Survivin inhibition with YM155 ameliorates experimental pulmonary arterial hypertension

Background: Imbalance between cell proliferation and apoptosis underlies the development of pulmonary arterial hypertension (PAH). Current vasodilator treatment of PAH does not target the uncontrolled proliferative process in pulmonary arteries. Proteins involved in the apoptosis pathway may play a role in PAH and their inhibition might represent a potential therapeutic target. Survivin is a member of the apoptosis inhibitor protein family involved in cell proliferation.Objectives: This study aimed to explore the potential role of survivin in the pathogenesis of PAH and the effects of its inhibition.Methods: In SU5416/hypoxia-induced PAH mice we assessed the expression of survivin by immunohistochemistry, western-blot analysis, and RT-PCR; the expression of proliferation-related genes (Bcl2 and Mki67); and the effects of the survivin inhibitor YM155. In explanted lungs from patients with PAH we assessed the expression of survivin, BCL2 and MKI67.Results: SU5416/hypoxia mice showed increased expression of survivin in pulmonary arteries and lung tissue extract, and upregulation of survivin, Bcl2 and Mki67 genes. Treatment with YM155 reduced right ventricle (RV) systolic pressure, RV thickness, pulmonary vascular remodeling, and the expression of survivin, Bcl2, and Mki67 to values similar to those in control animals. Lungs of patients with PAH also showed increased expression of survivin in pulmonary arteries and lung extract, and also that of BCL2 and MKI67 genes, compared with control lungs.Conclusion: We conclude that survivin might be involved in the pathogenesis of PAH and that its inhibition with YM155 might represent a novel therapeutic approach that warrants further evaluation

New Biochemical Insights into the Mechanisms of Pulmonary Arterial Hypertension in Humans

Diagnosis of pulmonary arterial hypertension (PAH) is difficult due to the lack of specific clinical symptoms and biomarkers, especially at early stages. We compared plasma metabolic fingerprints of PAH patients (n = 20) with matched healthy volunteers (n = 20) using, for the first time, untargeted multiplatform metabolomics approach consisting of high-performance liquid and gas chromatography coupled with mass spectrometry. Multivariate statistical analyses were performed to select metabolites that contribute most to groups' classification (21 from liquid in both ionization modes and 9 from gas chromatography-mass spectrometry). We found metabolites related to energy imbalance, such as glycolysis-derived metabolites, as well as metabolites involved in fatty acid, lipid and amino acid metabolism. We observed statistically significant changes in threitol and aminomalonic acid in PAH patients, which could provide new biochemical insights into the pathogenesis of the disease. The results were externally validated on independent case and control cohorts, confirming up to 16 metabolites as statistically significant in the validation study. Multiplatform metabolomics, followed by multivariate chemometric data analysis has a huge potential for explaining pathogenesis of PAH and for searching potential and new more specific and less invasive markers of the disease.This research was supported by the Polish National Science Center (2014/13/N/NZ7/04231), the Spanish Ministry of Economy and Competitiveness (MINECO) (SAF2014-58920R), by the Fondo de Investigacion Sanitaria del Instituto de Salud Carlos III and co-funding by Fondo Europeo de Desarrollo Regional (FEDER) (PI14-01427), and by the quality-promoting subsidy from the Ministry of Science and Higher Education of Poland, Leading National Research Centre (KNOW programme 2012-2017). The CNIC is supported by the Spanish Ministry of Economy and Competitiveness and the Pro-CNIC Foundation, and is a Severo Ochoa Center of Excellence (MINECO award SEV-2015-0505). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S

Survivin inhibition with YM155 ameliorates experimental pulmonary arterial hypertension.

Peer reviewed: TrueAcknowledgements: The authors wish to acknowledge the invaluable contribution of the CIBERES Biobank for the samples provided, and would also like to thank Susana Maqueda, Neus Luque, Victoria Pisano, Cristina Bonjoch and Angela Vea for their technical support, Nick W Morrell for his support providing the funding and facilities for the MCT model and to Fernanda Hernández-González and Rodrigo Torres-Castro for helping in the final editing of the manuscript.Background: Imbalance between cell proliferation and apoptosis underlies the development of pulmonary arterial hypertension (PAH). Current vasodilator treatment of PAH does not target the uncontrolled proliferative process in pulmonary arteries. Proteins involved in the apoptosis pathway may play a role in PAH and their inhibition might represent a potential therapeutic target. Survivin is a member of the apoptosis inhibitor protein family involved in cell proliferation. Objectives: This study aimed to explore the potential role of survivin in the pathogenesis of PAH and the effects of its inhibition. Methods: In SU5416/hypoxia-induced PAH mice we assessed the expression of survivin by immunohistochemistry, western-blot analysis, and RT-PCR; the expression of proliferation-related genes (Bcl2 and Mki67); and the effects of the survivin inhibitor YM155. In explanted lungs from patients with PAH we assessed the expression of survivin, BCL2 and MKI67. Results: SU5416/hypoxia mice showed increased expression of survivin in pulmonary arteries and lung tissue extract, and upregulation of survivin, Bcl2 and Mki67 genes. Treatment with YM155 reduced right ventricle (RV) systolic pressure, RV thickness, pulmonary vascular remodeling, and the expression of survivin, Bcl2, and Mki67 to values similar to those in control animals. Lungs of patients with PAH also showed increased expression of survivin in pulmonary arteries and lung extract, and also that of BCL2 and MKI67 genes, compared with control lungs. Conclusion: We conclude that survivin might be involved in the pathogenesis of PAH and that its inhibition with YM155 might represent a novel therapeutic approach that warrants further evaluation

Identified metabolites that significantly change in human plasma from PAH patients <i>vs</i>. Control group, detected in LC-MS.

<p>Identified metabolites that significantly change in human plasma from PAH patients <i>vs</i>. Control group, detected in LC-MS.</p

Identified metabolites that significantly change in human plasma from PAH patients <i>vs</i>. Control group, detected in GC-Q-MS.

<p>Identified metabolites that significantly change in human plasma from PAH patients <i>vs</i>. Control group, detected in GC-Q-MS.</p

The connections between metabolic pathways altered in plasma of PAH patients as compared to control group.

<p>TCA: tricarboxylic acid.</p

OPLS-DA plots for plasma metabolic fingerprints obtained from C and PAH groups.

<p>(A) OPLS-DA model (R² = 0.844, Q² = 0.653) for LC-MS data in positive ionization mode. (B) OPLS-DA model (R² = 0.897, Q² = 0.618) for LC-MS data in negative ionization mode. (C) OPLS-DA model (R² = 0.825, Q² = 0.649) for GC-MS data. Pulmonary hypertensive group (PAH) and control (C) have been marked as red triangles and green circles, respectively. OPLS-DA: orthogonal partial least squares discriminant analysis.</p

Results of univariate statistical analysis in the independent validation study.

<p>Results of univariate statistical analysis in the independent validation study.</p

Epigenetic SMAD3 Repression in Tumor-Associated Fibroblasts Impairs Fibrosis and Response to the Antifibrotic Drug Nintedanib in Lung Squamous Cell Carcinoma

The tumor-promoting fibrotic stroma rich in tumor-associated fibroblasts (TAF) is drawing increased therapeutic attention. Intriguingly, a trial with the antifibrotic drug nintedanib in non– small cell lung cancer reported clinical benefits in adenocarcinoma (ADC) but not squamous cell carcinoma (SCC), even though the stroma is fibrotic in both histotypes. Likewise, we reported that nintedanib inhibited the tumor-promoting fibrotic phenotype of TAFs selectively in ADC. Here we show that tumor fibrosis is actually higher in ADC-TAFs than SCC-TAFs in vitro and patient samples. Mechanistically, the reduced fibrosis and nintedanib response of SCC-TAFs was associated with increased promoter methylation of the profibrotic TGFb transcription factor SMAD3 compared with ADC-TAFs, which elicited a compensatory increase in TGFb1/SMAD2 activation. Consistently, forcing global DNA demethylation of SCC-TAFs with 5-AZA rescued TGFb1/SMAD3 activation, whereas genetic downregulation of SMAD3 in ADCTAFs and control fibroblasts increased TGFb1/SMAD2 activation, and reduced their fibrotic phenotype and antitumor responses to nintedanib in vitro and in vivo. Our results also support that smoking and/or the anatomic location of SCC in the proximal airways, which are more exposed to cigarette smoke particles, may prime SCC-TAFs to stronger SMAD3 epigenetic repression, because cigarette smoke condensate selectively increased SMAD3 promoter methylation. Our results unveil that the histotype-specific regulation of tumor fibrosis in lung cancer is mediated through differential SMAD3 promoter methylation in TAFs and provide new mechanistic insights on the selective poor response of SCCTAFs to nintedanib. Moreover, our findings support that patients with ADC may be more responsive to antifibrotic drugs targeting their stromal TGFb1/SMAD3 activation. Significance: This study implicates the selective epigenetic repression of SMAD3 in SCC-TAFs in the clinical failure of nintedanib in SCC and supports that patients with ADC may benefit from antifibrotic drugs targeting stromal TGFb1/ SMAD3