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The influence of monoacylglycerol lipase inhibition upon the expression of epidermal growth factor receptor in human PC-3 prostate cancer cells.

Cipriano M, Gouveia-Figueira S, Persson E, Nording M, Fowler CJ - BMC Res Notes (2014)

Bottom Line: CB1 receptor expression levels were found to differ greatly between two experimental series conducted using PC-3 cells.In the first series of experiments, JZL184 produced a small mitogenic effect for cells that had not been treated with EGF, whereas an anti-proliferative effect was seen for EGF-treated cells.An anti-proliferative effect for the EGF-treated cells was also seen with the CB receptor agonist CP55,940.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden. cf@pharm.umu.se.

ABSTRACT

Background: It has been reported that direct activation of the cannabinoid CB1 receptor in epidermal growth factor (EGR)-stimulated PC-3 prostate cancer cells results in an anti-proliferative effect accompanied by a down-regulation of EGF receptors (EGFR). In the present study, we investigated whether similar effects are seen following inhibition of the endocannabinoid hydrolytic enzyme monoacylglycerol lipase (MGL).

Results: CB1 receptor expression levels were found to differ greatly between two experimental series conducted using PC-3 cells. The monoacylglycerol lipase inhibitor JZL184 increased levels of 2-arachidonoylglycerol in the PC-3 cells without producing changes in the levels of anandamide and related N-acylethanolamines. In the first series of experiments, JZL184 produced a small mitogenic effect for cells that had not been treated with EGF, whereas an anti-proliferative effect was seen for EGF-treated cells. An anti-proliferative effect for the EGF-treated cells was also seen with the CB receptor agonist CP55,940. In the second batch of cells, there was an interaction between JZL184 and CB1 receptor expression densities in linear regression analyses with EGFR expression as the dependent variable.

Conclusions: Inhibition of MGL by JZL184 can affect EGFR expression. However, the use in our hands of PC-3 cells as a model to investigate the therapeutic potential of MGL inhibitors and related compounds is compromised by their variability of CB1 receptor expression.

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Related in: MedlinePlus

CB1 receptor expression in PC-3 cells: effect of EGF. Cells were incubated for 3 weeks in the absence or presence of EGF (10 ng/ml). The x-axis shows the CB1 receptor expression, normalised to β-actin for the individual samples, colour coded on the basis of their experimental series. The y-axis shows the CB1 receptor expression, normalised to β-actin, in the presence of EGF as a ratio of the expression from another well in the same culture plate cultured in the absence of EGF. The dotted line is at a value of unity, i.e. no stimulation of CB1 receptor expression by EGF. The Spearman rho values are shown in the Panel.
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Figure 1: CB1 receptor expression in PC-3 cells: effect of EGF. Cells were incubated for 3 weeks in the absence or presence of EGF (10 ng/ml). The x-axis shows the CB1 receptor expression, normalised to β-actin for the individual samples, colour coded on the basis of their experimental series. The y-axis shows the CB1 receptor expression, normalised to β-actin, in the presence of EGF as a ratio of the expression from another well in the same culture plate cultured in the absence of EGF. The dotted line is at a value of unity, i.e. no stimulation of CB1 receptor expression by EGF. The Spearman rho values are shown in the Panel.

Mentions: Two series of experiments were undertaken using PC-3 cells. The cells were cultured for a total of three weeks without medium change in the absence or presence of EGF (10 ng/ml) (for details, see Methods section). In the first series, a robust expression of CB1 receptors was seen. However, in the second series of experiments conducted about half a year later with a new batch of cells but using the same methodology, the levels were very much lower (Figure 1). The cells also behaved differently in their responsiveness to long-term treatment with EGF. For the first experimental series, the EGF treatment increased the observed CB1 receptor expression by ~5 fold (median value), whereas no such increase was seen for the second series (Figure 1).


The influence of monoacylglycerol lipase inhibition upon the expression of epidermal growth factor receptor in human PC-3 prostate cancer cells.

Cipriano M, Gouveia-Figueira S, Persson E, Nording M, Fowler CJ - BMC Res Notes (2014)

CB1 receptor expression in PC-3 cells: effect of EGF. Cells were incubated for 3 weeks in the absence or presence of EGF (10 ng/ml). The x-axis shows the CB1 receptor expression, normalised to β-actin for the individual samples, colour coded on the basis of their experimental series. The y-axis shows the CB1 receptor expression, normalised to β-actin, in the presence of EGF as a ratio of the expression from another well in the same culture plate cultured in the absence of EGF. The dotted line is at a value of unity, i.e. no stimulation of CB1 receptor expression by EGF. The Spearman rho values are shown in the Panel.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4109781&req=5

Figure 1: CB1 receptor expression in PC-3 cells: effect of EGF. Cells were incubated for 3 weeks in the absence or presence of EGF (10 ng/ml). The x-axis shows the CB1 receptor expression, normalised to β-actin for the individual samples, colour coded on the basis of their experimental series. The y-axis shows the CB1 receptor expression, normalised to β-actin, in the presence of EGF as a ratio of the expression from another well in the same culture plate cultured in the absence of EGF. The dotted line is at a value of unity, i.e. no stimulation of CB1 receptor expression by EGF. The Spearman rho values are shown in the Panel.
Mentions: Two series of experiments were undertaken using PC-3 cells. The cells were cultured for a total of three weeks without medium change in the absence or presence of EGF (10 ng/ml) (for details, see Methods section). In the first series, a robust expression of CB1 receptors was seen. However, in the second series of experiments conducted about half a year later with a new batch of cells but using the same methodology, the levels were very much lower (Figure 1). The cells also behaved differently in their responsiveness to long-term treatment with EGF. For the first experimental series, the EGF treatment increased the observed CB1 receptor expression by ~5 fold (median value), whereas no such increase was seen for the second series (Figure 1).

Bottom Line: CB1 receptor expression levels were found to differ greatly between two experimental series conducted using PC-3 cells.In the first series of experiments, JZL184 produced a small mitogenic effect for cells that had not been treated with EGF, whereas an anti-proliferative effect was seen for EGF-treated cells.An anti-proliferative effect for the EGF-treated cells was also seen with the CB receptor agonist CP55,940.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden. cf@pharm.umu.se.

ABSTRACT

Background: It has been reported that direct activation of the cannabinoid CB1 receptor in epidermal growth factor (EGR)-stimulated PC-3 prostate cancer cells results in an anti-proliferative effect accompanied by a down-regulation of EGF receptors (EGFR). In the present study, we investigated whether similar effects are seen following inhibition of the endocannabinoid hydrolytic enzyme monoacylglycerol lipase (MGL).

Results: CB1 receptor expression levels were found to differ greatly between two experimental series conducted using PC-3 cells. The monoacylglycerol lipase inhibitor JZL184 increased levels of 2-arachidonoylglycerol in the PC-3 cells without producing changes in the levels of anandamide and related N-acylethanolamines. In the first series of experiments, JZL184 produced a small mitogenic effect for cells that had not been treated with EGF, whereas an anti-proliferative effect was seen for EGF-treated cells. An anti-proliferative effect for the EGF-treated cells was also seen with the CB receptor agonist CP55,940. In the second batch of cells, there was an interaction between JZL184 and CB1 receptor expression densities in linear regression analyses with EGFR expression as the dependent variable.

Conclusions: Inhibition of MGL by JZL184 can affect EGFR expression. However, the use in our hands of PC-3 cells as a model to investigate the therapeutic potential of MGL inhibitors and related compounds is compromised by their variability of CB1 receptor expression.

Show MeSH
Related in: MedlinePlus