Ageing gets in the way of cancer, finds research

A study published in a journal - Aging Cell - has found that ageing gets in the way of development and further progression of cancer cells.

Ageing is often considered as one of the biggest risk factors for cancer, the biological mechanisms behind this link are yet to be ascertained.

Each cell in the human body is specialised to carry out certain tasks and they only need to express certain genes. Gene expression is the process by which specific genes are activated to produce a required protein.

Gene expression analyses have been used to study cancer and ageing, but only a few studies have investigated the relationship between gene expression changes in these two processes.

In an effort to better understand the biological mechanisms researchers from the University of Liverpool's Integrative Genomics of Ageing Group, led by Dr Joao Pedro De Magalhaes, compared how genes differentially expressed with age and genes differentially expressed in cancer among nine human tissues.

Normally, a healthy cell can divide in a controlled manner. In contrast, senescent or 'sleeping' cells have lost their ability to divide.

As we age, the number of senescent cells in our bodies increase, which then drive many age-related processes and diseases.

Genetic mutations triggered by things such as UV exposure can sometimes cause cells to replicate uncontrollably -- and uncontrolled cell growth is cancer.

Researchers found that in most of the tissues examined, ageing and cancer gene expression 'surprisingly' changed in the opposite direction.

These overlapping gene sets were related to several processes, mainly cell cycle and the immune system. Moreover, cellular senescence changed in the same direction as ageing and in the opposite direction of cancer signatures.

Researchers believe that the changes in ageing and cellular senescence might relate to a decrease in cell proliferation, while cancer changes shift towards an increase in cell division.

Dr De Magalhaes, said, "One of the reasons our bodies have evolved to have senescent cells is to suppress cancers. But then it seems that senescent cells accumulate in aged human tissues and may contribute to ageing and degeneration."

"Ageing tissues may hinder cell proliferation and consequently cancer," he added.

However, an alternative explanation comes from evolutionary biology.

First author Kasit Chatsirisupachai, explained, "Aged tissue might actually be a better environment for a rogue cancer cell to proliferate because the cancer cell will have an evolutionary advantage.