Bufalin Inhibits Proliferation and Induces Apoptosis in Osteosarcoma Cells by Downregulating MicroRNA-221.

Jianjun Zhang,Xiuyi Yin,Kun Han,Yan Zhou,Yang Yao,Yaling Wang,Yang Su,Haiyan Hu,Jingjing Sha

doi:10.1155/2016/7319464

Abstract

Bufalin, a major component of the Chinese medicine ChanSu, which is prepared from the skin and parotid venom glands of toads, has shown cytotoxicity in several malignant tumors. Here, we reported that bufalin inhibited proliferation and induced mitochondria-dependent apoptosis in U-2OS and Saos-2 osteosarcoma cells with intracellular reactive oxygen species (ROS) production. By microRNA (miR) array analysis and quantitative reverse transcription polymerase chain reaction, we found that miR-221 was downregulated after treatment with bufalin. In accordance with TargetScan prediction and luciferase reporter assay, Bcl2 binding component 3 (BBC3) was the direct target of miR-221. Furthermore, upregulating miR-221 by its MIMIC and suppressing BBC3 by small interfering RNA (siRNA) reversed the effects of bufalin on osteosarcoma cells. Collectively, our data indicate that bufalin inhibits cell proliferation and induces mitochondria-dependent apoptosis in osteosarcoma cells through downregulating miR-221 and triggering BBC3 expression.

Highlights

Osteosarcoma (OS) is the most common primary sarcoma of bone in children and adolescents
Bufalin is the major component of the Chinese medicine ChanSu, which is obtained from the skin and parotid venom glands of toads
In order to explore the mechanism by which bufalin inhibits the proliferation of OS cells, we screened the miRNAs that were modulated by bufalin in Saos-2 cells using miRNA microarray. miR-221 was one of the markedly downregulated miRNAs, which provokes our interest due to its tumor suppressor role in many other cancer cells (Figure 2(a))

Summary

Introduction

Osteosarcoma (OS) is the most common primary sarcoma of bone in children and adolescents. After high-dose, frequent neoadjuvant, and adjuvant chemotherapy, numerous patients with OS become multidrug resistant. The prognosis for those with recurrent or metastatic diseases remains very poor [3]. The skin and parotid venom glands of toads have been widely used for centuries in traditional Chinese medicine for the treatment of various ailments such as heart failure, hypertension, cancer, and sores [4,5,6]. Bufalin is the major component of the Chinese medicine ChanSu, which is obtained from the skin and parotid venom glands of toads. The effects of bufalin on OS remain poorly understood. Our findings suggested that bufalin activated the mitochondria-dependent apoptosis via downregulation of miR-221

Methods

Results

Conclusion