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Application of the proteomics

Genome is entire set of genes that one organism can express while proteome is set of proteins that one organism can produce. Since all PROTEins are expressed from the genOME - name of the scientific discipline focused on protein examination and discovery was easily coined. Proteomics is more complex field compared to genomics; each cell contains same set of genes, but they will express differently depending on the cells type (protein expression is tissue/organ specific), developmental stage (from embryo to adult stage), environmental effects….

Expression of 20,000 – 25,000 genes results in ~ 1,000,000 functional proteins in the human body. Alternative splicing and post-translational modifications increase both protein number and their diversity. Disagreement in number of available genes and end product proteins suggests that genomics can’t provide all necessary info in the protein discovery. That’s why proteomics is so important. Proteins play multiple roles in our body: they regulate genetic expression, induce immune response (antibodies), allow muscles contraction, transport various larger or smaller molecules, act like hormones, accelerate biochemical reactions (enzymes)… Focused discovery and characterization of proteins makes proteomics applicable to many scientific fields and provide a lot of medical solutions.

Proteomics in biomarker discovery

Biomarkers are all molecules (genes, proteins, hormones…) that could indicate specific physiological or pathological process. Increased level of antibodies indicates infection, elevated AST or ALT serum levels could suggest liver damage, beta-hCG (both in serum and urine) is early marker of pregnancy… In medical field they are important for disease prevention and for early diagnostics. Pharmaceutical industry could accelerate drug discovery process by narrowing selection of potential candidates based on drug target identification and drug response (drug efficacy and/or toxicity) in organism. Most biomarker discovery experiments are applying mass spectral-based proteomic technologies using biological samples of unknown protein quantity. Success in biomarker discovery always depends on the quality of biological sample, ability to determine precise protein level and in correct interpretation of the collected data.

Proteomics in the study of the cancer metastasis

Tumor metastasis is the leading cause of death in cancer patients. Metastasis could spread locally (in the same organ where cancer is generated) or travel to a distant part of the body via lymphatic and vascular system, resulting in metastatic (secondary) tumor formation. Most commonly, secondary tumors are detected in the brain, lungs, bones and liver. Routes of cancer spreading are well studied, but molecular and cellular mechanisms of metastasis are still poorly identified. Proteomics is focused on identification of the proteins associated with metastatic process with the main goal to facilitate clinical management and improve therapeutic strategies necessary for metastasis prevention.

Proteomics in neurology

Neurodegeneration can be described as loss of structure and function of neural cells. Genetic mutation can be a trigger for different neurodegenerative disorders. For example, CAG nucleotide triplet repeats (encoding amino acid glutamine) are common feature in polyglutamine diseases such as Huntington’s disease or spinocerebellar ataxia. Protein misfolding and its aggregation is common feature in neurodegenerative proteopathies such as Parkinson’s (result of alpha synuclein aggregation) and Alzheimer’s disease (alpha synuclein, tau and beta amiloid aggregation). Also, altered protein degradation pathways could result in neurodegenerative disorder. Toxic accumulation of proteins in cytosol is typical for Parkinson’s and Huntington’s disease, in nucleus for spinalcerebellar ataxia, in endoplasmatic reticulum for familial encephalopathy with neuroserpin inclusion bodies, and extracellulary for Alzheimer’s disease. Neurodegenerative disorders are associated with impaired cognition, reduced mobility (neuro-muscular impairments), speech difficulties, pain…. Most commonly applied techniques for protein analyses in this field are two-dimensional gel electrophoresis while mass spectrometry is used for protein identification. Current therapeutic approaches could be improved by revealing pathophysiological protein networks in neural tissue. Proteomics could be of great value by discovering enzymes, cytoskeleton, synaptosomal and antioxidant proteins implicated in disease genesis.

Proteomics in cardiovascular disorders

All disorders that are affecting hearth and vascular system are known as cardiovascular disorders. This is large and diverse class of pathologies triggered (usually) by atherosclerosis and hypertension. Cardiovascular disorders are very common today, affecting mostly older people. Cardiovascular impairment is the number one cause of death in the modern society. Proteomics is used to identify modified proteins and delicate processes in cardiac and vascular tissue during development and progression of the disease. Novel insight in pathological processes could improve therapeutics and reduce mortality rate.

Proteomics can be applied in many other (important) fields, from antibody profiling, diabetes and nutrition research to fetal and maternal medicine.