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Erythropoietin improves the accumulation and therapeutic effects of carboplatin by enhancing tumor vascularization and perfusion.

Doleschel D, Rix A, Arns S, Palmowski K, Gremse F, Merkle R, Salopiata F, Klingmüller U, Jarsch M, Kiessling F, Lederle W - Theranostics (2015)

Bottom Line: In both xenografts, rhuEpo co-medication significantly increased vessel densities, diameters and the amount of perfused vessels.However, compared with solely carboplatin-treated tumors, tumor growth was significantly slower in the groups co-medicated with rhuEpo.Doses and indications may be personalized and refined using theranostic EpoR-probes.

View Article: PubMed Central - PubMed

Affiliation: 1. Experimental Molecular Imaging, Medical Faculty, RWTH Aachen University, Aachen, Germany.

ABSTRACT
Recombinant human erythropoietin (rhuEpo) is currently under debate for the treatment of chemotherapy-induced anemia due to clinical trials showing adverse effects in Epo-treated patients and the discovery of the erythropoietin-receptor (EpoR) in tumor and endothelial cells. Here, using Epo-Cy5.5 as theranostic near-infrared fluorescent probe we analyzed the effects of rhuEpo as co-medication to carboplatin in non-small-cell-lung-cancer (NSCLC)-xenografts with different tumor cell EpoR-expression (H838 ~8-fold higher than A549). Nude mice bearing subcutaneous A549 and H838 NSCLC-xenografts received either only carboplatin or carboplatin and co-medication of rhuEpo in two different doses. Tumor sizes and relative blood volumes (rBV) were longitudinally measured by 3D-contrast-enhanced ultrasound (3D-US). Tumoral EpoR-levels were determined by combined fluorescence molecular tomography (FMT)/ micro computed tomography (µCT) hybrid imaging. We found that rhuEpo predominantly acted on the tumor endothelium. In both xenografts, rhuEpo co-medication significantly increased vessel densities, diameters and the amount of perfused vessels. Accordingly, rhuEpo induced EpoR-phoshorylation and stimulated proliferation of endothelial cells. However, compared with solely carboplatin-treated tumors, tumor growth was significantly slower in the groups co-medicated with rhuEpo. This is explained by the Epo-mediated vascular remodeling leading to improved drug delivery as obvious by a more than 2-fold higher carboplatin accumulation and significantly enhanced tumor apoptosis. In addition, co-medication of rhuEpo reduced tumor hypoxia and diminished intratumoral EpoR-levels which continuously increased during carboplatin (Cp) -treatment. These findings suggest that co-medication of rhuEpo in well balanced doses can be used to improve the accumulation of anticancer drugs. Doses and indications may be personalized and refined using theranostic EpoR-probes.

No MeSH data available.


Related in: MedlinePlus

Epo stimulates endothelial cell proliferation and EpoR-expression in vitro. A: Stimulation of HUVECs with Epo in vitro significantly increased the cell numbers starting at day three compared with non-stimulated controls (n = 3 per condition, *p < 0.05, **p < 0.001). B: Comparison of EpoR mRNA expression in HUVECs with A549 and H838 reveals higher transcript levels than in A549 (0.6 fold) and lower levels compared with H838 (4.3 fold). C: Phosphorylated EpoR was detected on HUVECs by immunoblotting. Significant pEpoR up-regulation was measured in HUVECs after stimulation with rhuEpo-β (300 ng/ml) (+) in comparison to untreated control cells (-) (n = 3, *p < 0.05).
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Figure 4: Epo stimulates endothelial cell proliferation and EpoR-expression in vitro. A: Stimulation of HUVECs with Epo in vitro significantly increased the cell numbers starting at day three compared with non-stimulated controls (n = 3 per condition, *p < 0.05, **p < 0.001). B: Comparison of EpoR mRNA expression in HUVECs with A549 and H838 reveals higher transcript levels than in A549 (0.6 fold) and lower levels compared with H838 (4.3 fold). C: Phosphorylated EpoR was detected on HUVECs by immunoblotting. Significant pEpoR up-regulation was measured in HUVECs after stimulation with rhuEpo-β (300 ng/ml) (+) in comparison to untreated control cells (-) (n = 3, *p < 0.05).

Mentions: In order to analyze whether Epo exerts direct effects on endothelial cells, HUVECs were stimulated in vitro with Epo-doses corresponding to the amount expected per ml blood in vivo. When assuming a 30 g mouse with a mean blood volume of 2 ml, 5 µg/kg and 20 µg/kg of Epo correspond to 70 ng/ml and 300 ng/ml, respectively. At day three and four of Epo-stimulation, significantly higher cell numbers were measured for both Epo-concentrations, demonstrating that Epo directly enhances endothelial cell proliferation (Fig. 4 A, *p < 0.05, **p < 0.01). Analysis of EpoR mRNA-expression demonstrated that the transcript levels in HUVECs were 1.7-fold higher than in A549 but 4.3-fold lower than in H838 (Fig. 4 B). At the protein level, a 2.8 fold increased amount of phosphorylated EpoR was detected in upon Epo-stimulation indicating Epo-mediated signaling (Fig. 4 C).


Erythropoietin improves the accumulation and therapeutic effects of carboplatin by enhancing tumor vascularization and perfusion.

Doleschel D, Rix A, Arns S, Palmowski K, Gremse F, Merkle R, Salopiata F, Klingmüller U, Jarsch M, Kiessling F, Lederle W - Theranostics (2015)

Epo stimulates endothelial cell proliferation and EpoR-expression in vitro. A: Stimulation of HUVECs with Epo in vitro significantly increased the cell numbers starting at day three compared with non-stimulated controls (n = 3 per condition, *p < 0.05, **p < 0.001). B: Comparison of EpoR mRNA expression in HUVECs with A549 and H838 reveals higher transcript levels than in A549 (0.6 fold) and lower levels compared with H838 (4.3 fold). C: Phosphorylated EpoR was detected on HUVECs by immunoblotting. Significant pEpoR up-regulation was measured in HUVECs after stimulation with rhuEpo-β (300 ng/ml) (+) in comparison to untreated control cells (-) (n = 3, *p < 0.05).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4440446&req=5

Figure 4: Epo stimulates endothelial cell proliferation and EpoR-expression in vitro. A: Stimulation of HUVECs with Epo in vitro significantly increased the cell numbers starting at day three compared with non-stimulated controls (n = 3 per condition, *p < 0.05, **p < 0.001). B: Comparison of EpoR mRNA expression in HUVECs with A549 and H838 reveals higher transcript levels than in A549 (0.6 fold) and lower levels compared with H838 (4.3 fold). C: Phosphorylated EpoR was detected on HUVECs by immunoblotting. Significant pEpoR up-regulation was measured in HUVECs after stimulation with rhuEpo-β (300 ng/ml) (+) in comparison to untreated control cells (-) (n = 3, *p < 0.05).
Mentions: In order to analyze whether Epo exerts direct effects on endothelial cells, HUVECs were stimulated in vitro with Epo-doses corresponding to the amount expected per ml blood in vivo. When assuming a 30 g mouse with a mean blood volume of 2 ml, 5 µg/kg and 20 µg/kg of Epo correspond to 70 ng/ml and 300 ng/ml, respectively. At day three and four of Epo-stimulation, significantly higher cell numbers were measured for both Epo-concentrations, demonstrating that Epo directly enhances endothelial cell proliferation (Fig. 4 A, *p < 0.05, **p < 0.01). Analysis of EpoR mRNA-expression demonstrated that the transcript levels in HUVECs were 1.7-fold higher than in A549 but 4.3-fold lower than in H838 (Fig. 4 B). At the protein level, a 2.8 fold increased amount of phosphorylated EpoR was detected in upon Epo-stimulation indicating Epo-mediated signaling (Fig. 4 C).

Bottom Line: In both xenografts, rhuEpo co-medication significantly increased vessel densities, diameters and the amount of perfused vessels.However, compared with solely carboplatin-treated tumors, tumor growth was significantly slower in the groups co-medicated with rhuEpo.Doses and indications may be personalized and refined using theranostic EpoR-probes.

View Article: PubMed Central - PubMed

Affiliation: 1. Experimental Molecular Imaging, Medical Faculty, RWTH Aachen University, Aachen, Germany.

ABSTRACT
Recombinant human erythropoietin (rhuEpo) is currently under debate for the treatment of chemotherapy-induced anemia due to clinical trials showing adverse effects in Epo-treated patients and the discovery of the erythropoietin-receptor (EpoR) in tumor and endothelial cells. Here, using Epo-Cy5.5 as theranostic near-infrared fluorescent probe we analyzed the effects of rhuEpo as co-medication to carboplatin in non-small-cell-lung-cancer (NSCLC)-xenografts with different tumor cell EpoR-expression (H838 ~8-fold higher than A549). Nude mice bearing subcutaneous A549 and H838 NSCLC-xenografts received either only carboplatin or carboplatin and co-medication of rhuEpo in two different doses. Tumor sizes and relative blood volumes (rBV) were longitudinally measured by 3D-contrast-enhanced ultrasound (3D-US). Tumoral EpoR-levels were determined by combined fluorescence molecular tomography (FMT)/ micro computed tomography (µCT) hybrid imaging. We found that rhuEpo predominantly acted on the tumor endothelium. In both xenografts, rhuEpo co-medication significantly increased vessel densities, diameters and the amount of perfused vessels. Accordingly, rhuEpo induced EpoR-phoshorylation and stimulated proliferation of endothelial cells. However, compared with solely carboplatin-treated tumors, tumor growth was significantly slower in the groups co-medicated with rhuEpo. This is explained by the Epo-mediated vascular remodeling leading to improved drug delivery as obvious by a more than 2-fold higher carboplatin accumulation and significantly enhanced tumor apoptosis. In addition, co-medication of rhuEpo reduced tumor hypoxia and diminished intratumoral EpoR-levels which continuously increased during carboplatin (Cp) -treatment. These findings suggest that co-medication of rhuEpo in well balanced doses can be used to improve the accumulation of anticancer drugs. Doses and indications may be personalized and refined using theranostic EpoR-probes.

No MeSH data available.


Related in: MedlinePlus