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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.

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Related in: MedlinePlus

MTM inhibits proliferation and induces apoptosis in 5TGM1 cells.A Effect of MTM on 5TGM1 cell proliferation and viability. Cells were treated with various concentrations of MTM for 24 h and viability was assessed using an MTT assay. There was a dose dependent inhibition in DNA synthesis observed with an IC50 of 600 nM B The induction of apoptosis was determined by FACS analysis. Cells were incubated during 24 h or 48 h with MTM (0 nM, 200 nM, 400 nM and 800 nM) and annexin V/PI stainings were performed. A representative picture of FACS analysis shows no induction of apoptosis after 24 h and the presence of late apoptotic cells after 48 h of treatment.
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pone-0062818-g001: MTM inhibits proliferation and induces apoptosis in 5TGM1 cells.A Effect of MTM on 5TGM1 cell proliferation and viability. Cells were treated with various concentrations of MTM for 24 h and viability was assessed using an MTT assay. There was a dose dependent inhibition in DNA synthesis observed with an IC50 of 600 nM B The induction of apoptosis was determined by FACS analysis. Cells were incubated during 24 h or 48 h with MTM (0 nM, 200 nM, 400 nM and 800 nM) and annexin V/PI stainings were performed. A representative picture of FACS analysis shows no induction of apoptosis after 24 h and the presence of late apoptotic cells after 48 h of treatment.

Mentions: We initially assessed the effect of MTM on 5TGM1 cell proliferation and viability in vitro using aMTT assay. In this setting, 5TGM1 cells were treated for 24 h with increasing concentrations of MTM (ranging from 25 nM to 800 nM). As shown in Figure 1A, treatment with MTM induced a dose-dependent decrease of cell proliferation and the median inhibitory concentration (IC50) was 600 nM. To determine whether the reduction in 5TGM1 cell proliferation was accompanied by apoptosis induction, cells were incubated with MTM or vehicle for 24 h and 48 h and early and late apoptosis rates were assessed by flow cytometry using a double annexin V/PI-staining (Figure 1B). When cells were treated for 24 h with the drug, no effect on early apoptosis was observed. However, a significant effect on late apoptosis and necrosis was observed with high concentrations of MTM (p<0.01). After 48 h of MTM treatment, a dose-dependent increase of late apoptosis/necrosis rate was observed in each condition compared to the control condition.


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 and induces apoptosis in 5TGM1 cells.A Effect of MTM on 5TGM1 cell proliferation and viability. Cells were treated with various concentrations of MTM for 24 h and viability was assessed using an MTT assay. There was a dose dependent inhibition in DNA synthesis observed with an IC50 of 600 nM B The induction of apoptosis was determined by FACS analysis. Cells were incubated during 24 h or 48 h with MTM (0 nM, 200 nM, 400 nM and 800 nM) and annexin V/PI stainings were performed. A representative picture of FACS analysis shows no induction of apoptosis after 24 h and the presence of late apoptotic cells after 48 h of treatment.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0062818-g001: MTM inhibits proliferation and induces apoptosis in 5TGM1 cells.A Effect of MTM on 5TGM1 cell proliferation and viability. Cells were treated with various concentrations of MTM for 24 h and viability was assessed using an MTT assay. There was a dose dependent inhibition in DNA synthesis observed with an IC50 of 600 nM B The induction of apoptosis was determined by FACS analysis. Cells were incubated during 24 h or 48 h with MTM (0 nM, 200 nM, 400 nM and 800 nM) and annexin V/PI stainings were performed. A representative picture of FACS analysis shows no induction of apoptosis after 24 h and the presence of late apoptotic cells after 48 h of treatment.
Mentions: We initially assessed the effect of MTM on 5TGM1 cell proliferation and viability in vitro using aMTT assay. In this setting, 5TGM1 cells were treated for 24 h with increasing concentrations of MTM (ranging from 25 nM to 800 nM). As shown in Figure 1A, treatment with MTM induced a dose-dependent decrease of cell proliferation and the median inhibitory concentration (IC50) was 600 nM. To determine whether the reduction in 5TGM1 cell proliferation was accompanied by apoptosis induction, cells were incubated with MTM or vehicle for 24 h and 48 h and early and late apoptosis rates were assessed by flow cytometry using a double annexin V/PI-staining (Figure 1B). When cells were treated for 24 h with the drug, no effect on early apoptosis was observed. However, a significant effect on late apoptosis and necrosis was observed with high concentrations of MTM (p<0.01). After 48 h of MTM treatment, a dose-dependent increase of late apoptosis/necrosis rate was observed in each condition compared to the control condition.

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