Effect of PD-L1 on proliferation,migration,and invasion of human oral squamous carcinoma cells / 吉林大学学报(医学版)

ABSTRACT

Objective:To discuss the expression of programmed cell death-ligand 1(PD-L1)in the oral squamous cell carcinoma(OSCC)cells and its effect on biological behavior of the OSCC CAL27 cells,and to clarify the possible mechanism.Methods:Western blotting method was used to detect the expression levels of PD-L1 protein in the oral epithelial HOK cells and OSCC CAL27,TCA8113,and SCC15 cells;immunofluorescence staining method was used to detect the expression and localization of PD-L1 protein in the CAL27 cells.The CAL27 cells were divided into control group(transfected with si-NC)and si-PD-L1 group(transfected with si-PD-L1).Western blotting method was used to detect the interference efficiency of the cells in two groups;CCK-8 assay was used to detect the proliferative activities of the cells in two groups at different time points;plate clone formation assay was used to detect the numbers of clone formation of the cells in two groups;cell scratch healing assay was used to detect the scratch healing rates of the cells in two groups;Transwell chamber assay was used to detect the numbers of migration and invasion cells in two groups.Results:The expression level of PD-L1 protein in the OSCC cells was higher than that in the HOK cells(P<0.05 or P<0.01);PD-L1 expressed in the cytoplasm and nucleus of the CAL27 cells.The CCK-8 assay and plate clone formation assay results showed that compared with control group,the proliferative activities of the CAL27 cells in si-PD-L1 group at different time points were significantly decreased(P<0.05 or P<0.01),and the numbers of clone formation were significantly decreased(P<0.01).The cell scratch healing assay results showed that compared with control group,the scratch healing rates of the cells in si-PD-L1 group were significantly decreased(P<0.05 or P<0.01).The Transwell chamber assay results showed that compared with control group,the numbers of migration and invasion cells in si-PD-L1 group were significantly decreased(P<0.01).Conclusion:The expression of PD-L1 in the OSCC cells is higher than that in normal oral epithelial cells,and knocking down PD-L1 expression can inhibit the proliferation,clone formation,migration and invasion capabilities of the OSCC cells.