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Death receptor 6 (DR6) is required for mouse B16 tumor angiogenesis via the NF-κB, P38 MAPK and STAT3 pathways.

Yang X, Shi B, Li L, Xu Z, Ge Y, Shi J, Liu Y, Zheng D - Oncogenesis (2016)

Bottom Line: Although death receptor 6 (DR6) is aberrantly expressed in certain cancer cell lines, its function, signaling pathway and potential clinical significance in tumor progression are not well characterized.Deficiency of DR6 changes cytokine expression and secretion; in particular, it inhibits the proinflammatory cytokine interleukin-6 (IL-6), which is able to induce the expression of the angiogenesis-related factors: vascular endothelial growth factor-A, platelet-derived growth factor-β, vascular endothelial growth factor-D and platelet-derived growth factor receptor-α.Further experiments demonstrate that DR6-dependent angiogenesis is involved in the IL-6/P38 MAPK and IL-6/STAT3 pathways.

View Article: PubMed Central - PubMed

Affiliation: National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.

ABSTRACT
Although death receptor 6 (DR6) is aberrantly expressed in certain cancer cell lines, its function, signaling pathway and potential clinical significance in tumor progression are not well characterized. We report here that knocking down DR6 in the mouse B16 cell line has no effect on B16 cell death in vitro but suppresses xenograft B16 tumor growth by preventing tumor blood vessel formation in vivo. Deficiency of DR6 changes cytokine expression and secretion; in particular, it inhibits the proinflammatory cytokine interleukin-6 (IL-6), which is able to induce the expression of the angiogenesis-related factors: vascular endothelial growth factor-A, platelet-derived growth factor-β, vascular endothelial growth factor-D and platelet-derived growth factor receptor-α. Further experiments demonstrate that DR6-dependent angiogenesis is involved in the IL-6/P38 MAPK and IL-6/STAT3 pathways. Our novel findings demonstrate for the first time that DR6 expression in B16 cells facilitates tumor growth by accelerating tumor angiogenesis. Moreover, these results suggest that DR6 is involved in three important intracellular pathways that lead to homeostatic angiogenesis in tumor growth.

No MeSH data available.


Related in: MedlinePlus

DR6 is required for tumor angiogenesis. (a) Immune cells were isolated by Percoll centrifugation and analyzed by flow cytometry. Label X and Y represent FSC-A and SSC-A, respectively. Gate P1 represents lymphocytes and Gate P2 represents mononuclear cells. The gated cells were counted. (b) Immunohistochemistry assay. The sections of DR6-deficient (siDR6) B16 tumors and controls (siNC) were stained with hematoxylin and eosin. DR6-, CD31- and PDGFR-α-specific antibodies were used to visualize blood vessels and/or as a positive control. The scale bar represents 100 μm. (c) Quantification of the vascular vessels. The arrows indicate representative blood vessels. The blood vessels were counted in 6/15 randomly selected fields from three mouse tumor sections under a microscope (P=0.01).
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fig2: DR6 is required for tumor angiogenesis. (a) Immune cells were isolated by Percoll centrifugation and analyzed by flow cytometry. Label X and Y represent FSC-A and SSC-A, respectively. Gate P1 represents lymphocytes and Gate P2 represents mononuclear cells. The gated cells were counted. (b) Immunohistochemistry assay. The sections of DR6-deficient (siDR6) B16 tumors and controls (siNC) were stained with hematoxylin and eosin. DR6-, CD31- and PDGFR-α-specific antibodies were used to visualize blood vessels and/or as a positive control. The scale bar represents 100 μm. (c) Quantification of the vascular vessels. The arrows indicate representative blood vessels. The blood vessels were counted in 6/15 randomly selected fields from three mouse tumor sections under a microscope (P=0.01).

Mentions: To test whether DR6 deficiency affects the infiltration of microenvironmental cells into melanoma tissue, immune cells were isolated from mouse tumor tissues by Percoll gradient centrifugation and analyzed by flow cytometry. As shown in Figure 2a, two populations, consisting of lymphocytes (Gate P1) and mononuclear cells (Gate P2), were observed by flow cytometry assays. Cell counting revealed that there were 50% fewer lymphocytes and mononuclear cells in the DR6 knockdown (siDR6) tumors than in the control (siNC) tumors. This suggested that a decrease of DR6 expression can prevent two subsets of immune cells infiltration into the tumor microenvironment. CD3, CTLA-4 and DC antibodies marked cells were analyzed by flow cytometry, but it showed no significant difference between siDR6 and siNC tumors (Supplementary Figure S2).


Death receptor 6 (DR6) is required for mouse B16 tumor angiogenesis via the NF-κB, P38 MAPK and STAT3 pathways.

Yang X, Shi B, Li L, Xu Z, Ge Y, Shi J, Liu Y, Zheng D - Oncogenesis (2016)

DR6 is required for tumor angiogenesis. (a) Immune cells were isolated by Percoll centrifugation and analyzed by flow cytometry. Label X and Y represent FSC-A and SSC-A, respectively. Gate P1 represents lymphocytes and Gate P2 represents mononuclear cells. The gated cells were counted. (b) Immunohistochemistry assay. The sections of DR6-deficient (siDR6) B16 tumors and controls (siNC) were stained with hematoxylin and eosin. DR6-, CD31- and PDGFR-α-specific antibodies were used to visualize blood vessels and/or as a positive control. The scale bar represents 100 μm. (c) Quantification of the vascular vessels. The arrows indicate representative blood vessels. The blood vessels were counted in 6/15 randomly selected fields from three mouse tumor sections under a microscope (P=0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4815052&req=5

fig2: DR6 is required for tumor angiogenesis. (a) Immune cells were isolated by Percoll centrifugation and analyzed by flow cytometry. Label X and Y represent FSC-A and SSC-A, respectively. Gate P1 represents lymphocytes and Gate P2 represents mononuclear cells. The gated cells were counted. (b) Immunohistochemistry assay. The sections of DR6-deficient (siDR6) B16 tumors and controls (siNC) were stained with hematoxylin and eosin. DR6-, CD31- and PDGFR-α-specific antibodies were used to visualize blood vessels and/or as a positive control. The scale bar represents 100 μm. (c) Quantification of the vascular vessels. The arrows indicate representative blood vessels. The blood vessels were counted in 6/15 randomly selected fields from three mouse tumor sections under a microscope (P=0.01).
Mentions: To test whether DR6 deficiency affects the infiltration of microenvironmental cells into melanoma tissue, immune cells were isolated from mouse tumor tissues by Percoll gradient centrifugation and analyzed by flow cytometry. As shown in Figure 2a, two populations, consisting of lymphocytes (Gate P1) and mononuclear cells (Gate P2), were observed by flow cytometry assays. Cell counting revealed that there were 50% fewer lymphocytes and mononuclear cells in the DR6 knockdown (siDR6) tumors than in the control (siNC) tumors. This suggested that a decrease of DR6 expression can prevent two subsets of immune cells infiltration into the tumor microenvironment. CD3, CTLA-4 and DC antibodies marked cells were analyzed by flow cytometry, but it showed no significant difference between siDR6 and siNC tumors (Supplementary Figure S2).

Bottom Line: Although death receptor 6 (DR6) is aberrantly expressed in certain cancer cell lines, its function, signaling pathway and potential clinical significance in tumor progression are not well characterized.Deficiency of DR6 changes cytokine expression and secretion; in particular, it inhibits the proinflammatory cytokine interleukin-6 (IL-6), which is able to induce the expression of the angiogenesis-related factors: vascular endothelial growth factor-A, platelet-derived growth factor-β, vascular endothelial growth factor-D and platelet-derived growth factor receptor-α.Further experiments demonstrate that DR6-dependent angiogenesis is involved in the IL-6/P38 MAPK and IL-6/STAT3 pathways.

View Article: PubMed Central - PubMed

Affiliation: National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.

ABSTRACT
Although death receptor 6 (DR6) is aberrantly expressed in certain cancer cell lines, its function, signaling pathway and potential clinical significance in tumor progression are not well characterized. We report here that knocking down DR6 in the mouse B16 cell line has no effect on B16 cell death in vitro but suppresses xenograft B16 tumor growth by preventing tumor blood vessel formation in vivo. Deficiency of DR6 changes cytokine expression and secretion; in particular, it inhibits the proinflammatory cytokine interleukin-6 (IL-6), which is able to induce the expression of the angiogenesis-related factors: vascular endothelial growth factor-A, platelet-derived growth factor-β, vascular endothelial growth factor-D and platelet-derived growth factor receptor-α. Further experiments demonstrate that DR6-dependent angiogenesis is involved in the IL-6/P38 MAPK and IL-6/STAT3 pathways. Our novel findings demonstrate for the first time that DR6 expression in B16 cells facilitates tumor growth by accelerating tumor angiogenesis. Moreover, these results suggest that DR6 is involved in three important intracellular pathways that lead to homeostatic angiogenesis in tumor growth.

No MeSH data available.


Related in: MedlinePlus