Grapefruit-Derived Micro and Nanovesicles Show Distinct Metabolome Profiles and Anticancer Activities in the A375 Human Melanoma Cell Line.

Gabriella Pocsfalvi,Alfredo Ambrosone,Antonietta Leone,Immacolata Fiume,Mariaevelina Alfieri,Christopher Stanly

doi:10.3390/cells9122722

Abstract

Fruit juice is one of the most easily accessible resources for the isolation of plant-derived vesicles. Here we found that micro- and nano-sized vesicles (MVs and NVs) from four Citrus species, C. sinensis, C. limon, C. paradisi and C. aurantium, specifically inhibit the proliferation of lung, skin and breast cancer cells, with no substantial effect on the growth of non-cancer cells. Cellular and molecular analyses demonstrate that grapefruit-derived vesicles cause cell cycle arrest at G2/M checkpoint associated with a reduced cyclins B1 and B2 expression levels and the upregulation of cell cycle inhibitor p21. Further data suggest the inhibition of Akt and ERK signalling, reduced intercellular cell adhesion molecule-1 and cathepsins expressions, and the presence of cleaved PARP-1, all associated with the observed changes at the cellular level. Gas chromatography-mass spectrometry-based metabolomics reveals distinct metabolite profiles for the juice and vesicle fractions. NVs exhibit a high relative amount of amino acids and organic acids whereas MVs and fruit juice are characterized by a high percentage of sugars and sugar derivatives. Grapefruit-derived NVs are in particular rich in alpha–hydroxy acids and leucine/isoleucine, myo-inositol and doconexent, while quininic acid was detected in MVs. Our findings reveal the metabolite signatures of grapefruit-derived vesicles and substantiate their potential use in new anticancer strategies.

Highlights

There are several types of biomembrane-enclosed vesicles within and outside a cell that can transport or store bioactive molecules such as proteins, nucleic acids, lipids and other metabolites [1].Secreted vesicles, called extracellular vesicles (EVs) are actively studied in mammalian systems due to their importance in cell-cell communication [2]
As for grapefruit, NVs reduced more than 40% the viability of all cancer cells showing the most pronounced effects among the vesicles investigated in this work
Citrus fruits have long been used in the traditional medicine of several Asian countries to ameliorate indigestion, cough, skin inflammation and cardiovascular dysfunctions [37]

Summary

Introduction

Secreted vesicles, called extracellular vesicles (EVs) are actively studied in mammalian systems due to their importance in cell-cell communication [2]. Mammalian EVs were shown to modulate the immune responses and play roles in physiological and pathological processes through the intercellular trafficking of functional molecules, including RNA, proteins and metabolites and are being exploited in both therapeutics and diagnostics [2]. EV-like vesicles have been isolated from apoplast and there are few pieces of evidence demonstrating their role in unconventional protein secretion, plant cell wall remodelling [2] and plant defence [3,4,5]. Apoplastic vesicles were shown to be involved in inter-kingdom communication by the intercellular transfer of small non-coding RNAs to fungal pathogens [3] and in long-distance gene regulations [6].

Methods

Results

Conclusion