A Novel Signaling Complex between TROY and EGFR Mediates Glioblastoma Cell Invasion

• Published in: Molecular cancer research 2018-02, Vol.16 (2), p.322-332
• Main Authors: Ding, Zonghui, Roos, Alison, Kloss, Jean, Dhruv, Harshil, Peng, Sen, Pirrotte, Patrick, Eschbacher, Jennifer M, Tran, Nhan L, Loftus, Joseph C
• Format: Article
• Language: English
• Subjects: Activation; Adults; Binding Sites; Brain; Brain cancer; Brain Neoplasms - genetics; Brain Neoplasms - metabolism; Brain tumors; Cancer; Cell Line, Tumor; Chemotherapy; Epidermal Growth Factor - metabolism; Epidermal growth factor receptors; ErbB Receptors - genetics; ErbB Receptors - metabolism; Gene Expression Regulation, Neoplastic; Glioblastoma; Glioblastoma - genetics; Glioblastoma - metabolism; Humans; Internalization; Invasiveness; Malignancy; Medical innovations; Medical treatment; NF-κB protein; Pathogens; Radiation; Radiation therapy; Radiation tolerance; Receptors, Tumor Necrosis Factor - chemistry; Receptors, Tumor Necrosis Factor - genetics; Receptors, Tumor Necrosis Factor - metabolism; Signal Transduction; Signaling; Surgery; Survival; Temozolomide; Tumor cells; Tumor necrosis factor; Tumor necrosis factor-TNF; Tumors; Up-Regulation; Xenografts; Xenotransplantation
• ISSN: 1541-7786; 1557-3125
• DOI: 10.1158/1541-7786.mcr-17-0454

Glioblastoma is the most frequent primary brain tumor in adults and a highly lethal malignancy with a median survival of about 15 months. The aggressive invasion of the surrounding normal brain makes complete surgical resection impossible, increases the resistance to radiation and chemotherapy, and assures tumor recurrence. Thus, there is an urgent need to develop innovative therapeutics to target the invasive tumor cells for improved treatment outcomes of this disease. Expression of TROY (TNFRSF19), a member of the tumor necrosis factor (TNF) receptor family, increases with increasing glial tumor grade and inversely correlates with patient survival. Increased expression of TROY stimulates glioblastoma cell invasion and and increases resistance to temozolomide and radiation therapy. Conversely, silencing TROY expression inhibits glioblastoma cell invasion, increases temozolomide sensitivity, and prolongs survival in an intracranial xenograft model. Here, a novel complex is identified between TROY and EGFR, which is mediated predominantly by the cysteine-rich CRD3 domain of TROY. Glioblastoma tumors with elevated TROY expression have a statistically positive correlation with increased EGFR expression. TROY expression significantly increases the capacity of EGF to stimulate glioblastoma cell invasion, whereas depletion of TROY expression blocks EGF stimulation of glioblastoma cell invasion. Mechanistically, TROY expression modulates EGFR signaling by facilitating EGFR activation and delaying EGFR receptor internalization. Moreover, the association of EGFR with TROY increases TROY-induced NF-κB activation. These findings substantiate a critical role for the TROY-EGFR complex in regulation of glioblastoma cell invasion. The TROY-EGFR signaling complex emerges as a potential therapeutic target to inhibit glioblastoma cell invasion. .