Hindawi Publishing Corporation
Evidence-Based Complementary and Alternative Medicine
Volume 2013, Article ID 548929, 11 pages
http://dx.doi.org/10.1155/2013/548929
Research Article
Destruxin B Isolated from Entomopathogenic Fungus
Metarhizium anisopliae Induces Apoptosis via
a Bcl-2 Family-Dependent Mitochondrial Pathway in
Human Nonsmall Cell Lung Cancer Cells
Chun-Chi Wu,
1,2
Tzu-Hsiu Chen,
3
Bing-Lan Liu,
4
Li-Chen Wu,
5
Yung-Ching Chen,
1
Yew-Min Tzeng,
4
and Shih-Lan Hsu
1,6
1
Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
2
Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan
3
Department of Health and Nutrition, Chia Nan University of Pharmacy & Science, Tainan, Taiwan
4
Department of Applied Chemistry, Chaoyang University of Technology, Taichung, Taiwan
5
Department of Applied Chemistry, National Chi Nan University, Puli, Nantou, Taiwan
6
Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan
Correspondence should be addressed to Yew-Min Tzeng; ymtzeng@cyut.edu.tw and Shih-Lan Hsu; h2326@vghtc.gov.tw
Received 20 March 2013; Accepted 20 August 2013
Academic Editor: Mei Tian
Copyright © 2013 Chun-Chi Wu et al. Tis is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Destruxin B, isolated from entomopathogenic fungus Metarhizium anisopliae, is one of the cyclodepsipeptides with insecticidal
and anticancer activities. In this study, destruxin B was extracted and purifed by ion-exchange chromatography, silica gel
chromatography, and semipreparative high-performance liquid chromatography. Te potential anticancer efects and molecular
mechanisms of destruxin B in human nonsmall cell lung cancer cell lines were characterized. Our results showed that destruxin
B induced apoptotic cell death in A549 cells. Tis event was accompanied by the activation of caspase-2, -3, and -9. Moreover,
destruxin B increased the expression level of proapoptotic molecule, PUMA, while decreased antiapoptotic molecule Mcl-1.
Additionally, the translocation of Bax from cytosol to mitochondrial membrane was observed upon destruxin B treatment.
Knockdown of Bax by shRNA efectively attenuated destruxin-B-triggered apoptosis in A549 cells. Interestingly, similar toxic efects
and underlying mechanisms including caspase activation, upregulation of PUMA, and downregulation of Mcl-1 were also observed
in a p53-null lung cancer H1299 cell line upon destruxin B treatment. Taken together, our fndings suggest that destruxin-B-induced
apoptosis in human nonsmall cell lung cancer cells is via a Bcl-2 family-dependent mitochondrial pathway.
1. Introduction
Lung cancer is the leading cause of death for both men and
women in many countries, including Taiwan, which exhibited
the highest rate of increase in lung cancer mortality in recent
years [1, 2]. Te fve-year survival rate of lung cancer patient
is only 13–25% [3]. Although target therapy emerged for
treatment of lung cancer patients in the past decade [4], there
is still a large amount of patients who are uncured. It appears
that the drugs with greater efcacy than existing treatments
are urgently required for these patients.
Growing evidence demonstrates that apoptosis is
involved in many biological events including physiological
homeostasis and embryogenesis [5] and is also an important
determinant of the response of cancers to chemo-, radiation,
or target-therapy [6, 7]; compounds that induce these
events may provide potent anticancer efects for cancer
treatment. Te regulatory mechanisms of apoptosis are
quite complicated networks. Two major types of apoptosis
pathways are mentioned: one is the intrinsic pathway which
is mediated by the regulators located in the mitochondrial
[8] and the other is the extrinsic pathway which is regulated