Question

Many scientists believe strongly that the signaling pathway that regulates aging has an influence on cancer development. Describe the evidence that supports this argument and is there any types of cancers that seem exempt?  

Answer 1

Telomeres are the ends of DNA molecules which are conserved by the action of Telomerase enzymes which uses RNA sequences to add deoxy nucleotides to the end portion. Aging of a cell is often related to the shortening of DNA due to the loss of these telomeres due to low expeession levels of telomerase enzymes. As a result the cell which has divided for long, after it crosses hayflick limit , undergoes apoptosis due to the short DNA. This process is related to aging and the cells stop dividing due to shortening of its chromosomes.

Most of the cancer cells have unlimited expression of this telomerase enzyme which in turn leads to the conservation of telomeres and in turn leads to uninterrupted division of the cell.

The pathway which connects both of them is the P13K-AKT pathway. TRF - Telomere repeat factor binds to the telomeres protecting.When P13k pathway is activated which is hyperactive in cancer cells, this P13k leads to the activation of AKT which in turn phosphorylates TRF and makes it active. TRF binds to telomeric ends thus protecting it from degradation. By using P13k inhibitors the TRF phosphorylation can be hampered and this will in turn leads to the protected telomeres in many cancers.