Conserved long non-coding RNAs (lncRNAs) have not thoroughly been studied in many cancers, including gastric cancer (GC). We have identified a novel lncRNA PTCHD4-AS which was highly conserved between humans and mice and naturally downregulated in GC cell lines and tissues. Notably, PTCHD4-AS was found to be transcriptionally induced by DNA damage agents and its upregulation led to cell cycle arrest at the G2/M phase, in parallel, it facilitated the cell apoptosis induced by cisplatin (CDDP) in GC. Mechanistically, PTCHD4-AS directly bound to the DNA mismatch repair protein MSH2-MSH6 dimer, and facilitated the binding of dimer to ATM, thereby promoting the expression of phosphorylated ATM, p53 and p21. Here we conclude that the upregulation of PTCHD4-AS inhibits proliferation and increases CDDP sensitivity of GC cells via binding with MSH2-MSH6 dimer, activating the ATM-p53-p21 pathway.
Keywords: DNA mismatch repair proteins; MSH2-MSH6; cisplatin; gastric cancer; long non-coding RNA PTCHD4-AS.