The process of a normal human cell replication is characterised by shorting their genetic material every time cell goes under division, as a result the cell daughter will obtain shorter DNA. After a while the cell will stop to divide reaching their limited of replication, which is called hayflick and under normal mechanism apoptosis occurs. However if the cell goes under certain epigenetic or genetic alteration, cell would continue their reproduction, as a result of overcomes the senescence (M1) followed by crisis (M2) the cell became immortal (Shay and Wright, 2011)
When there is a higher telomerase enzyme activity, some of this cell escapes from the crisis and there are enlargement of the telomeres length and promoting cancer pathways (Artandi
…show more content…
They are composed of a long double stranded (kilobases). The double strand telomere sequence are linked to specific place on the DNA (telomeric repeat binding factor 1- TRF1, and telomeric repeat binding factor 2 – TRF2). The TRF2 is very important for protection and the loop conformation. The short overhang single stranded 3’ (few hundred) contains 3′ hydroxyl group, and is the substrate where the enzyme telomerase make the addition of the nucleotides. The TRF1 is the facilitator of DNA replication, which implicate on telomere length. (Artandi and DePinho, …show more content…
Leonard Hayflick, and in his studies was described the limit of proliferation and the cessation of fibroblast division. The cell containing lifespan around 50 replicative and potentially will stop to divide demonstrating ageing after certain period, resulting senescence phenomenon which is a natural tumour suppressor mechanism. According to the theory, telomeres have shown shortness each cell division. During each cycle, the deficiency of polymerases to replicate the entire linear DNA causes the loss of around 50 to 200 base pairs (Kunlin,