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Gemcitabine and radiosensitization in human tumor cells

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Summary

Gemcitabine is a nucleoside analogue with excellent clinical activity against solid tumors. Within the cell, gemcitabine is rapidly phosphorylated to its active di-and triphosphate metabolites. Cytotoxicity with gemcitabine appears to be related to multiple effects on DNA replication, where gemcitabine triphosphate can serve as both an inhibitor and substrate for DNA synthesis. Gemcitabine diphosphate inhibits ribonucleotide reductase, producing decreases in cellular dNTP pool levels in a cell-specific manner. These two major characteristics of gemcitabine, reduction in cellular dNTP pools and incorporation into DNA, are features of other antimetabolites antitumor agents which also exhibit radiosensitizing properties. Based on these favorable metabolic characteristics and the clinical activity of gemcitabine in tumor types which are commonly treated with radiation, the ability of gemcitabine to enhance X-radiation induced cytotoxicity was evaluated. Gemcitabine has been shown to be a potent radiosensitizer in a variety of tumor cell lines, including HT-29 colorectal carcinoma, pancreatic cancer, breast, non-small cell lung and head and neck cancer cell lines. Gemcitabine was most effective as a radiosensitizer when administered at least 2 hours prior to irradiation. For most cell lines, radiosensitization was evident at non-cytotoxic concentrations. The extent of radiosensitization increased with both increasing gemcitabine concentration and duration of exposure. Radiosensitization did not require redistribution of cells into a more radiosensitive phase of the cell cycle. The major metabolic effects observed under radiosensitizing conditions were the accumulation of high levels of gemcitabine triphosphate, and a selective decrease in the cellular dATP pool. The pattern of dATP decrease paralleled the increase in radiosensitization, whereas the level of gemcitabine triphosphate was not associated with the enhanced sensitivity to radiation. Compared to other radiosensitizers, the advantage of gemcitabine is that is can induce radiosensitization at concentrations that are 1000 times lower than typical plasma levels obtained with this drug. These studies will be used as guidelines for developing clinical trials of gemcitabine with radiation.

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References

  1. Abbruzzese JL, Grunewald R, Weeks EA et al.: A phase I clinical, plasma and cellular pharmacology study of gemcitabine. J Clin Oncol 9:491–498, 1991

    PubMed  CAS  Google Scholar 

  2. Poplin EA, Corbett T, Flaherty L et al.: Difluorodeoxycytidine (dFdC)-gemcitabine. A phase I study. Invest New Drugs 10:165–170, 1992

    Article  PubMed  CAS  Google Scholar 

  3. Lund B, Kristjansen PEG, Hansen HH: Clinical and preclinical activity of 2′,2′difluorodeoxycytidine (gemcitabine). Cancer Treat Rev 19:45–55, 1993

    Article  PubMed  CAS  Google Scholar 

  4. Hertel LW, Kroin JS, Misner JW, Tustin JM: Synthesis of 2-deoxy-2,2-difluoro-D-ribose and 2-deoxy-2,2-difluoro-Dribofuranosyl nucleosides. J Org Chem 53:2406–2409, 1988

    Article  CAS  Google Scholar 

  5. Hertel LW, Boder GB, Kroin JS et al.: Evaluation of the antitumor activity of gemcitabine (2′,2′-difluoro-2'deoxycytidine). Cancer Res 50:4417–4422, 1990

    PubMed  CAS  Google Scholar 

  6. Heinemann B, Hertel LW, Grindey GB, Plunkett W: Comparison of the cellular pharmacokinetics and toxicity of 2′2′-difluorodeoxycytidine and 1-Darabinofuranosylcytosine. Cancer Res 48:4024–4031, 1988

    PubMed  CAS  Google Scholar 

  7. Merriman RL, Schultz RM, Hertel LW et al.: Evaluation of the antitumor activity of gemcitabine against human carcinoma xenografts. Proc Am Assoc Cancer Res 35:448, 1994

    Google Scholar 

  8. Ruiz van Haperen VWT, Veerman G, Vermorken JB, Peters GJ: Improved antitumor effect of 2′,2′-difluorodeoxycytidine (Gemcitabine) in murine colon carcinomas, when administered as continuous infusions. Proc Am Assoc Cancer Res 35:447, 1994

    Google Scholar 

  9. Braakhuis BJM, Dongen GAMS, Vermorken JB, Snow GB: Preclinical in vivo activity of 2′,2′-difluorodeoxycytidine (gemcitabine) against human head and neck cancer. Cancer Res 51:211–214, 1994

    Google Scholar 

  10. Grunewald R, Kantarjian H, Du M et al.: Gemcitabine in leukemia: a phase I clinical, plasma, and cellular pharmacology study. J Clin Oncol 10:406–413, 1992

    PubMed  CAS  Google Scholar 

  11. DeVita VT, Hellman S, Rosenberg SA: In: Cancer Principles and Practice of Oncology, 3rd edition. Lippincott, Philadelphia, 1989

    Google Scholar 

  12. Kaye SB: Gemcitabine: current status of phase I and II trials. J Clin Oncol 12:1527–1531, 1994

    PubMed  CAS  Google Scholar 

  13. Fossella FV, Lippman SM, Tarassoff P: Phase I/II study of gemcitabine, an active agent for advanced non-small cell lung cancer (NSCLC). Proc Am Soc Clin Oncol 14:371 (abstr 1144), 1995

    Google Scholar 

  14. Carmichael J, Possinger K, Phillip P et al.: Advanced breast cancer: a phase II trial with gemcitabine. J Clin Oncol (in press)

  15. Lund B, Hansen OP, Theilade K et al.: Phase II study of gemcitabine (2′,2′-difluorodeoxycytidine) in previously treated ovarian cancer. J Nat Cancer Inst 86:1530–1533, 1994

    PubMed  CAS  Google Scholar 

  16. Moore M, Andersen J, Burris H et al.: A randomized trial of gemcitabine (GEM) versus 5FU as first-line therapy in advanced pancreatic cancer. Proc Am Soc Clin Oncol 14:199 (abstr 473), 1995

    Google Scholar 

  17. Anderson H, Lund B, Bach F et al.: Single-agent activity of weekly gemcitabine in advanced non-small cell lung cancer. A phase II study. J Clin Oncol 12:1821–1826, 1994

    PubMed  CAS  Google Scholar 

  18. Szybalski W: X-ray sensitization by halopyrimidines. Cancer Chemother Reports 58:539–557, 1974

    CAS  Google Scholar 

  19. Kim JH, Alfieri AA, Kim SH, Fuks Z: The potentiation of radiation response on murine tumor by fludarabine phosphate. Cancer Lett 31:69–76, 1986

    Article  PubMed  CAS  Google Scholar 

  20. Iliakis G, Seaner P: Differences in inhibition by beta-arabinofuranosyladenine (araA) of radiation induced DNA damage repair in exponentially growing and plateau-phase CHO cells. Radiat Environ Biol Phys 27:295–305, 1988

    Article  CAS  Google Scholar 

  21. Bruso CE, Shewac DS, Lawrence TS: Fluorodeoxyuridine-induced radiosensitization and inhibition of NA double strand break repair in human colon cancer cells. Int J Radiat Oncol Biol Phys 19:1411–1417, 1990

    PubMed  CAS  Google Scholar 

  22. Gregoire V, Hunter N, Milas L et al.: Potentiation of radiation-induced regrowth delay in murine tumors by fludarabine. Cancer Res 54:468–474, 1994

    PubMed  CAS  Google Scholar 

  23. Rockwell S, Grindey GB: Effect of 2′,2′-difluorodeoxycytidine on the viability and radiosensitivity of EMT6 cells in vitro. Oncol Res 4:151–155, 1992

    PubMed  CAS  Google Scholar 

  24. Shewach DS, Hahn TM, Chang E et al.: Metabolism of 2′,2′-difluoro-2′-deoxycytidine and radiation sensitization of human colon carcinoma cells. Cancer Res 54:3218–3223, 1994

    PubMed  CAS  Google Scholar 

  25. Ruiz van Haperen VWT, Veerman G, Boven E et al.: Schedule dependence of sensitivity to 2′,2′-difluorodeoxycytidine (gemcitabine) in relation to accumulation and retention of its triphosphate in solid tumor cell lines and solid tumors. Biochem Pharmacol 48:1327–1339, 1994

    Article  Google Scholar 

  26. Ruiz van Haperen VWT, Veerman G, Eriksson S et al.: Development and molecular characterization of a 2′,2′-difluorodeoxycytidine-resistant variant of the human ovarian carcinoma cell line A2780. Cancer Res 54:4138–4143, 1994

    Google Scholar 

  27. Shewach DS, Reynolds KK, Hertel LW: Nucleotide specificity of deoxycytidine kinase. Mol Pharmacol 42:518–524, 1992

    PubMed  CAS  Google Scholar 

  28. Grunewald R, Kanatarjian H, Keating MJ et al.: Pharmaco-logically directed design of the dose rate and schedule of 2′,2′-difluorodeoxycytidine (gemcitabine) administration in leukemia. Cancer Res 50:6823–6826, 1990

    PubMed  CAS  Google Scholar 

  29. Grunewald R, Abbruzzese JL, Tarassoff P, Plunkett W: Saturation of 2′,2′-difluorodeoxycytidine 5′-triphosphate accumulation by mononuclear cells during a phase I trial of gemcitabine. Cancer Chemother Pharmacol 27:285–292, 1991

    Article  Google Scholar 

  30. Heinemann V, Xu Y-Z, Chubb S et al.: Cellular elimination of 2′,2′-difluorodeoxycytidine 5′-triphosphate: a mechanism of self-potentiation. Cancer Res 52:53–539, 1991

    Google Scholar 

  31. Xu Y-Z, Plunkett W: Modulation of deoxycytidylate deaminase in intact human leukemia cells. Action of 2′,2′-difluorodeoxycytidine. Biochem Pharmacol 44:1819–1827, 1992

    Article  PubMed  CAS  Google Scholar 

  32. Ruiz van Haperen VWT, Veerman G, Vermorken JB, Peters GJ: 2′,2′-difluorodeoxycytidine (gemcitabine) incorporation into RNA and DNA of tumor cell lines. Biochem Pharmacol 46:762–766, 1993

    Article  Google Scholar 

  33. Huang P, Chubb S, Hertel LW et al.: Action of 2′,2′-difluorodeoxycytidine on DNA synthesis. Cancer Res 51:6110–6117, 1991

    PubMed  CAS  Google Scholar 

  34. Ross DD, Cuddy DP: Molecular effects of 2′,2′difluorodeoxycytidine (gemcitabine) on DNA replication in intact HL-60 cells. Biochem Pharmacol 48:1619–1630, 1994

    Article  PubMed  CAS  Google Scholar 

  35. Schy WE, Hertel LW, Kroin JS et al.: Effect of a template-located 2′,2′-difluorodeoxycytidine on the kinetics and fidelity of base insertion by Klenow (3′-5′exonuclease) fragment. Cancer Res 53:4582–4587, 1993

    PubMed  CAS  Google Scholar 

  36. Heinemann V, Xu Y-Z, Chubb S, Sen A et al.: Inhibition of ribonucleotide reduction in CCRF-CEM cells by 2′,2′-difluorodeoxycytidine. Mol Pharmacol 38:567–572, 1990

    PubMed  CAS  Google Scholar 

  37. Baker CH, Banzon J, Bollinger JM: 2′-Deoxy-2′-methy-lenecytidine and 2′-deoxy-2′,2′difluorocytidine 5′-diphosphates: potent mechanism-based inhibitors of ribonucleotide reductase. J Med Chem 34:1879–1884, 1991

    Article  PubMed  CAS  Google Scholar 

  38. Stubbe J: Ribonucleotide reductases. Adv Enzymol 63:349–419, 1990

    PubMed  CAS  Google Scholar 

  39. Goz B: The effects of incorporation of 5-halogenated deoxyuridines into the DNA of eukaryotic cells. Pharmacol Rev 29:249–272, 1978

    Google Scholar 

  40. Kinsella TJ, Dobson PP, Mitchell JB, Fornace AJ Jr: Enhancement of X-ray induced DNA damage by pre-treatment with halogenated pyrimidine analogs. Int J Radiat Oncol Biol Phys 13:733–739, 1987

    PubMed  CAS  Google Scholar 

  41. Lawrence TS, Davis MA, Stetson PL, Ensminger WD: The effect of single versus double-strand substitution on halogenated pyrimidine-induced radiosensitization and DNA strand breakage in human tumor cells. Radiat Res 123:192–198, 1990

    PubMed  CAS  Google Scholar 

  42. Shewach DS, Ellero J, Mancini WR, Ensminger WD: Decrease in TTP pools mediated by 5-bromo-2′-deoxyuridine exposure in a human glioblastoma cell line. Biochem Pharmacol 43:1579–1585, 1992

    Article  PubMed  CAS  Google Scholar 

  43. Sinclair WK: The combined effect of hydroxyurea and X-rays on Chinese hamster cells in vitro. Cancer Res 28:190–196, 1992

    Google Scholar 

  44. Shewach DS, Hahn T, Chang EY et al.: Depletion of dNTP pools and radiosensitization by difluorodeoxycytidine in HT-29 colon carcinoma cells. Proc Am Assoc Cancer Res 34:418, 1993

    Google Scholar 

  45. Lawrence TS, Chang EY, Hahn TM et al.: Radiosensitization of pancreatic cancer cells by 2′,2′-difluoro-2′deoxycytidine. Radiat Res (in press)

  46. Terasima T, Tolmach LJ: Variations in several responses of HeLa cells to X-irradiation during the division cycle. Biophys J 3:11–33, 1963

    Article  PubMed  CAS  Google Scholar 

  47. Dewey WC, Noel JS, Dettor CM: Changes in radiosensitivity and dispersion of chromatin during the cell cycle of synchronous Chinese hamster cells. Radiat Res 52:373–394, 1972

    PubMed  CAS  Google Scholar 

  48. Okayasu R, Bloecher D, Iliakis G: Variation through the cell cycle in the dose-response of DNA neutral filter elution in X-irradiated synchronous CHO-cells. Int J Radiat Biol 53:729–747, 1988

    CAS  Google Scholar 

  49. Sinclair WK: Sensitivity to mitotic delay and stage in the cycle. Curr Topics Radiat Res 7:323–327, 1972

    CAS  Google Scholar 

  50. Shewach DS, Hahn TM, Chang E et al.: Radiosensitization of HT-29 human colon carcinoma cells after 2 hours exposure to difluorodeoxycytidine. Proc Am Assoc Cancer Res 36:405, 1995

    Google Scholar 

  51. Crino L, Scagliotti G, Marangolo M et al.: Cisplatin-gemcitabine combination in non-small cell lung cancer (NSCLC). A phase II study. Proc Am Soc Clin Oncol 14:352 (abstr 1066), 1995

    Google Scholar 

  52. Rich TA, Lokich JJ, Chaffey JT: A pilot study of protracted venous infusion of 5-fluorouracil and concomitant radiation therapy. J Clin Oncol 3:402–406, 1985

    PubMed  CAS  Google Scholar 

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  1. Departments of Pharmacology and Radiation Oncology, University of Michigan Medical Center, 48109-0504, Ann Arbor, MI, USA

    Donna S. Shewach & Theodore S. Lawrence

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  1. Donna S. Shewach
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  2. Theodore S. Lawrence
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Shewach, D.S., Lawrence, T.S. Gemcitabine and radiosensitization in human tumor cells. Invest New Drugs 14, 257–263 (1996). https://doi.org/10.1007/BF00194528

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