Ray bars) or pchMR-transfected (white bars) HCT116 cells were transfected with pMMTV-Luc to express firefly luciferase from an MR dependent promoter. Cell culture, aldosterone or spironolactone treatment and normoxia or hypoxia conditions are detailed in Materials and Methods section. Values of firefly luciferase activity of aldosterone-stimulated pchMR-transfected cells in 10 stripped FCS or 0.1 FCS, both in normoxic or hypoxic conditions, were compared to those of unstimulated pchMR-transfected LED 209 control cells, set as 1. Values of firefly luciferase activity of pchMR-transfected cells in 10 FCS were compared to that of pcDNA3-transfected control cells, set as 1. Results were expressed as Mean6 SEM (n = 4?). **p,0.005 and ***p,0.001, vs control cells, #p,0.001 vs FCS- or aldosterone-treated cells, ANOVA followed by Bonferroni t-test or Student t-test when appropriate. (C) MR subcellular localization. PchMR-transfected HCT116 cells treated with aldosterone (3 nM) and/or spironolactone (1 mM) for 30 minutes and stained with an anti-MR antibody (green) and DAPI (blue). Images were taken with a confocal laser scanning microscope. doi:10.1371/journal.pone.0059410.gconditions. These data provide a direct demonstration of a suppressive role of MR in tumor angiogenesis driven by the malignant epithelium. It is noteworthy that our findings in colon cells are consistent with the results of a recent study in a transgenic mouse model showing that long-term in vivo MR overexpression,in the presence of physiological amount of aldosterone, specifically downregulated VEGFA gene expression in the heart [33]. Little is known about the regulation of angiogenic growth factors in tissue under normoxic conditions. I-BRD9 
However it is well accepted that physiological stimuli, other than hypoxia, includingMR Activity Attenuates VEGF/KDR Pathways in CRCFigure 4. MR activation specifically decreases VEGFA mRNA expression levels in HCT116 cells. Effects of aldosterone on VEGFA (A), bFGF (B), PGF2 (C) and EGF (D) mRNA 
levels in pchMR-transfected HCT116 cells under normoxic culture conditions. Cells were treated with 3 nM aldosterone in 10 stripped FCS in the absence or in the presence of 1 mM spironolactone and the analysis of mRNA levels were performed by Realtime PCR. For each panel, mRNA expression values of treated pchMR-transfected cells were compared to those of unstimulated pchMR-transfected control cells, set as 1. Results are expressed as Mean6SEM (n = 3). 1662274 *p,0.05 vs pchMR-transfected control cells, ANOVA followed by Bonferroni t-test. doi:10.1371/journal.pone.0059410.ggrowth factor activated signaling pathways, can also induce HIF1a activation and the consequent transcription of hypoxiainducible genes under non hypoxic conditions. [34] In addition many genetic alterations present in cancer cells can directly increase HIF-1a expression, leading to the activation of VEGFA gene expression, independently from intratumoral hypoxia. [14,35] These data provide the molecular mechanisms linking specific genetic alterations present in cancer cells with increased tumor vascularization. Based on these literature data and on our results from the analysis of VEGFA mRNA expression in MRtransfected colon cancer cells grown under normoxic conditionsupon activation by the relative agonists, we suggest that MR may inhibit deregulated angiogenesis in CRC. However, here we suggest that activated MR also dampens hypoxia-regulated angiogenesis, which is crucial for tumor cells to.Ray bars) or pchMR-transfected (white bars) HCT116 cells were transfected with pMMTV-Luc to express firefly luciferase from an MR dependent promoter. Cell culture, aldosterone or spironolactone treatment and normoxia or hypoxia conditions are detailed in Materials and Methods section. Values of firefly luciferase activity of aldosterone-stimulated pchMR-transfected cells in 10 stripped FCS or 0.1 FCS, both in normoxic or hypoxic conditions, were compared to those of unstimulated pchMR-transfected control cells, set as 1. Values of firefly luciferase activity of pchMR-transfected cells in 10 FCS were compared to that of pcDNA3-transfected control cells, set as 1. Results were expressed as Mean6 SEM (n = 4?). **p,0.005 and ***p,0.001, vs control cells, #p,0.001 vs FCS- or aldosterone-treated cells, ANOVA followed by Bonferroni t-test or Student t-test when appropriate. (C) MR subcellular localization. PchMR-transfected HCT116 cells treated with aldosterone (3 nM) and/or spironolactone (1 mM) for 30 minutes and stained with an anti-MR antibody (green) and DAPI (blue). Images were taken with a confocal laser scanning microscope. doi:10.1371/journal.pone.0059410.gconditions. These data provide a direct demonstration of a suppressive role of MR in tumor angiogenesis driven by the malignant epithelium. It is noteworthy that our findings in colon cells are consistent with the results of a recent study in a transgenic mouse model showing that long-term in vivo MR overexpression,in the presence of physiological amount of aldosterone, specifically downregulated VEGFA gene expression in the heart [33]. Little is known about the regulation of angiogenic growth factors in tissue under normoxic conditions. However it is well accepted that physiological stimuli, other than hypoxia, includingMR Activity Attenuates VEGF/KDR Pathways in CRCFigure 4. MR activation specifically decreases VEGFA mRNA expression levels in HCT116 cells. Effects of aldosterone on VEGFA (A), bFGF (B), PGF2 (C) and EGF (D) mRNA levels in pchMR-transfected HCT116 cells under normoxic culture conditions. Cells were treated with 3 nM aldosterone in 10 stripped FCS in the absence or in the presence of 1 mM spironolactone and the analysis of mRNA levels were performed by Realtime PCR. For each panel, mRNA expression values of treated pchMR-transfected cells were compared to those of unstimulated pchMR-transfected control cells, set as 1. Results are expressed as Mean6SEM (n = 3). 1662274 *p,0.05 vs pchMR-transfected control cells, ANOVA followed by Bonferroni t-test. doi:10.1371/journal.pone.0059410.ggrowth factor activated signaling pathways, can also induce HIF1a activation and the consequent transcription of hypoxiainducible genes under non hypoxic conditions. [34] In addition many genetic alterations present in cancer cells can directly increase HIF-1a expression, leading to the activation of VEGFA gene expression, independently from intratumoral hypoxia. [14,35] These data provide the molecular mechanisms linking specific genetic alterations present in cancer cells with increased tumor vascularization. Based on these literature data and on our results from the analysis of VEGFA mRNA expression in MRtransfected colon cancer cells grown under normoxic conditionsupon activation by the relative agonists, we suggest that MR may inhibit deregulated angiogenesis in CRC. However, here we suggest that activated MR also dampens hypoxia-regulated angiogenesis, which is crucial for tumor cells to.