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TRAIL-R2 promotes skeletal metastasis in a breast cancer xenograft mouse model.

Fritsche H, Heilmann T, Tower RJ, Hauser C, von Au A, El-Sheikh D, Campbell GM, Alp G, Schewe D, Hübner S, Tiwari S, Kownatzki D, Boretius S, Adam D, Jonat W, Becker T, Glüer CC, Zöller M, Kalthoff H, Schem C, Trauzold A - Oncotarget (2015)

Bottom Line: Strikingly, in addition to the reduced levels of the proliferation-promoting factor HMGA2 and corresponding inhibition of cell proliferation, knockdown of TRAIL-R2 increased the levels of E-Cadherin and decreased migration.In accordance, cell migration towards SDF-1 was significantly impaired by TRAIL-R2 knockdown.Conversely, overexpression of TRAIL-R2 upregulated CXCR4 levels and enhanced SDF-1-directed migration.

View Article: PubMed Central - PubMed

Affiliation: Division of Molecular Oncology, Institute for Experimental Cancer Research, CCC-North, University of Kiel, Kiel, Germany.

ABSTRACT
Despite improvements in detection, surgical approaches and systemic therapies, breast cancer remains typically incurable once distant metastases occur. High expression of TRAIL-R2 was found to be associated with poor prognostic parameters in breast cancer patients, suggesting an oncogenic function of this receptor. In the present study, we aimed to determine the impact of TRAIL-R2 on breast cancer metastasis. Using an osteotropic variant of MDA-MB-231 breast cancer cells, we examine the effects of TRAIL-R2 knockdown in vitro and in vivo. Strikingly, in addition to the reduced levels of the proliferation-promoting factor HMGA2 and corresponding inhibition of cell proliferation, knockdown of TRAIL-R2 increased the levels of E-Cadherin and decreased migration. In vivo, these cells were strongly impaired in their ability to form bone metastases after intracardiac injection. Evaluating possible underlying mechanisms revealed a strong downregulation of CXCR4, the receptor for the chemokine SDF-1 important for homing of cancers cells to the bone. In accordance, cell migration towards SDF-1 was significantly impaired by TRAIL-R2 knockdown. Conversely, overexpression of TRAIL-R2 upregulated CXCR4 levels and enhanced SDF-1-directed migration. We therefore postulate that inhibition of TRAIL-R2 expression could represent a promising therapeutic strategy leading to an effective impairment of breast cancer cell capability to form skeletal metastases.

No MeSH data available.


Related in: MedlinePlus

Overexpression of TRAIL-R2 in MDA-MB-231 cells upregulates the expression of CXCR4 and enhances migration towards SDF-1Expression of TRAIL-R2, CXCR4 and EGFR in control cells (pCR3.1) and cells overexpressing the long (R2-long) or short (R2-short) isoforms was assessed by flow cytometry in non-permeabilized and permeabilized cells and percent of stained cells (A) and staining intensities per cell (B), relative to non-specific antibody controls, were quantified. (C) Cells were analyzed in regard to their migration capacity towards SDF-1 in a trans-well assay. Graphs represent average values ± SD. (A–B: n = 3, C: n = 4) (*p < 0.05, **p < 0.01 ***p < 0.001).
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Figure 7: Overexpression of TRAIL-R2 in MDA-MB-231 cells upregulates the expression of CXCR4 and enhances migration towards SDF-1Expression of TRAIL-R2, CXCR4 and EGFR in control cells (pCR3.1) and cells overexpressing the long (R2-long) or short (R2-short) isoforms was assessed by flow cytometry in non-permeabilized and permeabilized cells and percent of stained cells (A) and staining intensities per cell (B), relative to non-specific antibody controls, were quantified. (C) Cells were analyzed in regard to their migration capacity towards SDF-1 in a trans-well assay. Graphs represent average values ± SD. (A–B: n = 3, C: n = 4) (*p < 0.05, **p < 0.01 ***p < 0.001).

Mentions: Importantly, while EGFR remained unchanged, overexpression of either TRAIL-R2-short or TRAIL-R2-long isoform in parental MDA-MB-231 cells strongly and specifically enhanced the plasma membrane and overall expression levels of CXCR4 as shown by FACS analyses (Figure 7A and 7B, Supplementary Table 2). In accordance, overexpression of either isoform resulted in strongly enhanced migration towards SDF-1 (Figure 7C).


TRAIL-R2 promotes skeletal metastasis in a breast cancer xenograft mouse model.

Fritsche H, Heilmann T, Tower RJ, Hauser C, von Au A, El-Sheikh D, Campbell GM, Alp G, Schewe D, Hübner S, Tiwari S, Kownatzki D, Boretius S, Adam D, Jonat W, Becker T, Glüer CC, Zöller M, Kalthoff H, Schem C, Trauzold A - Oncotarget (2015)

Overexpression of TRAIL-R2 in MDA-MB-231 cells upregulates the expression of CXCR4 and enhances migration towards SDF-1Expression of TRAIL-R2, CXCR4 and EGFR in control cells (pCR3.1) and cells overexpressing the long (R2-long) or short (R2-short) isoforms was assessed by flow cytometry in non-permeabilized and permeabilized cells and percent of stained cells (A) and staining intensities per cell (B), relative to non-specific antibody controls, were quantified. (C) Cells were analyzed in regard to their migration capacity towards SDF-1 in a trans-well assay. Graphs represent average values ± SD. (A–B: n = 3, C: n = 4) (*p < 0.05, **p < 0.01 ***p < 0.001).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4496234&req=5

Figure 7: Overexpression of TRAIL-R2 in MDA-MB-231 cells upregulates the expression of CXCR4 and enhances migration towards SDF-1Expression of TRAIL-R2, CXCR4 and EGFR in control cells (pCR3.1) and cells overexpressing the long (R2-long) or short (R2-short) isoforms was assessed by flow cytometry in non-permeabilized and permeabilized cells and percent of stained cells (A) and staining intensities per cell (B), relative to non-specific antibody controls, were quantified. (C) Cells were analyzed in regard to their migration capacity towards SDF-1 in a trans-well assay. Graphs represent average values ± SD. (A–B: n = 3, C: n = 4) (*p < 0.05, **p < 0.01 ***p < 0.001).
Mentions: Importantly, while EGFR remained unchanged, overexpression of either TRAIL-R2-short or TRAIL-R2-long isoform in parental MDA-MB-231 cells strongly and specifically enhanced the plasma membrane and overall expression levels of CXCR4 as shown by FACS analyses (Figure 7A and 7B, Supplementary Table 2). In accordance, overexpression of either isoform resulted in strongly enhanced migration towards SDF-1 (Figure 7C).

Bottom Line: Strikingly, in addition to the reduced levels of the proliferation-promoting factor HMGA2 and corresponding inhibition of cell proliferation, knockdown of TRAIL-R2 increased the levels of E-Cadherin and decreased migration.In accordance, cell migration towards SDF-1 was significantly impaired by TRAIL-R2 knockdown.Conversely, overexpression of TRAIL-R2 upregulated CXCR4 levels and enhanced SDF-1-directed migration.

View Article: PubMed Central - PubMed

Affiliation: Division of Molecular Oncology, Institute for Experimental Cancer Research, CCC-North, University of Kiel, Kiel, Germany.

ABSTRACT
Despite improvements in detection, surgical approaches and systemic therapies, breast cancer remains typically incurable once distant metastases occur. High expression of TRAIL-R2 was found to be associated with poor prognostic parameters in breast cancer patients, suggesting an oncogenic function of this receptor. In the present study, we aimed to determine the impact of TRAIL-R2 on breast cancer metastasis. Using an osteotropic variant of MDA-MB-231 breast cancer cells, we examine the effects of TRAIL-R2 knockdown in vitro and in vivo. Strikingly, in addition to the reduced levels of the proliferation-promoting factor HMGA2 and corresponding inhibition of cell proliferation, knockdown of TRAIL-R2 increased the levels of E-Cadherin and decreased migration. In vivo, these cells were strongly impaired in their ability to form bone metastases after intracardiac injection. Evaluating possible underlying mechanisms revealed a strong downregulation of CXCR4, the receptor for the chemokine SDF-1 important for homing of cancers cells to the bone. In accordance, cell migration towards SDF-1 was significantly impaired by TRAIL-R2 knockdown. Conversely, overexpression of TRAIL-R2 upregulated CXCR4 levels and enhanced SDF-1-directed migration. We therefore postulate that inhibition of TRAIL-R2 expression could represent a promising therapeutic strategy leading to an effective impairment of breast cancer cell capability to form skeletal metastases.

No MeSH data available.


Related in: MedlinePlus