Abstract 4808
Background
NORE1A/RASSF5 is a tumor suppressor that is commonly inactivated in a variety of cancers. NORE1A is frequently down-regulated during tumor development and its inactivation often correlates with up-regulation of Ras activity. Although NORE1A was reported to be activated by NF-kB, its role in NF-kB signaling and the underlying mechanism have not been addressed. In this study, we explored the role for NORE1A in the regulation and function of the TNF-NF-kB pathway.
Methods
NORE1A effect on TNF regulation of inflammation, growth, and apoptosis was examined by flow cytometry, migration and invasion, and apoptosis assays. NORE1A regulation of TNF-NF-kB signaling was analyzed by quantitative RT-PCR, immunoblot, immunoprecipitation, and promoter luciferase assay.
Results
Upon exposure to TNF-a, NORE1A is induced by NF-kB signaling at the level of transcription while its activation suppresses TNF activation of NF-kB, indicating that NORE1A functions as a feedback terminator of TNF-NF-kB signaling. As predicted, NORE1A blocks TNF activation of pro-inflammatory gene transcription, epithelial-to-mesenchymal transition (EMT), invasion and migration. Mechanistically, NORE1A binds directly to TNF receptor I (TNFR1) and ubiquitin E3 ligase ITCH to promote ITCH-mediated K48-linked ubiquitination of TNFR1 and subsequent lysosomal degradation. Additionally, we identified that the PPXY motif of NORE1A interacts directly with ITCH using a series of deletion mutants. This interaction protects BAX from ITCH-mediated ubiquitination and thus activates its apoptotic function. NORE1A interaction with ITCH plays a crucial role for both TNFR1 degradation and BAX stabilization and activation.
Conclusions
In this study, we demonstrate first that NORE1A is a feedback terminator of TNF-NF-kB signaling, which directly antagonizes TNFR1 by facilitating the ITCH-TNFR1 interaction. Our study also shows that NORE1A binding to ITCH releases ITCH from BAX and activates BAX-mediated apoptosis. These data illuminate the mechanistic consequence of NORE1A inactivation in tumorigenesis.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Sung-gil, Chi.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3305 - A phase I dose-escalation and expansion trial of intratumorally administered CV8102, alone and in combination with anti-PD-1 in patients with advanced solid tumors
Presenter: Jürgen Krauss
Session: Poster Display session 1
Resources:
Abstract
5353 - Phase 1/2 Study of 9-ING-41, a small molecule selective Glycogen Synthase Kinase-3 Beta (GSK-3β) Inhibitor, as a Single Agent and Combined with Chemotherapy, in Patients with Refractory Hematological Malignancies or Solid Tumors
Presenter: Benedito Carneiro
Session: Poster Display session 1
Resources:
Abstract
3946 - Trial in progress: a Phase I, open-label study of GSK1795091 administered in combination with immunotherapies in participants with advanced solid tumors (NCT03447314).
Presenter: Aaron Hansen
Session: Poster Display session 1
Resources:
Abstract
3449 - Radiographic Phenotyping to Identify Intracranial Disseminated Recurrence in Brain metastases Treated With Radiosurgery Using Contrast-enhanced MR Imaging
Presenter: CheYu Hsu
Session: Poster Display session 1
Resources:
Abstract
4553 - Association between TP53 mutations and efficacy of Osimertinib for brain metastasis from EGFR-mutant lung cancer
Presenter: Lijuan Chen
Session: Poster Display session 1
Resources:
Abstract
4942 - Response assessment of melanoma brain metastases treated by stereotactic radiotherapy or immunotherapy or both: a comparison of RECIST 1.1, RANO and iRANO criteria
Presenter: Emilie Le Rhun
Session: Poster Display session 1
Resources:
Abstract
3529 - Management of multiple brain metastases by Staged SRS focusing on utmost risk lesions
Presenter: shaoqun Li
Session: Poster Display session 1
Resources:
Abstract
5315 - Whole brain radiotherapy plus simultaneous in-field boost versus whole brain radiotherapy plus fractionated stereotactic radiotherapy for multiple brain metastases of non-small cell lung cancer
Presenter: Lu Li
Session: Poster Display session 1
Resources:
Abstract
1116 - 3D based texture analysis serving as potential diagnostic factor in discriminating primary central nervous system lymphoma from metastatic brain tumors: A preliminary study
Presenter: Wen Guo
Session: Poster Display session 1
Resources:
Abstract
5344 - Global trends in population-based survival for 303,169 adults diagnosed with glioblastoma in 44 countries during 2000-2014 (CONCORD-3)
Presenter: Fabio Girardi
Session: Poster Display session 1
Resources:
Abstract