Editorial [Hot Topic: Chemogenomics: A Discipline at the Crossroad of High Throughput Technologies, Biomarker Research, Combinatorial Chemistry, Genomics, Cheminformatics, Bioinformatics and Artificial Intelligence Chemogenomics (Guest Editor: Eric Marechal) ]

Chemogenomics is a recent scientific discipline that can be defined as the study of the interaction of functional biological systems with exogenous small molecules, or in broader sense the study of the intersection of biological and chemical spaces. This ambitious objective requires expertise in biology, chemistry and computational sciences (bioinformatics, cheminformatics, large scale statistics and machine learning methods) but it is more than a simple apposition of each of these disciplines. Working together, biologists, chemists, and computer scientists have to find their common language and shared concepts. Biological entities interacting with small molecules can be isolated proteins or more elaborate systems, from single cells to complete organisms. The biological space is therefore analyzed at various genomic levels (genomic, transcriptomic, proteomic or any phenotypic level). The space of small molecules is partially real, corresponding to commercial and academic collections of compounds, and partially virtual, corresponding to the chemical space possibly synthesizable. Synthetic chemistry has developed novel strategies allowing a physical exploration of this universe of possibilities. A major challenge of cheminformatics is to charter the virtual space of small molecules using realistic biological constraints (bioavailability, druggability, structural biological information). Chemogenomics is a descendent of conventional pharmaceutical approaches, since it involves the screening of chemolibraries for their effect on biological targets, and benefits from the advances in the corresponding enabling technologies and the introduction of new biological markers. Screening was originally motivated by the rigorous discovery of new drugs, neglecting and throwing away any molecule that would fail to meet the standards required for a therapeutic treatment. It is now the basis for the discovery of small molecules that might or might not be directly used as drugs, but which have an immense potential for basic research, as probes to explore an increasing number of biological phenomena. Concerns about the environmental impact of chemical industry also open new fields of research for chemogenomics. In this special issue (CCHTS Vol. 11, No. 8), biologists, chemists, computer scientists and mathematicians help to capture a global view, shedding light on the diverse aspects of chemogenomics. Together, their focused reviews illustrate how this discipline is at the crossroad of high throughput technologies, biomarker research, combinatorial chemistry, genomics, cheminformatics, bioinformatics and artificial intelligence.