Telomeres – a puzzle piece in the mapping of the development of cancer
Name: Göran Roos
Göran Roos conducts research on telomeres – a puzzle piece in the mapping of the development of cancer, the aging of cells and eternal life.
For the past ten years, Göran Roos’ research has focused on the mechanisms of cell division. Particular focus has been on the ends of chromosomes, telomeres, and the enzyme telomerase and their significance to the length of a cell’s life and the development of cancer.
Telomeres are at the end of each chromosome, like a protective cap so that the chromosome’s information will not be damaged or create confusion in the cellular machinery. The telomeres consist of a repeated DNA sequence, TTAGGG, which is exactly the same in all mammals.
“It was long believed that this was non-sense DNA, that the information did not mean anything, but we now know that these sequences play a role in the development of cancer,” explains Göran Roos.
In every cell division, the telomeres are shortened.
“Short telomeres lead to genetic instability, which in turn increases the likelihood of changes to the genetic material, which can in turn increase the risk of tumour formation,” explains Göran.
The telomeres protect the genetic material and their length is linked with the aging of the cell. When the cell is old and the telomeres are too short, it stops dividing. Consequently, the telomeres are a pre-requisite for “eternal life”. The telomeres can be extended by an enzyme called telomerase.
“In most regular cells, the telomerase is inactive, but in tumours it is activated. This means that the telomeres never become so short that the cells stop dividing. The tumour is given ‘eternal life’.”
But telomerase is not only found in tumours, but also in cells that must be replaced often such as the skin or testicles.
“Mice that completely lack telomerase lose their hair, suffer anaemia and become sterile. Plants also need it to grow and survive,” explains Göran.
Telomerase was first found in tumours in 1994. Göran Roos and his research group were among the first to discover it. They have already proven that people with chronic lymphatic leukaemia, the most common form of leukaemia among adults, who had long telomeres in their leukaemia cells at the time of falling ill were those who lived the longest, almost twice as long as those who had short telomeres. Accordingly, the length of the telomeres in tumour cells is of significance to the patient’s survival, which is also true of other types of tumours.
But when the researchers analysed telomere length in normal blood cells of tumour patients, the reverse was surprisingly discovered.
“For example, it turns out that breast cancer patients with long telomeres in their blood cells have a worse survival rate. We do not yet know why, but we believe it may be linked to the immune system. A strong immune system implies a high degree of cell replacement, which in turn leads to shorter telomeres.”
In other words, the length of telomeres in the blood cells can say something about a breast cancer patient’s future outlook.
“It is one of several indicators that can be weighed together. But we also now know that it can have the same function with other types of cancer. In the long term, it may also be of significance to the choice of treatment,” says Göran Roos.
Göran and his research team have also found that there is a link between the father’s and the children’s telomere length.
“Children largely inherit their telomere length from their father, but this link has proven to thin out in the course of life, which can be an effect of our lifestyle.”
Can long telomeres be a guarantee for a long and healthy life?
“There has been a great deal of speculation on this point. But unfortunately it is not quite so simple. Other factors such as how we live surely play a more important role,” says Göran Roos.
Name: Göran Roos
Profession: Professor of Pathology
Leisure activities: Tries to exercise, gardening, photography, relaxing in front of the TV
Likes to read: Håkan Nesser, the Swedish daily Dagens Nyheter
Likes to eat: Grilled entrecôte
Listens to: Jazz, Dire Straits, Katie Melua