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.     

PRODUCTION AND CHARACTERIZATION OF THE CASHEW APPLE (ANACARDIUM OCCIDENTALE L.) AND GUAVA (PSIDIUM GUAJAVA L.) FRUIT POWDERS

Cashew apple and guava residues from fruit juice processing industry were prepared as dehydrated fruit powders. Differences in compositional and physicochemical characteristics between both fruit powders were significant at the 5% probability level, with exception to ash content. It is important to point out that despite the dehydration process, both samples can still be considered good sources of vitamin C. In addition, the results show that the guava and cashew apple powders may be useful in the food industry as high dietary "fiber ingredients." Higher lipid (14.05%) content was observed in guava powder. The guava powder could be an alternative source of lipid. The data also indicated that these materials are good sources of ash. The results suggest further utilization of these residues as valuable food ingredients or as a resource for nutraceuticals.

PRACTICAL APPLICATIONS

Large quantity of agro-industrial residues formed by fruit juice extraction represents a major disposal problem. An alternative to recycling the fruit-industrial residue is to submit it to drying processes and transform into value-added products as dehydrated fruit powder. In this way, this process contributes to diminish the problem and to recover valuable biomass and nutrients. The purpose of this study was to develop a technology to obtain guava and cashew apple powders with the objective of finding alternatives to the exploitation of these residues as valuable sources of vitamin C, as ashes and lipid that should also be regarded as potential nutraceutical resources in future or functional ingredients.     

Identification of Gene encoding a Putative RNA-Helicase,Homologous to SKI2, in Chromosome VII of Saccharomyces cerevisiae

We have determined the nucleotide sequence of a segment of chromosome VII of the yeast Saccharomyces cerevisiae contained in the cosmid clone pEGH101 for a total of 7 kbp. This sequence contains a large open reading frame (ORF) called G9365, coding for a protein of 1967 amino acids that shows a significant homology with the product of the SKI2 gene of S. cerevisiae and contains domains characteristic of RNA-helicases. The ORF is transcribed in vegetative cells but it is not essential for viability as demonstrated by gene disruption. The sequence has been deposited in the GenBank data library under Accession Number U35242. © 1997 John Wiley & Sons, Ltd.