Skip to main content
NCBI home page
Molecular and Cellular Biology logoLink to Molecular and Cellular Biology
. 1996 Jan;16(1):53–65. doi: 10.1128/mcb.16.1.53

Effects of reverse transcriptase inhibitors on telomere length and telomerase activity in two immortalized human cell lines.

C Strahl 1, E H Blackburn 1
PMCID: PMC230978  PMID: 8524329

Abstract

The ribonucleoprotein telomerase, a specialized cellular reverse transcriptase, synthesizes one strand of the telomeric DNA of eukaryotes. We analyzed telomere maintenance in two immortalized human cell lines: the B-cell line JY616 and the T-cell line Jurkat E6-1, and determined whether known inhibitors of retroviral reverse transcriptases could perturb telomere lengths and growth rates of these cells in culture. Dideoxyguanosine (ddG) caused reproducible, progressive telomere shortening over several weeks of passaging, after which the telomeres stabilized and remained short. However, the prolonged passaging in ddG caused no observable effects on cell population doubling rates or morphology. Azidothymidine (AZT) caused progressive telomere shortening in some but not all T- and B-cell cultures. Telomerase activity was present in both cell lines and was inhibited in vitro by ddGTP and AZT triphosphate. Prolonged passaging in arabinofuranyl-guanosine, dideoxyinosine (ddI), dideoxyadenosine (ddA), didehydrothymidine (d4T), or phosphonoformic acid (foscarnet) did not cause reproducible telomere shortening or decreased cell growth rates or viabilities. Combining AZT, foscarnet, and/or arabinofuranyl-guanosine with ddG did not significantly augment the effects of ddG alone. Strikingly, with or without inhibitors, telomere lengths were often highly unstable in both cell lines and varied between parallel cell cultures. We propose that telomere lengths in these T- and B-cell lines are determined by both telomerase and telomerase-independent mechanisms.

Full Text

The Full Text of this article is available as a PDF (760.4 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Allshire R. C., Gosden J. R., Cross S. H., Cranston G., Rout D., Sugawara N., Szostak J. W., Fantes P. A., Hastie N. D. Telomeric repeat from T. thermophila cross hybridizes with human telomeres. Nature. 1988 Apr 14;332(6165):656–659. doi: 10.1038/332656a0. [DOI] [PubMed] [Google Scholar]
  2. Bernards A., Michels P. A., Lincke C. R., Borst P. Growth of chromosome ends in multiplying trypanosomes. Nature. 1983 Jun 16;303(5918):592–597. doi: 10.1038/303592a0. [DOI] [PubMed] [Google Scholar]
  3. Blackburn E. H., Chiou S. S. Non-nucleosomal packaging of a tandemly repeated DNA sequence at termini of extrachromosomal DNA coding for rRNA in Tetrahymena. Proc Natl Acad Sci U S A. 1981 Apr;78(4):2263–2267. doi: 10.1073/pnas.78.4.2263. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Blackburn E. H. Structure and function of telomeres. Nature. 1991 Apr 18;350(6319):569–573. doi: 10.1038/350569a0. [DOI] [PubMed] [Google Scholar]
  5. Blackburn E. H. Telomeres: no end in sight. Cell. 1994 Jun 3;77(5):621–623. doi: 10.1016/0092-8674(94)90046-9. [DOI] [PubMed] [Google Scholar]
  6. Broccoli D., Young J. W., de Lange T. Telomerase activity in normal and malignant hematopoietic cells. Proc Natl Acad Sci U S A. 1995 Sep 26;92(20):9082–9086. doi: 10.1073/pnas.92.20.9082. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Brown W. R., MacKinnon P. J., Villasanté A., Spurr N., Buckle V. J., Dobson M. J. Structure and polymorphism of human telomere-associated DNA. Cell. 1990 Oct 5;63(1):119–132. doi: 10.1016/0092-8674(90)90293-n. [DOI] [PubMed] [Google Scholar]
  8. Counter C. M., Avilion A. A., LeFeuvre C. E., Stewart N. G., Greider C. W., Harley C. B., Bacchetti S. Telomere shortening associated with chromosome instability is arrested in immortal cells which express telomerase activity. EMBO J. 1992 May;11(5):1921–1929. doi: 10.1002/j.1460-2075.1992.tb05245.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Counter C. M., Hirte H. W., Bacchetti S., Harley C. B. Telomerase activity in human ovarian carcinoma. Proc Natl Acad Sci U S A. 1994 Apr 12;91(8):2900–2904. doi: 10.1073/pnas.91.8.2900. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Gilley D., Blackburn E. H. Specific RNA residue interactions required for enzymatic functions of Tetrahymena telomerase. Mol Cell Biol. 1996 Jan;16(1):66–75. doi: 10.1128/mcb.16.1.66. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Gilley D., Lee M. S., Blackburn E. H. Altering specific telomerase RNA template residues affects active site function. Genes Dev. 1995 Sep 15;9(18):2214–2226. doi: 10.1101/gad.9.18.2214. [DOI] [PubMed] [Google Scholar]
  12. Gottschling D. E., Zakian V. A. Telomere proteins: specific recognition and protection of the natural termini of Oxytricha macronuclear DNA. Cell. 1986 Oct 24;47(2):195–205. doi: 10.1016/0092-8674(86)90442-3. [DOI] [PubMed] [Google Scholar]
  13. Greider C. W., Blackburn E. H. A telomeric sequence in the RNA of Tetrahymena telomerase required for telomere repeat synthesis. Nature. 1989 Jan 26;337(6205):331–337. doi: 10.1038/337331a0. [DOI] [PubMed] [Google Scholar]
  14. Greider C. W., Blackburn E. H. Identification of a specific telomere terminal transferase activity in Tetrahymena extracts. Cell. 1985 Dec;43(2 Pt 1):405–413. doi: 10.1016/0092-8674(85)90170-9. [DOI] [PubMed] [Google Scholar]
  15. Grundel R., Rubin H. Maintenance of multiplication rate stability by cell populations in the face of heterogeneity among individual cells. J Cell Sci. 1988 Dec;91(Pt 4):571–576. doi: 10.1242/jcs.91.4.571. [DOI] [PubMed] [Google Scholar]
  16. Harley C. B., Futcher A. B., Greider C. W. Telomeres shorten during ageing of human fibroblasts. Nature. 1990 May 31;345(6274):458–460. doi: 10.1038/345458a0. [DOI] [PubMed] [Google Scholar]
  17. Hastie N. D., Dempster M., Dunlop M. G., Thompson A. M., Green D. K., Allshire R. C. Telomere reduction in human colorectal carcinoma and with ageing. Nature. 1990 Aug 30;346(6287):866–868. doi: 10.1038/346866a0. [DOI] [PubMed] [Google Scholar]
  18. Hiyama E., Hiyama K., Yokoyama T., Matsuura Y., Piatyszek M. A., Shay J. W. Correlating telomerase activity levels with human neuroblastoma outcomes. Nat Med. 1995 Mar;1(3):249–255. doi: 10.1038/nm0395-249. [DOI] [PubMed] [Google Scholar]
  19. Ho D. D., Neumann A. U., Perelson A. S., Chen W., Leonard J. M., Markowitz M. Rapid turnover of plasma virions and CD4 lymphocytes in HIV-1 infection. Nature. 1995 Jan 12;373(6510):123–126. doi: 10.1038/373123a0. [DOI] [PubMed] [Google Scholar]
  20. Holzmann K., Blin N., Welter C., Zang K. D., Seitz G., Henn W. Telomeric associations and loss of telomeric DNA repeats in renal tumors. Genes Chromosomes Cancer. 1993 Mar;6(3):178–181. doi: 10.1002/gcc.2870060308. [DOI] [PubMed] [Google Scholar]
  21. Kim N. W., Piatyszek M. A., Prowse K. R., Harley C. B., West M. D., Ho P. L., Coviello G. M., Wright W. E., Weinrich S. L., Shay J. W. Specific association of human telomerase activity with immortal cells and cancer. Science. 1994 Dec 23;266(5193):2011–2015. doi: 10.1126/science.7605428. [DOI] [PubMed] [Google Scholar]
  22. Klingelhutz A. J., Barber S. A., Smith P. P., Dyer K., McDougall J. K. Restoration of telomeres in human papillomavirus-immortalized human anogenital epithelial cells. Mol Cell Biol. 1994 Feb;14(2):961–969. doi: 10.1128/mcb.14.2.961. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Larson D. D., Spangler E. A., Blackburn E. H. Dynamics of telomere length variation in Tetrahymena thermophila. Cell. 1987 Jul 31;50(3):477–483. doi: 10.1016/0092-8674(87)90501-0. [DOI] [PubMed] [Google Scholar]
  24. Levy M. Z., Allsopp R. C., Futcher A. B., Greider C. W., Harley C. B. Telomere end-replication problem and cell aging. J Mol Biol. 1992 Jun 20;225(4):951–960. doi: 10.1016/0022-2836(92)90096-3. [DOI] [PubMed] [Google Scholar]
  25. Lundblad V., Blackburn E. H. An alternative pathway for yeast telomere maintenance rescues est1- senescence. Cell. 1993 Apr 23;73(2):347–360. doi: 10.1016/0092-8674(93)90234-h. [DOI] [PubMed] [Google Scholar]
  26. Lundblad V., Szostak J. W. A mutant with a defect in telomere elongation leads to senescence in yeast. Cell. 1989 May 19;57(4):633–643. doi: 10.1016/0092-8674(89)90132-3. [DOI] [PubMed] [Google Scholar]
  27. McCaffrey R., Harrison T. A., Parkman R., Baltimore D. Terminal deoxynucleotidyl transferase activity in human leukemic cells and in normal human thymocytes. N Engl J Med. 1975 Apr 10;292(15):775–780. doi: 10.1056/NEJM197504102921504. [DOI] [PubMed] [Google Scholar]
  28. McClintock B. The Behavior in Successive Nuclear Divisions of a Chromosome Broken at Meiosis. Proc Natl Acad Sci U S A. 1939 Aug;25(8):405–416. doi: 10.1073/pnas.25.8.405. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. McEachern M. J., Blackburn E. H. Runaway telomere elongation caused by telomerase RNA gene mutations. Nature. 1995 Aug 3;376(6539):403–409. doi: 10.1038/376403a0. [DOI] [PubMed] [Google Scholar]
  30. Morin G. B. The human telomere terminal transferase enzyme is a ribonucleoprotein that synthesizes TTAGGG repeats. Cell. 1989 Nov 3;59(3):521–529. doi: 10.1016/0092-8674(89)90035-4. [DOI] [PubMed] [Google Scholar]
  31. Moyzis R. K., Buckingham J. M., Cram L. S., Dani M., Deaven L. L., Jones M. D., Meyne J., Ratliff R. L., Wu J. R. A highly conserved repetitive DNA sequence, (TTAGGG)n, present at the telomeres of human chromosomes. Proc Natl Acad Sci U S A. 1988 Sep;85(18):6622–6626. doi: 10.1073/pnas.85.18.6622. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Murnane J. P., Sabatier L., Marder B. A., Morgan W. F. Telomere dynamics in an immortal human cell line. EMBO J. 1994 Oct 17;13(20):4953–4962. doi: 10.1002/j.1460-2075.1994.tb06822.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Nilsson P., Mehle C., Remes K., Roos G. Telomerase activity in vivo in human malignant hematopoietic cells. Oncogene. 1994 Oct;9(10):3043–3048. [PubMed] [Google Scholar]
  34. Prowse K. R., Greider C. W. Developmental and tissue-specific regulation of mouse telomerase and telomere length. Proc Natl Acad Sci U S A. 1995 May 23;92(11):4818–4822. doi: 10.1073/pnas.92.11.4818. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Rogalla P., Kazmierczak B., Rohen C., Trams G., Bartnitzke S., Bullerdiek J. Two human breast cancer cell lines showing decreasing telomeric repeat length during early in vitro passaging. Cancer Genet Cytogenet. 1994 Oct;77(1):19–25. doi: 10.1016/0165-4608(94)90143-0. [DOI] [PubMed] [Google Scholar]
  36. Schmitt H., Blin N., Zankl H., Scherthan H. Telomere length variation in normal and malignant human tissues. Genes Chromosomes Cancer. 1994 Nov;11(3):171–177. doi: 10.1002/gcc.2870110306. [DOI] [PubMed] [Google Scholar]
  37. Shippen-Lentz D., Blackburn E. H. Functional evidence for an RNA template in telomerase. Science. 1990 Feb 2;247(4942):546–552. doi: 10.1126/science.1689074. [DOI] [PubMed] [Google Scholar]
  38. Singer M. S., Gottschling D. E. TLC1: template RNA component of Saccharomyces cerevisiae telomerase. Science. 1994 Oct 21;266(5184):404–409. doi: 10.1126/science.7545955. [DOI] [PubMed] [Google Scholar]
  39. Strahl C., Blackburn E. H. The effects of nucleoside analogs on telomerase and telomeres in Tetrahymena. Nucleic Acids Res. 1994 Mar 25;22(6):893–900. doi: 10.1093/nar/22.6.893. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Walmsley R. M., Petes T. D. Genetic control of chromosome length in yeast. Proc Natl Acad Sci U S A. 1985 Jan;82(2):506–510. doi: 10.1073/pnas.82.2.506. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Wang S. S., Zakian V. A. Telomere-telomere recombination provides an express pathway for telomere acquisition. Nature. 1990 May 31;345(6274):456–458. doi: 10.1038/345456a0. [DOI] [PubMed] [Google Scholar]
  42. Wei X., Ghosh S. K., Taylor M. E., Johnson V. A., Emini E. A., Deutsch P., Lifson J. D., Bonhoeffer S., Nowak M. A., Hahn B. H. Viral dynamics in human immunodeficiency virus type 1 infection. Nature. 1995 Jan 12;373(6510):117–122. doi: 10.1038/373117a0. [DOI] [PubMed] [Google Scholar]
  43. Yu G. L., Bradley J. D., Attardi L. D., Blackburn E. H. In vivo alteration of telomere sequences and senescence caused by mutated Tetrahymena telomerase RNAs. Nature. 1990 Mar 8;344(6262):126–132. doi: 10.1038/344126a0. [DOI] [PubMed] [Google Scholar]
  44. de Lange T. Activation of telomerase in a human tumor. Proc Natl Acad Sci U S A. 1994 Apr 12;91(8):2882–2885. doi: 10.1073/pnas.91.8.2882. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. de Lange T., Shiue L., Myers R. M., Cox D. R., Naylor S. L., Killery A. M., Varmus H. E. Structure and variability of human chromosome ends. Mol Cell Biol. 1990 Feb;10(2):518–527. doi: 10.1128/mcb.10.2.518. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Molecular and Cellular Biology are provided here courtesy of Taylor & Francis

RESOURCES