Thrombospondin-1 and transforming growth factor-β levels in prolactinoma and their clinical significance

Abstract

To investigate the roles of angiogenesis, thrombospondin-1 (TSP-I) and transforming growth factor-β1 (TGFβ1 in invasive and noninvasive prolactinoma. METHODS: TSPl and TGFβ1 protein were examined using immunohistochemistry and Western blotting in 81 prolactinomas. Angiogenesis was assessed by measuring microvessel density via CD34 immunostaining. RESULTS: Microvessel density was significantly higher in invasive prolactinomas than in noninvasive prolactinomas. Immunohistochemistry demonstrated that significantly fewer invasive prolactinomas were positive for TSP-I compared with noninvasive prolactinomas (17.9% versus 50.0%, respectively), and significantly higher numbers of invasive prolactinomas were positive for TGF-β1 compared with noninvasive prolactinomas (82.1% versus 42.9%, respectively). Microvessel density was significantly lower in TSP-1-positive prolactinomas than in TSP-1-negative prolactinomas, and significantly higher in TGF-β1-positive prolactinomas than in TGF-β1-negative prolactinomas. CONCLUSIONS: These results suggest a close relationship between angiogenesis and tumour invasiveness in prolactinoma. TSP-I and TGF-β1 may play important roles in the progression of prolactinoma, by affecting angiogenesis. © 2012 Field House Publishing LLP.