Transient Exposure of Endothelial Cells to Doxorubicin Leads to Long-Lasting Vascular Endothelial Growth Factor Receptor 2 Downregulation.

Silvia Graziani,Luca Scorrano,Giovanna Pontarin

doi:10.3390/cells11020210

Abstract

Doxorubicin (Dox) is an effective antineoplastic drug with serious cardiotoxic side effects that persist after drug withdrawal and can lead to heart failure. Dysregulation of vascular endothelium has been linked to the development of Dox-induced cardiotoxicity, but it is unclear whether and how transient exposure to Dox leads to long-term downregulation of Endothelial Vascular Endothelial Growth Factor Receptor type2 (VEGFR2), essential for endothelial cells function. Using an in vitro model devised to study the long-lasting effects of brief endothelial cells exposure to Dox, we show that Dox leads to sustained protein synthesis inhibition and VEGFR2 downregulation. Transient Dox treatment led to the development of long-term senescence associated with a reduction in VEGFR2 levels that persisted days after drug withdrawal. By analyzing VEGFR2 turnover, we ruled out that its downregulation was depended on Dox-induced autophagy. Conversely, Dox induced p53 expression, reduced mTOR-dependent translation, and inhibited global protein synthesis. Our data contribute to a mechanistic basis to the permanent damage caused to endothelial cells by short-term Dox treatment.

Highlights

Doxorubicin (Dox) is an effective chemotherapeutic used for the treatment of numerous cancers
In order to overcome this limitation and to evaluate short as well as long term effects of endothelial cells exposure to Dox, we setup an in vitro system where HUVECs were treated with 250 nM Dox, a concentration commonly obtained in clinical use for 24 h, followed by extensive washing and culturing in drug-free complete medium for several additional days
24 h after Dox treatment, total Vascular Endothelial Growth Factor Receptor type2 (VEGFR2) levels were almost nil and that even eight days after. Dox removal they were reduced by ~75% (Figure 1C,D). These results indicate that VEGFR2 levels are extremely sensitive to Dox and call for a more detailed time course analysis of the impact of Dox on VEGFR2 expression

Summary

Introduction

Doxorubicin (Dox) is an effective chemotherapeutic used for the treatment of numerous cancers (leukemia, breast, gastric, and ovarian cancer). Dox therapy is associated with cardiotoxic effect that can manifest acutely as well as years after treatment has been discontinued [1]. Current strategies to prevent Dox-induced cardiotoxicity are scarce and ineffective. In former cancer patients, Dox cardiomyopathy is difficult to treat and can progress to fatal heart failure. Cardiomyocytes have been long considered the main target in the progressive alterations of the cardiac muscle caused by Dox. Cardiomyocytes have been long considered the main target in the progressive alterations of the cardiac muscle caused by Dox In this classic model of Dox cardiotoxicity, cardiomyocyte mitochondrial damage plays a key role [2]. Dox accumulates in mitochondria by binding to cardiolipin in the inner mitochondrial membrane and participates to several processes leading to enhanced

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Conclusion