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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 induced anti-myeloma activity in vivo. SCID mice (n=5 per group) were inoculated s.c. with 3 × 107 8226 cells in RPMI medium along with matrigel matrix. Tumour-bearing mice were randomly assigned into two cohorts receiving daily i.p. injection of MIRA-1 (10 mg kg−1) or with vehicle (PBS) alone for 15 days. (A) MIRA-1 treatment resulted in tumour growth inhibition (*P<0.05). (B) Prolonged survival was observed in the treatment group of mice (P=0.007). (C) No significant loss of body weight was observed. (D–F) MIRA-1 enhanced anti-tumour activity of dexamethasone in vivo. SCID mice were inoculated s.c. with 3 × 107 8226 cells in 100 μl RPMI medium together with matrigel matrix. Twenty tumour-bearing mice were randomly assigned to four groups and treated for 13 days with control (PBS), MIRA-1 (5 mg kg−1), dexamethasone (1 mg kg−1), or the combination once daily. At day 15, the treatment was discontinued and mice were monitored for tumour dynamics and body weight. (D) MIRA-1 and dexamethasone combination therapy triggered more potent inhibition of tumour growth in mice treated with MIRA-1 or dexamethasone alone or control (*P<0.05). (E) Combination therapy markedly prolonged survival compared with mice treated with control (P=0.003), MIRA-1 (P=0.005) or dexamethasone (P<0.045) alone. (F) Mice body weight was used to assess toxicity of the treatment. C = control; M = MIRA-1; D = dexamethasone; M+D = MIRA-1 + dexamethasone.
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fig6: MIRA-1 induced anti-myeloma activity in vivo. SCID mice (n=5 per group) were inoculated s.c. with 3 × 107 8226 cells in RPMI medium along with matrigel matrix. Tumour-bearing mice were randomly assigned into two cohorts receiving daily i.p. injection of MIRA-1 (10 mg kg−1) or with vehicle (PBS) alone for 15 days. (A) MIRA-1 treatment resulted in tumour growth inhibition (*P<0.05). (B) Prolonged survival was observed in the treatment group of mice (P=0.007). (C) No significant loss of body weight was observed. (D–F) MIRA-1 enhanced anti-tumour activity of dexamethasone in vivo. SCID mice were inoculated s.c. with 3 × 107 8226 cells in 100 μl RPMI medium together with matrigel matrix. Twenty tumour-bearing mice were randomly assigned to four groups and treated for 13 days with control (PBS), MIRA-1 (5 mg kg−1), dexamethasone (1 mg kg−1), or the combination once daily. At day 15, the treatment was discontinued and mice were monitored for tumour dynamics and body weight. (D) MIRA-1 and dexamethasone combination therapy triggered more potent inhibition of tumour growth in mice treated with MIRA-1 or dexamethasone alone or control (*P<0.05). (E) Combination therapy markedly prolonged survival compared with mice treated with control (P=0.003), MIRA-1 (P=0.005) or dexamethasone (P<0.045) alone. (F) Mice body weight was used to assess toxicity of the treatment. C = control; M = MIRA-1; D = dexamethasone; M+D = MIRA-1 + dexamethasone.

Mentions: Next, we sought to examine whether in vitro MIRA-1-induced MM cytotoxicity can be translated into effective in vivo anti-MM activity in SCID mice xenografted 8226 cells. Treatment with MIRA-1 significantly retarded tumour growth, with maximum tumour growth inhibition noted at day 15 (Figure 6A) (P<0.05). MIRA-1 treatment was also associated with improved survival, evidenced by first death at day 20 in control versus day 45 in treated group (Figure 6B) (P=0.007). There were no obvious toxic effects of the treatments as evaluated by mouse body weight data (Figure 6C).


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 induced anti-myeloma activity in vivo. SCID mice (n=5 per group) were inoculated s.c. with 3 × 107 8226 cells in RPMI medium along with matrigel matrix. Tumour-bearing mice were randomly assigned into two cohorts receiving daily i.p. injection of MIRA-1 (10 mg kg−1) or with vehicle (PBS) alone for 15 days. (A) MIRA-1 treatment resulted in tumour growth inhibition (*P<0.05). (B) Prolonged survival was observed in the treatment group of mice (P=0.007). (C) No significant loss of body weight was observed. (D–F) MIRA-1 enhanced anti-tumour activity of dexamethasone in vivo. SCID mice were inoculated s.c. with 3 × 107 8226 cells in 100 μl RPMI medium together with matrigel matrix. Twenty tumour-bearing mice were randomly assigned to four groups and treated for 13 days with control (PBS), MIRA-1 (5 mg kg−1), dexamethasone (1 mg kg−1), or the combination once daily. At day 15, the treatment was discontinued and mice were monitored for tumour dynamics and body weight. (D) MIRA-1 and dexamethasone combination therapy triggered more potent inhibition of tumour growth in mice treated with MIRA-1 or dexamethasone alone or control (*P<0.05). (E) Combination therapy markedly prolonged survival compared with mice treated with control (P=0.003), MIRA-1 (P=0.005) or dexamethasone (P<0.045) alone. (F) Mice body weight was used to assess toxicity of the treatment. C = control; M = MIRA-1; D = dexamethasone; M+D = MIRA-1 + dexamethasone.
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fig6: MIRA-1 induced anti-myeloma activity in vivo. SCID mice (n=5 per group) were inoculated s.c. with 3 × 107 8226 cells in RPMI medium along with matrigel matrix. Tumour-bearing mice were randomly assigned into two cohorts receiving daily i.p. injection of MIRA-1 (10 mg kg−1) or with vehicle (PBS) alone for 15 days. (A) MIRA-1 treatment resulted in tumour growth inhibition (*P<0.05). (B) Prolonged survival was observed in the treatment group of mice (P=0.007). (C) No significant loss of body weight was observed. (D–F) MIRA-1 enhanced anti-tumour activity of dexamethasone in vivo. SCID mice were inoculated s.c. with 3 × 107 8226 cells in 100 μl RPMI medium together with matrigel matrix. Twenty tumour-bearing mice were randomly assigned to four groups and treated for 13 days with control (PBS), MIRA-1 (5 mg kg−1), dexamethasone (1 mg kg−1), or the combination once daily. At day 15, the treatment was discontinued and mice were monitored for tumour dynamics and body weight. (D) MIRA-1 and dexamethasone combination therapy triggered more potent inhibition of tumour growth in mice treated with MIRA-1 or dexamethasone alone or control (*P<0.05). (E) Combination therapy markedly prolonged survival compared with mice treated with control (P=0.003), MIRA-1 (P=0.005) or dexamethasone (P<0.045) alone. (F) Mice body weight was used to assess toxicity of the treatment. C = control; M = MIRA-1; D = dexamethasone; M+D = MIRA-1 + dexamethasone.
Mentions: Next, we sought to examine whether in vitro MIRA-1-induced MM cytotoxicity can be translated into effective in vivo anti-MM activity in SCID mice xenografted 8226 cells. Treatment with MIRA-1 significantly retarded tumour growth, with maximum tumour growth inhibition noted at day 15 (Figure 6A) (P<0.05). MIRA-1 treatment was also associated with improved survival, evidenced by first death at day 20 in control versus day 45 in treated group (Figure 6B) (P=0.007). There were no obvious toxic effects of the treatments as evaluated by mouse body weight data (Figure 6C).

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