A team of researchers at the Universitat Autňnoma de Barcelona (UAB) has discovered a new mechanism that accelerates the shortening of telomeres (structures that protect the ends of chromosomes) involved in genetic instability and a predisposition to cancer.
The research is published in the journal Human Molecular Genetics.
DNA in higher organisms is organized into individual chromosomes, the ends of which are protected by structures called telomeres. Telomeres are very important in maintaining the cells’ genetic integrity, as they prevent the chromosomes from joining together, protect their ends from degradation and are involved in segregating chromosomes properly during cellular division.
They also play a decisive role in two fields that are important in social and biological terms: cancer and aging. Telomeres gradually shorten and thus indicate the point at which the cell dies and control the proper proliferation of tissues.
For the first time, a team of researchers at the Universitat Autňnoma de Barcelona has observed that telomeres may shorten more quickly due to sudden breakages in the DNA sequence that they consist of.
The scientists made this discovery by analyzing cells from a genetic syndrome called Fanconi’s anemia, which is typified by a high genetic instability and chromosomal fragility, and which causes a very high predisposition to contracting cancer in harborers (a risk of leukemia 15,000 times higher than in a healthy person).
The researchers have observed that the telomeres of affected patients present an accelerated shortening owing to breakages in the telomeric DNA sequence, leading to chromosomes being unprotected and joining together.
This mechanism may explain patients’ symptomatology and their tendency to contract cancer. The research thus provides a first experimental link between a predisposition to cancer with the mechanism of sudden shortening of telomeres.
Fanconi’s anemia came to public notice a little over a year ago (4th October 2000) when the parents of a patient (Molly Nash) genetically selected an embryo so that the newborn baby could become a donor of histocompatible blood for a bone marrow transplant to the infant’s elder sibling.
The interdisciplinary research was carried out by Research Fellow Elsa Callén under the supervision of Dr. Jordi Surrallés, the Mutagenesis Group “Ramón y Cajal” Researcher in the genetics and Microbiology Department of the UAB, in co-operation with the Spanish National Biotechnology Centre, the Vall d’Hebron Hospital and the Hospital de la Santa Creu i Sant Pau in Barcelona.
The study was carried out within the framework of a scientific collaboration agreement between the UAB and the Fanconi Anemia Research Fund, Inc. in Oregon (USA) and was supported by the Ministry of Health and Consumption Fund for Health Research.
(Reference: Hum Mol Genet 2002 11: 439-444)