ABSTRACT
Objective: To investigate the effect of CK2 (casein kinase 2) inhibitor CX4945 on the cisplatin (DDP)-resistance of lung cancer A549/DDP cells and the underlying molecular mechanism. Methods: The CCK-8 assay was used to detect the half maximal inhibitory concentration (IC50) of DDP in lung cancer A549 and A549/DDP cells, and to compare the DDP-resistance of two cell lines. The effect of CX4945 on DDP-resistance of A549/DDP cells was tested by CCK-8 method. Western blotting was used to detect the expressions of Wnt signaling pathway-related proteins (CK2α, β-catenin and cyclin D1), drug resistance-related proteins [multidrug resistance-associated protein 1 (MRP1) and lung resistance-related protein (LRP)] and apoptosis-related protein [cleaved caspase-3 (c-caspase-3)] in A549 and A549/DDP cells treated with DDP or not. The A549/DDP cells were treated with no drug (as the control group), CX4945, DDP and their combination (as CX4945+DDP group), then the expressions of Wnt signaling pathway-, drug resistance- and apoptosis-related proteins were detected by Western blotting, and the apoptosis of A549/DDP cells was detected by FCM method. Results: The IC50 value of DDP in A549/DDP cells was 4.59 times higher than that in A549 cells, and the DDP-resistance of A549/DDP cells was decreased by CX4945 pretreatment (P 0.05). Compared with the control group and DDP group, the expression levels of β-catenin, cyclin D1, MRP1 and LRP proteins in A549/DDP cells of CX4945 group and CX4945+DDP group were significantly declined (all P < 0.01). In addition, the apoptosis rate of A549/DDP cells and the expression level of c-caspase-3 in CX4945+DDP group were significantly higher than those in the control group and DDP group (all P < 0.001). Conclusion: CK2 inhibitor CX4945 can reverse the DDP resistance of lung cancer A549/ DDP cells through blocking Wnt signal pathway and decreasing the expressions of drug resistance-relatied proteins.
ABSTRACT
Objective To identify the effect of both high glucose and high insulin on miR-145 level.Methods The human vascular smooth muscle cells ( VSMCs) were cultured and the proliferation of VSMCs was induced by high glucose and high insulin medium.The samples were divided into 4 groups: normal group, high glu-cose group (25 mmol/L), high insulin group (300 mU/L), high glucose and high insulin group.The ex-pression of miR-145 in VSMCs was assayed by real-time PCR.Proliferation of VSMCs was determined by MTT method After 72 h cultivation.The migration of VSMCs was analyzed by cell scratch test .VSMCs in each group was transfected by miR-145 virus ( lentiviral vector ) .Proliferation and migration were assayed after 48 h transfection.Results The expression of miR-145 in VSMCs of other three groups was decreased ( P<0.05 ) , especially the expression in the high glucose and insulin group was the lowest ( P<0.01 ) .Prolifera-tion and migration of VSMCs was promoted by high glucose and/or high insulin medium.Under fluorescent, transfection rate of VSMCs was about 80%after 48 h transfection.Proliferation and migration of VSMCs in each group after transfection were significantly lower than before ( P<0.05 ) .Conclusions High glucose and high in-sulin could decrease the expression of miR-145 in VSMCs, The overexpression of miR-145 may inhibit the prolif-eration and migration of VSMCs .