ORIGINAL ARTICLE In papillary thyroid carcinoma BRAF V600E is associated with increased expression of the urokinase plasminogen activator and its cognate receptor, but not with disease-free interval Salvatore Ulisse* ,1 , Enke Baldini* ,1 , Salvatore Sorrenti†, Susi Barollo‡, Natalie Prinzi*, Antonio Catania†, Angela Nesca*, Lucio Gnessi*, Maria R. Pelizzo§, Caterina Mian§, Corrado De Vito¶, Anna Calvanese*, Silvio Palermo†, Severino Persechino**, Enrico De Antoni† and Massimino D’Armiento* *Department of Experimental Medicine, University of Rome, †Department of Surgical Sciences, ‘Sapienza’ University of Rome, ‡Veneto Institute of Oncology IOV - IRCCS, §Department of Medical and Surgical Sciences, University of Padova, Padova, ¶Department of Public Health and Infectious Diseases, ‘Sapienza’ University of Rome, and **Department of Neurosciences, Mental Health and Sensory Organs, ‘Sapienza’ University of Rome, Rome, Italy Summary Context It has been suggested that patients with papillary thyroid cancer (PTC) harbouring the BRAF V600E mutation have a worse prognosis. We showed in PTC that high levels of uroki- nase plasminogen activator (uPA) and its cognate receptor (uPAR) inversely correlate with disease-free interval (DFI). Objectives To investigate the effects of BRAF V600E on the expres- sion of uPA and uPAR and to evaluate the prognostic relevance of BRAF V600E alone or in combination with uPA and uPAR. Design/Setting/Patients/Intervention The case study included 91 patients with PTC. All patients underwent thyroidec- tomy and radioiodine therapy. Follow-up was available for 75 patients. Main outcome measures The BRAF V600E mutation was analy- sed by sequencing and mutant allele-specific PCR amplification; uPA and uPAR expression by quantitative RT-PCR. Results BRAF V600E PA and uPAR mRNA levels were higher in tumour tissues by 9·51 ± 1·30 and 4·64 ± 0·44 fold, respectively, compared to normal matched tissues, being significantly higher in BRAF V600E -positive patients. In vitro induction of BRAF V600E in PCCL3 cells caused a significant increase in both uPA and uPAR mRNAs. Higher levels of uPA and uPAR correlated with lymph node metastases, TNM stage and disease recurrences. Kaplan–Meier and multivariate analyses demonstrated that uPA and uPAR were associated with shorter DFI, while the BRAF V600E was not. Conclusion In PTC, BRAF V600E induces uPA and uPAR expression. The latter, but not BRAF V600E , associates with advanced stages and shorter DFI. If confirmed in larger case studies, they may represent reliable prognostic markers for more accurate risk stratification and postoperative decision-making in patients with PTC. (Received 22 April 2012; returned for revision 30 April 2012; finally revised 30 May 2012; accepted 6 June 2012) Introduction The urokinase plasminogen activating system (uPAS) consists of the urokinase plasminogen activator (uPA), its cognate cell membrane receptor (uPAR) and two main inhibitors, the plas- minogen activator inhibitor-1 (PAI-1) and -2 (PAI-2). The uPAS is present in many human tissues where it exerts a multifunc- tional role in various pathophysiological processes, relying on both proteolytic activation of plasmin and intracellular signalling initiated by uPAR interactome. 1 A wide variety of human can- cers overexpress one or more uPAS members, which significantly contribute to tumour progression by inducing extracellular matrix degradation, activation of latent growth factors, malig- nant cell spread and tumour neoangiogenesis. 1,2 The relevance of such proteins has emerged from a number of studies on xenograft tumour models that show that uPAS inhibition can greatly reduce cancer growth and metastasis formation. 3,4 More- over, the prognostic and/or predictive value of uPAS compo- nents has been validated for different cancer types in numerous extensive studies. As a rule, overexpression of one or more com- ponents has been shown to be associated with a higher risk of relapse and poor clinical outcome. 1,2,5–8 Over the last decade, several studies have indicated the uPAS components as new potential molecular biomarkers and therapeutic targets also for thyroid tumours. 9–12 These represent the most common Correspondence: Prof. Massimino D’Armiento, Department of Experi- mental Medicine, ‘Sapienza’ University of Rome, Viale Regina Elena 324, 00161 Roma, Italy. Tel.: (+39) 06 49972601; Fax: (+39) 06 49972606; E-mail: massimino.darmiento@uniroma1.it 1 The first two authors made an equal contribution. 780 © 2012 Blackwell Publishing Ltd Clinical Endocrinology (2012) 77, 780–786 doi: 10.1111/j.1365-2265.2012.04465.x