The ectopic expression of telomerase1,2 in normal human cells results in an extended lifespan3,4, indicating that telomere shortening regulates the timing of cellular senescence. As telomerase expression is a hallmark of cancer, we investigated the long–term effects of forced expression of human telomerase catalytic component (hTERT) in normal human fibroblasts. In vitro growth requirements, cell–cycle checkpoints and karyotypic stability in telomerase–expressing cells are similar to those of untransfected controls. In addition, co–expression of telomerase, the viral oncoproteins HPV16 E6/E7 (which inactivate p53 and pRB) and oncogenic HRAS does not result in growth in soft agar. Thus, although ectopic expression of telomerase in human fibroblasts is sufficient for immortalization, it does not result in changes typically associated with malignant transformation.
This is a preview of subscription content
Subscribe to Journal
Get full journal access for 1 year
only $4.92 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Get time limited or full article access on ReadCube.
All prices are NET prices.
Nakamura, T.M. et al. Telomerase catalytic subunit homologs from fission yeast and human. Science 277, 955– 959 (1997).
Meyerson, M. et al. hEST2, the putative human telomerase catalytic subunit gene, is up–regulated in tumor cells and during immortalization. Cell 90, 785–795 ( 1997).
Bodnar, A.G. et al. Extension of life–span by introduction of telomerase into normal human cells. Science 279, 349 –352 (1998).
Vaziri, H. & Benchimol, S. Reconstitution of telomerase activity in normal human cells leads to elongation of telomeres and extended replicative life span. Curr. Biol. 8, 279– 282 (1998).
Shay, J.W., Wright, W.E. & Werbin, H. Defining the molecular mechanisms of human cell immortalization. Biochim. Biophys. Acta 1072, 1– 7 (1991).
Abercrombie, M. Contact inhibition in tissue culture. In Vitro 6, 128–142 (1970).
Scher, C.D. & Todaro, G.J. Selective growth of human neoplastic cells in medium lacking serum growth factor. Exp. Cell Res. 68, 479–481 (1971).
Buchovitch, K., Duffy, L.A. & Harlow, E. The retinoblastoma protein is phosphorylated during specific phases of the cell cycle. Cell 58, 1097–1105 (1989).
DeCaprio, J.A. et al. The product of the retinoblastoma susceptibility gene has properties of a cell cycle regulatory element. Cell 58, 1085–1095 (1989).
Kastan, M.B., Onyekwere, O., Sidransky, D., Vogelstein, B. & Craig, R.W. Participation of p53 protein in the cellular response to DNA damage. Cancer Res. 51 , 6304–6311 (1991).
Levine, A.J., Momand, J. & Finlay, C.A. The p53 tumor suppressor gene. Nature 351, 453–456 (1991).
DiLeonardo, A., Linke, S.P., Clarkin, K. & Wahl, G.M. DNA damage triggers a prolonged p53–dependent G1 arrest and long term induction of Cip1 in normal human fibroblasts. Genes Dev. 8, 2540–2551 (1994).
Brown, J.P., Wei, W. & Sedivy, J.M. Bypass of senescence after disruption of p21Cip1/Waf1 gene in normal diploid human fibroblasts. Science 277, 831–834 (1997).
White, A.E., Livanos, E.M. & Tlsty, T.D. Differential disruption of genomic integrity and cell cycle regulation in normal human fibroblasts by the HPV oncoproteins. Genes Dev. 8, 666–677 ( 1994).
Serrano, M., Lin, A.W., McCurrach, M.E., Beach, D. & Lowe, S.W. Oncogenic ras provokes premature cell senescence associated with accumulation of p53 and p16INK4a. Cell 88, 593–602 (1997).
Dimri, G.P. et al. A biomarker that identifies senscent human cells in culture and in aging skin in vivo. Proc. Natl Acad. Sci. USA 92, 9363–9367 (1995).
Land, H., Parada, L.F. & Weinberg, R.A. Tumorigenic conversion of primary embryo fibroblasts requires at least two cooperating oncogenes. Nature 304, 596–602 (1983).
Newbold, R.F. & Overell, R.W. Fibroblast immortality is a prerequisite for transformation by EJ c–Ha–ras oncogene. Nature 304, 648–651 ( 1983).
Sager, R. Senescence as a mode of tumor suppression. Environ. Health Perspect. 93, 59–62 ( 1991).
Nowell, P.C. & Croce, C.M. Cytogenetics of neoplasia. in Development and Recognition of the Transformed Cell (eds Greene, M.I. & Hamaoka, T.) 1–19 (Plenum, New York, 1987).
Honda, T. et al. Spontaneous immortalization of cultured skin fibroblasts obtained from a high–dose atomic bomb survivor. Mutat. Res. 354, 15–26 ( 1996).
Saksela, E. & Moorhead, P.S. Aneuploidy in the degenerative phase of serial cultivation of human cell strains. Proc. Natl Acad. Sci. USA 50, 390–395 ( 1963).
Benn, P.A. Specific chromosome abberations in senescent fibroblast cell lines derived from human embryos. Am. J. Hum. Genet. 28, 465–473 (1976).
Halbert, C.L., Demers, G.W. & Galloway, D.A. The E6 and E7 genes of human papillomavirus type 6 have weak immortalizing activity in human epithelial cells. J. Virol. 66, 2125–2134 ( 1992).
Holt, S.E., Gollahon, L.S., Willingham, T., Barbosa, M.S. & Shay, J.W. p53 levels in human mammary epithelial cells expressing wild–type and mutant human papilloma virus type 16 (HPV–16) E6 proteins: relationship to reactivation of telomerase and immortalization. Inter. J. Oncol. 8, 263 –270 (1996).
Shay, J.W., Tomlinson, G., Piatyszek, M.A. & Gollahon, L.S. Spontaneous in vitro immortalization of breast epithelial cells from a patient with Li–Fraumeni syndrome. Mol. Cell. Biol. 15, 425–432 (1995).
Holt, S.E., Aisner, D.L., Shay, J.W. & Wright, W.E. Lack of cell cycle regulation of telomerase activity in human cells. Proc. Natl Acad. Sci. USA 94, 10687–10692 (1997).
Clark, G.J., Cox, A.D., Graham, S.M. & Der, C.J. in Methods in Enzymology (eds Balch, W.E., Der, C.J. & Hall, A.) 395– 412 (Academic Press, San Diego, 1995).
Gustashaw K.M. in The AGT Cytogenetics Laboratory Manual (eds Barch, M.J., Knutsen, T. & Spurbeck, J.L.) 259–324 (Lippincott–Raven, Philadelphia, 1997).
We acknowledge J. Rohde, M. Liao, D. Cohen, J. Doolittle, S. Donovan and S. Patel for excellent technical assistance. This work was supported in part by the National Institutes of Aging (AG07992), the National Cancer Institute (CA71443) and Geron Corporation. C.P.M. is supported by The Robert Wood Johnson Foundation Minority Medical Faculty Development Program. J.W.S. is an Ellison Medical Foundation Senior Scholar. S.E.H. was supported by a postdoctoral fellowship from the National Institute of Aging.
About this article
Cite this article
Morales, C., Holt, S., Ouellette, M. et al. Absence of cancer–associated changes in human fibroblasts immortalized with telomerase. Nat Genet 21, 115–118 (1999). https://doi.org/10.1038/5063
EML4-ALK induces cellular senescence in mortal normal human cells and promotes anchorage-independent growth in hTERT-transduced normal human cells
BMC Cancer (2021)
Nature Structural & Molecular Biology (2021)
Calcium-sensing receptor bridges calcium and telomerase reverse transcriptase in gastric cancers via Akt
Clinical and Translational Oncology (2020)
Narrowing the field: cancer-specific promoters for mitochondrially-targeted p53-BH3 fusion gene therapy in ovarian cancer
Journal of Ovarian Research (2019)
A prospect of cell immortalization combined with matrix microenvironmental optimization strategy for tissue engineering and regeneration
Cell & Bioscience (2019)