title: Ehd3, a regulator of vesicular trafficking, is silenced in gliomas and functions as a tumor suppressor by controlling cell cycle arrest and apoptosis.
abstract: EHD3 [Eps15 homology (EH) domain-containing protein 3] is a protein that resides in tubular and vesicular membrane structures and participates in endocytic recycling, although all its functions are unknown. Since Ehd3 is most abundantly expressed in brain tissues, we examined its role in brain cancer progression. Using immunohistochemistry, we report loss of EHD3 expression in gliomas, including low-grade astrocytomas, suggesting that this is an early event in gliomagenesis. EHD3 expression is also very low in most of glioma cell lines tested. In two cell lines, a bisulfite sequencing method identifies promoter hypermethylation as a mechanism of Ehd3 silencing, and its expression was restored by the demethylating agent 5-Azacytidine. Doxycycline-inducible restoration of EHD3 expression to glioma cells decreases their growth and invasiveness and induces cell cycle arrest and apoptosis. Furthermore, shRNA-mediated Ehd3 silencing increases cell growth. Using a xenograft model, we demonstrate Ehd3 growth inhibitory functions in glioma cells in vivo. We suggest that Ehd3 functions as a tumor suppressor gene and loss of its expression is a very common event in gliomas. This is the first study to highlight the importance of a member of the C-terminal EHD proteins in cancer and to link their functions to the cell cycle and apoptosis.
authors.affiliation: Department of Pathology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
authors.forename: Sahiti
authors.initials: S
authors.lastname: Chukkapalli
authors.forename: Mohamed
authors.initials: M
authors.lastname: Amessou
authors.forename: Hafedh
authors.initials: H
authors.lastname: Dekhil
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Dilly
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.forename: Sudeshna
authors.initials: S
authors.lastname: Bandyopadhyay
authors.forename: Ron Dan
authors.initials: RD
authors.lastname: Thomas
authors.forename: Alex
authors.initials: A
authors.lastname: Bejna
authors.forename: Gerald
authors.initials: G
authors.lastname: Batist
authors.forename: Mustapha
authors.initials: M
authors.lastname: Kandouz
mesh_terms: D017209:Apoptosis / Q000235:genetics*; D001483:Base Sequence; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology; D002352:Carrier Proteins / Q000235:genetics*; D002453:Cell Cycle / Q000235:genetics*; D002455:Cell Division; D045744:Cell Line, Tumor; D019175:DNA Methylation; D017931:DNA Primers; D020868:Gene Silencing; D016147:Genes, Tumor Suppressor; D005910:Glioma / Q000235:genetics* / Q000473:pathology; D006801:Humans; D009361:Neoplasm Invasiveness; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D046888:Tissue Array Analysis
chemical_list: D002352:Carrier Proteins; D017931:DNA Primers; C406447:EHD3 protein, human