Chemotherapy administration to breast cancer patients affects extracellular vesicles thrombogenicity and function

Abstract

Breast cancer (BC) is the most prevalent type of malignancy in women. Extracellular vesicles (EVs) are subcellular membrane blebs that include exosomes and microparticles.Study aimsTo elucidate the effects of chemotherapy administration on BC patients’ EVs characteristics and their effects on endothelial cells (EC) functions.MethodsEVs were isolated from the blood samples of 54 BC patients treated by chemotherapy (25 neo-adjuvant, 29 adjuvant) and from 20 healthy women (control group). Blood samples were taken before chemotherapy and on the day of last chemotherapy administration. In some patients, samples were also evaluated 24 hours after chemotherapy treatment. EVs were characterized by cell origin, thrombogenicity and cytokine content. EVs effects on coagulation, migration, apoptosis and proliferation of endothelial cells were assessed as well.ResultsPatient characteristics of the two subgroups were similar except for tumor size. Change in EV expression of BC markers, MUC1 and EpCAM, were found in patient subgroups. EC-EVs were significantly higher in both patient subgroups compared to healthy controls. Higher EVs pro-coagulant activity was found at the end of chemotherapy and a significant increase in the ratio between tissue factor (TF) and TF pathway inhibitor was documented after the first 24hours of exposure to doxorubicin treatment. Furthermore, EVs of neo-adjuvant patients obtained before chemotherapy contained more pro-angiogenic proteins, reduced endothelial cells apoptosis and increased their migration compared to EVs obtained at the same timing from adjuvant patients.ConclusionsEVs may serve as a biomarker for chemotherapy-related thrombogenicity and may indicate vascular damage even before chemotherapy.

Apoptotic vesicles: deathly players in cancer‐associated coagulation

“…Cancer patients have an approximately four‐fold increased risk of developing VTE . Multiple mechanisms for the prothrombotic effects of tumors have been suggested from both in vitro and clinical studies (Figure ) . For example, enhanced TF expression by monocytes and subendothelial vascular cells may be increased following the secretion of tumor‐derived vascular endothelial cell growth factor .…”

“…Anticoagulation co‐therapy can decrease the risk of VTE, but increase the risk of hemorrhage in cancer patients receiving chemotherapy . While the pathogenicity of chemotherapy‐associated thrombosis remains poorly understood, several potential mechanisms have been proposed by which chemotherapy may provoke a procoagulant state (Figure ) . For example, cisplatin may increase TF activity, induce endothelial damage in patients, and enhance platelet activation .…”

“…Cancer patients have a significantly higher number of circulating EV compared to healthy controls, and chemotherapy increases both the risk of thrombosis and can elevate the numbers of circulating EV . The elevated level of circulating EV in cancer patients undergoing chemotherapy could be explained by the release of ApoV from dying tumor cells.…”

“…In 1868, Armand Trousseau published his observations of the link between cancer and thrombosis and 100 years later, experimental evidence for this connection was provided . Since then, there has been an expanding interest in the ability of tumors and their extracellular vesicles (EV) to contribute to both thrombotic and metastatic events . Although the link of cancer to thrombosis and cancer progression is complex and not fully understood, a multitude of studies have shown that coagulation and their signaling pathways contribute to metastasis and cancer progression …”

“…In some studies, cancer patients have been shown to have a significantly higher number of circulating EV, compared to healthy controls . In addition, chemotherapy increases the risk of thrombosis and may elevate the levels of circulating EV . Despite the fact that numerous mechanisms have been identified for tumor‐associated thrombosis (Figure ), the study of a possible direct involvement of tumor‐derived ApoV has been neglected.…”