Related Experiment Video
Updated: Feb 11, 2026

Molecular Analysis of Endothelial-mesenchymal Transition Induced by Transforming Growth Factor-β Signaling
Published on: August 3, 2018
Long noncoding RNA NORAD regulates transforming growth factor-β signaling and epithelial-to-mesenchymal
Natsumi Kawasaki1, Toshiki Miwa1, Satoshi Hokari1,2
1Department of Molecular Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Abstract:
Long noncoding RNAs are involved in a variety of cellular functions. In particular, an increasing number of studies have revealed the functions of long noncoding RNA in various cancers; however, their precise roles and mechanisms of action remain to be elucidated. NORAD, a cytoplasmic long noncoding RNA, is upregulated by irradiation and functions as a potential oncogenic factor by binding and inhibiting Pumilio proteins (PUM1/PUM2). Here, we show that NORAD upregulates transforming growth factor-β (TGF-β) signaling and regulates TGF-β-induced epithelial-to-mesenchymal transition (EMT)-like phenotype, which is a critical step in the progression of lung adenocarcinoma, A549 cells. However, PUM1 does not appear to be involved in this process. We thus focused on importin β1 as a binding partner of NORAD and found that knockdown of NORAD partially inhibits the physical interaction of importin β1 with Smad3, inhibiting the nuclear accumulation of Smad complexes in response to TGF-β. Our findings may provide a new mechanism underlying the function of NORAD in cancer cells.
Insights
Long noncoding RNA NORAD promotes lung adenocarcinoma by upregulating transforming growth factor-β (TGF-β) signaling. NORAD influences TGF-β-induced epithelial-to-mesenchymal transition via importin β1, not Pumilio proteins.
Area of Science:
- Molecular Biology
- Cancer Research
- Cell Biology
Background:
- Long noncoding RNAs (lncRNAs) play diverse cellular roles, with emerging evidence highlighting their involvement in cancer.
- NORAD, a lncRNA, is implicated as an oncogenic factor, potentially by inhibiting Pumilio proteins (PUM1/PUM2).
Purpose of the Study:
- To elucidate the precise roles and mechanisms of NORAD in lung adenocarcinoma progression.
- To investigate NORAD's regulation of transforming growth factor-β (TGF-β) signaling and associated cellular phenotypes.
Main Methods:
- Investigated NORAD's effect on TGF-β signaling and epithelial-to-mesenchymal transition (EMT)-like phenotype in A549 lung adenocarcinoma cells.
- Examined the interaction of NORAD with Pumilio proteins (PUM1/PUM2) and importin β1.
- Assessed the impact of NORAD knockdown on importin β1 and Smad3 interaction and nuclear accumulation.
Main Results:
- NORAD upregulates TGF-β signaling and promotes a TGF-β-induced EMT-like phenotype in lung adenocarcinoma cells.
- Pumilio proteins (PUM1/PUM2) were not found to be involved in this NORAD-mediated process.
- NORAD knockdown partially inhibits the interaction between importin β1 and Smad3, thereby reducing Smad complex nuclear accumulation in response to TGF-β.
Conclusions:
- NORAD functions as an oncogenic factor in lung adenocarcinoma by modulating TGF-β signaling.
- The mechanism involves NORAD's interaction with importin β1, influencing Smad3 nuclear translocation, rather than Pumilio proteins.
- These findings reveal a novel mechanism for NORAD's function in cancer cells.
Related Concept Videos
Epigenetic Regulation
Basic signals of Fourier Transform
The sinc function, defined as sinc(x) = sin(πx)/(πx), is particularly notable for its symmetry and behavior at...
Phase Transitions
Role of Hematopoietic Growth Factors
Thrombopoietin (TPO), mainly released by the liver,...
Factors Influencing Microbial Growth: pH
Bacterial RNA Polymerase
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...

