title: Characterizing nanoscale changes in the activity of VEGFR-2 on glioma microvascular endothelial cell membranes using atomic force microscopy.
abstract: The aim of the current study was to demonstrate the distribution of VEGFR-2 on glioma microvascular endothelial cells on a nanoscale and investigate changes in VEGFR-2 activity following treatment with the VEGFR-2 inhibitor and agonist sorafenib and bradykinin, respectively. Three groups were evaluated in this study: Control glioma microvascular endothelial cells, sorafenib-treated glioma microvascular endothelial cells and bradykinin-treated glioma microvascular endothelial cells. Changes in the activity of VEGFR-2 on the glioma microvascular endothelial cell membranes following treatment with sorafenib and bradykinin were characterized by atomic force microscopy (AFM). Colloidal gold-labeled immune complexes and AFM were used to visualize the distribution of VEGFR-2 on the cell membranes. In the control group, VEGFR-2, which was observed as numerous globular structures, was evenly distributed on the cell surface membranes. The majority of the receptors were active. In the sorafenib group, only a few globular structures were observed on the cell membranes, with a density significantly lower than that in the control group (P<0.01). Furthermore, compared with the control group, fewer of the receptors were active. In the bradykinin group, numerous globular structures were densely distributed on the cell membranes, with a density significantly higher than that in the control group (P<0.01). The distribution and activity of VEGFR-2 on glioma microvascular endothelial cell membranes treated with sorafenib and bradykinin suggested that the activity of VEGFR-2 could be regulated by its inhibitor or agonist.
authors.affiliation: Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Dexiang
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Shengquan
authors.initials: S
authors.lastname: Zhan
authors.affiliation: Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Guangzhong
authors.initials: G
authors.lastname: Chen
authors.affiliation: Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Kun
authors.initials: K
authors.lastname: Qin
authors.affiliation: Department of Neurosurgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Lin
keywords: atomic force microscopy; bradykinin; endothelial cell; glioma; sorafenib; vascular endothelial growth factor receptor-2