Effects of miR-384 and miR-134-5p Acting on YY1 Signaling Transduction on Biological Function of Gastric Cancer Cells.

Objective: To explore the related influencing mechanism of miR-384 and miR-134-5p acting on Yin Yang 1 ( YY1 ) signaling transduction on the biological function of gastric cancer (GC) cells.

Methods: miR-384, miR-134-5p and YY1 levels in human GC cell lines KATO III, MKN-45, SNU-1 and normal gastric cell line GES-1 were measured by polymerase chain reaction (PCR). Dual luciferase reporter (DLR) gene assay and Western blot (WB) were employed for correlation analysis between miR-384, miR-134-5p and YY1 . miR-384-inhibitor, miR-384-mimics, empty plasmid (miRNA-NC) and sh-YY1 were transfected into KATO III cells. Cell proliferation was determined by 3-(4,5-Dimethylthiazolyl-2)-2,5-Diphenyl Tetrazolium Bromide (MTT), cell invasion was measured by Transwell, and apoptosis was analyzed by flow cytometry (FC).

Results: In KATO III, MKN-45 and SNU-1 cell lines, YY1 was upregulated while miR-384 and miR-134-5p were downregulated (P<0.001). The expression of miR-134-5p in the miR-134-5p-inhibitor group was significantly lower (P<0.001), while that in the miR-134-5p-mimics group was significantly higher (P<0.001). The expression of miR-384 in the miR-384-inhibitor group was significantly lower (P<0.001), and that in the miR-384-mimics group was significantly higher as compared to the NC group (P<0.001). Both miR-384 and miR-134-5p overexpression could inhibit cell proliferation and invasion, and promote apoptosis. As detected by WB, overexpressed miR-384 and miR-134-5p inhibited the expression of EMT-related molecular markers. Compared with sh-YY1, the number of cells in S phase decreased, the pro-apoptotic proteins boosted statistically, and the anti-apoptotic proteins declined notably after transfecting miR-134-5p-mimics/sh-YY1 or miR-384-mimics/sh-YY1 (P<0.05). The tumor growth rate of nude mice in miR-134-5p/sh-YY1 and miR-384/sh-YY1 groups were significantly lower than those in sh-YY1 group (all P<0.001).

Conclusion: By targeting YY1 signaling transduction, miR-134-5p and miR-384 can alter the growth and apoptosis of GC cells, which are promising targets for new therapeutics of GC.