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Reactive oxygen species regulate urokinase plasminogen activator expression and cell invasion via mitogen-activated protein kinase pathways after treatment with hepatocyte growth factor in stomach cancer cells.

Lee KH, Kim SW, Kim JR - J. Exp. Clin. Cancer Res. (2009)

Bottom Line: We confirmed that Rac-1 regulated ROS production after activation of the AKT pathway with HGF.Exogenously added H2O2 promoted the expression of HGF, but not in a dose-dependent manner and also showed negative expression of HGF after co-treatment with H2O2 and HGF.We clarified the downstream pathways regulated by ROS after treatment with H2O2, which showed negative control between FRK and p38 kinase activities for uPA regulation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, Daegu, Korea. lkhee@med.yu.ac.kr

ABSTRACT

Background: Reactive oxygen species (ROS) are closely associated with the intracellular signal cascade, thus strongly implicating involvement in tumor progression. However, the mechanism by which ROS are generated and how ROS target downstream molecules to trigger tumor metastasis is unclear. In this study, we investigated the underlying signal pathways in ROS-induced urokinase plasminogen activator (uPA) expression in the human gastric cancer cells, NUGC-3 and MKN-28.

Methods and results: Intracellular ROS, as determined using the fluorescent probe, 2'-7' dichlorofluorescein diacetate, decreased after treatment with hepatocyte growth factor (HGF). We confirmed that Rac-1 regulated ROS production after activation of the AKT pathway with HGF. Exogenously added H2O2 promoted the expression of HGF, but not in a dose-dependent manner and also showed negative expression of HGF after co-treatment with H2O2 and HGF. Treatment with NAC, an intracellular free radical scavenger, decreased the enhancement of uPA production and tumor invasion in both cells. We clarified the downstream pathways regulated by ROS after treatment with H2O2, which showed negative control between FRK and p38 kinase activities for uPA regulation.

Conclusion: HGF regulates Rac-1-induced ROS production through the Akt pathway and ROS regulates uPA production and invasion via MAP kinase, which provides novel insight into the mechanisms underlying the progression of gastric cancer.

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Effects of H2O2 and NAC on HGF-mediated upregulation of uPA. Serum-starved cells were pretreated with or without H2O2 (100 μM) and NAC (5 mM) for 30 min, and then treated with or without HGF (10 ng/ml). After incubation for 24 h, uPA secreted in culture media was measured by Western blot analysis with a uPA antibody. Representative data from 3 independent experiments were shown.
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Figure 8: Effects of H2O2 and NAC on HGF-mediated upregulation of uPA. Serum-starved cells were pretreated with or without H2O2 (100 μM) and NAC (5 mM) for 30 min, and then treated with or without HGF (10 ng/ml). After incubation for 24 h, uPA secreted in culture media was measured by Western blot analysis with a uPA antibody. Representative data from 3 independent experiments were shown.

Mentions: uPA gradually accumulated in both cell lines after treatment with HGF. Treatment with H2O2 resulted in an increase in the uPA protein level in both cell lines. When we treated cells with H2O2 and HGF, the uPA protein level was decreased. To investigate the effect of N-acetylcysteine (NAC), a precursor of glutathione and an intracellular free radical scavenger, on HGF-induced uPA production, we treated both cell lines with NAC. NAC decreased the HGF-induced uPA production (Figure 8).


Reactive oxygen species regulate urokinase plasminogen activator expression and cell invasion via mitogen-activated protein kinase pathways after treatment with hepatocyte growth factor in stomach cancer cells.

Lee KH, Kim SW, Kim JR - J. Exp. Clin. Cancer Res. (2009)

Effects of H2O2 and NAC on HGF-mediated upregulation of uPA. Serum-starved cells were pretreated with or without H2O2 (100 μM) and NAC (5 mM) for 30 min, and then treated with or without HGF (10 ng/ml). After incubation for 24 h, uPA secreted in culture media was measured by Western blot analysis with a uPA antibody. Representative data from 3 independent experiments were shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2698863&req=5

Figure 8: Effects of H2O2 and NAC on HGF-mediated upregulation of uPA. Serum-starved cells were pretreated with or without H2O2 (100 μM) and NAC (5 mM) for 30 min, and then treated with or without HGF (10 ng/ml). After incubation for 24 h, uPA secreted in culture media was measured by Western blot analysis with a uPA antibody. Representative data from 3 independent experiments were shown.
Mentions: uPA gradually accumulated in both cell lines after treatment with HGF. Treatment with H2O2 resulted in an increase in the uPA protein level in both cell lines. When we treated cells with H2O2 and HGF, the uPA protein level was decreased. To investigate the effect of N-acetylcysteine (NAC), a precursor of glutathione and an intracellular free radical scavenger, on HGF-induced uPA production, we treated both cell lines with NAC. NAC decreased the HGF-induced uPA production (Figure 8).

Bottom Line: We confirmed that Rac-1 regulated ROS production after activation of the AKT pathway with HGF.Exogenously added H2O2 promoted the expression of HGF, but not in a dose-dependent manner and also showed negative expression of HGF after co-treatment with H2O2 and HGF.We clarified the downstream pathways regulated by ROS after treatment with H2O2, which showed negative control between FRK and p38 kinase activities for uPA regulation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, Daegu, Korea. lkhee@med.yu.ac.kr

ABSTRACT

Background: Reactive oxygen species (ROS) are closely associated with the intracellular signal cascade, thus strongly implicating involvement in tumor progression. However, the mechanism by which ROS are generated and how ROS target downstream molecules to trigger tumor metastasis is unclear. In this study, we investigated the underlying signal pathways in ROS-induced urokinase plasminogen activator (uPA) expression in the human gastric cancer cells, NUGC-3 and MKN-28.

Methods and results: Intracellular ROS, as determined using the fluorescent probe, 2'-7' dichlorofluorescein diacetate, decreased after treatment with hepatocyte growth factor (HGF). We confirmed that Rac-1 regulated ROS production after activation of the AKT pathway with HGF. Exogenously added H2O2 promoted the expression of HGF, but not in a dose-dependent manner and also showed negative expression of HGF after co-treatment with H2O2 and HGF. Treatment with NAC, an intracellular free radical scavenger, decreased the enhancement of uPA production and tumor invasion in both cells. We clarified the downstream pathways regulated by ROS after treatment with H2O2, which showed negative control between FRK and p38 kinase activities for uPA regulation.

Conclusion: HGF regulates Rac-1-induced ROS production through the Akt pathway and ROS regulates uPA production and invasion via MAP kinase, which provides novel insight into the mechanisms underlying the progression of gastric cancer.

Show MeSH
Related in: MedlinePlus