Comparison of two different methods to detect telomerase activity in normal and neoplastic lymph nodes in the dog

摘要

One of the several differences between a normal and a neoplastic cell is that there is a phisiological limit to the number of possible cell replications in the former, whereas it appears to be unlimited in the latter.For this reason, cancer cells are thought to undergo a phenomenon of immortalization.The chromosome extremities contain structurally defined elements called telomeres.In normal somatic cells, each mitotic cycle leads to a reduction of telomere lenght until a critical point is reached.Telomere erosion to this critical lenght presents a signal for the cell to arrest further divisions and to undergo cellular senescence or to activate apoptosis.Telomeres that avoid critical shortening could, theoretically, replicate endlessly, thereby immortalizing the cell.One mechanism to restore telomere lenght is the activation of a specific reverse transcriptase called telomerase.The telomerase is a ribonucleoprotein that contains a 9-base-pair RNA template to rapidly construct telomeric repeats.Upregulation of the telomerase enzyme provides immortalizing capacity to neoplastic cells. Based on the hypothesis that telomerase is a specific marker of neoplastic tissues, the development of methods to detect its activity may represent an accurate, non-invasive diagnostic and prognostic tool.