The TGFB2-AS1 lncRNA regulates TGF-beta signaling by modulating corepressor activity

Molecular processes involving lncRNAs regulate cell function. By applying transcriptomics, we identify lncRNAs whose expression is regulated by transforming growth factor beta (TGF-beta). Upon silencing individual lncRNAs, we identify several that regulate TGF-beta signaling. Among these lncRNAs, TGFB2-antisense RNA1 (TGFB2-AS1) is induced by TGF-beta through Smad and protein kinase pathways and resides in the nucleus. Depleting TGFB2-AS1 enhances TGF-beta/Smad-mediated transcription and expression of hallmark TGF-beta-target genes. Increased dose of TGFB2-AS1 reduces expression of these genes, attenuates TGF-beta-induced cell growth arrest, and alters BMP and Wnt pathway gene profiles. Mechanistically, TGFB2-AS1, mainly via its 3' terminal region, binds to the EED adaptor of the Polycomb repressor complex 2 (PRC2), promoting repressive histone H3K27me(3) modifications at TGF-beta-target gene promoters. Silencing EED or inhibiting PRC2 methylation activity partially rescues TGFB2-AS1-mediated gene repression. Thus, the TGF-beta-induced TGFB2-AS1 lncRNA exerts inhibitory functions on TGF-beta/BMP signaling output, supporting auto-regulatory negative feedback that balances TGF-beta/BMP-mediated responses