Presence of Cx43 in extracellular vesicles reduces the cardiotoxicity of the anti-tumour therapeutic approach with doxorubicin

Abstract

Extracellular vesicles (EVs) are major conveyors of biological information, mediating local and systemic cell-to-cell communication under physiological and pathological conditions. These endogenous vesicles have been recognized as prominent drug delivery vehicles of several therapeutic cargoes, including doxorubicin (dox), presenting major advantages over the classical approaches. Although dox is one of the most effective anti-tumour agents in the clinical practice, its use is very often hindered by its consequent dramatic cardiotoxicity. Despite significant advances witnessed in the past few years, more comprehensive studies, supporting the therapeutic efficacy of EVs, with decreased side effects, are still scarce. The main objective of this study was to evaluate the role of the gap junction protein connexin43 (Cx43) in mediating the release of EV content into tumour cells. Moreover, we investigated whether Cx43 improves the efficiency of dox-based anti-tumour treatment, with a concomitant decrease of cardiotoxicity. In the present report, we demonstrate that the presence of Cx43 in EVs increases the release of luciferin from EVs into tumour cells in vitro and in vivo. In addition, using cell-based approaches and a subcutaneous mouse tumour model, we show that the anti-tumour effect of dox incorporated into EVs is similar to the administration of the free drug, regardless the presence of Cx43. Strikingly, we demonstrate that the presence of Cx43 in dox-loaded EVs reduces the cardiotoxicity of the drug. Altogether, these results bring new insights into the concrete potential of EVs as therapeutic vehicles and open new avenues toward the development of strategies that help to reduce unwanted side effects.

• extracellular vesicles
• drug delivery
• cancer
• cardioprotection
• intercellular communication

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Conflict of interest and funding

The authors declare no conflicts of interest. This work was supported by the Portuguese Foundation for Science and Technology (FCT) grant FCT-UID/NEU/04539/2013. TMM was supported by a Ph.D. grant from FCT, PD/BD/106043/2015. IPATIMUP, part of the i3S Research Unit, was supported by FEDER (Fundo Europeu de Desenvolvimento Regional)/COMPETE 2020 [Operacional Programme for Competitiveness and Internationalisation (POCI)], Portugal 2020, FCT grant POCI-01-0145-FEDER-007274, Programa Operacional Regional do Norte (ON.2 – O Novo Norte), through FEDER/QREN (Quadro de Referência Estratégico Nacional) grants NORTE-07-0162-FEDER-000118 and NORTE-07-0162-FEDER-000067. CO is a Management Committee Member of the COST Action BM1202 “European Network On Microvesicles And Exosomes In Health And Disease (Me-Had).” The 4T1^luc2 cells were kindly provided by L. G. Arnaut.

Notes

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