Protein to protein interaction map for a better insight in cancer development

With the completion of the genome sequence of a number of organisms, analysis of the gene products, the proteins, is the on-going challenge.

Researchers from the Institut Curie and from the Paris-based biotechnology company Hybrigenics announced today that they have built a protein-protein interaction map of the fruit fly, Drosophila melanogaster. This ‘simple’ model organism allows them to study a ‘reference set’ of proteins that includes most of those known to be involved in human cancer. Since proteins function in networks, the systematic identification of the physical interactions that occur between proteins will help understanding their biological function, and improve our capacity to intervene and, ultimately, to discover novel, more specific therapeutic targets.

Their results are published in the March 1st issue of Genome Research.

The completion of the sequencing of the genome from diverse organisms comes with a big surprise: a human being has ‘only’ 25,000 to 30,000 genes. This is roughly 2 times more than a fly (13,600 genes) and much less than rice (50,000 genes).

Could it be that the complexity of a human being comes from the proteins? The number and biological functions of most of these gene-encoded biomolecules are not yet known. What we do know is that a single gene can contain information to build different ‘forms’ of a protein. Furthermore, these related proteins can be part of similar or, conversely, different biological pathways and thus can convey very diverse biological functions. Studying the full protein repertoire at the scale of a whole organism is the current challenge of proteomics.

Tell me whom you’re interacting with... I shall tell you who you are

The number of interactions between proteins is thought to be huge. Exploration of these complex protein networks requires specific methodologies as well as powerful bioinformatic tools to analyze them.

By putting together their complementary expertise, researchers from the Institut Curie and from Hybrigenics have analyzed protein-protein interactions from the fruit fly. While not exhaustive, this study focuses on a ‘reference set’ of proteins from this ‘simplified’ biological model and includes most of the proteins implicated in human cancer developmen(1).

The study has identified over 2,300 protein interactions. The full dataset and the resulting protein interaction map can be visualized and explored using a dedicated software platform, the PIMRider™(2). By assigning specific functions to cancer-related proteins, this protein-protein interaction map constitutes a first step towards the identification of novel therapeutic targets.

Such synergy between public and private research should speed up the valorisation of scientific knowledge and their translation into novel medical applications. This project received in March 2002 a GenHomme network grant of 2.4 millions euros from the Ministère de l’Industrie. The GenHomme network aims at coordinating the efforts of academic labs and privately owned companies in order to speed up valorisation of human genomics-derived knowledge.

The Hybrigenics-Institut Curie association favours breakthroughs in functional proteomics, an essential step towards a better understanding of important cellular processes.