Limits...
Inhibition of iNOS as a novel effective targeted therapy against triple-negative breast cancer.

Granados-Principal S, Liu Y, Guevara ML, Blanco E, Choi DS, Qian W, Patel T, Rodriguez AA, Cusimano J, Weiss HL, Zhao H, Landis MD, Dave B, Gross SS, Chang JC - Breast Cancer Res. (2015)

Bottom Line: We hypothesized that inhibition of endogenous iNOS would decrease TNBC aggressiveness by reducing tumor initiation and metastasis through modulation of epithelial-mesenchymal transition (EMT)-inducing factors. iNOS protein levels were determined in 83 human TNBC tissues and correlated with clinical outcome.High endogenous iNOS expression was associated with worse prognosis in patients with TNBC by gene expression as well as immunohistochemical analysis.Impairment of hypoxia-inducible factor 1α, endoplasmic reticulum stress (IRE1α/XBP1), and the crosstalk between activating transcription factor 3/activating transcription factor 4 and transforming growth factor β was observed. iNOS inhibition significantly reduced tumor growth, the number of lung metastases, tumor initiation, and self-renewal.

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer with no effective targeted therapy. Inducible nitric oxide synthase (iNOS) is associated with poor survival in patients with breast cancer by increasing tumor aggressiveness. This work aimed to investigate the potential of iNOS inhibitors as a targeted therapy for TNBC. We hypothesized that inhibition of endogenous iNOS would decrease TNBC aggressiveness by reducing tumor initiation and metastasis through modulation of epithelial-mesenchymal transition (EMT)-inducing factors.

Methods: iNOS protein levels were determined in 83 human TNBC tissues and correlated with clinical outcome. Proliferation, mammosphere-forming efficiency, migration, and EMT transcription factors were assessed in vitro after iNOS inhibition. Endogenous iNOS targeting was evaluated as a potential therapy in TNBC mouse models.

Results: High endogenous iNOS expression was associated with worse prognosis in patients with TNBC by gene expression as well as immunohistochemical analysis. Selective iNOS (1400 W) and pan-NOS (L-NMMA and L-NAME) inhibitors diminished cell proliferation, cancer stem cell self-renewal, and cell migration in vitro, together with inhibition of EMT transcription factors (Snail, Slug, Twist1, and Zeb1). Impairment of hypoxia-inducible factor 1α, endoplasmic reticulum stress (IRE1α/XBP1), and the crosstalk between activating transcription factor 3/activating transcription factor 4 and transforming growth factor β was observed. iNOS inhibition significantly reduced tumor growth, the number of lung metastases, tumor initiation, and self-renewal.

Conclusions: Considering the effectiveness of L-NMMA in decreasing tumor growth and enhancing survival rate in TNBC, we propose a targeted therapeutic clinical trial by re-purposing the pan-NOS inhibitor L-NMMA, which has been extensively investigated for cardiogenic shock as an anti-cancer therapeutic.

Show MeSH

Related in: MedlinePlus

Clinically relevant dose regimen of L-NMMA in orthotopic mouse models of triple-negative breast cancer. (A) Mean systolic pressure of mice (n = 5) giving one cycle of the dose rate proposed in this study. (B) Mean systolic pressure of mice 30 minutes and 24 hours after the last injection of one cycle treatment (n = 5). (C) Tumor volume of MDA-MB-231 xenografts (n = 10 per group) treated with vehicle, docetaxel, and combination (docetaxel + amlodipine + L-NMMA). (D) Kaplan-Meier survival curve of vehicle-, chemotherapy-, and combo-treated MDA-MB-231 xenograft-bearing mice. (E) Tumor volume of SUM159 xenografts (n = 10 per group) treated with vehicle, docetaxel, and combination. (F) Effects of amlodipine on tumor volume in MDA-MB-231 xenografts (n = 5 per group). Data are presented as mean ± standard error of the mean. *P <0.05, **P <0.01, ***P <0.001, ****P <0.0001. L-NMMA, NG-monomethyl-L-arginine; ns, not significant.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4384389&req=5

Fig6: Clinically relevant dose regimen of L-NMMA in orthotopic mouse models of triple-negative breast cancer. (A) Mean systolic pressure of mice (n = 5) giving one cycle of the dose rate proposed in this study. (B) Mean systolic pressure of mice 30 minutes and 24 hours after the last injection of one cycle treatment (n = 5). (C) Tumor volume of MDA-MB-231 xenografts (n = 10 per group) treated with vehicle, docetaxel, and combination (docetaxel + amlodipine + L-NMMA). (D) Kaplan-Meier survival curve of vehicle-, chemotherapy-, and combo-treated MDA-MB-231 xenograft-bearing mice. (E) Tumor volume of SUM159 xenografts (n = 10 per group) treated with vehicle, docetaxel, and combination. (F) Effects of amlodipine on tumor volume in MDA-MB-231 xenografts (n = 5 per group). Data are presented as mean ± standard error of the mean. *P <0.05, **P <0.01, ***P <0.001, ****P <0.0001. L-NMMA, NG-monomethyl-L-arginine; ns, not significant.

Mentions: Clinically, L-NMMA causes acute BP elevation through inhibition of constitutive eNOS [30]. Here, we propose a regimen with an attenuated duration of L-NMMA, at a dose comparable to that previously described clinically [31], together with the anti-hypertensive amlodipine and docetaxel. Oral L-NMMA significantly increased the mean systolic pressure compared with basal levels in mice, and this elevation was efficiently reversed by amlodipine (Figure 6A). This elevation in BP was transient and disappeared 24 hours after the last injection of L-NMMA (Figure 6B).Figure 6


Inhibition of iNOS as a novel effective targeted therapy against triple-negative breast cancer.

Granados-Principal S, Liu Y, Guevara ML, Blanco E, Choi DS, Qian W, Patel T, Rodriguez AA, Cusimano J, Weiss HL, Zhao H, Landis MD, Dave B, Gross SS, Chang JC - Breast Cancer Res. (2015)

Clinically relevant dose regimen of L-NMMA in orthotopic mouse models of triple-negative breast cancer. (A) Mean systolic pressure of mice (n = 5) giving one cycle of the dose rate proposed in this study. (B) Mean systolic pressure of mice 30 minutes and 24 hours after the last injection of one cycle treatment (n = 5). (C) Tumor volume of MDA-MB-231 xenografts (n = 10 per group) treated with vehicle, docetaxel, and combination (docetaxel + amlodipine + L-NMMA). (D) Kaplan-Meier survival curve of vehicle-, chemotherapy-, and combo-treated MDA-MB-231 xenograft-bearing mice. (E) Tumor volume of SUM159 xenografts (n = 10 per group) treated with vehicle, docetaxel, and combination. (F) Effects of amlodipine on tumor volume in MDA-MB-231 xenografts (n = 5 per group). Data are presented as mean ± standard error of the mean. *P <0.05, **P <0.01, ***P <0.001, ****P <0.0001. L-NMMA, NG-monomethyl-L-arginine; ns, not significant.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4384389&req=5

Fig6: Clinically relevant dose regimen of L-NMMA in orthotopic mouse models of triple-negative breast cancer. (A) Mean systolic pressure of mice (n = 5) giving one cycle of the dose rate proposed in this study. (B) Mean systolic pressure of mice 30 minutes and 24 hours after the last injection of one cycle treatment (n = 5). (C) Tumor volume of MDA-MB-231 xenografts (n = 10 per group) treated with vehicle, docetaxel, and combination (docetaxel + amlodipine + L-NMMA). (D) Kaplan-Meier survival curve of vehicle-, chemotherapy-, and combo-treated MDA-MB-231 xenograft-bearing mice. (E) Tumor volume of SUM159 xenografts (n = 10 per group) treated with vehicle, docetaxel, and combination. (F) Effects of amlodipine on tumor volume in MDA-MB-231 xenografts (n = 5 per group). Data are presented as mean ± standard error of the mean. *P <0.05, **P <0.01, ***P <0.001, ****P <0.0001. L-NMMA, NG-monomethyl-L-arginine; ns, not significant.
Mentions: Clinically, L-NMMA causes acute BP elevation through inhibition of constitutive eNOS [30]. Here, we propose a regimen with an attenuated duration of L-NMMA, at a dose comparable to that previously described clinically [31], together with the anti-hypertensive amlodipine and docetaxel. Oral L-NMMA significantly increased the mean systolic pressure compared with basal levels in mice, and this elevation was efficiently reversed by amlodipine (Figure 6A). This elevation in BP was transient and disappeared 24 hours after the last injection of L-NMMA (Figure 6B).Figure 6

Bottom Line: We hypothesized that inhibition of endogenous iNOS would decrease TNBC aggressiveness by reducing tumor initiation and metastasis through modulation of epithelial-mesenchymal transition (EMT)-inducing factors. iNOS protein levels were determined in 83 human TNBC tissues and correlated with clinical outcome.High endogenous iNOS expression was associated with worse prognosis in patients with TNBC by gene expression as well as immunohistochemical analysis.Impairment of hypoxia-inducible factor 1α, endoplasmic reticulum stress (IRE1α/XBP1), and the crosstalk between activating transcription factor 3/activating transcription factor 4 and transforming growth factor β was observed. iNOS inhibition significantly reduced tumor growth, the number of lung metastases, tumor initiation, and self-renewal.

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer with no effective targeted therapy. Inducible nitric oxide synthase (iNOS) is associated with poor survival in patients with breast cancer by increasing tumor aggressiveness. This work aimed to investigate the potential of iNOS inhibitors as a targeted therapy for TNBC. We hypothesized that inhibition of endogenous iNOS would decrease TNBC aggressiveness by reducing tumor initiation and metastasis through modulation of epithelial-mesenchymal transition (EMT)-inducing factors.

Methods: iNOS protein levels were determined in 83 human TNBC tissues and correlated with clinical outcome. Proliferation, mammosphere-forming efficiency, migration, and EMT transcription factors were assessed in vitro after iNOS inhibition. Endogenous iNOS targeting was evaluated as a potential therapy in TNBC mouse models.

Results: High endogenous iNOS expression was associated with worse prognosis in patients with TNBC by gene expression as well as immunohistochemical analysis. Selective iNOS (1400 W) and pan-NOS (L-NMMA and L-NAME) inhibitors diminished cell proliferation, cancer stem cell self-renewal, and cell migration in vitro, together with inhibition of EMT transcription factors (Snail, Slug, Twist1, and Zeb1). Impairment of hypoxia-inducible factor 1α, endoplasmic reticulum stress (IRE1α/XBP1), and the crosstalk between activating transcription factor 3/activating transcription factor 4 and transforming growth factor β was observed. iNOS inhibition significantly reduced tumor growth, the number of lung metastases, tumor initiation, and self-renewal.

Conclusions: Considering the effectiveness of L-NMMA in decreasing tumor growth and enhancing survival rate in TNBC, we propose a targeted therapeutic clinical trial by re-purposing the pan-NOS inhibitor L-NMMA, which has been extensively investigated for cardiogenic shock as an anti-cancer therapeutic.

Show MeSH
Related in: MedlinePlus