Background: MicroRNAs (miRNAs) play key regulatory roles as oncogenes or anti-oncogenes at the posttranscriptional level in human cancers. Plant miRNAs can regulate mammalian systems across kingdoms. The present study investigated the effects of plant miRNA157 (miR157) on the viability and proliferation of human hepatoma cells and the underlying mechanisms.

Method: The potential targets of miR157 were predicted by bioinformatics methods; the targeted regulatory relationship between miR157 and MTDH was detected by dual luciferase reporter assay; hepatoma cells HepG2 were cultured in vitro and divided into control group (transfected with negative control SNC mimics) and miR157 transfection group (transfected with miR157 mimics). After transfection, cell counting kit-8 and colony formation were used to detect cell proliferation ability, and RT-qPCR and Western blot were used to detect the effect of miR157 on MTDH expression in HepG2 cells.

Results: miR157 had an inhibitory effect on the proliferative capacity of hepatoma cells HepG2 (P<0.05); dual-luciferase reporter gene assay showed that MTDH is a target gene of miR157; miR157 could be directly targeted to down-regulate the expression of MTDH (P<0.01).

Conclusion: These preliminary pieces of evidence suggest that miR157 inhibits the proliferation of HepG2 cells by targeting MTDH.