PLK1 as a potential prognostic marker of gastric cancer through MEK-ERK pathway on PDTX models

Background: PLK1 has been identified as having a great effect on cell division and maintaining genomic stability in mitosis, spindle assembly, and DNA damage response by current studies. Materials and methods: We assessed PLK1 expression in cervical cancer tissues and cells. We have also evaluated the effects of PLK1 on gastric cancer cell proliferation, migration, and apoptosis both in vitro and in vivo. Results: Our results show that PLK1 is overexpressed in gastric cancer tissues and cells. Inhibition of PLK1 contributes cell cycle G2-phase arrest and inhibits the proliferation, migration, and apoptosis of gastric cancer (GC) cells, whereas its overexpression promotes proliferation, migration, and apoptosis in these cells. Moreover, PLK1 inhibition reduces expression of pMEK and pERK. More importantly, in vivo by analyzing tumorigenesis in patient-derived tumor xenograft (PDTX) models, the inhibition of PLK1 activity by BI6727 significantly decreased the volume and weight of the tumors compared with control group (P<0.01). Conclusion: Our results found that PLK1 has a significant impact on the survival of GC cells; it may become a prognostic judge, a potential therapeutic target, and a preventative biomarker of GC.