Departments

Medical Departments

Functional Genomic Unit

Mission

With only a few exceptions, every cell of the body contains a full set of chromosomes and identical genes. Only a fraction of these genes is turned on, however, and it is the subset that is "expressed" that confers unique properties to each cell type. "Gene expression" is the term used to describe the transcription of the information contained within the DNA, the repository of genetic information into messenger RNA (mRNA) molecules that are then translated into the proteins that perform most of the critical functions of cells. Scientists study the kinds and amounts of mRNA produced by a cell to learn which genes are expressed, which in turn provides insights into how the cell responds to its changing needs. Gene expression is a highly complex and tightly regulated process.

The scientists who work in the biomedical field are living a revolution, especially in the development of functional genomics, the aim of which is to functionally analyse genes and proteins. These progresses are due to a series of circumstances, the most important of which being the progress made through the human genome sequencing, that enables to identify new genes linked with human diseases, and the development of new techniques of molecular analysis such as microarrays.

Microarrays allow scientists to analyze expression of many genes in a single experiment quickly and efficiently. Microarrays are a significant advance both because they may contain a very large number of genes and because of their small size. Microarrays are therefore useful when one wants to survey a large number of genes quickly or when the sample to be studied is small. Microarrays may be used to assay gene expression within a single sample or to compare gene expression in two different cell types or tissue samples, such as in healthy and diseased tissue. Indeed, in addition to a better understanding of the cells' complex molecular system, we hope that it will improve our knowledge of tumours' molecular mechanisms in order to identify new targets in the treatment of the disease and to develop new anticancer drugs.

One of the laboratory's ambitious projects (the laboratory was set up in September 2001) consists in using high-troughput techniques, such as microarrays, multiplex RT-PCR, CGH,… to identify the "key" genes involved in the carcinogenesis and the genes involved in the response to anticancer treatments. This technology also enables to study genes'expression profile by studying tumoral tissues which were removed in a context of multicentric, clinical studies such as BREAST and BIG coordinated studies. The resulting genes' expression profiles should allow to determine new sub-types of cancer that are not recognised by the clinico-pathological factors, and to identify new prognostic or predictive markers involved in the response to anticancer treatments.

Here is an illustration which shows how a gene expression analysis is performed : Klik here

 

Person in charge : Dr Sotiriou Christos