Enhanced erythrocyte membrane exposure of phosphatidylserine following sorafenib treatment: an in vivo and in vitro study.

Abstract

BACKGROUND:

Sorafenib (Nexavar(®)), a polytyrosine kinase inhibitor, stimulates apoptosis and is thus widely used for chemotherapy in hepatocellular carcinoma (HCC). Hematological side effects of Nexavar(®) chemotherapy include anemia. Erythrocytes may undergo apoptosis-like suicidal death or eryptosis, which is characterized by cell shrinkage and phosphatidylserine-exposure at the cell surface. Signaling leading to eryptosis include increase in cytosolic Ca(2+)activity ([Ca(2+)](i)), formation of ceramide, ATP-depletion and oxidative stress. The present study explored, whether sorafenib triggers eryptosis in vitro and in vivo.

METHODS:

[Ca(2+)](i )was estimated from Fluo3-fluorescence, cell volume from forward scatter, phosphatidylserine-exposure from annexin-V-binding, hemolysis from hemoglobin release, ceramide with antibody binding-dependent fluorescence, cytosolic ATP with a luciferin-luciferase-based assay, and oxidative stress from 2',7' dichlorodihydrofluorescein diacetate (DCFDA) fluorescence.

RESULTS:

A 48 h exposure of erythrocytes to sorafenib (≥0.5 µM) significantly increased Fluo 3 fluorescence, decreased forward scatter, increased annexin-V-binding and triggered slight hemolysis (≥5 µM), but did not significantly modify ceramide abundance and cytosolic ATP. Sorafenib treatment significantly enhanced DCFDA-fluorescence and the reducing agents N-acetyl-L-cysteine and tiron significantly blunted sorafenib-induced phosphatidylserine exposure. Nexavar(®) chemotherapy in HCC patients significantly enhanced the number of phosphatidylserine-exposing erythrocytes.

CONCLUSIONS:

The present observations disclose novel effects of sorafenib, i.e. stimulation of suicidal erythrocyte death or eryptosis, which may contribute to the pathogenesis of anemia in Nexavar(®)-based chemotherapy.

• Authors: Adrian Lupescu, Nazneen Shaik, Kashif Jilani, Christine Zelenak, Elisabeth Lang, Venkanna Pasham, Mohanad Zbidah, Ansgar Plate, Michael Bitzer, Michael Föller, Syed M Qadri, Florian Lang
• Journal: Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology (Cell Physiol Biochem) Vol. 30 Issue 4 Pg. 876-88 ( 2012) ISSN: 1421-9778 [Electronic] Germany
• PMID: 22907570 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2012 S. Karger AG, Basel.

Chemical References

• Antineoplastic Agents
• Ceramides
• Phenylurea Compounds
• Phosphatidylserines
• Protein Kinase Inhibitors
• Niacinamide
• Adenosine Triphosphate
• Sorafenib

Topics

• Adenosine Triphosphate (metabolism)
• Antineoplastic Agents (adverse effects)
• Carcinoma, Hepatocellular (drug therapy)
• Cell Death (drug effects)
• Cell Size (drug effects)
• Ceramides (metabolism)
• Erythrocytes (cytology, drug effects, metabolism, pathology)
• Hemolysis (drug effects)
• Humans
• Liver Neoplasms (drug therapy)
• Niacinamide (adverse effects, analogs & derivatives)
• Oxidative Stress (drug effects)
• Phenylurea Compounds (adverse effects)
• Phosphatidylserines (metabolism)
• Protein Kinase Inhibitors (adverse effects)
• Sorafenib