SMAD3 and p300 complex scaffolding by long non-coding RNA LIMD1-AS1 promotes TGF-β-induced breast cancer cell plasticity [CRISPR screen, inhibition]
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ABSTRACT: Transforming growth factor (TGF)-β signaling enhances cancer cell plasticity by inducing epithelial-to-mesenchymal transition (EMT). Here, we identified a TGF-β-induced long non-coding RNA (lncRNA) LIMD1 Antisense RNA 1 (LIMD1-AS1) that strengthens the SMAD-mediated transcriptional response to TGF-β. The expression of LIMD1-AS1 is upregulated in breast cancer tissues compared to that of normal breast tissues, and high LIMD1-AS1 expression is associated with poor prognosis in breast cancer patients. Depletion of LIMD1-AS1 hinders TGF-β-induced EMT, migration, and extravasation of breast cancer cells. Mechanistically, LIMD1-AS1 promotes the interaction between SMAD3 and its transcriptional coactivator p300, and thereby enhances SMAD3 transcriptional activity and TGF-β/SMAD signaling. We showed that LIMD1-AS1 binds to the MAD homology 2 (MH2) domain of SMAD3 and the interferon-binding domain (IBiD) of p300. Displacing the binding of LIMD1-AS1 to p300 with its competitor interferon regulatory factor 3 (IRF3) suppressed the effects of LIMD1-AS1 on potentiating TGF-β/SMAD signaling. Moreover, blockage of p300 acetyltransferase activity with a pharmacological inhibitor, A-485, reduces the ability of LIMD1-AS1 to enhance SMAD3 transcriptional activity, TGF-β-induced EMT, and migration. This study reveals LIMD1-AS1 as a novel stimulator of TGF-β signaling by establishing a positive feedback loop and highlights its potential as a therapeutic target for breast cancer.
ORGANISM(S): Homo sapiens
PROVIDER: GSE288909 | GEO | 2025/07/08
REPOSITORIES: GEO
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