Limits...
Mithramycin exerts an anti-myeloma effect and displays anti-angiogenic effects through up-regulation of anti-angiogenic factors.

Otjacques E, Binsfeld M, Rocks N, Blacher S, Vanderkerken K, Noel A, Beguin Y, Cataldo D, Caers J - PLoS ONE (2013)

Bottom Line: In rat aortic ring assays, a strong anti-angiogenic effect was seen, which could be explained by a decrease of VEGF production and an up-regulation of anti-angiogenic proteins such as IP10 after MTM treatment.The administration of MTM to mice injected with 5TGM1 decreased 5TGM1 cell invasion into bone marrow and myeloma neovascularisation.These data suggest that MTM displays anti-myeloma and anti-angiogenic effects that are not mediated by an inhibition of SP1 but rather through c-Myc inhibition and p53 activation.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Hematology, Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA-Research), University of Liège, Liège, Belgium.

ABSTRACT
Mithramycin (MTM), a cytotoxic compound, is currently being investigated for its anti-angiogenic activity that seems to be mediated through an inhibition of the transcription factor SP1. In this study we evaluated its anti-myeloma effects in the syngenic 5TGM1 model in vitro as well as in vivo. In vitro, MTM inhibited DNA synthesis of 5TGM1 cells with an IC50 of 400 nM and induced an arrest in cell cycle progression at the G1/S transition point. Western-blot revealed an up-regulation of p53, p21 and p27 and an inhibition of c-Myc, while SP1 remained unaffected. In rat aortic ring assays, a strong anti-angiogenic effect was seen, which could be explained by a decrease of VEGF production and an up-regulation of anti-angiogenic proteins such as IP10 after MTM treatment. The administration of MTM to mice injected with 5TGM1 decreased 5TGM1 cell invasion into bone marrow and myeloma neovascularisation. These data suggest that MTM displays anti-myeloma and anti-angiogenic effects that are not mediated by an inhibition of SP1 but rather through c-Myc inhibition and p53 activation.

Show MeSH

Related in: MedlinePlus

MTM inhibits proliferation, migration and invasion of endothelial cell lines STR4 and STR10.Proliferation and viability was assessed using an MTT assay. Wound healing assay and Boyden chamber assay were used to study migration. Cell sprouting was assessed using a spheroid sprouting assay. Cells were treated with various concentrations of MTM during 24 h and 48 h. (A) Increasing concentrations of MTM resulted in a minor anti-proliferative effect in STR-4 cells, while MTM inhibited STR-10 proliferation with an IC-50 of 200 nM. (B) MTM inhibited both STR-4 and STR-10 cell migration in the Boyden Chamber assay. (C,D) Wound healing assay showed that adding 200 nM MTM decreased cell repopulation by both cells lines. In the spheroid sprouting assay (E, F), treatment with 200 nM or 400 nM had only an effect on the STR4 cell line whereas 800 nM of MTM caused an significant decrease in vessel sprouting by both cell lines.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3646989&req=5

pone-0062818-g007: MTM inhibits proliferation, migration and invasion of endothelial cell lines STR4 and STR10.Proliferation and viability was assessed using an MTT assay. Wound healing assay and Boyden chamber assay were used to study migration. Cell sprouting was assessed using a spheroid sprouting assay. Cells were treated with various concentrations of MTM during 24 h and 48 h. (A) Increasing concentrations of MTM resulted in a minor anti-proliferative effect in STR-4 cells, while MTM inhibited STR-10 proliferation with an IC-50 of 200 nM. (B) MTM inhibited both STR-4 and STR-10 cell migration in the Boyden Chamber assay. (C,D) Wound healing assay showed that adding 200 nM MTM decreased cell repopulation by both cells lines. In the spheroid sprouting assay (E, F), treatment with 200 nM or 400 nM had only an effect on the STR4 cell line whereas 800 nM of MTM caused an significant decrease in vessel sprouting by both cell lines.

Mentions: To assess the direct effect of MTM on murine bone marrow endothelial cells, we used the immortalized BM endothelial cell lines STR-4 and STR-10. In the MTT assay, increasing concentrations of MTM (ranging from 100 nM to 800 nM) resulted in a minor anti-proliferative effect in STR-4 cells, while MTM inhibited STR-10 proliferation with an IC-50 of 200 nM (shown in Figure 7A). MTM inhibited both STR-4 and STR-10 cell migration in the Boyden Chamber assay. As shown in Figure 7B and Figure S2 C, treatment with 200 nM and 400 nM reduced migration with 1,25-fold (200 nM STR4), 1,74-fold (400 nM STR4), 1,41-fold (200 nM STR10) and 1,66-fold (400 nM STR10) compared to vehicle treated cells. To confirm the anti-migratory effects of MTM, a wound healing assay using a IBIDI culture insert was performed. As shown in Figure 7C and 7 D, treatment with MTM induced a decrease of cell migration in both cell lines (61% and 85% of wound closed after 48 h of treatment with 200 nM of MTM for STR-4 and STR-10 respectively compared to total closure of control condition). Results of this assay are also illustrated in Figure S2 A Capillary-like sprout formation from spheroid cultures was only inhibited at high concentrations (800 nM) of MTM in both STR-4 and STR-10 endothelial cells. Lower concentrations of MTM (200 and 400 nM had only significant effect on STR-4 (Figure 7D and Figure S2B), while sprouting by STR-10 cells was unaffected at these concentrations (Figure 7F).


Mithramycin exerts an anti-myeloma effect and displays anti-angiogenic effects through up-regulation of anti-angiogenic factors.

Otjacques E, Binsfeld M, Rocks N, Blacher S, Vanderkerken K, Noel A, Beguin Y, Cataldo D, Caers J - PLoS ONE (2013)

MTM inhibits proliferation, migration and invasion of endothelial cell lines STR4 and STR10.Proliferation and viability was assessed using an MTT assay. Wound healing assay and Boyden chamber assay were used to study migration. Cell sprouting was assessed using a spheroid sprouting assay. Cells were treated with various concentrations of MTM during 24 h and 48 h. (A) Increasing concentrations of MTM resulted in a minor anti-proliferative effect in STR-4 cells, while MTM inhibited STR-10 proliferation with an IC-50 of 200 nM. (B) MTM inhibited both STR-4 and STR-10 cell migration in the Boyden Chamber assay. (C,D) Wound healing assay showed that adding 200 nM MTM decreased cell repopulation by both cells lines. In the spheroid sprouting assay (E, F), treatment with 200 nM or 400 nM had only an effect on the STR4 cell line whereas 800 nM of MTM caused an significant decrease in vessel sprouting by both cell lines.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3646989&req=5

pone-0062818-g007: MTM inhibits proliferation, migration and invasion of endothelial cell lines STR4 and STR10.Proliferation and viability was assessed using an MTT assay. Wound healing assay and Boyden chamber assay were used to study migration. Cell sprouting was assessed using a spheroid sprouting assay. Cells were treated with various concentrations of MTM during 24 h and 48 h. (A) Increasing concentrations of MTM resulted in a minor anti-proliferative effect in STR-4 cells, while MTM inhibited STR-10 proliferation with an IC-50 of 200 nM. (B) MTM inhibited both STR-4 and STR-10 cell migration in the Boyden Chamber assay. (C,D) Wound healing assay showed that adding 200 nM MTM decreased cell repopulation by both cells lines. In the spheroid sprouting assay (E, F), treatment with 200 nM or 400 nM had only an effect on the STR4 cell line whereas 800 nM of MTM caused an significant decrease in vessel sprouting by both cell lines.
Mentions: To assess the direct effect of MTM on murine bone marrow endothelial cells, we used the immortalized BM endothelial cell lines STR-4 and STR-10. In the MTT assay, increasing concentrations of MTM (ranging from 100 nM to 800 nM) resulted in a minor anti-proliferative effect in STR-4 cells, while MTM inhibited STR-10 proliferation with an IC-50 of 200 nM (shown in Figure 7A). MTM inhibited both STR-4 and STR-10 cell migration in the Boyden Chamber assay. As shown in Figure 7B and Figure S2 C, treatment with 200 nM and 400 nM reduced migration with 1,25-fold (200 nM STR4), 1,74-fold (400 nM STR4), 1,41-fold (200 nM STR10) and 1,66-fold (400 nM STR10) compared to vehicle treated cells. To confirm the anti-migratory effects of MTM, a wound healing assay using a IBIDI culture insert was performed. As shown in Figure 7C and 7 D, treatment with MTM induced a decrease of cell migration in both cell lines (61% and 85% of wound closed after 48 h of treatment with 200 nM of MTM for STR-4 and STR-10 respectively compared to total closure of control condition). Results of this assay are also illustrated in Figure S2 A Capillary-like sprout formation from spheroid cultures was only inhibited at high concentrations (800 nM) of MTM in both STR-4 and STR-10 endothelial cells. Lower concentrations of MTM (200 and 400 nM had only significant effect on STR-4 (Figure 7D and Figure S2B), while sprouting by STR-10 cells was unaffected at these concentrations (Figure 7F).

Bottom Line: In rat aortic ring assays, a strong anti-angiogenic effect was seen, which could be explained by a decrease of VEGF production and an up-regulation of anti-angiogenic proteins such as IP10 after MTM treatment.The administration of MTM to mice injected with 5TGM1 decreased 5TGM1 cell invasion into bone marrow and myeloma neovascularisation.These data suggest that MTM displays anti-myeloma and anti-angiogenic effects that are not mediated by an inhibition of SP1 but rather through c-Myc inhibition and p53 activation.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Hematology, Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA-Research), University of Liège, Liège, Belgium.

ABSTRACT
Mithramycin (MTM), a cytotoxic compound, is currently being investigated for its anti-angiogenic activity that seems to be mediated through an inhibition of the transcription factor SP1. In this study we evaluated its anti-myeloma effects in the syngenic 5TGM1 model in vitro as well as in vivo. In vitro, MTM inhibited DNA synthesis of 5TGM1 cells with an IC50 of 400 nM and induced an arrest in cell cycle progression at the G1/S transition point. Western-blot revealed an up-regulation of p53, p21 and p27 and an inhibition of c-Myc, while SP1 remained unaffected. In rat aortic ring assays, a strong anti-angiogenic effect was seen, which could be explained by a decrease of VEGF production and an up-regulation of anti-angiogenic proteins such as IP10 after MTM treatment. The administration of MTM to mice injected with 5TGM1 decreased 5TGM1 cell invasion into bone marrow and myeloma neovascularisation. These data suggest that MTM displays anti-myeloma and anti-angiogenic effects that are not mediated by an inhibition of SP1 but rather through c-Myc inhibition and p53 activation.

Show MeSH
Related in: MedlinePlus