p53 is a downstream mediator of MALAT1.

<p>(A) Immuno-localization of α- and γ-tubulin in control (scr-oligo) and MALAT1-depleted (MALAT1-AS1) HeLa cells. Note the presence of monopolar and multipolar asters and highly condensed chromosomes in MALAT1-depleted cells, indicating chromosome segregation defects. (Ba) DNA staining (using Hoechst 33258 dye) in WI-38 cells reveals that co-depletion of MALAT1 and p53 or p53/p16^Ink4A results in nuclear breakdown defects. (Bb) Percentage of broken nuclei in control and MALAT1-depleted WI-38 cells in presence or absence of p53 and/or p16^Ink4A. (C) The relative expression of indicated genes is determined by qRT-PCR analyses from RNA isolated from WI-38 cells that are treated with control or p53 siRNAs and/or control or MALAT1 antisense oligonucleotides. (Da–b) Serum-starved WI-38 cells that are depleted of p53 or MALAT1 or p53 + MALAT1 followed by serum stimulation, and relative mRNA levels of indicated genes are determined by qRT-PCR analyses. The DNA is counterstained with DAPI (A) or Hoechst 33258 (B). Scale bar represents 5 µm. Mean ± SEM,**p<0.01 and ***p<0.001.