MicroRNAs (miRNAs/miRs) are highly conserved, endogenous, small and single-stranded RNA molecules that promote the degradation and translational inhibition of specific target mRNAs in order to regulate cell proliferation and differentiation, and organism growth and development. MiR-23a has been demonstrated to function as an oncogene in certain types of tumor. The aim of the present study was to provide a tool for elucidating the mechanisms of action of miR-23a in gastric cancer, and identify the function of miR-23a in a human gastric epithelium cell line, by establishing a human gastric epithelial GES-1 cell line that stably expressed miR-23a. A plasmid was constructed for the expression of miR-23a by inserting the miR-23a primary sequence into a pcDNA3 vector (pcDNA3/pri-23a). PcDNA3/pri-23a or the empty pcDNA3 vector (EV), which was then transfected into human gastric epithelium GES-1 cells using Lipofectamine to produce GES-1/miR-23a cells and GES-1/EV cells, respectively. G418 (Geneticin) was used to select and expand the G418-resistant colonies, and miR-23a expression was assessed by reverse transcription-semi-quantitative polymerase chain reaction. The proliferation of the cells was assessed using cell counting and MTT assays. The invasive ability of the cells was evaluated using a Transwell assay. The colony-forming ability of the cells was assessed using a colony formation assay. A human gastric epithelium GES-1/miR-23a cell line with the stable expression of miR-23a was successfully established. Compared with the control GES-1 and GES-1/EV cells, the mRNA expression of the miR-23a gene in GES-1/miR-23a cells was significantly increased (P<0.05). The proliferation rate, invasive ability and colony-forming ability of the GES-1/miR-23a cells were significantly higher compared with those of the control GES-1/EV cells and the parental GES-1 cells (P<0.05). Additionally, the results of the present study demonstrated that miR-23a enhanced the cell proliferation rate, invasive ability and cell colony forming ability of GES-1 cells. This data provides a solid experimental foundation for further studies on the function of miRNAs in the development and progression of gastric cancer.
Keywords: gastric cancer; human gastric epithelial cell line GES-1; miR-23a; plasmid; transfection.