Usnea Acid as Multidrug Resistance (MDR) Reversing Agent against Human Chronic Myelogenous Leukemia K562/ADR Cells via an ROS Dependent Apoptosis.

Wenjing Wang,Shanshan Wang,Shubin Niu,Feili Wei,Dexi Chen,Yabo Ouyang,Luxin Qiao,Jiming Yin

doi:10.1155/2019/8727935

Abstract

Purpose Multidrug resistance (MDR) is a major obstacle in chemotherapy of leukemia treatments. In this paper, we investigated Usnea Acid (UA) as MDR reversal agent on hematologic K562/ADR cells via ROS dependent apoptosis. Methods CCK8 assay was used to measure cell viability rate of K562/ADR. Intracellular reactive oxygen species (ROS) generation, cell cycle distribution, cell apoptosis were measured with flow cytometry, respectively. Proteins related to apoptosis were measured by Western blot. Intracellular Adriamycin accumulation was observed by confocal microscopy and measured by flow cytometry. Results In vitro study showed intracellular Adriamycin accumulation was remarkably increased by UA. Cell viability treated with Adr (4 μM) was decreased from 89.8% ± 4.7 to 32% ± 8.9 by combined with UA (4 μM). Adr-induced apoptosis and G1/G0 phase cell cycle arrest were remarkably increased by UA, as well as, intracellular ROS level. However, MDR reversing activity of UA was inhibited by N-acetyl cysteine (NAC), a ROS scavenger. Conclusion These data provide compelling evidence that UA is a promising agent against MDR in leukemia cell line and suggest a promising therapeutic approach for leukemia.

Highlights

Leukemia originates from abnormal hematopoietic stem cells which can result in a high number of deaths annually [1].Over the past decades, major advances have been achieved in clinical treatment of leukemia
By combining confocal microscopy and flow cytometry analyses, we found that fluorescence intensity of Adr in K562/ADR cells became markedly higher in Usnea Acid (UA) plus Adr group compared with
By using CCK8 assay, we observed that cell viability was significantly increased when adding Nacetyl cysteine (NAC) in UA plus Adr group (Figure 3(a)), which indicated that enhanced cytotoxicity of Adr by UA was reversed by NAC

Summary

Introduction

Leukemia originates from abnormal hematopoietic stem cells which can result in a high number of deaths annually [1]. Adriamycin (Adr) belongs to the anthracycline antibiotic family, displaying strong cytotoxicity and generally being used as chemotherapeutic agents in clinical including leukemia [12]. MRNA or/and overexpression of proteins of ABS-transporter family induced MDR challenging Adr treatment against leukemia [13]. Based on this situation, developing of novel therapeutic strategies to reverse MDR is extremely important in the clinical of leukemia therapy. In vitro study using UA against malignant cells suggesting it can induce cell cycle arrest, autophagy, and apoptosis, thereby, has potential to be developed as a chemotherapeutic agent [15]. We demonstrated that UA may increase the accumulation of Adriamycin in hematologic K562/ADR cells, reverse MDR via ROS dependent apoptosis induction

Materials and Methods

Usnea Acid Effects on the Proliferation and Intracellular

Increased Intracellular ROS Level Is Essential for Usnea

Discussion