Abstract

Oxidative stress or excessive antioxidant levels-caused redox imbalance can alter apoptotic responses, and N-acetyl-L-cysteine (NAC) was able to inhibit H2O2-mediated cell death, but unable to prevent apoptosis induced by other chemicals such as etoposide. We now demonstrate that 10 and 20mM NAC, non-toxic concentrations, can enhance fisetin (FIS)-mediated apoptosis in colon cancer cells COLO205. Compared to treatment with FIS alone, combination treatment with NAC increased the expression of cleaved caspase-3 and PAPR protein, and produced greater density of DNA ladders. NAC reduced the mitochondrial membrane potential of FIS-treated COLO205 cells with induction of caspase 9 protein cleavage. DNA ladders induced by FIS+NAC were diminished by adding the caspase 3 inhibitor, DEVD-FMK, and the caspase 9 inhibitor, YVAD-FMK. Combinatorial treatment COLO205 cells with NAC and FIS showed potent inhibition on ERK protein phosphorylation, compared with those from FIS or NAC-treated groups by Western blotting using specific antibodies. Addition of the chemical ERK inhibitors, PD98059 and U0126, significantly inhibited ERK protein phosphorylation, accompanied by induced DNA ladder formation, cleavage of caspase 3 and PARP protein in COLO205 cells. Furthermore, NAC showed an enhancement on a FIS-related chemical chrysin-induced apoptosis of COLO205 cells, and NAC sensitization of colon cancer cells to FIS-induced apoptosis was also identify in colonic cancer cells HCT-116, HT-29, and HCT-15 cells. The evidence to support NAC sensitizing human colon cancer cells to FIS-induced apoptosis was provided, and application of NAC and FIS as a strategy to treat colonic cancer deserved for further in vivo study.

Original languageEnglish
JournalMolecular Carcinogenesis
Volume53
Issue numberS1
DOIs
Publication statusPublished - 2014

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Acetylcysteine
Colonic Neoplasms
Apoptosis
Caspase 3
Caspase Inhibitors
Caspase 9
Proteins
DNA
fisetin
Phosphorylation
HCT116 Cells
Mitochondrial Membrane Potential
Etoposide
Oxidation-Reduction
Oxidative Stress
Cell Death
Antioxidants
Western Blotting

Keywords

  • Apoptosis
  • Colonic cancer
  • Fisetin
  • N-acetyl-L-cysteine
  • Reactive oxygen species

ASJC Scopus subject areas

  • Cancer Research
  • Molecular Biology

Cite this

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title = "N-acetyl-L-cysteine enhances fisetin-induced cytotoxicity via induction of ROS-independent apoptosis in human colonic cancer cells",
abstract = "Oxidative stress or excessive antioxidant levels-caused redox imbalance can alter apoptotic responses, and N-acetyl-L-cysteine (NAC) was able to inhibit H2O2-mediated cell death, but unable to prevent apoptosis induced by other chemicals such as etoposide. We now demonstrate that 10 and 20mM NAC, non-toxic concentrations, can enhance fisetin (FIS)-mediated apoptosis in colon cancer cells COLO205. Compared to treatment with FIS alone, combination treatment with NAC increased the expression of cleaved caspase-3 and PAPR protein, and produced greater density of DNA ladders. NAC reduced the mitochondrial membrane potential of FIS-treated COLO205 cells with induction of caspase 9 protein cleavage. DNA ladders induced by FIS+NAC were diminished by adding the caspase 3 inhibitor, DEVD-FMK, and the caspase 9 inhibitor, YVAD-FMK. Combinatorial treatment COLO205 cells with NAC and FIS showed potent inhibition on ERK protein phosphorylation, compared with those from FIS or NAC-treated groups by Western blotting using specific antibodies. Addition of the chemical ERK inhibitors, PD98059 and U0126, significantly inhibited ERK protein phosphorylation, accompanied by induced DNA ladder formation, cleavage of caspase 3 and PARP protein in COLO205 cells. Furthermore, NAC showed an enhancement on a FIS-related chemical chrysin-induced apoptosis of COLO205 cells, and NAC sensitization of colon cancer cells to FIS-induced apoptosis was also identify in colonic cancer cells HCT-116, HT-29, and HCT-15 cells. The evidence to support NAC sensitizing human colon cancer cells to FIS-induced apoptosis was provided, and application of NAC and FIS as a strategy to treat colonic cancer deserved for further in vivo study.",
keywords = "Apoptosis, Colonic cancer, Fisetin, N-acetyl-L-cysteine, Reactive oxygen species",
author = "Wu, {Ming Shun} and Lien, {Gi Shih} and Shen, {Shing Chuan} and Yang, {Liang Yo} and Chen, {Yen Chou}",
year = "2014",
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language = "English",
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TY - JOUR

T1 - N-acetyl-L-cysteine enhances fisetin-induced cytotoxicity via induction of ROS-independent apoptosis in human colonic cancer cells

AU - Wu, Ming Shun

AU - Lien, Gi Shih

AU - Shen, Shing Chuan

AU - Yang, Liang Yo

AU - Chen, Yen Chou

PY - 2014

Y1 - 2014

N2 - Oxidative stress or excessive antioxidant levels-caused redox imbalance can alter apoptotic responses, and N-acetyl-L-cysteine (NAC) was able to inhibit H2O2-mediated cell death, but unable to prevent apoptosis induced by other chemicals such as etoposide. We now demonstrate that 10 and 20mM NAC, non-toxic concentrations, can enhance fisetin (FIS)-mediated apoptosis in colon cancer cells COLO205. Compared to treatment with FIS alone, combination treatment with NAC increased the expression of cleaved caspase-3 and PAPR protein, and produced greater density of DNA ladders. NAC reduced the mitochondrial membrane potential of FIS-treated COLO205 cells with induction of caspase 9 protein cleavage. DNA ladders induced by FIS+NAC were diminished by adding the caspase 3 inhibitor, DEVD-FMK, and the caspase 9 inhibitor, YVAD-FMK. Combinatorial treatment COLO205 cells with NAC and FIS showed potent inhibition on ERK protein phosphorylation, compared with those from FIS or NAC-treated groups by Western blotting using specific antibodies. Addition of the chemical ERK inhibitors, PD98059 and U0126, significantly inhibited ERK protein phosphorylation, accompanied by induced DNA ladder formation, cleavage of caspase 3 and PARP protein in COLO205 cells. Furthermore, NAC showed an enhancement on a FIS-related chemical chrysin-induced apoptosis of COLO205 cells, and NAC sensitization of colon cancer cells to FIS-induced apoptosis was also identify in colonic cancer cells HCT-116, HT-29, and HCT-15 cells. The evidence to support NAC sensitizing human colon cancer cells to FIS-induced apoptosis was provided, and application of NAC and FIS as a strategy to treat colonic cancer deserved for further in vivo study.

AB - Oxidative stress or excessive antioxidant levels-caused redox imbalance can alter apoptotic responses, and N-acetyl-L-cysteine (NAC) was able to inhibit H2O2-mediated cell death, but unable to prevent apoptosis induced by other chemicals such as etoposide. We now demonstrate that 10 and 20mM NAC, non-toxic concentrations, can enhance fisetin (FIS)-mediated apoptosis in colon cancer cells COLO205. Compared to treatment with FIS alone, combination treatment with NAC increased the expression of cleaved caspase-3 and PAPR protein, and produced greater density of DNA ladders. NAC reduced the mitochondrial membrane potential of FIS-treated COLO205 cells with induction of caspase 9 protein cleavage. DNA ladders induced by FIS+NAC were diminished by adding the caspase 3 inhibitor, DEVD-FMK, and the caspase 9 inhibitor, YVAD-FMK. Combinatorial treatment COLO205 cells with NAC and FIS showed potent inhibition on ERK protein phosphorylation, compared with those from FIS or NAC-treated groups by Western blotting using specific antibodies. Addition of the chemical ERK inhibitors, PD98059 and U0126, significantly inhibited ERK protein phosphorylation, accompanied by induced DNA ladder formation, cleavage of caspase 3 and PARP protein in COLO205 cells. Furthermore, NAC showed an enhancement on a FIS-related chemical chrysin-induced apoptosis of COLO205 cells, and NAC sensitization of colon cancer cells to FIS-induced apoptosis was also identify in colonic cancer cells HCT-116, HT-29, and HCT-15 cells. The evidence to support NAC sensitizing human colon cancer cells to FIS-induced apoptosis was provided, and application of NAC and FIS as a strategy to treat colonic cancer deserved for further in vivo study.

KW - Apoptosis

KW - Colonic cancer

KW - Fisetin

KW - N-acetyl-L-cysteine

KW - Reactive oxygen species

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U2 - 10.1002/mc.22053

DO - 10.1002/mc.22053

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VL - 53

JO - Molecular Carcinogenesis

JF - Molecular Carcinogenesis

SN - 0899-1987

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