Limits...
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.

Show MeSH

Related in: MedlinePlus

Effects of NAC on in vitro invasiveness. Cells in RPMI 1640 media supplemented with 5% FBS were placed in the upper chamber of Matrigel chamber and treated with or without NAC. The bottom chamber was filled with media containing 5% FBS and HGF with or without NAC. After 48 h of incubation, the cells which migrated through the filter were counted under light microscopy (10 fields at 200× power). Values are the means ± SD of triplicates of three independent experiments. Statistical significance was estimated by Student's t-test (*, P < 0.05; **, p < 0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2698863&req=5

Figure 9: Effects of NAC on in vitro invasiveness. Cells in RPMI 1640 media supplemented with 5% FBS were placed in the upper chamber of Matrigel chamber and treated with or without NAC. The bottom chamber was filled with media containing 5% FBS and HGF with or without NAC. After 48 h of incubation, the cells which migrated through the filter were counted under light microscopy (10 fields at 200× power). Values are the means ± SD of triplicates of three independent experiments. Statistical significance was estimated by Student's t-test (*, P < 0.05; **, p < 0.01).

Mentions: To examine the effects of HGF/c-Met-mediated uPA induction on the invasive properties of tumor cell phenotypes, we performed an in vitro invasion assay using a matrigal migration chamber. The invasiveness of HGF-treated cells was 2.7-fold higher in NUGC-3 cells, and 1.8-fold higher in the MKN-28 cells than in the untreated cells. We hypothesized that HGF-mediated uPA upregulation is responsible for the invasive properties of tumor cell phenotypes, and consequently blocking uPA activity could be a potential target in inhibiting tumor cell invasion. To test this hypothesis, we studied the effects of NAC on tumor cell invasiveness, and showed that invasiveness of NAC- treated cells was 50% lower in NUGC-3 cells and 90% lower in the MKN-28 cells than in the untreated cells. When we co-treated with exogenous HGF and NAC, cell invasion was also decreased. The fact that the invasive properties of these cells can be inhibited by NAC suggests that the regulation of ROS may be useful for a therapeutic target to halt metastasis in stomach cancers (Figure 9).


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 NAC on in vitro invasiveness. Cells in RPMI 1640 media supplemented with 5% FBS were placed in the upper chamber of Matrigel chamber and treated with or without NAC. The bottom chamber was filled with media containing 5% FBS and HGF with or without NAC. After 48 h of incubation, the cells which migrated through the filter were counted under light microscopy (10 fields at 200× power). Values are the means ± SD of triplicates of three independent experiments. Statistical significance was estimated by Student's t-test (*, P < 0.05; **, p < 0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 9: Effects of NAC on in vitro invasiveness. Cells in RPMI 1640 media supplemented with 5% FBS were placed in the upper chamber of Matrigel chamber and treated with or without NAC. The bottom chamber was filled with media containing 5% FBS and HGF with or without NAC. After 48 h of incubation, the cells which migrated through the filter were counted under light microscopy (10 fields at 200× power). Values are the means ± SD of triplicates of three independent experiments. Statistical significance was estimated by Student's t-test (*, P < 0.05; **, p < 0.01).
Mentions: To examine the effects of HGF/c-Met-mediated uPA induction on the invasive properties of tumor cell phenotypes, we performed an in vitro invasion assay using a matrigal migration chamber. The invasiveness of HGF-treated cells was 2.7-fold higher in NUGC-3 cells, and 1.8-fold higher in the MKN-28 cells than in the untreated cells. We hypothesized that HGF-mediated uPA upregulation is responsible for the invasive properties of tumor cell phenotypes, and consequently blocking uPA activity could be a potential target in inhibiting tumor cell invasion. To test this hypothesis, we studied the effects of NAC on tumor cell invasiveness, and showed that invasiveness of NAC- treated cells was 50% lower in NUGC-3 cells and 90% lower in the MKN-28 cells than in the untreated cells. When we co-treated with exogenous HGF and NAC, cell invasion was also decreased. The fact that the invasive properties of these cells can be inhibited by NAC suggests that the regulation of ROS may be useful for a therapeutic target to halt metastasis in stomach cancers (Figure 9).

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