Exosomes: Key tools for cancer liquid biopsy

Precision medicine is based on the identification of biomarkers of tumor development and progression. Liquid biopsy is at the forefront of the ability to gather diagnostic and prognostic information on tumors, as it can be noninvasively performed prior or during treatment. Liquid biopsy mostly utilizes circulating tumor cells, or free DNA, but also exosomes. The latter are nanovesicles secreted by most cell types, found in any body fluid that deliver proteins, nucleic acids and lipids to nearby and distant cells with a unique homing ability. Exosomes function in signalling between the tumor microenvironment and the rest of the body, promoting metastasis, immune remodelling and drug resistance. Exosomes are emerging as a key tool in precision medicine for cancer liquid biopsy, as they efficiently preserve their biomarker cargo. Moreover, exosomes strongly resemble the parental cell, which can help in assessing the oxidative and metabolic state of the donor cell. In this respect, exosomes represent one of the most promising new tools to fight cancer. This review will discuss the clinical applications of profiling exosomal proteins and lipids by high-throughput proteomics and metabolomics, and nucleic acids by next generation sequencing, as well as how this may allow cancer diagnosis, therapy response monitoring and recurrence detection.     

OXIDOREDUCTASES FROM TOMATO FRUIT: INHIBITORY EFFECT OF A FUNGAL GLUCOSE OXIDASE

Glucose oxidase (GOD) produced by a strain of Penicillium (Penicillium variabile P16) was employed, in a model system, to control the activities of tomato lipoxygenase (LPO), polyphenoloxidase (PPO), and peroxidase (POD). GOD in-hibited all three enzymes, at the typical pH of tomato fruit (4.3), i.e., the LPO was inhibited up to ca. 88%, the PPO up to ca. 63% and the POD up to ca. 50%. GOD also prevented β-carotene bleaching caused by these enzymes.     

Comparison between Measured and Model ( LBLand BRE) Predicted Infiltration Rates for a Passive Solar Test Cell

The pressurization technique is applied to the test cell at the JRC, Ispra, and important parameters for the LBL and BRE air infiltration models are calculated. The predictions of these models are compared with the tracer gas (SF₆) measurements. The differences between measured and predicted values of the air infiltration rates axe quite large. When the model parameters calculated from the tracer gas measurements are used, both models predict infiltration rates in good agreement with the field measurements. This means the physical models are acceptable but there is a need to refine the procedure for determination of model parameters.     

LIPOXYGENASE ACTIVITIES IN RIPENING OLIVE FRUIT TISSUE

Extracts of ripening olive fruits (Olea europaea L. cv. Kalamata) ‐were analyzed for the presence of lipoxygenase activity and for the content of phenolic compounds, which are lipoxygenase inhibitors. Two distinct lipoxygenase activities were identified by their pH optima and sensitivity to the inhibitor nordihydroguaiaretic acid (NDGA). Both activities were low during early ripening stages, and increased sharply between 57 and 94 days postanthesis, reaching a plateau at about 120 days. The content of phenolic compounds, mainly oleuropein, changed in the opposite way, suggesting their involvement in the regulation of the two lipoxygenase activities during the olive fruit development. The two lipoxygenase activities could have a role in fruit maturation and senescence.     

A Pictorial Query Language for Geographic Features in an Object-Oriented Environment

In this paper, a visual algebra and the relative pictorial query language (PQL) for geographic information systems (GIS) are proposed and discussed. The base data structure of the object oriented model for geographical data is defined and the symbolic features used in the PQL are described. The algebra operators are formally defined, besides their properties and applicability. The use of the symbolic features to express the queries is illustrated, as well as the possible pictorial operations are considered. The used interface is part of the Scenario GIS, developed using an object-oriented environment. This PQL makes easier the formulation of a complex query and simplifies user approach to the system, maintaining a strong expressive power. Finally, an example of query and its pictorial composition on the screen is shown.