Every day hundreds of billions of cells are renewed

Six hours after fertilization, an egg of Xenopus already contains 4.096 individual cells, result of a dozen successive divisions. Under the control of a few genes "architects", this Toad embryo double every thirty minutes to become a tadpole and then, after a few weeks, a lifeguard amphibian. Very quickly, the first initial cells differentiate and migrate to constitute future tissues and organs of the animal. This ballet is carefully regulated by specific biochemical instructions. Stem cells are aware of their position in space, their immediate environment and the role they will play in the future. They receive and emit newsletters as chemical messengers. Any departure from the Community rule is endangering the lives of all and gets a punishment without appeal: the deviant cell receives an order to self-destruct (apoptosis), disintegrates and its components are consumed and recycled by its neighbours.

Aberrant behaviour

These initial phases of the development of an organization interested in the highest point biologists from around the world. They represent somehow the missing link between the genetic information contained in chromosomes (the genome) and a "ready to live" organization. Understanding these mechanisms could help to solve one of the weightiest mysteries of the time: start of the process of cell benign. In fact, a tumor cell behaves a bit like an embryonic cell. But it meets none of the usual duties. It loses its capacity for dialogue with its neighbors, deserted his post, moves without permission, does not take account of the alert messages and multiplies without never die.

These aberrant behaviour and this immortality largely explain the formation of cancer. It is unlocking the secrets that the Curie Institute decided to establish a research centre dedicated specifically to the relationship between developmental biology and benign processes. In relying on simple organisms like Xenopus, the fruit fly or to nematode which development is perfectly documented, Parisian centre hopes to open new routes in oncology. "Are the same genes that produce a harmonious body or that cause cancer and it is the loss of control of spatial identity which induced metastasis", said Daniel Louvart, Director of research of the Institute.

Teams of high level

The new pole will install in early 2008 in a building designed to accommodate fifteen teams of small size and high level (120 persons in total). It will strengthen the Parisian pole of the life sciences of the mountain Sainte-Geneviève, which includes some high places in the life sciences hexagonal (ENS, ENSPCI). The total investment amounts to EUR 24 million (including EUR 16.5 million for the building). "It is an indispensable link in the understanding of tumor progression," adds Daniel Louvart. "The challenge is mainly in the explanation of the formation of metastases for which current treatments are not very effective," said Pierre Curie Institute Hospital Director Bey.

Distract information

The cancer cell is a specialist of the misuse of information. It uses to his benefit all processes invented by evolution for millions of years to divide, move or feed. When the genes responsible for architects of these basic functions are transferred, they become oncogenes or tumor suppressor genes. It is at this time that can be triggered tumor processes. It is this "mirror effect" genes, sometimes useful or harmful, interested researchers at Curie. Normally, cells are linked by a biological glue which prohibits any leakage. But when the gene responsible for the production of this protein accession is defective, the cells start their dangerous vagrants in the body.

A formidable machinery

In the same way, a tumour knows how to apply for the construction of new blood vessels source of oxygen and nutrients (angiogenesis). The productivity and effectiveness of this machinery defy comprehension. Every day hundreds of billions of cells are renewed. All the seconds, the bone marrow produces 70 million red blood cells.