Triptolide induces lysosomal-mediated programmed cell death in MCF-7 breast cancer cells

Chie Owa, Michael E. Messina, Reginald Halaby

Research output: Contribution to journalArticleResearchpeer-review

22 Citations (Scopus)

Abstract

Background: Breast cancer is a major cause of death; in fact, it is the most common type, in order of the number of global deaths, of cancer in women worldwide. This research seeks to investigate how triptolide, an extract from the Chinese herb Tripterygium wilfordii Hook F, induces apoptosis in MCF-7 human breast cancer cells. Accumulating evidence suggests a role for lysosomal proteases in the activation of apoptosis. However, there is also some controversy regarding the direct participation of lysosomal proteases in activation of key apoptosis-related caspases and release of mitochondrial cytochrome c. In the present study, we demonstrate that triptolide induces an atypical, lysosomal-mediated apoptotic cell death in MCF-7 cells because they lack caspase-3. Methods: MCF-7 cell death was characterized via cellular morphology, chromatin condensation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric cell growth inhibition assay and the expression levels of proapoptotic proteins. Acridine orange and LysoTracker® staining were performed to visualize lysosomes. Lysosomal enzymatic activity was monitored using an acid phosphatase assay and western blotting of cathepsin B protein levels in the cytosolic fraction, which showed increased enzymatic activity in drug-treated cells. Results: These experiments suggest that triptolide-treated MCF-7 cells undergo atypical apoptosis and that, during the early stages, lysosomal enzymes leak into the cytosol, indicating lysosomal membrane permeability. Conclusion: Our results suggest that further studies are warranted to investigate triptolide's potential as an anticancer therapeutic agent.

Original languageEnglish
Pages (from-to)557-569
Number of pages13
JournalInternational Journal of Women's Health
Volume5
Issue number1
DOIs
StatePublished - 4 Sep 2013

Fingerprint

MCF-7 Cells
Cell Death
Apoptosis
Breast Neoplasms
Peptide Hydrolases
Tripterygium
Cathepsin B
Acridine Orange
Caspases
Acid Phosphatase
Cytochromes c
Lysosomes
Caspase 3
Antineoplastic Agents
Cytosol
Chromatin
Cause of Death
Permeability
Proteins
Western Blotting

Keywords

  • Apoptosis
  • Lysosomal membrane permeabilization (lmp)
  • Lysosomes
  • Mcf-7 breast cancer cells
  • Triptolide

Cite this

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title = "Triptolide induces lysosomal-mediated programmed cell death in MCF-7 breast cancer cells",
abstract = "Background: Breast cancer is a major cause of death; in fact, it is the most common type, in order of the number of global deaths, of cancer in women worldwide. This research seeks to investigate how triptolide, an extract from the Chinese herb Tripterygium wilfordii Hook F, induces apoptosis in MCF-7 human breast cancer cells. Accumulating evidence suggests a role for lysosomal proteases in the activation of apoptosis. However, there is also some controversy regarding the direct participation of lysosomal proteases in activation of key apoptosis-related caspases and release of mitochondrial cytochrome c. In the present study, we demonstrate that triptolide induces an atypical, lysosomal-mediated apoptotic cell death in MCF-7 cells because they lack caspase-3. Methods: MCF-7 cell death was characterized via cellular morphology, chromatin condensation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric cell growth inhibition assay and the expression levels of proapoptotic proteins. Acridine orange and LysoTracker{\circledR} staining were performed to visualize lysosomes. Lysosomal enzymatic activity was monitored using an acid phosphatase assay and western blotting of cathepsin B protein levels in the cytosolic fraction, which showed increased enzymatic activity in drug-treated cells. Results: These experiments suggest that triptolide-treated MCF-7 cells undergo atypical apoptosis and that, during the early stages, lysosomal enzymes leak into the cytosol, indicating lysosomal membrane permeability. Conclusion: Our results suggest that further studies are warranted to investigate triptolide's potential as an anticancer therapeutic agent.",
keywords = "Apoptosis, Lysosomal membrane permeabilization (lmp), Lysosomes, Mcf-7 breast cancer cells, Triptolide",
author = "Chie Owa and Messina, {Michael E.} and Reginald Halaby",
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Triptolide induces lysosomal-mediated programmed cell death in MCF-7 breast cancer cells. / Owa, Chie; Messina, Michael E.; Halaby, Reginald.

In: International Journal of Women's Health, Vol. 5, No. 1, 04.09.2013, p. 557-569.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Triptolide induces lysosomal-mediated programmed cell death in MCF-7 breast cancer cells

AU - Owa, Chie

AU - Messina, Michael E.

AU - Halaby, Reginald

PY - 2013/9/4

Y1 - 2013/9/4

N2 - Background: Breast cancer is a major cause of death; in fact, it is the most common type, in order of the number of global deaths, of cancer in women worldwide. This research seeks to investigate how triptolide, an extract from the Chinese herb Tripterygium wilfordii Hook F, induces apoptosis in MCF-7 human breast cancer cells. Accumulating evidence suggests a role for lysosomal proteases in the activation of apoptosis. However, there is also some controversy regarding the direct participation of lysosomal proteases in activation of key apoptosis-related caspases and release of mitochondrial cytochrome c. In the present study, we demonstrate that triptolide induces an atypical, lysosomal-mediated apoptotic cell death in MCF-7 cells because they lack caspase-3. Methods: MCF-7 cell death was characterized via cellular morphology, chromatin condensation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric cell growth inhibition assay and the expression levels of proapoptotic proteins. Acridine orange and LysoTracker® staining were performed to visualize lysosomes. Lysosomal enzymatic activity was monitored using an acid phosphatase assay and western blotting of cathepsin B protein levels in the cytosolic fraction, which showed increased enzymatic activity in drug-treated cells. Results: These experiments suggest that triptolide-treated MCF-7 cells undergo atypical apoptosis and that, during the early stages, lysosomal enzymes leak into the cytosol, indicating lysosomal membrane permeability. Conclusion: Our results suggest that further studies are warranted to investigate triptolide's potential as an anticancer therapeutic agent.

AB - Background: Breast cancer is a major cause of death; in fact, it is the most common type, in order of the number of global deaths, of cancer in women worldwide. This research seeks to investigate how triptolide, an extract from the Chinese herb Tripterygium wilfordii Hook F, induces apoptosis in MCF-7 human breast cancer cells. Accumulating evidence suggests a role for lysosomal proteases in the activation of apoptosis. However, there is also some controversy regarding the direct participation of lysosomal proteases in activation of key apoptosis-related caspases and release of mitochondrial cytochrome c. In the present study, we demonstrate that triptolide induces an atypical, lysosomal-mediated apoptotic cell death in MCF-7 cells because they lack caspase-3. Methods: MCF-7 cell death was characterized via cellular morphology, chromatin condensation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric cell growth inhibition assay and the expression levels of proapoptotic proteins. Acridine orange and LysoTracker® staining were performed to visualize lysosomes. Lysosomal enzymatic activity was monitored using an acid phosphatase assay and western blotting of cathepsin B protein levels in the cytosolic fraction, which showed increased enzymatic activity in drug-treated cells. Results: These experiments suggest that triptolide-treated MCF-7 cells undergo atypical apoptosis and that, during the early stages, lysosomal enzymes leak into the cytosol, indicating lysosomal membrane permeability. Conclusion: Our results suggest that further studies are warranted to investigate triptolide's potential as an anticancer therapeutic agent.

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SN - 1179-1411

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