Limits...
Glucocorticoids suppress renal cell carcinoma progression by enhancing Na,K-ATPase beta-1 subunit expression.

Huynh TP, Barwe SP, Lee SJ, McSpadden R, Franco OE, Hayward SW, Damoiseaux R, Grubbs SS, Petrelli NJ, Rajasekaran AK - PLoS ONE (2015)

Bottom Line: Na,K-ATPase beta-subunit isoform 1 (NaK-β1) is a cell-cell adhesion molecule, and its expression is down-regulated in cancer cells undergoing epithelial-to mesenchymal-transition (EMT), a key event associated with cancer progression to metastatic disease.Treatment of NaK-β1 knockdown cells with these drug candidates confirmed that these compounds mediate their effects through up-regulating NaK-β1.Our results strongly indicate that the addition of glucocorticoids in the treatment of RCC may improve outcome for RCC patients by augmenting NaK-β1 cell-cell adhesion function.

View Article: PubMed Central - PubMed

Affiliation: Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, United States of America; Nemours Center for Childhood Cancer Research, A. I. DuPont Hospital for Children, Wilmington, Delaware, United States of America.

ABSTRACT
Glucocorticoids are commonly used as palliative or chemotherapeutic clinical agents for treatment of a variety of cancers. Although steroid treatment is beneficial, the mechanisms by which steroids improve outcome in cancer patients are not well understood. Na,K-ATPase beta-subunit isoform 1 (NaK-β1) is a cell-cell adhesion molecule, and its expression is down-regulated in cancer cells undergoing epithelial-to mesenchymal-transition (EMT), a key event associated with cancer progression to metastatic disease. In this study, we performed high-throughput screening to identify small molecules that could up-regulate NaK-β1 expression in cancer cells. Compounds related to the glucocorticoids were identified as drug candidates enhancing NaK-β1 expression. Of these compounds, triamcinolone, dexamethasone, and fluorometholone were validated to increase NaK-β1 expression at the cell surface, enhance cell-cell adhesion, attenuate motility and invasiveness and induce mesenchymal to epithelial like transition of renal cell carcinoma (RCC) cells in vitro. Treatment of NaK-β1 knockdown cells with these drug candidates confirmed that these compounds mediate their effects through up-regulating NaK-β1. Furthermore, we demonstrated that these compounds attenuate tumor growth in subcutaneous RCC xenografts and reduce local invasiveness in orthotopically-implanted tumors. Our results strongly indicate that the addition of glucocorticoids in the treatment of RCC may improve outcome for RCC patients by augmenting NaK-β1 cell-cell adhesion function.

No MeSH data available.


Related in: MedlinePlus

GCs promoted mesenchymal-to-epithelial transition of kidney cancer cells.Representative images of Caki-1 cells treated with GCs. Serum starved cells were treated with 10 μM GCs for three days and then immunostained. Staining of N-Cadherin (green) is shown with DAPI (red). F-Actin was stained with Alexa 488-conjugated phalloidin along with DAPI. Magnified images of the regions marked by white boxes are shown at the bottom. Scale bars represent 20 μm.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4383530&req=5

pone.0122442.g008: GCs promoted mesenchymal-to-epithelial transition of kidney cancer cells.Representative images of Caki-1 cells treated with GCs. Serum starved cells were treated with 10 μM GCs for three days and then immunostained. Staining of N-Cadherin (green) is shown with DAPI (red). F-Actin was stained with Alexa 488-conjugated phalloidin along with DAPI. Magnified images of the regions marked by white boxes are shown at the bottom. Scale bars represent 20 μm.

Mentions: We have shown earlier that NaK-β1 expression is reduced during TGF-β induced EMT [18]. Carcinoma cell lines which have lost their epithelial phenotype also revealed reduced levels of NaK-β1 [9]. In addition, knockdown of NaK-β1 in Caki-1 cells induced mesenchymal phenotype which was accompanied by enhanced expression of fibronectin and smooth muscle actin which are markers upregulated during EMT [18]. Since NaK-β1 levels are inversely correlated with the acquisition of EMT, we reasoned that upregulated NaK-β1 expression by GCs might suppress the EMT phenotype. Consistent with this notion, GC treated cells showed enhanced cell to cell contact and revealed a more compact epithelial phenotype (Fig 8). Immunofluorescence analysis of N-cadherin, a mesenchymal marker which is upregulated during EMT was reduced by GC treatment. Invasive carcinoma cells show extensive stress fibers which is essential for their invasiveness and motility. GC treated Caki-1 cells showed drastically reduced stress fibers and increased cortical actin networks (Fig 8). These results suggest that GCs induce MET like phenotype in RCC cells.


Glucocorticoids suppress renal cell carcinoma progression by enhancing Na,K-ATPase beta-1 subunit expression.

Huynh TP, Barwe SP, Lee SJ, McSpadden R, Franco OE, Hayward SW, Damoiseaux R, Grubbs SS, Petrelli NJ, Rajasekaran AK - PLoS ONE (2015)

GCs promoted mesenchymal-to-epithelial transition of kidney cancer cells.Representative images of Caki-1 cells treated with GCs. Serum starved cells were treated with 10 μM GCs for three days and then immunostained. Staining of N-Cadherin (green) is shown with DAPI (red). F-Actin was stained with Alexa 488-conjugated phalloidin along with DAPI. Magnified images of the regions marked by white boxes are shown at the bottom. Scale bars represent 20 μm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4383530&req=5

pone.0122442.g008: GCs promoted mesenchymal-to-epithelial transition of kidney cancer cells.Representative images of Caki-1 cells treated with GCs. Serum starved cells were treated with 10 μM GCs for three days and then immunostained. Staining of N-Cadherin (green) is shown with DAPI (red). F-Actin was stained with Alexa 488-conjugated phalloidin along with DAPI. Magnified images of the regions marked by white boxes are shown at the bottom. Scale bars represent 20 μm.
Mentions: We have shown earlier that NaK-β1 expression is reduced during TGF-β induced EMT [18]. Carcinoma cell lines which have lost their epithelial phenotype also revealed reduced levels of NaK-β1 [9]. In addition, knockdown of NaK-β1 in Caki-1 cells induced mesenchymal phenotype which was accompanied by enhanced expression of fibronectin and smooth muscle actin which are markers upregulated during EMT [18]. Since NaK-β1 levels are inversely correlated with the acquisition of EMT, we reasoned that upregulated NaK-β1 expression by GCs might suppress the EMT phenotype. Consistent with this notion, GC treated cells showed enhanced cell to cell contact and revealed a more compact epithelial phenotype (Fig 8). Immunofluorescence analysis of N-cadherin, a mesenchymal marker which is upregulated during EMT was reduced by GC treatment. Invasive carcinoma cells show extensive stress fibers which is essential for their invasiveness and motility. GC treated Caki-1 cells showed drastically reduced stress fibers and increased cortical actin networks (Fig 8). These results suggest that GCs induce MET like phenotype in RCC cells.

Bottom Line: Na,K-ATPase beta-subunit isoform 1 (NaK-β1) is a cell-cell adhesion molecule, and its expression is down-regulated in cancer cells undergoing epithelial-to mesenchymal-transition (EMT), a key event associated with cancer progression to metastatic disease.Treatment of NaK-β1 knockdown cells with these drug candidates confirmed that these compounds mediate their effects through up-regulating NaK-β1.Our results strongly indicate that the addition of glucocorticoids in the treatment of RCC may improve outcome for RCC patients by augmenting NaK-β1 cell-cell adhesion function.

View Article: PubMed Central - PubMed

Affiliation: Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, United States of America; Nemours Center for Childhood Cancer Research, A. I. DuPont Hospital for Children, Wilmington, Delaware, United States of America.

ABSTRACT
Glucocorticoids are commonly used as palliative or chemotherapeutic clinical agents for treatment of a variety of cancers. Although steroid treatment is beneficial, the mechanisms by which steroids improve outcome in cancer patients are not well understood. Na,K-ATPase beta-subunit isoform 1 (NaK-β1) is a cell-cell adhesion molecule, and its expression is down-regulated in cancer cells undergoing epithelial-to mesenchymal-transition (EMT), a key event associated with cancer progression to metastatic disease. In this study, we performed high-throughput screening to identify small molecules that could up-regulate NaK-β1 expression in cancer cells. Compounds related to the glucocorticoids were identified as drug candidates enhancing NaK-β1 expression. Of these compounds, triamcinolone, dexamethasone, and fluorometholone were validated to increase NaK-β1 expression at the cell surface, enhance cell-cell adhesion, attenuate motility and invasiveness and induce mesenchymal to epithelial like transition of renal cell carcinoma (RCC) cells in vitro. Treatment of NaK-β1 knockdown cells with these drug candidates confirmed that these compounds mediate their effects through up-regulating NaK-β1. Furthermore, we demonstrated that these compounds attenuate tumor growth in subcutaneous RCC xenografts and reduce local invasiveness in orthotopically-implanted tumors. Our results strongly indicate that the addition of glucocorticoids in the treatment of RCC may improve outcome for RCC patients by augmenting NaK-β1 cell-cell adhesion function.

No MeSH data available.


Related in: MedlinePlus