TY - JOUR
T1 - Pseudolaric acid B activates autophagy in MCF-7 human breast cancer cells to prevent cell death
AU - Yu, Jinghua
AU - Chen, Chunhai
AU - Xu, Tianyang
AU - Yan, Minghui
AU - Xue, Bianbian
AU - Wang, Ying
AU - Liu, Chunyu
AU - Zhong, Ting
AU - Wang, Zengyan
AU - Meng, Xianying
AU - Hu, Donghua
AU - Yu, Xiaofang
N1 - Publisher Copyright:
© 2016, Spandidos Publications. All rights reserved.
PY - 2016/3
Y1 - 2016/3
N2 - Pseudolaric acid B (PAB) has been demonstrated to exert antitumor effects in MCF-7 human breast cancer cells. The present study aimed to investigate the mechanism of resistance to PAB-induced cell death. Following incubation with 4 μM of PAB for 3 days, the majority of MCF-7 cells became senescent, while some retained the same morphology as control cells, as assessed using a senescence detection kit. Additionally, 36 h of treatment with 4 μM of PAB increased the positive staining of autophagy markers, as shown by monodansylcadaverine and acridine orange staining. Western blot analysis indicated that this treatment also increased expression of the autophagy-related proteins Beclin-1 and microtubule-associated protein 1 light chain 3. Furthermore, treatment with PAB and the autophagy inhibitor 3-methyl adenine significantly decreased the ratio of autophagy, as assessed by flow cytometric analysis of monodansylcadaverine staining density (P<0.001), and increased the ratio of cell death, as assessed by MTT analysis (P<0.001). This indicated that autophagy promotes cell survival as a resistance mechanism to PAB treatment. Additionally, the present study demonstrated that PAB treatment did not affect the mitochondrial membrane potential, which may be related to autophagy. Increased Bcl-2 expression may explain why PAB did not affect the mitochondrial membrane potential. A Bcl-2 binding test demonstrated that PAB treatment inhibits the binding of Bcl-2 and Beclin-1, which may free Beclin-1 to participate in autophagy. Therefore, the present study demonstrated that autophagy may be activated by PAB treatment in human breast cancer MCF-7 cells, contributing to resistance to cell death.
AB - Pseudolaric acid B (PAB) has been demonstrated to exert antitumor effects in MCF-7 human breast cancer cells. The present study aimed to investigate the mechanism of resistance to PAB-induced cell death. Following incubation with 4 μM of PAB for 3 days, the majority of MCF-7 cells became senescent, while some retained the same morphology as control cells, as assessed using a senescence detection kit. Additionally, 36 h of treatment with 4 μM of PAB increased the positive staining of autophagy markers, as shown by monodansylcadaverine and acridine orange staining. Western blot analysis indicated that this treatment also increased expression of the autophagy-related proteins Beclin-1 and microtubule-associated protein 1 light chain 3. Furthermore, treatment with PAB and the autophagy inhibitor 3-methyl adenine significantly decreased the ratio of autophagy, as assessed by flow cytometric analysis of monodansylcadaverine staining density (P<0.001), and increased the ratio of cell death, as assessed by MTT analysis (P<0.001). This indicated that autophagy promotes cell survival as a resistance mechanism to PAB treatment. Additionally, the present study demonstrated that PAB treatment did not affect the mitochondrial membrane potential, which may be related to autophagy. Increased Bcl-2 expression may explain why PAB did not affect the mitochondrial membrane potential. A Bcl-2 binding test demonstrated that PAB treatment inhibits the binding of Bcl-2 and Beclin-1, which may free Beclin-1 to participate in autophagy. Therefore, the present study demonstrated that autophagy may be activated by PAB treatment in human breast cancer MCF-7 cells, contributing to resistance to cell death.
KW - Autophagy
KW - MCF‑7 human breast cancer cells
KW - Pseudolaric acid B
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UR - http://www.scopus.com/inward/citedby.url?scp=84958073582&partnerID=8YFLogxK
U2 - 10.3892/ol.2016.4103
DO - 10.3892/ol.2016.4103
M3 - Article
C2 - 26998069
AN - SCOPUS:84958073582
SN - 1792-1074
VL - 11
SP - 1731
EP - 1737
JO - Oncology Letters
JF - Oncology Letters
IS - 3
ER -