| Background and PurposeTransforming growth factor-β1(TGF-β1)and immune checkpoint programmed cell death ligand 1(PD-L1)are two crucial factors which inhibits immune activity and promotes tumor immune escape.In addition,diabetes is also closely related to the development of colon cancer and colon cancer patients with diabetes are characterized by worse prognosis than colon cancer patients in clinic research.As one of the main features of diabetes,hyperglycemia can significantly promote tumor cell proliferation,migration and invasion,and induce further epithelial-mesenchymal transition(EMT)in the process of cancer metastasis.Therefore,this study is designed to explore the effect of TGF-β1 on PD-L1 expression and EMT in SW620 colon cancer cells with and without high glucose treatment.Further,both ERK and AKT signaling pathways were detected to analyze their roles in the process.MethodsIn this experiment,the effects of TGF-β1 and high glucose on the migration of SW620 cells were detected by wound healing assays;Western blot were used to test the phosphorylation of ERK and AKT after TGF-β1 treatment and these proteins profile such as PD-L1,E-cadherin,vimentin and Snail after ERK or/and AKT inhibition in TGF-β1 treated SW620 cells;the expressions of these proteins were also analyzed under high glucose condition by Western blot.ResultsIn this study,Western blot results showed that TGF-β1 could enhance the phosphorylation of both ERK and AKT kinases.Furthermore TGF-β1 promoted the expressions of PD-L1,Vimentin and Snail and suppressed E-cadherin in SW620 cells.After the inhibition of ERK and AKT kinases this promotions of PD-L1,Vimentin and Snail by TGF-β1 significantly decreased in this process.Interestedly,the promotion of TGF-β1 on the expressions of PD-L1,E-cadherin,Vimentin and Snail significantly increased in high glucose environment.Additionally,wound healing assay showed that TGF-β and high glucose had no effect on SW620 migration in this job.ConclusionsTGF-β1 can promote significantly the expression of PD-L1 and induce EMT through the ERK or AKT signaling pathways in SW620 cells.In a high glucose environment,the promotion of TGF-β1 on PD-L1 expression and EMT were strongly enhanced in SW620 cells. |
