Telomerase activity in HeLa cervical carcinoma cell line proliferation

@article{Ivankovi2006TelomeraseAI,
  title={Telomerase activity in HeLa cervical carcinoma cell line proliferation},
  author={Milena Ivankovi{\'c} and Andrea {\'C}uku{\vs}i{\'c} and Ivana Goti{\'c} and Nikolina {\vS}krobot and Mario Matija{\vs}i{\'c} and Denis Polan{\vc}ec and Ivica Rubelj},
  journal={Biogerontology},
  year={2006},
  volume={8},
  pages={163-172}
}
Normal human somatic cells in culture have a limited dividing potential. This is due to DNA end replication problem, whereby telomeres shorten with each subsequent cell division. When a critical telomere length is reached cells enter senescence. To overcome this problem, immortal HeLa cell line express telomerase, an enzyme that prevents telomere shortening. Although immortal, the existence of non-dividing cells that do not incorporate 3H-thymidine over 24 h of growth has been well documented… 

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References

SHOWING 1-10 OF 35 REFERENCES

Evidence That High Telomerase Activity May Induce a Senescent-like Growth Arrest in Human Fibroblasts*

Excessive telomerase activity may act as a hyperproliferative signal in cells and induce a senescent phenotype in a manner similar to that seen following overexpression of oncogenic Ras, Raf, and E2F1.

Induced senescence in HeLa cervical carcinoma cells containing elevated telomerase activity and extended telomeres.

  • E. GoodwinD. DiMaio
  • Biology
    Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research
  • 2001
The role of telomerase and telomere length in induced senescence is explored and an exogenous hTERT gene is expressed, which encodes the catalytic subunit of telomersase, to generate stable HeLa cell clones with elevated telomer enzyme activity and extended telomeres.

Telomere length dynamics in telomerase-positive immortal human cell populations.

Fluctuations in telomere length in telomerase-positive immortalized cells may contribute to chromosomal instability and clonal evolution.

Telomere elongation in immortal human cells without detectable telomerase activity.

It is suggested that the presence of lengthened or stabilized telomeres is necessary for immortalization, and that this may be achieved either by the reactivation of telomerase or by a novel and as yet unidentified mechanism.

Telomere shortening associated with chromosome instability is arrested in immortal cells which express telomerase activity.

The results suggest that chromosomes with short (TTAGGG)n tracts are recombinogenic, critically shortened telomeres may be incompatible with cell proliferation and stabilization of telomere length by telomerase may be required for immortalization.

Molecular Changes with in Vitro Cellular Senescence

It is proposed that subpopulations of senescent (late passage) cells can operationally be categorized into those that are slowly or very slowly cycling,Those that are conditionally arrested, and those thatAre irreversibly arrested, which are able to be rescued by chemica111 or viralI3 agents.

Telomerase activity in human germline and embryonic tissues and cells.

Elucidation of the regulatory pathways involved in the repression of telomerase activity during development may lead to the ability to manipulate telomere levels and explore the consequences both for cellular aging and for the survival of cancer cells.

Loss of T-antigen sequences allows SV40-transformed human cells in crisis to acquire a senescent-like phenotype.

Results are presented which indicate that crisis most likely depends on expression of the viral gene T-antigen, which is challenged by over-expression of the cell cycle inhibitors such as p21Sdi1.

Specific association of human telomerase activity with immortal cells and cancer.

Synthesis of DNA at chromosome ends by telomerase may be necessary for indefinite proliferation of human cells. A highly sensitive assay for measuring telomerase activity was developed. In cultured

Gene Expression in Quiescent and Senescent Fibroblasts

  • J. Campisi
  • Biology
    Annals of the New York Academy of Sciences
  • 1992
An important feature of senescent human fibroblasts is that they arrest growth with a G1 DNA content and cannot be stimulated to enter the S phase of the cell cycle by any known combination of physiological extracellular factors.