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HIF1α deficiency reduces inflammation in a mouse model of proximal colon cancer.

Mladenova DN, Dahlstrom JE, Tran PN, Benthani F, Bean EG, Ng I, Pangon L, Currey N, Kohonen-Corish MR - Dis Model Mech (2015)

Bottom Line: Microscopically, Hif1α(ΔIEC) mice had significantly less severe colon inflammation than Hif1α(F/F) mice.Molecular analysis showed reduced MIF expression and increased E-cadherin mRNA expression in the colon of sulindac-treated Hif1α(ΔIEC) mice.Taken together, HIF1α expression augments inflammation in the proximal colon of sulindac-treated mice, and AHR activation by sulindac might lead to the reduction of E-cadherin protein levels through the mitogen-activated protein kinase (MAPK) pathway.

View Article: PubMed Central - PubMed

Affiliation: Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia.

No MeSH data available.


Related in: MedlinePlus

Treatment of HCT15 cells with sulindac sulfide causes an increase in the level of total and phosphorylated c-Jun and a decrease of E-cadherin, β-catenin and p120-catenin levels. Western blot was performed on protein extracts from HCT15 cells treated with 50 μM sulindac sulfide (SS) over a time-course. Specific antibodies were used to detect the protein level of p120-catenin, E-cadherin, β-catenin, total c-Jun (t-c-Jun) and phosphorylated c-Jun (p-c-Jun). The membranes were also probed with an antibody against β-actin as a loading control. The relative intensity of protein bands was quantified using ImageJ 1.48v software (National Institutes of Health). The protein expression levels were normalised to the loading control β-actin and relative to the no-sulindac-sulfide treatment (0 hr).
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DMM019000F7: Treatment of HCT15 cells with sulindac sulfide causes an increase in the level of total and phosphorylated c-Jun and a decrease of E-cadherin, β-catenin and p120-catenin levels. Western blot was performed on protein extracts from HCT15 cells treated with 50 μM sulindac sulfide (SS) over a time-course. Specific antibodies were used to detect the protein level of p120-catenin, E-cadherin, β-catenin, total c-Jun (t-c-Jun) and phosphorylated c-Jun (p-c-Jun). The membranes were also probed with an antibody against β-actin as a loading control. The relative intensity of protein bands was quantified using ImageJ 1.48v software (National Institutes of Health). The protein expression levels were normalised to the loading control β-actin and relative to the no-sulindac-sulfide treatment (0 hr).

Mentions: We have previously shown that the sulfide metabolite of sulindac can induce NF-κB and AP-1 (c-Jun and JunD) signalling in colon cancer cells, which lead to upregulation of the chemokine IL8 (Mladenova et al., 2011, 2013). This resembles the activation of the aryl hydrocarbon receptor (AHR) signalling pathway that regulates detoxification of many environmental contaminants and pharmacological drugs but that can also lead to activation of inflammatory cytokines (Fardel, 2013; Safe et al., 2013). Sulindac is a known ligand and activator of AHR (Ciolino et al., 2006). Therefore, we next tested whether sulindac can activate AHR-associated pathways in our in vitro model. HCT15 cells were treated with 50 µM sulindac sulfide for 1-24 h. Q-PCR analysis of gene expression showed that sulindac sulfide upregulated CYP1A1, the prototype phase I response target of AHR, as well as c-JUN, IL8 and Hif1α. The upregulation of all four genes was abolished with AHR knockdown (Fig. 6). This suggests that sulindac can activate AHR, leading to activation of c-Jun signalling, which is a known EMT-promoting transcription factor. AHR activation through dioxin, the well-known AHR ligand, has been previously shown to lead to loss of cell-cell adhesion in MCF7 breast epithelial cells (Diry et al., 2006). In our model, sulindac-sulfide-induced phosphorylation of c-Jun increased until 24 h, whereas there was a gradual decrease in E-cadherin, β-catenin and p120-catenin levels (Fig. 7).Fig. 6.


HIF1α deficiency reduces inflammation in a mouse model of proximal colon cancer.

Mladenova DN, Dahlstrom JE, Tran PN, Benthani F, Bean EG, Ng I, Pangon L, Currey N, Kohonen-Corish MR - Dis Model Mech (2015)

Treatment of HCT15 cells with sulindac sulfide causes an increase in the level of total and phosphorylated c-Jun and a decrease of E-cadherin, β-catenin and p120-catenin levels. Western blot was performed on protein extracts from HCT15 cells treated with 50 μM sulindac sulfide (SS) over a time-course. Specific antibodies were used to detect the protein level of p120-catenin, E-cadherin, β-catenin, total c-Jun (t-c-Jun) and phosphorylated c-Jun (p-c-Jun). The membranes were also probed with an antibody against β-actin as a loading control. The relative intensity of protein bands was quantified using ImageJ 1.48v software (National Institutes of Health). The protein expression levels were normalised to the loading control β-actin and relative to the no-sulindac-sulfide treatment (0 hr).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4582097&req=5

DMM019000F7: Treatment of HCT15 cells with sulindac sulfide causes an increase in the level of total and phosphorylated c-Jun and a decrease of E-cadherin, β-catenin and p120-catenin levels. Western blot was performed on protein extracts from HCT15 cells treated with 50 μM sulindac sulfide (SS) over a time-course. Specific antibodies were used to detect the protein level of p120-catenin, E-cadherin, β-catenin, total c-Jun (t-c-Jun) and phosphorylated c-Jun (p-c-Jun). The membranes were also probed with an antibody against β-actin as a loading control. The relative intensity of protein bands was quantified using ImageJ 1.48v software (National Institutes of Health). The protein expression levels were normalised to the loading control β-actin and relative to the no-sulindac-sulfide treatment (0 hr).
Mentions: We have previously shown that the sulfide metabolite of sulindac can induce NF-κB and AP-1 (c-Jun and JunD) signalling in colon cancer cells, which lead to upregulation of the chemokine IL8 (Mladenova et al., 2011, 2013). This resembles the activation of the aryl hydrocarbon receptor (AHR) signalling pathway that regulates detoxification of many environmental contaminants and pharmacological drugs but that can also lead to activation of inflammatory cytokines (Fardel, 2013; Safe et al., 2013). Sulindac is a known ligand and activator of AHR (Ciolino et al., 2006). Therefore, we next tested whether sulindac can activate AHR-associated pathways in our in vitro model. HCT15 cells were treated with 50 µM sulindac sulfide for 1-24 h. Q-PCR analysis of gene expression showed that sulindac sulfide upregulated CYP1A1, the prototype phase I response target of AHR, as well as c-JUN, IL8 and Hif1α. The upregulation of all four genes was abolished with AHR knockdown (Fig. 6). This suggests that sulindac can activate AHR, leading to activation of c-Jun signalling, which is a known EMT-promoting transcription factor. AHR activation through dioxin, the well-known AHR ligand, has been previously shown to lead to loss of cell-cell adhesion in MCF7 breast epithelial cells (Diry et al., 2006). In our model, sulindac-sulfide-induced phosphorylation of c-Jun increased until 24 h, whereas there was a gradual decrease in E-cadherin, β-catenin and p120-catenin levels (Fig. 7).Fig. 6.

Bottom Line: Microscopically, Hif1α(ΔIEC) mice had significantly less severe colon inflammation than Hif1α(F/F) mice.Molecular analysis showed reduced MIF expression and increased E-cadherin mRNA expression in the colon of sulindac-treated Hif1α(ΔIEC) mice.Taken together, HIF1α expression augments inflammation in the proximal colon of sulindac-treated mice, and AHR activation by sulindac might lead to the reduction of E-cadherin protein levels through the mitogen-activated protein kinase (MAPK) pathway.

View Article: PubMed Central - PubMed

Affiliation: Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia.

No MeSH data available.


Related in: MedlinePlus