Proteomic profiling of ovarian cancer models using TMT-LC-MS/MS

Endothelial knockdown of the tumor suppressor, WWOX, increases inflammation in ventilator-induced lung injury

Chronic cigarette smoke exposure decreases lung expression of WWOX which is known to protect the endothelial barrier during infectious models of acute respiratory distress syndrome (ARDS). Proteomic analysis of WWOX-silenced endothelial cells (ECs) was done using tandem mass tag mass spectrometry (TMT-MS). WWOX-silenced ECs as well as those isolated from endothelial cell Wwox knockout (EC Wwox KO) mice were subjected to cyclic stretch (18% elongation, 0.5 Hz, 4 h). Cellular lysates and media supernatant were harvested for assays of cellular signaling, protein expression, and cytokine release. These were repeated with dual silencing of WWOX and zyxin. Control and EC Wwox KO mice were subjected to high tidal volume ventilation. Bronchoalveolar lavage fluid and mouse lung tissue were harvested for cellular signaling, cytokine secretion, and histological assays. TMT-MS revealed upregulation of zyxin expression during WWOX knockdown which predicted a heightened inflammatory response to mechanical stretch. WWOX-silenced ECs and ECs isolated from EC Wwox mice displayed significantly increased cyclic stretch-mediated secretion of various cytokines (IL-6, KC/IL-8, IL-1β, and MCP-1) relative to controls. This was associated with increased ERK and JNK phosphorylation but decreased p38 mitogen-activated kinases (MAPK) phosphorylation. EC Wwox KO mice subjected to VILI sustained a greater degree of injury than corresponding controls. Silencing of zyxin during WWOX knockdown abrogated stretch-induced increases in IL-8 secretion but not in IL-6. Loss of WWOX function in ECs is associated with a heightened inflammatory response during mechanical stretch that is associated with increased MAPK phosphorylation and appears, in part, to be dependent on the upregulation of zyxin.NEW & NOTEWORTHY Prior tobacco smoke exposure is associated with an increased risk of acute respiratory distress syndrome (ARDS) during critical illness. Our laboratory is investigating one of the gene expression changes that occurs in the lung following smoke exposure: WWOX downregulation. Here we describe changes in protein expression associated with WWOX knockdown and its influence on ventilator-induced ARDS in a mouse model.

Applications of Tandem Mass Spectrometry (MS/MS) in Protein Analysis for Biomedical Research

Mass Spectrometry (MS) allows the analysis of proteins and peptides through a variety of methods, such as Electrospray Ionization-Mass Spectrometry (ESI-MS) or Matrix-Assisted Laser Desorption Ionization-Mass Spectrometry (MALDI-MS). These methods allow identification of the mass of a protein or a peptide as intact molecules or the identification of a protein through peptide-mass fingerprinting generated upon enzymatic digestion. Tandem mass spectrometry (MS/MS) allows the fragmentation of proteins and peptides to determine the amino acid sequence of proteins (top-down and middle-down proteomics) and peptides (bottom-up proteomics). Furthermore, tandem mass spectrometry also allows the identification of post-translational modifications (PTMs) of proteins and peptides. Here, we discuss the application of MS/MS in biomedical research, indicating specific examples for the identification of proteins or peptides and their PTMs as relevant biomarkers for diagnostic and therapy.

Quantitative proteomic analysis of cervical cancer based on TMT-labeled quantitative proteomics

Cervical cancer is the second most common gynecological malignancy, which immensely threatens the well-being of women. However, the pathogenesis of cervical cancer is still unclear. Using tandem mass tags-labeled quantitative proteomic technology and bioinformatics tools, we analyzed the exfoliated cervical cells from the normal and cervical cancer groups to establish a cancer-specific protein profile, thereby identifying key proteins related to cervical oncogenesis. When compared with the normal group, a total of 351 differentially expressed proteins were identified in the cervical cancer group, including 247 up-regulated and 104 down-regulated proteins. Gene ontology function annotation revealed that the differentially expressed proteins were mainly involved in the single-multicellular organism process, multicellular organismal process, and negative regulation of biological process. These proteins were discerned to play a role in the extracellular membrane-bounded organelle, exosome of cell components, protein binding, structural molecule activity, and enzyme binding of molecular functions. The results of Kyoto Encyclopedia of Genes and Genomes signaling pathway enrichment proved that these differentially expressed proteins were mainly involved in PI3K - Akt, ECM-receptor interaction, complement and coagulation cascades, and other signaling pathways. Particularly, peroxiredoxin-2 may be involved in cervical tumor oncogenesis through inhibition of apoptosis signaling. SIGNIFICANCE: In this study, we determined that the proteins of the cervical cancer group exhibited qualitative and quantitative changes, and a total of 351 differentially expressed proteins were identified. The functions and signaling pathways of these differentially expressed proteins have laid a theoretical foundation for elucidating the molecular mechanism of cervical cancer.

Clinical Proteomics: Liquid Chromatography-Mass Spectrometry (LC-MS) Purification Systems

Liquid chromatography-mass spectrometry (LC-MS) has become a routine powerful technology in clinical proteomic studies for protein identification, protein characterization and the discovery of biomarkers. In this chapter, we describe two protocol methods to analyze clinical patient samples using a resin based depletion column followed by either protein In-gel enzymatic digestion or protein in-solution enzymatic digestion and then analysis by one-dimensional reverse-phase chromatography or two-dimensional strong cation exchange (SCX)-reverse-phase chromatography (RPC).