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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

Endogenous DR6 expression in B16 cell lines is required for B16 tumor growth. (a) Tumor volumes. From the fifth day after implantation, tumor was measured every 3 days for a total of 14 days. Tumor size was calculated by the formula V (mm3)=length × width2/2 (n=6, P<0.05). Tumor cells were isolated from tumor tissues by Percoll density gradient centrifugation. The expression of DR6 and VEGF-R-2 in the B16 tumor tissue was tested by western blotting. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as the loading control. (b) Tumor weights (n=6, P<0.05). At the end point of tumor growth measurement, the animals were killed, and the tumor tissues were excised. (c) Before the tumor excision, the body weight of the mice was measured (n=13, P<0.05). The error bars represent the standard deviation of the mean values obtained from triplicate experiments. P<0.05 is considered to be statistically significant.
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fig1: Endogenous DR6 expression in B16 cell lines is required for B16 tumor growth. (a) Tumor volumes. From the fifth day after implantation, tumor was measured every 3 days for a total of 14 days. Tumor size was calculated by the formula V (mm3)=length × width2/2 (n=6, P<0.05). Tumor cells were isolated from tumor tissues by Percoll density gradient centrifugation. The expression of DR6 and VEGF-R-2 in the B16 tumor tissue was tested by western blotting. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as the loading control. (b) Tumor weights (n=6, P<0.05). At the end point of tumor growth measurement, the animals were killed, and the tumor tissues were excised. (c) Before the tumor excision, the body weight of the mice was measured (n=13, P<0.05). The error bars represent the standard deviation of the mean values obtained from triplicate experiments. P<0.05 is considered to be statistically significant.

Mentions: DR6 expresses in mouse melanoma B16 cells, breast cancer 4T1 cells and colon cancer CT26 cells, especially highly in B16 cell lines (Supplementary Figures S1a and b). To determine the function of endogenous full-length DR6 in B16 cells, a small interfering RNA (siRNA) approach was used to knock down DR6. B16 cells were transfected with the siRNAs against DR6 (siDR6) or the negative control sequences (siNC) for 12 h, and then were implanted subcutaneously into C57BL mice. Tumor growth was measured every 3 days. As shown in Figure 1a, DR6 expression was decreased in DR6-deficient B16 tumor tissues. And knocking down DR6 (siDR6) remarkably suppressed tumor growth (Figure 1a). The expression of DR6 and VEGF-R-2 was lower in siDR6 tumors than in the control (siNC) (Figure 1a). The DR6 siRNAs reduced tumor weight (Figure 1b) as well as mouse body weight (Figure 1c) compared with the control (siNC).


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)

Endogenous DR6 expression in B16 cell lines is required for B16 tumor growth. (a) Tumor volumes. From the fifth day after implantation, tumor was measured every 3 days for a total of 14 days. Tumor size was calculated by the formula V (mm3)=length × width2/2 (n=6, P<0.05). Tumor cells were isolated from tumor tissues by Percoll density gradient centrifugation. The expression of DR6 and VEGF-R-2 in the B16 tumor tissue was tested by western blotting. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as the loading control. (b) Tumor weights (n=6, P<0.05). At the end point of tumor growth measurement, the animals were killed, and the tumor tissues were excised. (c) Before the tumor excision, the body weight of the mice was measured (n=13, P<0.05). The error bars represent the standard deviation of the mean values obtained from triplicate experiments. P<0.05 is considered to be statistically significant.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig1: Endogenous DR6 expression in B16 cell lines is required for B16 tumor growth. (a) Tumor volumes. From the fifth day after implantation, tumor was measured every 3 days for a total of 14 days. Tumor size was calculated by the formula V (mm3)=length × width2/2 (n=6, P<0.05). Tumor cells were isolated from tumor tissues by Percoll density gradient centrifugation. The expression of DR6 and VEGF-R-2 in the B16 tumor tissue was tested by western blotting. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as the loading control. (b) Tumor weights (n=6, P<0.05). At the end point of tumor growth measurement, the animals were killed, and the tumor tissues were excised. (c) Before the tumor excision, the body weight of the mice was measured (n=13, P<0.05). The error bars represent the standard deviation of the mean values obtained from triplicate experiments. P<0.05 is considered to be statistically significant.
Mentions: DR6 expresses in mouse melanoma B16 cells, breast cancer 4T1 cells and colon cancer CT26 cells, especially highly in B16 cell lines (Supplementary Figures S1a and b). To determine the function of endogenous full-length DR6 in B16 cells, a small interfering RNA (siRNA) approach was used to knock down DR6. B16 cells were transfected with the siRNAs against DR6 (siDR6) or the negative control sequences (siNC) for 12 h, and then were implanted subcutaneously into C57BL mice. Tumor growth was measured every 3 days. As shown in Figure 1a, DR6 expression was decreased in DR6-deficient B16 tumor tissues. And knocking down DR6 (siDR6) remarkably suppressed tumor growth (Figure 1a). The expression of DR6 and VEGF-R-2 was lower in siDR6 tumors than in the control (siNC) (Figure 1a). The DR6 siRNAs reduced tumor weight (Figure 1b) as well as mouse body weight (Figure 1c) compared with the control (siNC).

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