Cisplatin Combined With Metformin Inhibits Proliferation, Migration And Invasion Of Human Nasopharyngeal Carcinoma Cells

Objective: Nasopharyngeal cancer is a commol/Lon malignant tumor of head and neck. It has a high incidence in the south of C hina’s. Because of the anatomic location of hidden, and onset of clinical symptoms is not obvious, it is difficult to diagnose. The prognosis is poor. We aim to investigate the effects of cisplatin combined with metformin on the proliferation, invasion and migration of CNE-2 human nasopharyngeal carcinoma(NPC) cel s, and to provide a new thinking for treating metastasis.Methods: 1 We cultured human nasopharyngeal cancer cell line CNE-2 in vitro. And CNE-2 cell was exposed to different concentration of DDP(0,0.5,1,2,4,8mg/L) metformin(0,1,5,10,20,40mmol/L). According to previous cell proliferation, respectively, to select the best drug concentration: DDP(2mg/L) combined with 20mmol/L of metformin, the changes in cell viability were detected by MTT assay. 2 Boyden C hamber assays were performed to assess cell invasion. Met(20mmol/L), DDP(2mg/L) and the two combined treated CNE-2 cells 24 h, were observed differences in invasion among the different treatment. 3 Wound healing assays were performed to assess cell migration. Met(20mmol/L), DDP(2mg/L) and the two combined treated CNE-2 cells 24 h, were observed differences in migration among the different treatment. 4 Met(20mmol / L, 40mmol/L) treated CNE-2 cells 24 h, and we observed cell was by flow cytometry. 5 Met(20mmol/L, 40mmol/L) treated cells 48 h, then we observed expression of GAPDH, caspase-3, cleaved-PARP,Vim,MMP-9 was detected by Western blotting.Results:1 MTT assay showed that different concentrations of Met and DDP on nasopharyngeal carcinoma cell CNE-2 have a significant growth inhibition. And the combination showed more significant results. 2 Boyden C hamber assay showed that: different concentrations of Met and DDP for nasopharyngeal carcinoma cells had migrated CNE-2 inhibition, the combination migration inhibition rate was more significant than single-use DDP. 3 Wound healing assay showed that: different concentrations of Met and DDP for nasopharyngeal carcinoma cells had migrated CNE-2 inhibition, the combination migration inhibition rate was more significant than single-use DDP. 4 Flow cytometry analysis, the apoptosis rate reached 7.03%, 12.49%, it was a significantly divergence(p<0.05) to the control group(2.02%). 5 Western blot results showed: caspase-3, MMP-9, Vim expression decreased, E-cadherin,cleaved-PARP expression was increased.Conclusion: 1 Metformin can enhance the cytotoxic effect of cisplatin on CNE-2 cell 2 Metformin can inhibit the CNE-2 cell proliferation, migration and invasion. 3 Metformin can induce apoptosis, and apoptosis may be related to the key apoptotic protein caspase-3 activation. When caspase-3 was activated, it may affect enzyme PARP(poly ADP-ribose polymerase).These process changed stability of the CNE-2 cell and accelerated apoptosis. 4 Metformin inhibit CNE-2 migration and invasion may due to of epithelial cells-mesenchymal transition(EMT) process, the expression of EMT protein significantly alter.