Role of miR-489 in the proliferation and apoptosis of pancreatic carcinoma.

Purpose: The purpose of the present study was to detect the expression of miR-489 in pancreatic cancer (PC) tissues and cells, and to explore the effects of miR-489 on cell proliferation and apoptosis of human PC cells and to also uncover the underlying mechanism.

Methods: miR-489 expression was assessed by quantitative real time-polymerase chain reaction (qRT-PCR) in PC tissues and PANC-1 and HPDE6-C7 cell lines. The binding-site predictions by bioinformatics showed that AKT Serine/Threonine Kinase 3 (AKT3) might be a potential target of miR-489. AKT3 expression in PC tissues and cells was detected by qRT-PCR, luciferase report assay and Western blotting assay were used to verify the rationality of the target gene. The biological role of miR-489 on cell proliferation, cell cycle and apoptosis were determined in PANC-1 cells by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and flow cytometry after transfection with miR-NC, miR-489 mimics and si-AKT3.

Results: Compared with normal adjacent tissues and normal pancreatic cells, the expression of miR-489 was markedly down-regulated in PC tissues and cells. AKT3 was considered as a downstream gene of miR-489 and it was found that the expression levels of miR-489 and AKT3 were inversely proportional to each other, which was further confirmed by luciferase and Western blot assays. In subsequent experiments, up-regulation of miR-489 by transfection with miR-489 mimics significantly inhibited cell proliferation, blocked the G1/S transition and induced cell apoptosis of PANC-1 cells. However, overexpression of AKT3 significantly counteracted the biological effects of miR-489.

Conclusions: Our findings indicate that up-regulation of miR-489 could suppress PC cell proliferation and facilitate cell apoptosis through targeting AKT3. miR-489 and AKT3 might serve as potential targets in the therapy of PC.