Washington, October 5 : A new study at the Swiss Institute for Experimental Cancer Research (ISREC) has revealed that telomeres, the repeated DNA-protein complexes at the end of chromosomes that progressively shorten every time a cell divides, also contain RNA.

The researchers, who carried out the study with collaborators from the University of Pavia, said that their findings might help understand how telomeres function and how this function can be potentially manipulated, which might be important for understanding why cancer cells never stop dividing.

The DNA in the chromosome acts like a sort of instruction manual for the cell. Genetic information is transcribed into segments of RNA that then go out into the cell and carry out a variety of tasks such as making proteins, catalysing chemical reactions, or fulfilling structural roles.

Scientists have to date thought that telomeres are “silent”, and that their DNA is not transcribed into strands of RNA.

In embryonic cells and some stem cells, an enzyme called telomerase rebuilds the telomere so that the cells can keep dividing. Over time, the telomerase dwindles and eventually the telomere shortens and the cell becomes inactive.

In cancer cells, the telomerase enzyme keeps rebuilding telomeres long past the cell’s normal lifetime, which causes cells to divide endlessly, resulting in a tumour.

Although it has long been reckoned that telomere maintenance activity occurs in about 90 per cent of human cancers, scientists are to date not fully understood the mechanism by which this maintenance takes place.

The new study has now shown that the RNA in telomere is regulated by a protein in the telomerase enzyme. The researchers believe that this discovery may uncover key elements of telomere function.

“It’s too early to give yet a definitive answer,” to whether this could lead to new cancer therapies, notes Joachim Lingner, senior author on the paper.

“But the experiments published in the paper suggest that telomeric RNA may provide a new target to attack telomere function in cancer cells to stop their growth,” the author added.

The study has been published in the journal Science Express. (ANI)