Role of Hedgehog Signaling in Malignant Pleural Mesothelioma

• Published in: Clinical cancer research 2012-09, Vol.18 (17), p.4646-4656
• Main Authors: YANDONG SHI, MOURA, Ubiratan, OPITZ, Isabelle, SOLTERMANN, Alex, REHRAUER, Hubert, THIES, Svenja, WEDER, Walter, STAHEL, Rolf A, FELLEY-BOSCO, Emanuela
• Format: Article
• Language: English
• Subjects: Adaptor Proteins, Signal Transducing - metabolism; Adult; Aged; Anilides - administration & dosage; Animals; Antineoplastic agents; Biological and medical sciences; Cell Line, Tumor; Cell Proliferation - drug effects; Female; Gene Expression Regulation, Neoplastic - drug effects; Humans; Inhibitor of Apoptosis Proteins - blood; Lung Neoplasms - drug therapy; Lung Neoplasms - metabolism; Lung Neoplasms - pathology; Male; Medical sciences; Mesothelioma - drug therapy; Mesothelioma - metabolism; Mesothelioma - pathology; Mice; Middle Aged; NIH 3T3 Cells; Pharmacology. Drug treatments; Phosphoproteins - metabolism; Pleural Effusion, Malignant - drug therapy; Pleural Effusion, Malignant - metabolism; Pleural Effusion, Malignant - pathology; Pneumology; Pyridines - administration & dosage; Receptors, G-Protein-Coupled - antagonists & inhibitors; Receptors, G-Protein-Coupled - metabolism; RNA, Small Interfering; Signal Transduction; Smoothened Receptor; Survivin; Tomatine - administration & dosage; Tomatine - analogs & derivatives; Transcription Factors - antagonists & inhibitors; Transcription Factors - metabolism; Transplantation, Heterologous; Tumors of the respiratory system and mediastinum; Veratrum Alkaloids - administration & dosage; Zinc Finger Protein GLI1
• ISSN: 1078-0432; 1557-3265
• DOI: 10.1158/1078-0432.ccr-12-0599

The aim of this study was to assess the activity of hedgehog signaling pathway in malignant pleural mesothelioma (MPM). The expression of hedgehog signaling components was assessed by quantitative PCR and in situ hybridization in 45 clinical samples. Primary MPM cultures were developed in serum-free condition in 3% oxygen and were used to investigate the effects of smoothened (SMO) inhibitors or GLI1 silencing on cell growth and hedgehog signaling. In vivo effects of SMO antagonists were determined in an MPM xenograft growing in nude mice. A significant increase in GLI1, sonic hedgehog, and human hedgehog interacting protein gene expression was observed in MPM tumors compared with nontumoral pleural tissue. SMO antagonists inhibited GLI1 expression and cell growth in sensitive primary cultures. This effect was mimicked by GLI1 silencing. Reduced survivin and YAP protein levels were also observed. Survivin protein levels were rescued by overexpression of GLI1 or constitutively active YAP1. Treatment of tumor-bearing mice with the SMO inhibitor HhAntag led to a significant inhibition of tumor growth in vivo accompanied by decreased Ki-67 and nuclear YAP immunostaining and a significant difference in selected gene expression profile in tumors. An aberrant hedgehog signaling is present in MPM, and inhibition of hedgehog signaling decreases tumor growth indicating potential new therapeutic approach.