Original Article
GPD1L is down-regulated by a three-microRNA signature in pancreatic cancer
Abstract
Background: The prognosis of pancreatic ductal adenocarcinoma (PDAC) is very poor and its underlying mechanism is far from clear. Many studies show that PDAC has distinct microRNA signatures, but their target genes remain largely unknown.
Methods: Reproducible candidate microRNA signature of PDAC from three highly cited studies was measured in 20 pairs of PDAC tissues and adjacent normal tissues. The target genes of candidate microRNAs were predicted by miRDB and validated by quantitative real-time PCR, western blot and 3'UTR luciferase assay. The prognostic association of target gene was analyzed using PROGgeneV2 Database. The effects of target gene on tumor phenotypes were evaluated with MTT assay, clone formation assay and Annexin V-FITC apoptosis assay.
Results: Among the 5-microRNA panel, an up-regulation of 3-microRNA signature (miR155, miR181a and miR221) was validated in PDAC samples. The prediction of miRDB showed that the 3-microRNA signature shared four target genes: CREBRF, GABRA1, GPD1L and REPS2. GPD1L was down-regulated in PDAC and associated with poorer prognosis in three independent datasets (GSE21501, GSE28735 and GSE71729). In two PDAC cell lines, the 3-microRNA signature inhibited GPD1L expression through binding its 3'UTR and GPD1L reduction promoted cell proliferation and clone formation, and inhibited apoptosis.
Conclusions: GPD1L as a novel target gene for a 3-microRNA signature and GPD1L might be an important therapeutic target in PDAC.
Methods: Reproducible candidate microRNA signature of PDAC from three highly cited studies was measured in 20 pairs of PDAC tissues and adjacent normal tissues. The target genes of candidate microRNAs were predicted by miRDB and validated by quantitative real-time PCR, western blot and 3'UTR luciferase assay. The prognostic association of target gene was analyzed using PROGgeneV2 Database. The effects of target gene on tumor phenotypes were evaluated with MTT assay, clone formation assay and Annexin V-FITC apoptosis assay.
Results: Among the 5-microRNA panel, an up-regulation of 3-microRNA signature (miR155, miR181a and miR221) was validated in PDAC samples. The prediction of miRDB showed that the 3-microRNA signature shared four target genes: CREBRF, GABRA1, GPD1L and REPS2. GPD1L was down-regulated in PDAC and associated with poorer prognosis in three independent datasets (GSE21501, GSE28735 and GSE71729). In two PDAC cell lines, the 3-microRNA signature inhibited GPD1L expression through binding its 3'UTR and GPD1L reduction promoted cell proliferation and clone formation, and inhibited apoptosis.
Conclusions: GPD1L as a novel target gene for a 3-microRNA signature and GPD1L might be an important therapeutic target in PDAC.
