Lee, M.S. ; Minaskan Karabid, N. ; Wiedemann, T. ; Irmler, M. ; Beckers, J. ; Yousefi, B.H.* ; Kaissis, G.* ; Braren, R.* ; Laitinen, I.* ; Pellegata, N.S.
     
 
    
        
Targeting PI3K/mTOR signaling exerts potent antitumor activity in pheochromocytoma in vivo.
    
    
        
    
    
        
        Endocr. Relat. Cancer 24, 1-15 (2017)
    
    
    
		
		
			
				Pheochromocytomas (PCCs) are mostly benign tumors, amenable to complete surgical resection. However, 10–17% of cases can become malignant, and once metastasized, there is no curative treatment for this disease. Given the need to identify the effective therapeutic approaches for PCC, we evaluated the antitumor potential of the dual-PI3K/mTOR inhibitor BEZ235 against these tumors. We employed an in vivo model of endogenous PCCs (MENX mutant rats), which closely recapitulate the human tumors. Mutant rats with PCCs were treated with 2 doses of BEZ235 (20 and 30 mg/kg), or with placebo, for 2 weeks. Treatment with BEZ235 induced cytostatic and cytotoxic effects on rat PCCs, which could be appreciated by both staining the tumors ex vivo with appropriate markers and non-invasively by functional imaging (diffusion-weighted magnetic resonance imaging) in vivo. Transcriptomic analyses of tumors from rats treated with BEZ235 or placebo-identified potential mediators of therapy response were performed. Slc6a2, encoding the norepinephrine transporter (NET), was downregulated in a dose-dependent manner by BEZ235 in rat PCCs. Moreover, BEZ235 reduced Slc6a2/NET expression in PCC cell lines (MPC) also. Studies of a BEZ235-resistant derivative of the MPC cell line confirmed that the reduction of NET expression associates with the response to the drug. Reduction of NET expression after BEZ235 treatment in vivo could be monitored by positron emission tomography (PET) using a tracer targeting NET. Altogether, here we demonstrate the efficacy of BEZ235 against PCC in vivo, and show that functional imaging can be employed to monitor the response of PCC to PI3K/mTOR inhibition therapy.
			
			
				
			
		 
		
			
				
					
					Impact Factor
					Scopus SNIP
					Web of Science
Times Cited
					Scopus
Cited By
					
					Altmetric
					
				 
				
			 
		 
		
     
    
        Publikationstyp
        Artikel: Journalartikel
    
 
    
        Dokumenttyp
        Wissenschaftlicher Artikel
    
 
    
        Typ der Hochschulschrift
        
    
 
    
        Herausgeber
        
    
    
        Schlagwörter
        pheochromocytoma; MENX; PI3K/mTOR inhibition; NET; predictive biomarker; imaging; Phosphatidylinositol 3-kinase/mammalian Target; Malignant Pheochromocytoma; Neuroendocrine Tumors; Phosphoinositide 3-kinase; Inhibitor Nvp-bez235; Rapamycin Inhibitor; Pituitary-adenomas; Cancer-cells; Solid Tumors; Mtor
    
 
    
        Keywords plus
        
    
 
    
    
        Sprache
        
    
 
    
        Veröffentlichungsjahr
        2017
    
 
    
        Prepublished im Jahr 
        2016
    
 
    
        HGF-Berichtsjahr
        2016
    
 
    
    
        ISSN (print) / ISBN
        1351-0088
    
 
    
        e-ISSN
        1479-6821
    
 
    
        ISBN
        
    
 
    
        Bandtitel
        
    
 
    
        Konferenztitel
        
    
 
	
        Konferzenzdatum
        
    
     
	
        Konferenzort
        
    
 
	
        Konferenzband
        
    
 
     
		
    
        Quellenangaben
        
	    Band: 24,  
	    Heft: 1,  
	    Seiten: 1-15 
	    Artikelnummer: ,  
	    Supplement: ,  
	
    
 
  
        
            Reihe
            
        
 
        
            Verlag
            BioScientifica
        
 
        
            Verlagsort
            Bristol
        
 
	
        
            Tag d. mündl. Prüfung
            0000-00-00
        
 
        
            Betreuer
            
        
 
        
            Gutachter
            
        
 
        
            Prüfer
            
        
 
        
            Topic
            
        
 
	
        
            Hochschule
            
        
 
        
            Hochschulort
            
        
 
        
            Fakultät
            
        
 
    
        
            Veröffentlichungsdatum
            0000-00-00
        
 
         
        
            Anmeldedatum
            0000-00-00
        
 
        
            Anmelder/Inhaber
            
        
 
        
            weitere Inhaber
            
        
 
        
            Anmeldeland
            
        
 
        
            Priorität
            
        
 
    
        Begutachtungsstatus
        Peer reviewed
    
 
     
    
        POF Topic(s)
        30201 - Metabolic Health
30502 - Diabetes: Pathophysiology, Prevention and Therapy
    
 
    
        Forschungsfeld(er)
        Helmholtz Diabetes Center
Genetics and Epidemiology
    
 
    
        PSP-Element(e)
        G-502590-001
G-500600-004
G-500600-005
G-500600-006
    
 
    
        Förderungen
        
    
 
    
        Copyright
        
    
 	
    
    
    
    
    
        Erfassungsdatum
        2016-11-23