimbell R, Harrap K, Stephens T, Azab M, Boyle F (1995) A new thymidylate synthase inhibitor with activity in colorectal cancer. Eur J Cancer 31A:1277–1282

    PubMed  CAS  Article  Google Scholar 

  10. Koukourakis MI, Giatromanolaki A, Fountzilas G, Sivridis E, Gatter KC, Harris AL (2000) Angiogenesis, thymindine phosphorylase, and resistance of squamous cell head and neck cancer to cytotoxic and radiation therapy. Clin Cancer Res 6(2):381–389

    PubMed  CAS  Google Scholar 

  11. Melton RG, Boyle JMB, Rogers GT, Burke P, Bagshawe KD, Sherwood RF (1993) Optimization of small-scale coupling of A5b7-monoclonal antibody to carboxypeptidase-G2. J Immunol Methods 158(1):49–56

    Article  PubMed  CAS  Google Scholar 

  12. Metzger R, Danenberg K, Leichman CG, Salonga D, Schwartz EL, Wadler S, Lenz H-J, Groshen S, Leichman L, Danenberg PV (1998) High basal level gene expression of thymidine phosphorylase (platelet-derived endothelial cell growth factor) in colorectal tumors is associated with non-response to 5-fluorouracil. Clin Cancer Res 4:2371–2376

    PubMed  CAS  Google Scholar 

  13. Natsumeda Y, Ikegami T, Olah E, Weber G (1989) Significance of purine salvage in circumventing the action of antimetabolites in rat hepatoma cells. Cancer Res 49:88–92

    PubMed  CAS  Google Scholar 

  14. Patterson AV, Talbot DC, Stratford IJ, Harris AL (1998) Thymidine phosphorylase moderates thymidine-dependent rescue after exposure to the thymidylate synthase inhibitor ZD1694 (Tomudex) in vitro. Cancer Res 58:2737–2740

    PubMed  CAS  Google Scholar 

  15. Pedley R, Begent R, Boden J, Boxer G, Boden R, Keep P (1994) Enhancement of radioimmunotherapy by drugs modifying tumour blood flow in a colonic xenograft model. Int J Cancer 57:830–835

    PubMed  CAS  Google Scholar 

  16. Plagemann P, Wohlheuter R (1984) Nucleoside transport in cultured mammalian cells: multiple forms with different sensitivity to inhibition by nitrobenzylthioinosine or hypoxanthine. Biochim Biophys Acta 773:39–52

    PubMed  CAS  Article  Google Scholar 

  17. Pressacco J, Erlichman C (1993) Combination studies with 3′-azido-deoxythymidine (AZT) plus ICI D1694. Cytotoxic and biochemical effects. Biochem Pharmacol 46:1989–1997

    Article  PubMed  CAS  Google Scholar 

  18. Pressacco J, Mitrovski B, Erlichman C, Hedley D (1995) Effects of thymidylate synthase on thymidine kinase activity and nucleoside transporter expression. Cancer Res 55:1505–1508

    PubMed  CAS  Google Scholar 

  19. Schwartz E, Baptiste N, Megati S, Walder S, Otter B (1995) 5-Ethoxy-2′-deoxyuridine, a novel substrate for thymidine phosphorylase, potentiates the antitumour activity of 5-fluorouracil when used in combination with interferon, an inducer of thymidine phosphorylase expression. Cancer Res 55:3543–3550

    PubMed  CAS  Google Scholar 

  20. Sharma S, Bagshawe K, Burke P, Boden R, Rogers G (1990) Inactivation and clearance of an anti-CEA carboxypeptidase G2 conjugate in blood after localisation in a xenograft model. Br J Cancer 61:659–662

    PubMed  CAS  Google Scholar 

  21. Skehan P, Storeng R, Scudiero D, Monks A, McMahon J, Vistica D, Warren JT, Bokesch H, Kenney S, Boyd MR (1990) New colorimetric cytotoxicity assay for anticancer-drug screening. J Natl Cancer Inst 82(13):1107–1112

    PubMed  CAS  Google Scholar 

  22. Smith P, Marshman E, Newell DR, Curtin NJ (2000) Dipyridamole potentiates the in vitro activity of MTA (LY231514) by inhibition of thymidine transport. Br J Cancer 82:924–930

    Article  PubMed  CAS  Google Scholar 

  23. Takebayashi Y, Yamada K, Miyadera K, Sumizawa T, Furukawa T, Kinoshita F, Aoki D, Okumura H, Yamada Y, Akiyama S, Aikou T (1996) The activity and expression of thymidine phophorylase in human solid tumours. Eur J Cancer 32A(7):1227–1232

    Article  PubMed  CAS  Google Scholar 

  24. van Triest B, Pinedo HM, Blaauwegeers J, van Diest P, Schoenmakers P, Voorn D, Smid K, Hoekman K, Hoistma H, Peters G (2000) Prognostic role of thymidylate synthase, thymidine phosphorylase/platelet-derived endothelial cell growth factor and proliferation markers in colorectal cancer. Clin Cancer Res 6:1063–1072

    PubMed  Google Scholar 

  25. Webley S, Hardcastle A, Ladner R, Jackman A, Aherne WG (2000) Deoxyuridine triphosphatase (dUTPase) expression and sensitivity to the thymidylate syntahse (TS) inhibitor ZD9331. Br J Cancer 83:792–799

    Article  PubMed  CAS  Google Scholar 

  26. Zalcberg J, Cunningham D, Green M (1996) ZD1694: a novel thymidylate synthase inhibitor with substantial activity in the treatment of patients with advanced colorectal cancer. J Clin Oncol 14(3):716–721

    PubMed  CAS  Google Scholar 

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Correspondence to Alan V. Boddy.

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Graham-Cole, C.L., Thomas, H.D., Taylor, G.A. et al. An evaluation of thymidine phosphorylase as a means of preventing thymidine rescue from the thymidylate synthase inhibitor raltitrexed. Cancer Chemother Pharmacol 59, 197–206 (2007). https://doi.org/10.1007/s00280-006-0258-x

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  • DOI: https://doi.org/10.1007/s00280-006-0258-x

Keywords

  • Raltitrexed
  • Thymidine
  • Thymidine phosphorylase
  • Tumour-selectivity