Co-expression of vascular endothelial growth factor and its receptor f/t-1in malignant pleural mesothelioma

Background: Vascular endothelial growth factor (VEGF) is a potent angiogeni c protein with a selective mitogenic effect on endothelial cells known to b e involved in many normal and pathological processes, Coexpression of VEGF and its receptor flt-1 has been reported in different types of malignant tu mors. Objective: In the present study we investigated the expression of VEG F and flt-1 in 90 cases of diffuse malignant pleural mesotheliomas. Methods : VEGF and flt-1 expression was analyzed by immunohistochemistry and non-ra dioactive in situ hybridization. Results: VEGF expression was visualized im munohistochemically in tumor cells. flt-1 expression correlated with histol ogical differentiation (p < 0.013). Furthermore, expression of flt-1 was de tected in tumor cells, macrophages and microvessels adjacent to tumor cells , VEGF and flt-1 expression were confirmed by in situ hybridization. Conclu sion: There was a statistically significant correlation between VEGF and fl t-1 expression (p < 0.001). The observed coexpression of VEGF and flt-1 pos sibly suggests a potential autocrine loop for malignant pleural mesotheliom a cells, Copyright (C) 2000 S. Karger AG, Basel.