FIG. 4.

Regulation of lncRNA expression in the DDR. On DNA damage, ATM-induced transcription factors p53 and E2F1 transcriptionally activate the expression of, lincRNA-p21, PANDA, TUG1, and ANRIL. Up-regulated lincRNA-p21 functions as a guide to the hnRNP-K repressor complex, leading to p53-mediated apoptosis. Up-regulated PANDA acts as a decoy to interact with NF-YA, resulting in cell-cycle arrest. Induced TUG1 functions as a scaffold in the Polycomb body, repressing E2F1 target genes in cell-cycle control. Up-regulated ANRIL interacts with PRC1 and PRC2 complexes and represses the INK4b-ARF-INK4a locus, inhibiting cellular senescence.