Small extracellular vesicles convey the stress-induced adaptive responses of melanoma cells

Maria Harmati,Gabriella Dobra,Tamas Biro,Maria Kovacs,Laszlo Janovak,Edina Gyukity-Sebestyen,Peter Horvath,Istvan Nagy,Filippo Piccinini,Tibor Pankotai,Attila Farkas,Imre Dekany,Okay Saydam,Zsuzsanna Ujfaludi,Krisztina Buzas,Eva Hunyadi-Gulyas

doi:10.1038/s41598-019-51778-6

Abstract

Exosomes are small extracellular vesicles (sEVs), playing a crucial role in the intercellular communication in physiological as well as pathological processes. Here, we aimed to study whether the melanoma-derived sEV-mediated communication could adapt to microenvironmental stresses. We compared B16F1 cell-derived sEVs released under normal and stress conditions, including cytostatic, heat and oxidative stress. The miRNome and proteome showed substantial differences across the sEV groups and bioinformatics analysis of the obtained data by the Ingenuity Pathway Analysis also revealed significant functional differences. The in silico predicted functional alterations of sEVs were validated by in vitro assays. For instance, melanoma-derived sEVs elicited by oxidative stress increased Ki-67 expression of mesenchymal stem cells (MSCs); cytostatic stress-resulted sEVs facilitated melanoma cell migration; all sEV groups supported microtissue generation of MSC-B16F1 co-cultures in a 3D tumour matrix model. Based on this study, we concluded that (i) molecular patterns of tumour-derived sEVs, dictated by the microenvironmental conditions, resulted in specific response patterns in the recipient cells; (ii) in silico analyses could be useful tools to predict different stress responses; (iii) alteration of the sEV-mediated communication of tumour cells might be a therapy-induced host response, with a potential influence on treatment efficacy.

Highlights

Exosomes are small extracellular vesicles, playing a crucial role in the intercellular communication in physiological as well as pathological processes
In order to study the adaptive small extracellular vesicles’ (sEVs)-mediated communication under microenvironmental stress, we investigated cytostatic, heat and oxidative stress-induced alterations of the B16F1 mouse melanoma cell-derived sEVs
For the sEV production, we cultured the B16F1 cells under five different conditions in EV-depleted FBS-containing media; control cultures (Ctrl) received culture medium, cytostatic stressed cultures (Doxo) were treated with 0.6 μM doxorubicin, heat stressed cultures (Hs) were incubated at 42°C for 3 × 2 h, oxidative stressed cultures (Ag-TiO2) were treated with 2.5 μg/ml light-induced Ag-TiO2, and as a control of the oxidative stress (Ag Ctrl), additional cultures were treated with illuminated media (Table 1)

Summary

Introduction

Exosomes are small extracellular vesicles (sEVs), playing a crucial role in the intercellular communication in physiological as well as pathological processes. We concluded that (i) molecular patterns of tumourderived sEVs, dictated by the microenvironmental conditions, resulted in specific response patterns in the recipient cells; (ii) in silico analyses could be useful tools to predict different stress responses; (iii) alteration of the sEV-mediated communication of tumour cells might be a therapy-induced host response, with a potential influence on treatment efficacy. Melanoma-derived extracellular vesicles have a crucial role in the rapid tumour progression[8,9,10,11,12] They are capable to induce a tumour-favourable phenotype in the EV-recipient cells in the TME13 and the metastatic sites[14,15]. Following the guideline recommended by ISEV (International Society for Extracellular Vesicles), called MISEV2018 (Minimal information for studies of extracellular vesicles 2018)[23], we refer to the isolated vesicles based on their size by using the term ‘small extracellular vesicles’ (sEVs), even though their exosomal characteristics are demonstrated

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