Systems Biology can be defined as the combination of –omics technologies (genomics, transcriptomics, proteomics, metabolomics and lipidomics) that aim to explore the complex interactions in biological organisms (from cells, to organisms, to human populations) in a system-wide level. These –omics technologies have enabled novel diagnostic tools, named “biomarkers” that contributed immensely, mainly due to great advances in bioinformatics and to development of cutting edge instrumentations (i.e. mass spectrometry, MS) in precision medicine and personalized treatments.
In the last decade, -omics technologies (genomics, transcriptomics, proteomics, metabolomics and lipidomics) have contributed greatly to elucidate the pathogenesis of various diseases (e.g. obesity, metabolic syndrome, cancer, cardiovascular and Alzheimer’s disease, to name a few). These hypothesis-free technologies are complementary to other classical molecular biology techniques that are based on a reductionist approach. Since manifestation of diseases (or disease phenotypes) are rather attributed to a combination (or a synergy) of actions of different genes/proteins/metabolites, than to a single individual molecule, -omics platforms are deemed more suitable for the study of such complex diseases in biological systems.
Why Metabolomics for biomarkers?
Metabolomics, which measures the altered levels of low-molecular weight metabolites in a holistic approach, has emerged as a diagnostic tool in the discovery of novel biomarkers in various diseases. This is mainly due to the fact that the metabolome represents the endpoint of all other -omics interactions and, thus, is considered to be closer to the actual phenotype of disease. More importantly, the composition of the metabolome can be directly affected by environmental, diet and other endogenous factors such as subtle changes in DNA and proteins. Taking the above into consideration, metabolomics/clinical metabolomics is a robust, highly sensitive and selective approach for the discovery of biomarkers that can ultimately aid in early diagnosis of diseases.
Why Mass Spectrometry (MS)
Mass spectrometry (MS) has emerged over the last decade as a useful robust analytical tool for the measurement and identification of biomarkers in human clinical studies. This can be attributed to the unsurpassed sensitivity and superior specificity of MS-based methods, as well as the extended concentration range of biomarkers that can measured. More importantly, MS is a reliable quantitative method of many analytes/potential biomarkers simultaneously, a characteristic trait that is a great advantage to other classical “single analyte” analytical chemistry methods (ELISA, radio-immunoassays, immnunohistochemistry).