Neuroblastoma (NB) is the most common extracranial malignant solid tumor in children and contributes to more than 15% of all pediatric cancer-related deaths. Despite the overall improvement in the disease outcome, MYCN-amplified (MYCNA) NB largely remains an incurable disease. Unlike in adult tumors, recurrent somatic mutations in NB occur with relative paucity. Therefore, de-regulation of oncogenic signal transduction may contribute to NB tumorigenesis. This proposal will pursue that goal by defining the role and regulation of transmembrane protein 108 (TMEM108) in NB malignancy and examining the effect of TMEM108 inhibition on NB cell proliferation and tumor growth in an orthotopic mouse model. TMEM108 is a potential cell surface receptor-like protein with a signal peptide sequence at the N-terminal for protein secretion and an extracellular domain and intracellular domain separated by a transmembrane sequence. TMEM108 is highly overexpressed in NB tumor samples and its overexpression significantly predicts poor patient outcome in the Versteeg-88 data set (R2: http://r2.amc.nl). TMEM108 is a completely uncharacterized gene that is enriched in NB tumors and cell lines. In our preliminary studies, we have found that knockdown or knockout of TMEM108 expression caused a cell proliferation defect in one MYCN-amplified and one MYCN-non-amplified NB cell lines. In addition, we also found that overexpression of TMEM108 mutant (mt) with the deletion of its intracellular domain inhibited NB cell proliferation compared to vector control and TMEM108 full-length wild-type (wt). Rabbit polyclonal antibodies targeting its extracellular domain inhibited NB cell proliferation in culture and tumor growth in an orthotopic xenograft mouse model. These findings strongly suggest that TMEM108 mediates an oncogenic signaling pathway in NB cells. Therefore, targeting TMEM108 extracellular domain by an inhibitory antibody or its downstream signaling pathway has a great potential to be eastablished as novel treatment options for NB patients. The central hypothesis of this work is that TMEM108 is an ideal molecular target in NB for an antibody- based therapy. The proposed experiments will test this hypothesis by determining the effect of TMEM108 inhibition on NB tumor growth in cell culture and in an orthotopic mouse model.
The specific aims for this project are: 1) to determine the function of TMEM108 in the regulation of NB malignancy; and 2) to determine the therapeutic potential of TMEM108 inhibition in vivo. Targeting TMEM108 is a novel concept in the future treatment of NB. The proposed project, if successful, will establish TMEM108 as a therapeutic target in NB. TMEM108 inhibition may serve not only as a stand-alone therapy but also as an effective adjunct to current chemotherapeutic regimens for treating this aggressive pediatric malignancy.

Public Health Relevance

Cell surface receptors play critical roles in the regulation of cancer cell growth. In our preliminary studies, we identified TMEM108, an uncharacterized cell surface receptor-like molecule that is specifically overexpressed in neuroblastoma cells, as an important mediator in the regulation of neuroblastoma malignancy. In this research proposal, we aim to determine the regulation and oncogenic function of TMEM108 in neuroblastoma cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21NS094654-02
Application #
9276802
Study Section
Tumor Microenvironment Study Section (TME)
Program Officer
Fountain, Jane W
Project Start
2016-06-01
Project End
2019-04-30
Budget Start
2017-05-01
Budget End
2019-04-30
Support Year
2
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Baylor College of Medicine
Department
Pediatrics
Type
Schools of Medicine
DUNS #
051113330
City
Houston
State
TX
Country
United States
Zip Code
77030
Lu, Jiaxiong; Guan, Shan; Zhao, Yanling et al. (2017) The second-generation ALK inhibitor alectinib effectively induces apoptosis in human neuroblastoma cells and inhibits tumor growth in a TH-MYCN transgenic neuroblastoma mouse model. Cancer Lett 400:61-68
Mao, Xinfang; Chen, Zhenghu; Zhao, Yanling et al. (2017) Novel multi-targeted ErbB family inhibitor afatinib blocks EGF-induced signaling and induces apoptosis in neuroblastoma. Oncotarget 8:1555-1568
Bieerkehazhi, Shayahati; Chen, Zhenghu; Zhao, Yanling et al. (2017) Novel Src/Abl tyrosine kinase inhibitor bosutinib suppresses neuroblastoma growth via inhibiting Src/Abl signaling. Oncotarget 8:1469-1480
Li, Haoyu; Wang, Yongfeng; Chen, Zhenghu et al. (2017) Novel multiple tyrosine kinase inhibitor ponatinib inhibits bFGF-activated signaling in neuroblastoma cells and suppresses neuroblastoma growth in vivo. Oncotarget 8:5874-5884
Chen, Zhenghu; Zhao, Yanling; Yu, Yang et al. (2017) Small molecule inhibitor regorafenib inhibits RET signaling in neuroblastoma cells and effectively suppresses tumor growth in vivo. Oncotarget 8:104090-104103
Lu, Jiaxiong; Guan, Shan; Zhao, Yanling et al. (2016) Novel MDM2 inhibitor SAR405838 (MI-773) induces p53-mediated apoptosis in neuroblastoma. Oncotarget 7:82757-82769
Chen, Zhenghu; Wang, Long; Yao, Dayong et al. (2016) Wip1 inhibitor GSK2830371 inhibits neuroblastoma growth by inducing Chk2/p53-mediated apoptosis. Sci Rep 6:38011
Guan, Shan; Zhao, Yanling; Lu, Jiaxiong et al. (2016) Second-generation proteasome inhibitor carfilzomib sensitizes neuroblastoma cells to doxorubicin-induced apoptosis. Oncotarget 7:75914-75925
Li, Haoyu; Chen, Zhenghu; Hu, Ting et al. (2016) Novel proteasome inhibitor ixazomib sensitizes neuroblastoma cells to doxorubicin treatment. Sci Rep 6:34397