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Small molecule MIRA-1 induces in vitro and in vivo anti-myeloma activity and synergizes with current anti-myeloma agents.

Saha MN, Chen Y, Chen MH, Chen G, Chang H - Br. J. Cancer (2014)

Bottom Line: MIRA-1 treatment resulted in the inhibition of viability, colony formation, and migration and increase in apoptosis of MM cells irrespective of p53 status accompanied by upregulation of Puma and Bax and downregulation of Mcl-1 and c-Myc.Genetic knockdown of p53 did not abrogate apoptotic response of MIRA-1.Our data provide the preclinical framework for clinical evaluation of MIRA-1 as a novel therapeutic agent to improve patient outcome in MM.

View Article: PubMed Central - PubMed

Affiliation: 1] Division of Molecular and Cellular Biology, Toronto General Research Institute, Toronto, Ontario, Canada [2] Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada.

ABSTRACT

Background: Small molecule MIRA-1 induced mutant p53-dependent apoptosis in several types of solid tumours. However, anti-tumour activity of MIRA-1 in haematological malignancies including multiple myeloma (MM) is unknown. In this study, we evaluated the effect of MIRA-1 in MM.

Methods: We examined the anti-tumour activity of MIRA-1 alone or in combination with current anti-myeloma agents in a panel of MM cell lines, primary MM samples, and in a mouse xenograft model of MM.

Results: MIRA-1 treatment resulted in the inhibition of viability, colony formation, and migration and increase in apoptosis of MM cells irrespective of p53 status accompanied by upregulation of Puma and Bax and downregulation of Mcl-1 and c-Myc. Genetic knockdown of p53 did not abrogate apoptotic response of MIRA-1. MIRA-1 triggered activation of PERK and IRE-α leading to splicing of XBP1 indicating an association of endoplasmic reticulum stress response. Furthermore, combined treatment of MIRA-1 with dexamethasone, doxorubicin or velcade displayed synergistic response in MM cells. Importantly, MIRA-1 alone or in combination with dexamethasone retarded tumour growth and prolonged survival without showing any untoward toxicity in the mice bearing MM tumour.

Conclusions: Our data provide the preclinical framework for clinical evaluation of MIRA-1 as a novel therapeutic agent to improve patient outcome in MM.

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Related in: MedlinePlus

MIRA-1 in combination with current anti-myeloma agents displayed synergistic cytotoxic response in MM cells. Cells obtained from either cell lines or patient samples were treated with MIRA-1 (10 μmol l−1) in combination with (A) dexamethasone (1.0 μmol l−1) or (B) doxorubicin (1.0 μmol l−1). (C) MM.1S or U266 cells were treated with MIRA-1 (5 μmol l−1) and velcade (2.5 nmol l−1). 48 h after treatment, cells were assessed for survival by MTT viability assay (*<0.05). Data are expressed as mean ± s.d. of triplicate cultures of at least two independent experiments.
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fig5: MIRA-1 in combination with current anti-myeloma agents displayed synergistic cytotoxic response in MM cells. Cells obtained from either cell lines or patient samples were treated with MIRA-1 (10 μmol l−1) in combination with (A) dexamethasone (1.0 μmol l−1) or (B) doxorubicin (1.0 μmol l−1). (C) MM.1S or U266 cells were treated with MIRA-1 (5 μmol l−1) and velcade (2.5 nmol l−1). 48 h after treatment, cells were assessed for survival by MTT viability assay (*<0.05). Data are expressed as mean ± s.d. of triplicate cultures of at least two independent experiments.

Mentions: As novel anti-cancer agents are generally applied in combination with existing therapeutics, we examined whether MIRA-1 could potentiate the action of drugs currently used to treat MM. To this aim, MM cell lines or a primary MM sample were treated with combinations of MIRA-1 with either conventional drugs (dexamethasone or doxorubicin) or with novel antimyeloma agents (velcade). The cytotoxicity of the cells was analysed by MTT assays. As shown in Figure 5, simultaneous treatment of 8226 MM cell line or a patient sample with MIRA-1 and dexamethasone or doxorubicin resulted in a significant decrease in cell survival when compared with the single agents (P<0.05). When combined with low concentrations of these drugs, synergistic effects were observed (CI<1.0) (Figure 5A and B). We next assessed the ability of MIRA-1 to synergise with velcade. In both MM.1S and U266 cells, a significant decrease in the viability was observed in combination treatment compared with single treatment after 48 h of exposure of low doses of these drugs. The synergy was observed for these combinations with CI of lower than 1.0 (Figure 5C). These data demonstrated that combined treatment with equipotent doses of MIRA-1 and dexamethasone, doxorubicin, or velcade resulted in synergistic effects in MM cells.


Small molecule MIRA-1 induces in vitro and in vivo anti-myeloma activity and synergizes with current anti-myeloma agents.

Saha MN, Chen Y, Chen MH, Chen G, Chang H - Br. J. Cancer (2014)

MIRA-1 in combination with current anti-myeloma agents displayed synergistic cytotoxic response in MM cells. Cells obtained from either cell lines or patient samples were treated with MIRA-1 (10 μmol l−1) in combination with (A) dexamethasone (1.0 μmol l−1) or (B) doxorubicin (1.0 μmol l−1). (C) MM.1S or U266 cells were treated with MIRA-1 (5 μmol l−1) and velcade (2.5 nmol l−1). 48 h after treatment, cells were assessed for survival by MTT viability assay (*<0.05). Data are expressed as mean ± s.d. of triplicate cultures of at least two independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4007239&req=5

fig5: MIRA-1 in combination with current anti-myeloma agents displayed synergistic cytotoxic response in MM cells. Cells obtained from either cell lines or patient samples were treated with MIRA-1 (10 μmol l−1) in combination with (A) dexamethasone (1.0 μmol l−1) or (B) doxorubicin (1.0 μmol l−1). (C) MM.1S or U266 cells were treated with MIRA-1 (5 μmol l−1) and velcade (2.5 nmol l−1). 48 h after treatment, cells were assessed for survival by MTT viability assay (*<0.05). Data are expressed as mean ± s.d. of triplicate cultures of at least two independent experiments.
Mentions: As novel anti-cancer agents are generally applied in combination with existing therapeutics, we examined whether MIRA-1 could potentiate the action of drugs currently used to treat MM. To this aim, MM cell lines or a primary MM sample were treated with combinations of MIRA-1 with either conventional drugs (dexamethasone or doxorubicin) or with novel antimyeloma agents (velcade). The cytotoxicity of the cells was analysed by MTT assays. As shown in Figure 5, simultaneous treatment of 8226 MM cell line or a patient sample with MIRA-1 and dexamethasone or doxorubicin resulted in a significant decrease in cell survival when compared with the single agents (P<0.05). When combined with low concentrations of these drugs, synergistic effects were observed (CI<1.0) (Figure 5A and B). We next assessed the ability of MIRA-1 to synergise with velcade. In both MM.1S and U266 cells, a significant decrease in the viability was observed in combination treatment compared with single treatment after 48 h of exposure of low doses of these drugs. The synergy was observed for these combinations with CI of lower than 1.0 (Figure 5C). These data demonstrated that combined treatment with equipotent doses of MIRA-1 and dexamethasone, doxorubicin, or velcade resulted in synergistic effects in MM cells.

Bottom Line: MIRA-1 treatment resulted in the inhibition of viability, colony formation, and migration and increase in apoptosis of MM cells irrespective of p53 status accompanied by upregulation of Puma and Bax and downregulation of Mcl-1 and c-Myc.Genetic knockdown of p53 did not abrogate apoptotic response of MIRA-1.Our data provide the preclinical framework for clinical evaluation of MIRA-1 as a novel therapeutic agent to improve patient outcome in MM.

View Article: PubMed Central - PubMed

Affiliation: 1] Division of Molecular and Cellular Biology, Toronto General Research Institute, Toronto, Ontario, Canada [2] Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada.

ABSTRACT

Background: Small molecule MIRA-1 induced mutant p53-dependent apoptosis in several types of solid tumours. However, anti-tumour activity of MIRA-1 in haematological malignancies including multiple myeloma (MM) is unknown. In this study, we evaluated the effect of MIRA-1 in MM.

Methods: We examined the anti-tumour activity of MIRA-1 alone or in combination with current anti-myeloma agents in a panel of MM cell lines, primary MM samples, and in a mouse xenograft model of MM.

Results: MIRA-1 treatment resulted in the inhibition of viability, colony formation, and migration and increase in apoptosis of MM cells irrespective of p53 status accompanied by upregulation of Puma and Bax and downregulation of Mcl-1 and c-Myc. Genetic knockdown of p53 did not abrogate apoptotic response of MIRA-1. MIRA-1 triggered activation of PERK and IRE-α leading to splicing of XBP1 indicating an association of endoplasmic reticulum stress response. Furthermore, combined treatment of MIRA-1 with dexamethasone, doxorubicin or velcade displayed synergistic response in MM cells. Importantly, MIRA-1 alone or in combination with dexamethasone retarded tumour growth and prolonged survival without showing any untoward toxicity in the mice bearing MM tumour.

Conclusions: Our data provide the preclinical framework for clinical evaluation of MIRA-1 as a novel therapeutic agent to improve patient outcome in MM.

Show MeSH
Related in: MedlinePlus