Validation of Telomerase and Survivin as Anticancer Therapeutic Targets Using Ribozymes and Small-Interfering RNAs

  • Nadia Zaffaroni
  • Marzia Pennati
  • Marco Folini
Part of the Methods in Molecular Biology™ book series (MIMB, volume 361)

Abstract

In recent years expanding knowledge about basic biology and a detailed understanding of the molecular pathways involved in tumor cell growth and progression have allowed the identification of numerous genes as potential therapeutic targets. Studies in which the expression of these genes was manipulated by antisense strategies have provided clues as to how we can intervene to specifically kill tumor cells or sensitize them to conventional chemical and physical antitumor therapies. Such tumor specificity can only be obtained by exploiting a basic difference between normal and malignant cells. In this context, targeting cytoprotective factors such as telomerase and survivin is particularly attractive because of their almost selective expression in tumor cells and their proven association with disease progression. This chapter summarizes the results obtained with ribozymes and small-interfering RNAs in the functional validation of these two targets in cell cultures and animal tumor models.

Key Words

Human cancer ribozyme survivin siRNA telomerase 

References

  1. 1.
    Jansen, B. and Zangemeister-Wittke, U. (2002) Antisense therapy for cancer—the time of truth. Lancet Oncol. 3, 672–683.PubMedCrossRefGoogle Scholar
  2. 2.
    Kyo, S. and Inoue, M. (2002) Complex regulatory mechanisms of telomerase activity in normal and cancer cells: how can we apply them for cancer therapy? Oncogene 21, 688–697.PubMedCrossRefGoogle Scholar
  3. 3.
    Altieri, D. C. (2003) Survivin and apoptosis control. Adv. Cancer Res. 88, 31–52.PubMedCrossRefGoogle Scholar
  4. 4.
    Hahn, W. C. (2003) Role of telomeres and telomerase in the pathogenesis of human cancer. J. Clin. Oncol. 21, 2034–2043.PubMedCrossRefGoogle Scholar
  5. 5.
    Smogorzewska, A. and de Lange, T. (2004) Regulation of telomerase by telomeric proteins. Annu. Rev. Biochem. 73, 177–208.PubMedCrossRefGoogle Scholar
  6. 6.
    Karlseder, J. (2003) Telomere repeat binding factor: keeping the ends in check. Cancer Lett. 194, 189–197.PubMedCrossRefGoogle Scholar
  7. 7.
    Wright, W. E. and Shay, J. W. (2005) Telomere-binding factors and general DNA repair. Nat. Genet. 37, 116–118.PubMedCrossRefGoogle Scholar
  8. 8.
    Smogorzewska, A., Karlseder, J., Holtgreve-Grez, H., Jauch, A., and de Lange, T. (2002) DNA ligase IV-dependent NHEJ of deprotected mammalian telomeres in G1 and G2. Curr. Biol. 12, 1635–1644.PubMedCrossRefGoogle Scholar
  9. 9.
    Baumann, P. and Cech, T. R. (2001) Pot1, the putative telomere end-binding protein in fission yeast and humans. Science 292, 1171–1175.PubMedCrossRefGoogle Scholar
  10. 10.
    Lundblad, V. (2003) Telomeres: taking the measure. Nature 423, 926–927.PubMedCrossRefGoogle Scholar
  11. 11.
    Colgin, L. M., Baran, K., Baumann, P., Cech, T. R., and Reddel, R. R. (2003) Human POT1 facilitates telomere elongation by telomerase. Curr. Biol. 13, 942–946.PubMedCrossRefGoogle Scholar
  12. 12.
    Keith, W. N., Evans, T. R. J., and Glasspool, R. M. (2001) Telomerase and cancer: time to move from a promising target to a clinical reality. J. Pathol. 195, 404–414.PubMedCrossRefGoogle Scholar
  13. 13.
    Olovnikov, A. M. (1973) A theory of marginotomy. The incomplete copy of template margin in enzymatic synthesis of polynucleotides and biological significance of the phenomenon. J. Theor. Biol. 41, 181–190.PubMedCrossRefGoogle Scholar
  14. 14.
    Cong, Y. S., Wright, W. E., and Shay, J. W. (2002) Human telomerase and its regulation. Microbiol. Mol. Biol. Rev. 66, 407–425.PubMedCrossRefGoogle Scholar
  15. 15.
    Harrington, L., Zhou, W., McPhail, T., et al. (1997) Human telomerase contains evolutionarily conserved catalytic and structural subunits. Genes Dev. 11, 3109–3115.PubMedCrossRefGoogle Scholar
  16. 16.
    Feng, J., Funk, W. D., Wang, S. S., et al. (1995) The RNA component of human telomerase. Science 269, 1236–1241.PubMedCrossRefGoogle Scholar
  17. 17.
    Yi, X., White, D. M., Aisner, D. L., Baur, J. A., Wright, W. E., and Shay, J. W. (2000) An alternate splicing variant of the human telomerase catalytic subunit inhibits telomerase activity. Neoplasia 2, 433–440.PubMedCrossRefGoogle Scholar
  18. 18.
    Blackburn, E. H. (2005) Telomeres and telomerase: their mechanisms of action and the effects of altering their functions. FEBS Lett. 579, 859–862.PubMedCrossRefGoogle Scholar
  19. 19.
    Hahn, W. C. and Meyerson, M. (2001) Telomerase activation, cellular immortalization and cancer. Ann. Med. 2, 123–129.CrossRefGoogle Scholar
  20. 20.
    Shay, J. W. and Bacchetti, S. (1997) A survey of telomerase activity in human cancer. Eur. J. Cancer 33, 787–791.PubMedCrossRefGoogle Scholar
  21. 21.
    Hanahan, D. and Weinberg, R. A. (2000) The hallmarks of cancer. Cell 100, 57–70.PubMedCrossRefGoogle Scholar
  22. 22.
    Folini, M. and Zaffaroni, N. (2005) Targeting telomerase by antisense-based approaches: perspectives for new anti-cancer therapies. Curr. Pharm. Des. 11, 1105–1117.PubMedCrossRefGoogle Scholar
  23. 23.
    Blackburn, E. H. (2000) Telomere states and cell fates. Nature 408, 53–56.PubMedCrossRefGoogle Scholar
  24. 24.
    Sharma, G. G., Gupta, A., Wang, H., et al. (2003) hTERT associates with human telomeres and enhances genomic stability and DNA repair. Oncogene 22, 131–146.PubMedCrossRefGoogle Scholar
  25. 25.
    Cao, Y., Li, H., Deb, S., and Liu, J. P. (2004) TERT regulates cell survival independent of telomerase enzymatic activity. Oncogene 21, 3130–3138.CrossRefGoogle Scholar
  26. 26.
    Kelland, L. R. (2005) Overcoming the immortality of tumor cells by telomere and telomerase based cancer therapeutics—current status and future prospects. Eur. J. Cancer 41, 971–979.PubMedCrossRefGoogle Scholar
  27. 27.
    Altieri, D. (2004) Molecular circuits of apoptosis regulation and cell division control: the survivin paradigm. J. Cell. Biochem. 92, 656–663.PubMedCrossRefGoogle Scholar
  28. 28.
    Ambrosini, G., Adida, C., Sirugo, A., and Altieri, D. C. (1998) Induction of apoptosis and inhibition of cell proliferation by survivin gene targeting. J. Biol. Chem. 273, 11,177–11,182.PubMedCrossRefGoogle Scholar
  29. 29.
    Ambrosini, G., Adida, C., and Altieri, D. C. (1997) A novel anti-apoptosis gene, survivin, expressed in cancer and lymphoma. Nat. Med. 3, 917–921.PubMedCrossRefGoogle Scholar
  30. 30.
    LaCasse, E. C., Baird, S., Korneluk, R. G., and MacKenzie, A. E. (1998) The inhibitors of apoptosis (IAPs) and their emerging role in cancer. Oncogene 17, 3247–3259.PubMedCrossRefGoogle Scholar
  31. 31.
    Mahotka, C., Wenzel, M., Springer, E., Gabbert, H. E., and Gerharz, C. D. (1999) Survivin-ΔEx3 and survivin-2B: two novel splice variants of the apoptosis inhibitor survivin with different antiapoptotic properties. Cancer Res. 59, 6097–6102.PubMedGoogle Scholar
  32. 32.
    Badran, A., Yoshida, A., Ishikawa, K., et al. (2004) Identification of a novel splice variant of the human anti-apoptopsis gene survivin Biochem. Biophys. Res. Commun. 314, 902–907.PubMedCrossRefGoogle Scholar
  33. 33.
    Caldas, H., Honsey, L. E., and Altura, R. A. (2005) Survivin 2alpha: a novel Survivin splice variant expressed in human malignancies. Mol. Cancer 4, 11.PubMedCrossRefGoogle Scholar
  34. 34.
    Caldas, H., Jiang, Y., Holloway, M. P., et al. (2005) Survivin splice variants regulate the balance between proliferation and cell death. Oncogene 24, 1994–2007.PubMedCrossRefGoogle Scholar
  35. 35.
    Li, F. and Altieri, D. C. (1999) The cancer anti-apoptosis mouse survivin gene: characterization of locus and transcriptional requirements of basal and cell cycle-dependent expression. Cancer Res. 59, 3143–3151.PubMedGoogle Scholar
  36. 36.
    O’Connor, D. S., Grossman, D., Plescia, J., et al. (2000) Regulation of apoptosis at cell division by p34cdc2 phosphorylation of survivin. Proc. Natl. Acad. Sci. 97, 13,103–13,107.PubMedCrossRefGoogle Scholar
  37. 37.
    Fortugno, P., Wall, N. R., Giodini, A., et al. (2002) Survivin exists in immunochemically distinct subcellular pools and is involved in spindle microtubule function. J. Cell Sci. 115, 575–585.PubMedGoogle Scholar
  38. 38.
    Uren, A. G., Wong, L., Pakusch, M., et al. (2000) Survivin and the inner centromere protein INCENP show similar cell-cycle localization and gene knockout phenotype. Curr. Biol. 10, 1319–1328.PubMedCrossRefGoogle Scholar
  39. 39.
    Li, F., Ackermann, E. J., Bennett, C. F., et al. (1999) Pleiotropic cell-division defects and apoptosis induced by interference with survivin function. Nat. Cell Biol. 1, 461–466.PubMedCrossRefGoogle Scholar
  40. 40.
    Chen, J., Wu, W., Tahir, S. K., et al. (2000) Down-regulation of survivin by antisense oligonucleotides increases apoptosis, inhibits cytokinesis and anchorage-dependent growth. Neoplasia 2, 235–241.PubMedCrossRefGoogle Scholar
  41. 41.
    Giodini, A., Kallio, M. J., Wall, N. R., et al. (2002) Regulation of microtubule stability and mitotic progression by survivin. Cancer Res. 62, 2462–2467.PubMedGoogle Scholar
  42. 42.
    Kallio, M. J., Nieminen, M., and Eriksson, J. E. (2001) Human inhibitor of apoptosis protein (IAP) survivin participates in regulation of chromosome segregation and mitotic exit. FASEB 15, 2721–2723.Google Scholar
  43. 43.
    Carvalho, A., Carmena, M., Sambade, C., Earnshaw, W. C., and Wheatley, S. P. (2003) Survivin is required for stable checkpoint activation in taxol-treated HeLa cells. J. Cell. Sci. 116, 2987–2998.PubMedCrossRefGoogle Scholar
  44. 44.
    Dohi, T., Beltrami, E., Wall, N. R., Plescia, J., and Altieri, D. C. (2004) Mitochondrial survivin inhibits apoptosis and promotes tumorigenesis. J. Clin. Invest. 114, 1117–1127.PubMedGoogle Scholar
  45. 45.
    Fortugno, P., Beltrami, E., Plescia, J., et al. (2003) Regulation of survivin function by Hsp90. Proc. Natl. Acad. Sci. USA 100, 13,791–13,796.PubMedCrossRefGoogle Scholar
  46. 46.
    O’Connor, D. S., Grossman, D., Plescia, J., et al. (2000) Regulation of apoptosis at cell division by p34cdc2 phosphorylation of survivin. Proc. Natl. Acad. Sci. 97, 13,103–13,107.PubMedCrossRefGoogle Scholar
  47. 47.
    Song, Z., Yao, X., and Wu, M. (2003) Direct interaction between survivin and Smac/DIABLO is essential for the anti-apoptotic activity of survivin during taxolinduced apoptosis. J. Biol. Chem. 278, 23,130–23,140.PubMedCrossRefGoogle Scholar
  48. 48.
    Shiozaki, E. N. and Shi, Y. (2004) Caspases, IAPs and Smac/DIABLO: mechanisms from structural biology. Trends Biochem. Sci. 29, 486–494.PubMedCrossRefGoogle Scholar
  49. 49.
    Altieri, D. C. (2003) Survivin, versatile modulation of cell division and apoptosis in cancer. Oncogene 22, 8581–8589.PubMedCrossRefGoogle Scholar
  50. 50.
    O’Connor, D. S., Schechner, J. S., Adida, C., et al. (2000) Control of apoptosis during angiogenesis by survivin expression in endothelial cells. Am. J. Pathol. 156, 393–398.PubMedCrossRefGoogle Scholar
  51. 51.
    Velculescu, V. E., Madden, S. L., Zhang, L., et al. (1999) Analysis of human transcriptomes. Nat. Gen. 23, 387–388.CrossRefGoogle Scholar
  52. 52.
    Plantaz, D., Mohapatra, G., Matthay, K. K., Pellarin, M., Seeger, R. C., and Feuerstein, B. G. (1997) Gain of chromosome 17 is the most frequent abnormality detected in neuroblastoma by comparative genomic hybridization. Am. J. Pathol. 150, 81–89.PubMedGoogle Scholar
  53. 53.
    Hattori, M., Sakamoto, H., Satoh, K., and Yamamoto, T. (2001) DNA demethylase is expressed in ovarian cancers and the expression correlates with demethylation of CpG sites in the promoter region of c-erbB-2 and survivin genes. Cancer Lett. 169, 155–164.PubMedCrossRefGoogle Scholar
  54. 54.
    Mirza, A., McGuirk, M., Hockenberry, T. N., et al. (2002) Human survivin is negatively regulated by wild-type p53 and participates in p53-dependent apoptotic pathway. Oncogene 21, 2613–2622.PubMedCrossRefGoogle Scholar
  55. 55.
    Li, F., Ambrosini, G., Chu, E. Y., et al. (1998) Control of apoptosis and mitotic spindle checkpoint by survivin. Nature 396, 580–584.PubMedCrossRefGoogle Scholar
  56. 56.
    Zaffaroni, N., Pennati, M., Colella, G., et al. (2002) Expression of the antiapoptotic gene survivin correlates with taxol resistance in human ovarian cancer. Cell. Mol. Life Sci. 59, 1406–1412.PubMedCrossRefGoogle Scholar
  57. 57.
    Asanuma, K., Moriai, R., Yajima, T., et al. (2000) Survivin as a radio-resistance factor in pancreatic cancer. Jap. J. Cancer Res. 91, 1204–1209.Google Scholar
  58. 58.
    Zhang, M., Latham, D. E., Delaney, M. A., and Chakravarti, A. (2005) Survivin mediates resistance to antiandrogen therapy in prostate cancer. Oncogene 24, 2474–2482.PubMedCrossRefGoogle Scholar
  59. 59.
    Nicholson, D. W. (2000) From bench to clinic with apoptosis-based therapeutic agents. Nature 407, 810–816.PubMedCrossRefGoogle Scholar
  60. 60.
    Fischer, U. and Schulze-Osthoff, K. (2005) New approaches and therapeutics targeting apoptosis in disease. Pharmacol. Rev. 57, 187–215.PubMedCrossRefGoogle Scholar
  61. 61.
    Altieri, D. C. (2003) Validating survivin as a cancer therapeutic target. Nat. Rev. Cancer 3, 46–54.PubMedCrossRefGoogle Scholar
  62. 62.
    Puerta-Fernandez, E., Romer-Lopez, C., Barroso-delJesus, A., and Berzal-Herranz, A. (2003) Ribozymes: recent advances in the development of RNA tools. FEMS Microbiol. Rev. 27, 75–97.PubMedCrossRefGoogle Scholar
  63. 63.
    Kore, A. R., Vaish, N. K., Kutzke, U., and Eckstein, F. (1998) Sequence specificity of the hammerhead ribozyme revisited: the NHH rule. Nucleic Acids Res. 26, 4116–4120.PubMedCrossRefGoogle Scholar
  64. 64.
    Kurreck, J. (2003) Antisense technologies. Improvement through novel chemical modifications. Eur. J. Biochem. 270, 1628–1644.PubMedCrossRefGoogle Scholar
  65. 65.
    Kanazawa, Y., Ohkawa, K., Ueda, K., et al. (1996) Hammerhead ribozyme-mediated inhibition of telomerase activity in extracts of human hepatocellular carcinoma cells. Biochem. Biophys. Res Commun. 225, 570–576.PubMedCrossRefGoogle Scholar
  66. 66.
    Wan, M. S., Fell, P. L., and Akhtar, S. (1998) Synthetic 2′-O-methyl-modified hammerhead ribozymes targeted to the RNA component of telomerase as sequence-specific inhibitors of telomerase activity. Antisense Nucleic Acid Drug Dev. 8, 309–317.PubMedGoogle Scholar
  67. 67.
    Folini, M., Colella, G., Villa, R., Lualdi, S., Daidone, M. G., and Zaffaroni, N. (2000) Inhibition of telomerase activity by a hammerhead ribozyme targeting the RNA component of telomerase in human melanoma cells. J. Invest. Dermatol. 114, 259–267.PubMedCrossRefGoogle Scholar
  68. 68.
    Yokoyama, Y., Takahashi, Y., Shinohara, A., et al. (1998) Attenuation of telomerase activity by a hammerhead ribozyme targeting the template region of telomerase RNA in endometrial carcinoma cells. Cancer Res. 58, 5406–5410.PubMedGoogle Scholar
  69. 69.
    Yokoyama, Y., Wan, X., Takahashi, Y., Shinohara, A., Liulin, T., and Tamaya, T. (2002) Divalent hammerhead ribozyme targeting template region of human telomerase RNA has potent cleavage activity, but less inhibitory activity on telomerase. Arch. Biochem. Biophys. 405, 32–37.PubMedCrossRefGoogle Scholar
  70. 70.
    Yeo, M., Rha, S. Y., Jeung, H. C., et al. (2005) Attenuation of telomerase activity by hammerhead ribozyme targeting human telomerase RNA induces growth retardation and apoptosis in human breast tumor cells. Int. J. Cancer 114, 484–489.PubMedCrossRefGoogle Scholar
  71. 71.
    Yokoyama, Y., Takahashi, Y., Shinohara, A., et al. (2000) The 5′-end of hTERT mRNA is a good target for hammerhead ribozyme to suppress telomerase activity. Biochem. Biophys. Res Commun. 273, 316–321.PubMedCrossRefGoogle Scholar
  72. 72.
    Ludwig, A., Saretzki, G., Holm, P. S., et al. (2001) Ribozyme cleavage of telomerase mRNA sensitizes breast epithelial cells to inhibitors of topoisomerase. Cancer Res. 61, 3053–3061.PubMedGoogle Scholar
  73. 73.
    Saretzki, G., Ludwig, A., von Zglinicki, T., and Runnebaum, I. B. (2001) Ribozyme-mediated telomerase inhibition induces immediate cell loss but not telomere shortening in ovarian cancer cells. Cancer Gene Ther. 8, 827–834.PubMedCrossRefGoogle Scholar
  74. 74.
    Pennati, M., Colella, G., Folini, M., Citti, L., Daidone, M. G., and Zaffaroni, N. (2002) Ribozyme-mediated attenuation of survivin expression sensitizes human melanoma cells to cisplatin-induced apoptosis. J. Clin. Invest. 109, 285–286.PubMedGoogle Scholar
  75. 75.
    Pennati, M., Binda, M., De Cesare, M., et al. (2004) Ribozyme-mediated down-regulation of survivin expression sensitizes human melanoma cells to topotecan in vitro and in vivo. Carcinogenesis 25, 1129–1136.PubMedCrossRefGoogle Scholar
  76. 76.
    Pennati, M., Binda, M., Coltella, G., et al. (2003) Radiosensitization of human melanoma cells by ribozyme-mediated inhibition of survivin expression. J. Invest. Dermatol. 120, 648–654.PubMedCrossRefGoogle Scholar
  77. 77.
    Pennati, M., Binda, M., Coltella, G., et al. (2004) Ribozyme-mediated inhibition of survivin expression increases spontaneous and drug-induced apoptosis and decreases the tumorigenic potential of human prostate cancer cells. Oncogene 23, 386–394.PubMedCrossRefGoogle Scholar
  78. 78.
    Choi, K. S., Lee, T. H., and Jung, M. H. (2003) Ribozyme-mediated cleavage of the human survivin mRNA and inhibition of antiapoptotic function of survivin in MCF-7 cells. Cancer Gene Ther. 10, 87–95.PubMedCrossRefGoogle Scholar
  79. 79.
    Elbashir, S. M., Harborth, J., Weber, K., and Tuschl, T. (2002) Analysis of gene function in somatic mammalian cells using small interfering RNAs. Methods 26, 199–213.PubMedCrossRefGoogle Scholar
  80. 80.
    Dykxhoorn, D. M., Novina, C. D., and Sharp, P. A. (2003) Killing the messenger: short RNAs that silence gene expression. Nat. Rev. Mol. Cell. Biol. 4, 457–467.PubMedCrossRefGoogle Scholar
  81. 81.
    Izquierdo, M. (2005) Short interfering RNAs as a tool for cancer gene therapy. Cancer Gene Ther. 12, 217–227.PubMedCrossRefGoogle Scholar
  82. 82.
    Kosciolek, B. A., Kalantidis, K., Tabler, M., and Rowley, P. T. (2003) Inhibition of telomerase activity in human cancer cells by RNA interference. Mol. Cancer Ther. 2, 209–216.PubMedCrossRefGoogle Scholar
  83. 83.
    Li, S., Crothers, J., Haqq, C. M., and Blackburn, E. H. (2005) Cellular and gene expression responses involved in the rapid growth inhibition of human cancer cells by RNA interference-mediated depletion of telomerase RNA. J. Biol. Chem. 280, 23,709–23,717.PubMedCrossRefGoogle Scholar
  84. 84.
    Kappler, M., Bache, M., Bartel, F., et al. (2004) Knockdown of survivin expression by small interfering RNA reduces the clonogenic survival of human sarcoma cell lines independently of p53. Cancer Gene Ther. 11, 186–193.PubMedCrossRefGoogle Scholar
  85. 85.
    Kappler, M., Taubert, H., Bartel, F., et al. (2005) Radiosensitization, after a combined treatment of survivin siRNA and irradiation, is correlated with the activation of caspases 3 and 7 in a wt-p53 sarcoma cell line, but not in a mt-p53 sarcoma cell line. Oncol. Rep. 13, 167–172.PubMedGoogle Scholar
  86. 86.
    Chawla-Sarkar, M., Bae, S. I., Reu, F. J., Jacobs, B. S., Lindner, D. J., and Borden, E. C. (2004) Downregulation of Bcl-2, FLIP or IAPs (XIAP and survivin) by siRNAs sensitizes resistant melanoma cells to Apo2L/TRAIL-induced apoptosis. Cell Death Differ. 11, 915–923.PubMedCrossRefGoogle Scholar
  87. 87.
    Coma, S., Noe, V., Lavarino, C., et al. (2004) Use of siRNAs and antisense oligonucleotides against survivin RNA to inhibit steps leading to tumor angiogenesis. Oligonucleotides 14, 100–113.PubMedCrossRefGoogle Scholar
  88. 88.
    Coumoul, X., Li, W., Wang, R. H., and Deng, C. (2004) Inducible suppression of Fgfr2 and Survivin in ES cells using a combination of the RNA interference (RNAi) and the Cre-LoxP system. Nucleic Acids Res. 32, e85.PubMedCrossRefGoogle Scholar
  89. 89.
    Scherer, L. J. and Rossi, J. J. (2003) Approaches for the sequence-specific knockdown of mRNA. Nature Biotechnol. 21, 1457–1465.CrossRefGoogle Scholar
  90. 90.
    Caplen, N. J. (2004) Gene therapy progress and prospects. Downregulating gene expression: the impact of RNA interference. Gene Ther. 11, 1241–1248.PubMedCrossRefGoogle Scholar
  91. 91.
    Schubert, S., Grünweller, A., Erdmann, V. A., and Kurreck, J. (2005) Local RNA target structure influences siRNA efficacy: systematic analysis of intentionally designed binding regions. J. Mol. Biol. 348, 883–893.PubMedCrossRefGoogle Scholar
  92. 92.
    Overhoff, M., Alken, M., Far, R. K., et al. (2005) Local RNA target structure influences siRNA efficacy: a systematic global analysis. J. Mol. Biol. 348, 871–881.PubMedCrossRefGoogle Scholar
  93. 93.
    Lee, N. S., Lee, N. S., Bertrand, E., and Rossi, J. (1999) mRNA localizasion signals can enhance the intracellular effectiveness of hammerhead ribozymes. RNA 5, 1200–1209.PubMedCrossRefGoogle Scholar
  94. 94.
    Sullenger, B. A. and Gilboa, E. (2002) Emerging clinical application of RNA. Nature 418, 252–258.PubMedCrossRefGoogle Scholar
  95. 95.
    Bantounas, I., Phylactou, L. A., and Uney, J. B. (2004) RNA interference and the use of small interfering RNA to study gene function in mammalian systems. J. Mol. Endocrinol. 33, 545–557.PubMedCrossRefGoogle Scholar
  96. 96.
    Sledz, C. A. and Williams, B. R. G. (2004) RNA interference and double-stranded-RNA-activated pathways. Biochem. Soc. Trans. 32, 952–956.PubMedCrossRefGoogle Scholar
  97. 97.
    Sledz, C. A., Holko, M., de Veer, M. J., Silverman, R. H., and Williams, R. G. (2003) Activation of interferon system by short-interfering RNAs. Nat. Cell. Biol. 5, 834–839.PubMedCrossRefGoogle Scholar
  98. 98.
    Huppi, K., Martin, S. E., and Caplen, N. J. (2005) Defining and assaying RNAi in mammalian cells. Mol. Cell. 17, 1–10.PubMedCrossRefGoogle Scholar
  99. 99.
    Shay, J. W. and Wright, W. E. (2002) Telomerase: a target for cancer therapeutics. Cancer Cell 2, 257–265.PubMedCrossRefGoogle Scholar
  100. 100.
    Folini, M., Brambilla, C., Villa, R., et al. (2005) Antisense oligonucleotide-mediated inhibition of hTERT, but not hTERC, induces rapid cell growth decline and apoptosis in the absence of telomere shortening in human prostate cancer cells. Eur. J. Cancer 41, 624–634.PubMedCrossRefGoogle Scholar
  101. 101.
    Henson, J. D., Neumann, A. A., Yeager, T. R., and Reddel, R. R. (2002) Alternative lengthening of telomeres in mammalian cells. Oncogene 21, 598–610.PubMedCrossRefGoogle Scholar
  102. 102.
    Reddel, R. R. and Bryan, T. M. (2003) Alternative lengthening of telomeres: dangerous road less travelled. Lancet 361, 1840.PubMedCrossRefGoogle Scholar
  103. 103.
    Tran, J., Master, Z., Yu, J. L., Rak, J., Dumont, D. J., and Kerbel, R. S. (2002). A role for survivin in chemoresistance of endothelial cells mediated by VEGF. Proc. Natl. Acad. Sci. USA 99, 4349–4354.PubMedCrossRefGoogle Scholar
  104. 104.
    Mesri, M., Morales-Ruiz, M., Ackermann, E. J., et al. (2001) Suppression of vascular endothelial growth factor-mediated endothelial cell protection by survivin targeting. Am. J. Pathol. 158, 1757–1765.PubMedCrossRefGoogle Scholar

Copyright information

© Humana Press Inc. 2007

Authors and Affiliations

  • Nadia Zaffaroni
    • 1
  • Marzia Pennati
    • 1
  • Marco Folini
    • 1
  1. 1.Department of Experimental Oncology and LaboratoriesNational Cancer InstituteMilanItaly

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