Expression ofMet protein and urokinase-type plasminogen activator receptor (uPA-R) in papillary carcinoma of the thyroid

✍ Scribed by Zanetti, Antonio; Stoppacciaro, Antonella; Marzullo, Antonella; Ciabatta, Maria; Fazioli, Francesca; Prat, Maria; Comoglio, Paolo M.; Baroni, Carlo D.; Ruco, Luigi P.

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 314 KB
• Volume: 186
• Category: Article
• ISSN: 0022-3417
• DOI: 10.1002/(sici)1096-9896(199811)186:3<287::aid-path175>3.0.co;2-x

✦ Synopsis

Met protein encoded by MET oncogene is the high affinity receptor for hepatocyte growth factor (HGF)/scatter factor (SF). HGF/SF has to be cleaved in its heterodimeric form by the urokinase-type plasminogen activator (uPA) to become active as a ligand for Met receptor. The expression of Met protein and of the high affinity receptor for uPA (uPA-R) was investigated in 39 samples of papillary carcinoma using immunohistochemistry. Reactivity for Met protein was present in 33 of 34 tumours, mostly with a diffuse pattern of staining. Reactivity for uPA-R was present in 78 per cent of papillary tumours and exhibited a pattern of staining similar to that of Met protein. Staining for uPA-R was present in 23 of 25 cases (92 per cent) of papillary carcinoma with prominent sclerosis, and in only 1 of 7 cases (14 per cent) without sclerosis. Peritumoural normal thyroid, follicular adenomas, and follicular carcinomas were negative for Met protein and for uPA-R. Hyperfunctioning tall thyroid cells showed weak membrane reactivity for uPA-R and for Met protein. The findings of immunohistochemistry were confirmed at the mRNA level using in situ hybridization, since the signal for uPA-R and Met RNAs was detected in most tumour cells of five cases of papillary carcinoma.