Human cytomegalovirus infection contributes to glioma disease progression via upregulating endocan expression

• Published in: Translational research : the journal of laboratory and clinical medicine 2016-11, Vol.177, p.113-126
• Main Authors: Xing, Yan, Wang, Yisong, Wang, Shijie, Wang, Xin, Fan, Dongying, Zhou, Dabiao, An, Jing
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Brain Neoplasms - genetics; Brain Neoplasms - pathology; Brain Neoplasms - virology; Case-Control Studies; Cell Line, Tumor; Child; Cytokines - metabolism; Cytomegalovirus - drug effects; Cytomegalovirus - physiology; Cytomegalovirus Infections - complications; Cytomegalovirus Infections - drug therapy; Cytomegalovirus Infections - genetics; Cytomegalovirus Infections - pathology; Disease Progression; Female; Ganciclovir - pharmacology; Ganciclovir - therapeutic use; Gene Expression Regulation, Neoplastic - drug effects; Glioma - genetics; Glioma - pathology; Glioma - virology; Human Umbilical Vein Endothelial Cells - drug effects; Human Umbilical Vein Endothelial Cells - metabolism; Humans; Internal Medicine; Male; Middle Aged; Neoplasm Grading; Neoplasm Proteins - genetics; Neoplasm Proteins - metabolism; Phosphoproteins - metabolism; Proteoglycans - genetics; Proteoglycans - metabolism; Up-Regulation - genetics; Viral Matrix Proteins - metabolism; Young Adult
• ISSN: 1931-5244; 1878-1810
• DOI: 10.1016/j.trsl.2016.06.008

The etiology of malignant glioma remains unclear. To examine the association between glioma and human cytomegalovirus (HCMV) infection and the possible mechanism through which HCMV contributes to malignant glioma, we investigated the expression of HCMV components and an angiogenesis marker, endocan, in 79 glioma specimens and 8 control brain samples. HCMV pp65 protein and DNA were detected in 65.8% (52 of 79) and 54.4% (43 of 79) of glioma specimens, respectively. The positive rate and expression levels of pp65 were significantly correlated with the glioma grades. The endocan expression was detected in 78.5% (62 of 79) of glioma specimens, and elevated endocan immunoreactivity was also significantly associated with high-grade glioma. The pp65 was predominantly detected and colocalized with endocan in the cytoplasm of tumor cells. Importantly, there was a significant positive correlation in detection rates between those 2 proteins. In control samples, neither HCMV pp65 nor endocan expression was detected. Moreover, the serum endocan levels in glioma patients were markedly higher than that in healthy subjects. In in vitro study, HCMV infection induced the expression of interleukin 6 and tumor necrosis factor-α in human glioblastoma U87 MG (U87) cells and human umbilical vein endothelial cells (HUVECs). Furthermore, elevated endocan levels were also observed in HCMV-infected U87 cells and HUVECs and antiviral treatment with ganciclovir reduced the endocan expression. These results suggest HCMV infection leads to glioma progression through an upregulation of endocan and the secretion of inflammatory cytokines. Thus, anti-HCMV treatment may represent a potentially novel therapeutic strategy for glioma.