LAUSR

OBJECTIVE To uncover the biological effect of long non-coding RNA (lncRNA) PAPAS on the progression of gastric cancer (GC) by mediating microRNA-188-5p (miRNA-188-5p) level. PATIENTS AND METHODS The relative level of PAPAS was determined in GC tissues and cell lines by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The Kaplan-Meier method was introduced to assess the prognostic potential of PAPAS in the overall survival of GC patients. Regulatory effects of PAPAS on proliferative, migratory, and invasive abilities of HGC-27 and AGS cells were detected by cell counting kit-8 (CCK-8), transwell, and wound closure assay, respectively. Subsequently, the binding relation between PAPAS and miRNA-188-5p was verified by the Dual-luciferase reporter gene assay. Correlation between expression levels of PAPAS and miRNA-188-5p in GC tissues was explored. Finally, rescue experiments were conducted to uncover the role of PAPAS/miRNA-188-5p axis in the progression of GC. RESULTS PAPAS was upregulated in GC tissues and cell lines compared to controls. GC patients expressing a high level of PAPAS suffered worse prognosis relative to those with low level. The silence of PAPAS remarkably attenuated proliferative, migratory, and invasive abilities of HGC-27 cells. Overexpression of PAPAS in AGS cells obtained the opposite trends. MiRNA-188-5p was the direct target of PAPAS, which was negatively regulated by PAPAS. MiRNA-188-5p was able to reverse the regulatory effects of PA-PAS on proliferative, migratory, and invasive abilities of GC cells. CONCLUSIONS LncRNA PAPAS is upregulated in GC and closely related to lymphatic metastasis, distant metastasis, and poor prognosis of GC patients. PAPAS aggravate the malignant progression of GC by negatively regulating the miRNA-188-5p level.