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Growth and metastasis of B16-F10 melanoma cells is not critically dependent on host CD73 expression in mice.

Burghoff S, Gong X, Viethen C, Jacoby C, Flögel U, Bongardt S, Schorr A, Hippe A, Homey B, Schrader J - BMC Cancer (2014)

Bottom Line: Only peritumoral edema formation was significantly attenuated in global CD73-/- mice in the intradermal model.Immune cell composition revealed no differences in the different transgenic mice models.Also lung metastasis after intravenous B16-F10 injection was not altered in CD73-/- mice.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Cardiology, Heinrich Heine University Duesseldorf, 40225 Duesseldorf, Germany. schrader@uni-duesseldorf.de.

ABSTRACT

Background: Recent studies have suggested that adenosine generated by ecto-5'-nucleotidase (CD73) in the tumor microenvironment plays a major role in promoting tumor growth by suppressing the immune response and stimulating angiogenesis via A2A and A2B receptors. However, adenosine has also been reported to inhibit tumor growth acting via A1 and A3 receptors. Therefore the aim of this study was to clarify the role of host CD73, which catalyzes the extracellular hydrolysis of AMP to adenosine, on tumor growth and metastasis of B16-F10 melanoma cells.

Methods: CD73 and alkaline phosphatase (AP) activity of B16-F10 melanoma cells were measured by HPLC. Tumor cells were injected either subcutaneously or intradermally in WT and CD73-/- mice and tumor growth was monitored by MRI at 9.4 T. Immune cell subpopulations within tumors were assessed by FACS after enzymatic digestion. An endothelium specific CD73-/- was created using Tie2-Cre+ mice and CD73flox/flox (loxP) mice. Chimeric mice lacking CD73-/- on hematopoietic cells was generated by bone marrow transplantation. Lung metastatic spread was measured after intravenous B16-F10 application.

Results: B16-F10 cells showed very little CD73 and negligible AP activity. Neither complete loss of host CD73 nor specific knockout of CD73 on endothelial cells or hematopoietic cells affected tumor growth after subcutaneous or intradermal tumor cell application. Only peritumoral edema formation was significantly attenuated in global CD73-/- mice in the intradermal model. Immune cell composition revealed no differences in the different transgenic mice models. Also lung metastasis after intravenous B16-F10 injection was not altered in CD73-/- mice.

Conclusions: CD73 expression on host cells, particularly on endothelial and hematopoietic cells, does not modulate tumor growth and metastatic spread of B16-F10 melanoma cells most likely because of insufficient adenosine formation by the tumor itself.

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Global loss of host CD73 did not alter subcutaneous B16-F10 tumor growth. B16-F10 cells (25 × 104) were injected subcutaneously into the hindlimb of WT and CD73−/− mice. (A, B) Representative MRI measurements of the tumor and peritumoral edema were performed for 18 days post injection. Tumor volume and peritumoral edema are encircled in red and yellow respectively (C, D). No differences in tumor volume or peritumoral edema volume were observed (n = 10).
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Fig2: Global loss of host CD73 did not alter subcutaneous B16-F10 tumor growth. B16-F10 cells (25 × 104) were injected subcutaneously into the hindlimb of WT and CD73−/− mice. (A, B) Representative MRI measurements of the tumor and peritumoral edema were performed for 18 days post injection. Tumor volume and peritumoral edema are encircled in red and yellow respectively (C, D). No differences in tumor volume or peritumoral edema volume were observed (n = 10).

Mentions: Because B16-F10 cells exhibit only minimal CD73 activity, this enabled us to study the role of host CD73 on tumor growth. To this end B16-F10 cells were injected subcutaneously into the hindlimb of WT and CD73−/− mice at a concentration (25 × 104 cells) previously used by others [9, 14, 17, 25]. Tumor growth and peritumoral edema formation was monitored by MRI at 9.4 T for 18 days, as shown in representative images in Figure 2A-B. From the quantitative data summarized in Figure 2C-D it is obvious that there were no differences between WT and global CD73−/− mice when either tumor volume (Figure 2C) or peritumoral edema formation around the solid tumor was measured (Figure 2D).At the end of the experiments, B16-F10 tumors were excised and immune cell distribution within the tumor was measured by FACS (Figure 3A-E). As shown in Figure 3F, we found no differences between the two experimental groups regarding the distribution of lymphoid and myeloid immune cell subsets, thus suggesting no changes of immune response in absence of host CD73.Figure 2


Growth and metastasis of B16-F10 melanoma cells is not critically dependent on host CD73 expression in mice.

Burghoff S, Gong X, Viethen C, Jacoby C, Flögel U, Bongardt S, Schorr A, Hippe A, Homey B, Schrader J - BMC Cancer (2014)

Global loss of host CD73 did not alter subcutaneous B16-F10 tumor growth. B16-F10 cells (25 × 104) were injected subcutaneously into the hindlimb of WT and CD73−/− mice. (A, B) Representative MRI measurements of the tumor and peritumoral edema were performed for 18 days post injection. Tumor volume and peritumoral edema are encircled in red and yellow respectively (C, D). No differences in tumor volume or peritumoral edema volume were observed (n = 10).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4265456&req=5

Fig2: Global loss of host CD73 did not alter subcutaneous B16-F10 tumor growth. B16-F10 cells (25 × 104) were injected subcutaneously into the hindlimb of WT and CD73−/− mice. (A, B) Representative MRI measurements of the tumor and peritumoral edema were performed for 18 days post injection. Tumor volume and peritumoral edema are encircled in red and yellow respectively (C, D). No differences in tumor volume or peritumoral edema volume were observed (n = 10).
Mentions: Because B16-F10 cells exhibit only minimal CD73 activity, this enabled us to study the role of host CD73 on tumor growth. To this end B16-F10 cells were injected subcutaneously into the hindlimb of WT and CD73−/− mice at a concentration (25 × 104 cells) previously used by others [9, 14, 17, 25]. Tumor growth and peritumoral edema formation was monitored by MRI at 9.4 T for 18 days, as shown in representative images in Figure 2A-B. From the quantitative data summarized in Figure 2C-D it is obvious that there were no differences between WT and global CD73−/− mice when either tumor volume (Figure 2C) or peritumoral edema formation around the solid tumor was measured (Figure 2D).At the end of the experiments, B16-F10 tumors were excised and immune cell distribution within the tumor was measured by FACS (Figure 3A-E). As shown in Figure 3F, we found no differences between the two experimental groups regarding the distribution of lymphoid and myeloid immune cell subsets, thus suggesting no changes of immune response in absence of host CD73.Figure 2

Bottom Line: Only peritumoral edema formation was significantly attenuated in global CD73-/- mice in the intradermal model.Immune cell composition revealed no differences in the different transgenic mice models.Also lung metastasis after intravenous B16-F10 injection was not altered in CD73-/- mice.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Cardiology, Heinrich Heine University Duesseldorf, 40225 Duesseldorf, Germany. schrader@uni-duesseldorf.de.

ABSTRACT

Background: Recent studies have suggested that adenosine generated by ecto-5'-nucleotidase (CD73) in the tumor microenvironment plays a major role in promoting tumor growth by suppressing the immune response and stimulating angiogenesis via A2A and A2B receptors. However, adenosine has also been reported to inhibit tumor growth acting via A1 and A3 receptors. Therefore the aim of this study was to clarify the role of host CD73, which catalyzes the extracellular hydrolysis of AMP to adenosine, on tumor growth and metastasis of B16-F10 melanoma cells.

Methods: CD73 and alkaline phosphatase (AP) activity of B16-F10 melanoma cells were measured by HPLC. Tumor cells were injected either subcutaneously or intradermally in WT and CD73-/- mice and tumor growth was monitored by MRI at 9.4 T. Immune cell subpopulations within tumors were assessed by FACS after enzymatic digestion. An endothelium specific CD73-/- was created using Tie2-Cre+ mice and CD73flox/flox (loxP) mice. Chimeric mice lacking CD73-/- on hematopoietic cells was generated by bone marrow transplantation. Lung metastatic spread was measured after intravenous B16-F10 application.

Results: B16-F10 cells showed very little CD73 and negligible AP activity. Neither complete loss of host CD73 nor specific knockout of CD73 on endothelial cells or hematopoietic cells affected tumor growth after subcutaneous or intradermal tumor cell application. Only peritumoral edema formation was significantly attenuated in global CD73-/- mice in the intradermal model. Immune cell composition revealed no differences in the different transgenic mice models. Also lung metastasis after intravenous B16-F10 injection was not altered in CD73-/- mice.

Conclusions: CD73 expression on host cells, particularly on endothelial and hematopoietic cells, does not modulate tumor growth and metastatic spread of B16-F10 melanoma cells most likely because of insufficient adenosine formation by the tumor itself.

Show MeSH
Related in: MedlinePlus