Genetic and epigenetic changes in human epithelial cells immortalized by telomerase

D Gregory Farwell, K. A. Shera, J. I. Koop, G. A. Bonnet, C. P. Matthews, G. W. Reuther, M. D. Coltrera, J. K. McDougall, A. J. Klingelhutz

Research output: Contribution to journalArticle

128 Citations (Scopus)

Abstract

Exogenous expression of hTERT, the catalytic component of telomerase, is sufficient for the immortalization of human fibroblasts but insufficient for the immortalization of human foreskin keratinocytes (HFKs) and human mammary epithelial cells (HMECs). These latter cell types can overcome senescence by coexpression of hTERT and human papillomavirus (HPV) E7 or by expression of hTERT and loss of p16(INK4a) expression, indicating that the retinoblastoma (Rb) pathway, along with a telomere maintenance pathway, plays a role in determining the life span of epithelial cells. In this study, we further characterize hTERT-immortalized HFKs and human adenoid epithelial cells (HAKs) for genotypic and phenotypic alterations that are associated with immortalization. Of five hTERT-immortalized HFK and HAK cell lines examined, four exhibited repression of p16(INK4a) expression by promoter methylation or specific large-scale deletion of chromosome 9p, the location of p16(INK4a). Interestingly, one cell line exhibited complete down-regulation of expression of p14(ARF), with only slight down-regulation of expression of p16(INK4a). Yet, all of the immortal cells lines exhibited hyperphosphorylated Rb. Cytogenetic analysis revealed clonal chromosome aberrations in three of the five cell lines. All of the cell lines retained a growth block response with the expression of mutant ras. When grown on organotypic raft cultures, however, the hTERT-immortalized cells exhibited a maturation delay on terminal differentiation. Our results indicate that immortalization of epithelial cells may require both activation of telomerase and other genetic and/or epigenetic alterations that abrogate normal differentiation.

Original languageEnglish (US)
Pages (from-to)1537-1547
Number of pages11
JournalAmerican Journal of Pathology
Volume156
Issue number5
StatePublished - 2000
Externally publishedYes

Fingerprint

Telomerase
Epigenomics
Epithelial Cells
Foreskin
Cell Line
Keratinocytes
Retinoblastoma
Down-Regulation
Tumor Suppressor Protein p14ARF
Adenoids
Chromosome Deletion
Cytogenetic Analysis
Telomere
Chromosome Aberrations
Methylation
Breast
Fibroblasts
Maintenance
Growth

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

Cite this

Farwell, D. G., Shera, K. A., Koop, J. I., Bonnet, G. A., Matthews, C. P., Reuther, G. W., ... Klingelhutz, A. J. (2000). Genetic and epigenetic changes in human epithelial cells immortalized by telomerase. American Journal of Pathology, 156(5), 1537-1547.

Genetic and epigenetic changes in human epithelial cells immortalized by telomerase. / Farwell, D Gregory; Shera, K. A.; Koop, J. I.; Bonnet, G. A.; Matthews, C. P.; Reuther, G. W.; Coltrera, M. D.; McDougall, J. K.; Klingelhutz, A. J.

In: American Journal of Pathology, Vol. 156, No. 5, 2000, p. 1537-1547.

Research output: Contribution to journalArticle

Farwell, DG, Shera, KA, Koop, JI, Bonnet, GA, Matthews, CP, Reuther, GW, Coltrera, MD, McDougall, JK & Klingelhutz, AJ 2000, 'Genetic and epigenetic changes in human epithelial cells immortalized by telomerase', American Journal of Pathology, vol. 156, no. 5, pp. 1537-1547.
Farwell DG, Shera KA, Koop JI, Bonnet GA, Matthews CP, Reuther GW et al. Genetic and epigenetic changes in human epithelial cells immortalized by telomerase. American Journal of Pathology. 2000;156(5):1537-1547.
Farwell, D Gregory ; Shera, K. A. ; Koop, J. I. ; Bonnet, G. A. ; Matthews, C. P. ; Reuther, G. W. ; Coltrera, M. D. ; McDougall, J. K. ; Klingelhutz, A. J. / Genetic and epigenetic changes in human epithelial cells immortalized by telomerase. In: American Journal of Pathology. 2000 ; Vol. 156, No. 5. pp. 1537-1547.
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AU - Koop, J. I.

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AU - Matthews, C. P.

AU - Reuther, G. W.

AU - Coltrera, M. D.

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AU - Klingelhutz, A. J.

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