Telomerase+as+a+Biomarker

Telomerase as a Biomarker:
The production of telomerase in cells is restricted to gametes (sex cells), stem cells and immune cells [5] [6]. Normal somatic cells do not usually produce telomerase [5] [6]. Cancer cells, however, constantly produce telomerase [1] [2] [4]. This enzyme could hence prove to be an effective biomarker in distinguishing cancerous cells from normal cells [1] [2] [4]. Several investigations have researched this concept. A report by Naritoku et al (1999) outlines an experiment involving fine-needle aspiration (FNA) specimens of cancer cells [3]. In this experiment a polymerase chain reaction based assay was used to compare the telomerase activity of cancer cells with that of somatic cells [3]. The results show observations of telomerase activity in 88% of the FNA specimens, but none in the somatic cells [3]. Figure 1 below is a visual of the results of this experiment. Shay et al (2001) conducted a similar experiment in which the presence of hTERT, a specific protein of telomerase, was compared in cancerous and somatic cells [4]. The results of this experiment show hTERT to be present in the cancerous cells, but not in the somatic cells [4]. Both these experiments show compelling evidence that telomerase activity could be an effective marker in identifying cancerous cells [3] [4].

Figure 1: Results of polymerase chain reaction of detecting telomerase activity (Picture obtained from Naritoku et al 1999) By Ashlea Norton //Last edited 11/11/2011//

References:
[1] Aubert, G. & Landsdorp, P.M. 2008, "Telomeres and Aging", //Physiological Reviews,// vol. 88, no. 2, pp. 557-579.

[2] Dahse, R., Fiedler, W. & Ernst, G. 1997, "Telomeres and Telomerase: Biological and Clinical Importance", //Clinical Chemistry,// vol. 43, no. 5, pp. 708-714.

[3] Naritoku, W.Y., Datar, R.H., Li, P., Groshen, S.L., Taylor, C.R. & Imam, A. 1999, "Telomerase Activity", //Cancer Cytopathology,// vol. 87, no. 4, pp. 210-215.

[4] Shay, J.W., Zou, Y., Hiyama, E. & Wright, W.E. 2001, "Telomerase and Cancer", //Human Molecular Genetics,// vol. 10, no. 7, pp. 677-685.

[5] Wright, D.L., Jones, E.L., Mayer, J.F., Oehninger, S., Gibbons, W.E. & Lanzendorf, S.E. 2001, "Characterisation of Telomerase Activity in the Human Oocyte and Preimplantation Embryo", //Molecular Human Reproduction,// vol. 7, no. 10, pp. 947-955.

[6] Zvereva, M.I., Shcherbakova, D.M. & Dontsova, O.A. 2010, "Telomerase: Structure, Functions, and Activity Regulation", //Biochemistry (Moscow),// vol. 75, no. 13, pp. 1563-1583.