The orphan nuclear receptor TR3 (NR41A and Nur77) is overexpressed in most lung cancer patients and is a negative prognostic factor for patient survival. The function of TR3 was investigated in non-small-cell lung cancer A549 and H460 cells, and knockdown of TR3 by RNA interference (siTR3) inhibited cancer cell growth and induced apoptosis. The prosurvival activity of TR3 was due, in part, to formation of a p300/TR3/ specificity protein 1 complex bound to GC-rich promoter regions of survivin and other Sp-regulated genes (mechanism 1). However, in p53 wild-type A549 and H460 cells, siTR3 inhibited the mTORC1 pathway, and this was due to activation of p53 and induction of the p53-responsive gene sestrin 2, which subsequently activated the mTORC1 inhibitor AMP-activated protein kinase α (AMPKα) (mechanism 2). This demonstrates that the pro-oncogenic activity of TR3 in lung cancer cells was due to inhibition of p53 and activation of mTORC1. 1,1-Bis(3'-indolyl)-1-(p-hydroxyphenyl)methane (DIM-C-pPhOH) is a recently discovered inhibitor of TR3, which mimics the effects of siTR3. DIM-C-pPhOH inhibited growth and induced apoptosis in lung cancer cells and lung tumors in murine orthotopic and metastatic models, and this was accompanied by decreased expression of survivin and inhibition of mTORC1 signaling, demonstrating that inactivators of TR3 represent a novel class of mTORC1 inhibitors.
Pubmed ID: 22081070 RIS Download
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THIS RESOURCE IS NO LONGER IN SERVICE.Documented on February 25, 2022.Software tool as knowledge environment resource that accrues, develops, and communicates information that advances understanding of structure, function, and role in disease of nuclear receptors (NRs) and coregulators. It specifically seeks to elucidate roles played by NRs and coregulators in metabolism and development of metabolic disorders. Includes large validated data sets, access to reagents, new findings, library of annotated prior publications in field, and journal covering reviews and techniques.As of March 20, 2020, NURSA is succeeded by the Signaling Pathways Project (SPP).
View all literature mentionsCell line A-549 is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentionsCell line NCI-H1299 is a Cancer cell line with a species of origin Homo sapiens (Human)
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