'Omics'-based imaging in cancer detection and therapy

Genomics, proteomics and metabolomics, which can be also summarized as 'omics', have become increasingly inter-related with imaging. Gene expression profiling may be assessed using high-density microarrays for the detection of overexpression patterns, followed by the development of histochemical assays. Next, antibodies to the gene-corresponding proteins (for example, receptors) can be produced, leading to serum immunoassays for follow-up, as well as antibody-guided in vivo imaging or therapy. In vivo imaging for cancer detection and/or therapy can be performed by applying nonlabeled antibodies, by using radiolabeled antibodies for detection using single-photon tomography or positron emission tomography (PET), or by other tracers, for example, for magnetic resonance imaging tomography (MRI, MRT). Protein profiles from protein chips can be derived from mass maps obtained through mass spectrometry (MS). Electrophoretic separation of proteins has also been combined with MS to produce a two-dimensional assignment of proteins within a complex mixture. Overexpression of tumor-related proteins can be used for the development of antibodies to develop noninvasive assays that can be used in the screening of risk groups as a basis for further investigation by invasive imaging methods. Metabolomic profiling by nuclear magnetic resonance spectroscopy can be applied for the detection of biomarkers of the metabolome. Metabolite profiles in cells, tissues, and organisms can be generated with nuclear magnetic resonance spectroscopy and MS. Metabolic information provided by magnetic resonance spectroscopic imaging (MRSI) combined with the anatomical information provided by MRI can significantly improve the assessment of cancer location and extent, and cancer aggressiveness. Biomarkers found by MRSI can lead to new PET tracers. This article provides examples and discusses some of the recent achievements to bring forward novel strategies for the diagnosis and therapy of cancer.