Downregulation of lncRNA PMS2L2 in patients with gastric adenocarcinoma predicts poor prognosis

Long non-coding RNA PMS1 homolog 2 mismatch repair system component pseudogene 2 (PMS2L2) is a key player in lipopolysaccharide-induced inflammatory responses. Preliminary deep sequencing data revealed that PMS2L2 was downregulated in gastric adenocarcinoma (GA) tissues compared with healthy adjacent tissues and the aim of the present study was to investigate the role of PMS2L2 in GA. In the present study, reverse transcription-quantitative PCR assays were performed to analyze gene expression. Cell transfections were performed to analyze gene interactions and Transwell assays were performed to analyze cell invasion and migration. The results revealed that PMS2L2 expression was downregulated in cancer tissues obtained from patients with GA compared with healthy adjacent tissues and was not significantly affected by clinical stage. Furthermore, low levels of PMS2L2 in cancer tissues were closely associated with a low overall 5-year survival rate in patients. MicroRNA (miR)-25 was upregulated in GA tissues compared with healthy adjacent tissues and inversely associated with PMS2L2 levels. In GA cells in vitro, overexpression of PMS2L2 downregulated the expression of miR-25, while miR-25 overexpression did not significantly affect PMS2L2 expression. Furthermore, PMS2L2 overexpression inhibited the migration and invasion of GA cells. miR-25 overexpression partially rescued the decreased migration and invasion of GA cells caused by PMS2L2 overexpression. Therefore, PMS2L2 may downregulate miR-25 expression to inhibit GA.