Abstract
Hirsutine extracted from Uncaria rhynchophylla has been shown to exhibit anti-cancer activity. However, the molecular mechanism by which hirsutine exhibits anti-lung cancer activity remains unclear. In the present study, we showed that hirsutine induces apoptosis in human lung cancer cells via loss of mitochondrial membrane potential (∆ψm), adenosine triphosphate (ATP) depletion, ROS production, as well as cytochrome c release. Dephosphorylation of GSK3β is involved in hirsutine-mediated mitochondrial permeability transition pore (mPTP) opening through ANT1/CypD interaction. Mechanistic study revealed that interruption of ROCK1/PTEN/PI3K/Akt signaling pathway plays a critical role in hirsutine-mediated GSK3β dephosphorylation and mitochondrial apoptosis. Our in vivo study also showed that hirsutine effectively inhibits tumor growth in a A549 xenograft mouse model through ROCK1/PTEN/PI3K/Akt signaling-mediated GSK3β dephosphorylation and apoptosis. Collectively, these findings suggest a hierarchical model in which induction of apoptosis by hirsutine stems primarily from activation of ROCK1 and PTEN, inactivation of PI3K/Akt, leading in turn to GSK3β dephosphorylation and mPTP opening, and culminating in caspase-3 activation and apoptosis. These findings could provide a novel mechanistic basis for the application of hirsutine in the treatment of human lung cancer.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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A549 Cells
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Adenine Nucleotide Translocator 1 / metabolism
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Adenosine Triphosphate / metabolism
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Alkaloids / chemistry
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Alkaloids / pharmacology*
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Animals
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Apoptosis / drug effects*
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Cell Proliferation / drug effects
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Cyclophilins / metabolism
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Cytochromes c / metabolism
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Glycogen Synthase Kinase 3 beta / metabolism
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Humans
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Lung Neoplasms / metabolism
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Lung Neoplasms / pathology*
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Lung Neoplasms / ultrastructure
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Membrane Potential, Mitochondrial / drug effects
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Mice, Nude
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Mitochondria / drug effects
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Mitochondria / metabolism
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Mitochondria / ultrastructure
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Mitochondrial Membrane Transport Proteins / metabolism*
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Mitochondrial Permeability Transition Pore
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Models, Biological
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PTEN Phosphohydrolase / metabolism
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Peptidyl-Prolyl Isomerase F
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Phosphatidylinositol 3-Kinases / metabolism
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Phosphorylation / drug effects
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Reactive Oxygen Species / metabolism
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Signal Transduction*
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Xenograft Model Antitumor Assays
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rho-Associated Kinases / metabolism
Substances
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Adenine Nucleotide Translocator 1
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Alkaloids
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Peptidyl-Prolyl Isomerase F
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Mitochondrial Membrane Transport Proteins
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Mitochondrial Permeability Transition Pore
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PPIF protein, mouse
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Reactive Oxygen Species
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SLC25A4 protein, human
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Adenosine Triphosphate
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Cytochromes c
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Glycogen Synthase Kinase 3 beta
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ROCK1 protein, human
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rho-Associated Kinases
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PTEN Phosphohydrolase
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PTEN protein, human
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Cyclophilins
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hirsutine