Oxygen-related Differences in Cellular and Vesicular Phenotypes Observed for Ovarian Cell Cancer Lines

Extracellular vesicles (EVs) are one of several tools that cells use to communicate with each other. This communication is facilitated by a number of surface-associated proteins and the cargo of the vesicles. For several cancer types, the amount of EVs is observed to be up-regulated in patients compared to healthy individuals, possibly signifying the presence of an aberrant process. The hypoxia-induced release of EVs from cancer cells has been hypothesized to cause the malignant transformation of healthy recipient cells. In this study, the phenotype of cells and EVs from the ovarian cancer cell lines, COV504, SKOV3, and Pt4, were quantified and analysed under normoxic and hypoxic conditions. It was shown that both cells and EVs express common markers and that the EV phenotype varies more than the cellular phenotype. Additionally, cells subjected to 24 hours of hypoxia compared to normoxia produced more EVs. The phenotyping of EVs from cancer cell lines provides information about their molecular composition. This information may be translated to knowledge regarding the functionality of EVs and lead to a better understanding of their role in cancer

Antibody-Based Assays for Phenotyping of Extracellular Vesicles

Extracellular vesicles (EVs) are a heterogeneous population of membrane-enclosed vesicles. EVs are recognized as important players in cell-to-cell communication and are described to be involved in numerous biological and pathological processes. The fact that EVs are involved in the development and progression of several diseases has formed the basis for the use of EV analysis in a clinical setting. As the interest in EVs has increased immensely, multiple techniques have been developed aiming at characterizing these vesicles. These techniques characterize different features of EVs, like the size distribution, enumeration, protein composition, and the intravesicular cargo (e.g., RNA). This review focuses on techniques that exploit the specificity and sensitivity associated with antibody-based assays to characterize the protein phenotype of EVs. The protein phenotype of EVs can provide information on the functionality of the vesicles and may be used for identification of disease-related biomarkers. Thus, protein profiling of EVs holds great diagnostic and prognostic potential

Alpha-Synuclein filaments bind the transcriptional regulator HMGB-1

Abnormal accumulation of alpha-synuclein filaments in Lewy bodies is a neuropathological hallmark of Parkinson's disease and sequestration of cellular protein into these protein aggregates may contribute to the degenerative process. We identified the transcriptional co-factor high mobility group protein 1 (HMGB-1) as a ligand for alpha-synuclein filaments by a filament spin-down technique, mass spectrometric peptide mapping and immunoblotting. HMGB-1 binds preferentially to aggregated alpha-synuclein and is present in alpha-synuclein filament-containing Lewy bodies isolated from brain tissue affected with dementia with Lewy bodies or Parkinson's disease. Our results demonstrate that alpha-synuclein filaments hold the potential for disturbing the cellular gene expression as they can sequester a component involved in cellular transcription regulation

Proteasomal inhibition by alpha-synuclein filaments and oligomers

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