microRNA-143 acts as a prognostic marker in gastric cancer and its role in cell proliferation and invasion

Background: MiR-143 is frequently downregulated in different cancer types and is involved in the progression of tumorigenesis. However, the molecular mechanism of miR-143 in gastric cancer is still unclear. Methods: RT-PCR was used to test the expression of miRNAs and BACH1 mRNA in 44 gastric cancer tissues and Kaplan-Meier survival analysis to verify the correlation between miR-143 and prognosis of GC patients. The correlation between miR-143 and BACH1 was analyzed by Pearson correlation. In vitro, RT-PCR was used to determine the expression of miR-143 in GES-1 cells and other GC cell lines. The biological function of miR-143 was examined using MTT assay, transwell chamber and Western blot in HGC-27 cells. The miR-143 target was validated using luciferase reporter and Western blot. Results: The expression of miR-143 was decreased in gastric cancer (P < 0.01). MiR-143 was downregulated in patients with poor differentiation and high clinical stage (P < 0.01). Furthermore, patients with high miR-143 expression showed longer survival time after surgery (P < 0.01). Besides, BACH1 mRNA, which was significantly increased (P < 0.01) in GC tissues, showed a significantly negative correlation with miR143 (r = -0.6458, P < 0.001). The proliferative and invasive activity of HGC-27 cells was decreased in the miR-143 group (P < 0.01); the luciferase activity of the BACH1-3'-UTR plasmid was suppressed following miR-143 binding (P < 0.01); BACH1 Overexpression partly reversed the inhibitory effect of miR-143 on HGC-27 cells. Conclusion: The expression of miR-143 was increased in GC tissues and it inhibits HGC-27 cell proliferation and invasion by downregulating BACH1. In addition, MiR-143 may be a prognostic biomarker of GC.