Cells discontinuing nucleotide synthesis could be a key factor in ageing, new research has revealed. Understanding this process could enable treatments that ensure healthier ageing.

The process by which cells become unable to replicate after a certain number of divisions is known as senescence. As cell division is essential the body’s repair processes, senescence can cause disorders associated with age such as arthritis, heart disease and osteoporosis. Senescence is also one of the body’s key defences against cancer, as it prevents the excessive replication of cells.

Previous research on senescence has focused on fibroblasts, the cells that make up the body’s connective tissues. However, the majority of cancers are formed in the body’s epithelial tissues.

The researchers discovered that senescent epithelial cells no longer produced nucleotides, the building blocks of DNA. DNA replication is a vital part of the cell division process and requires newly synthesized nucleotides.  3D imaging also showed that the senescent cells had two nuclei. Further research is required to determine if senescent cells with restored nucleotide synthesizing capabilities could start dividing again.

Treatments that prevent senescence could delay the onset of age-associated diseases. This could ensure people enjoy good quality of life even as they age. However, future anti-senescence treatments must exclusively target already senescent cells to reduce cancer risk.

Further research is therefore required to understand exactly what differentiates normal cells from senescent cells to enable selective treatments.

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