The Expression,Role And Clinical Significance Of PD-L1,Foxp3 And TOPK In Breast Cancer

?Object?To detect the expression of PD-L1 in three breast cancer cell lines and to determine whether it can induce differentiation of Tregs from activated PBMCs.To explore the expression and clinical significance of Foxp3 and TOPK in breast cancer respectively.?Method?The expression of PD-L1,Foxp3,PD-1 and TOPK in breast cancer were detected by IHC staining and Western Blot.Density-gradient centrifugation method was used to separate PBMCs from the peripheral blood.CD3 and CD28 were used to activate PBMCs.Activated PBMCs were induced into Tregs by co-culturing with the breast cancer cells in different conditions.Immunofluorescence staining was performed to mark the interested cells.FCM was used to detect the interested cells.Finally,the statistics were analyzed by SPSS20 using t-test,Chi-square test,one-way ANOVA and SNK test.?Result?1.In all the three cell lines that be detected,only MDA-MB-231 is found to express PD-L1 and the relative expression is 0.84.In breast cancer tissues,TNBC has the highest expression of PD-L1,in which the average relative expression is 1.32,while Luminal A,Luminal B and HER2+ have a lower expression of PD-L1,in which the average relative expression are 0.66,0.77 and 0.80 respectively.2.In breast cancer tissues,Foxp3 mainly expresses on the tumor infiltrating lymphocytes and locates in the cyteblast.TNBC has the highest expression of Foxp3,in which the average relative expression is 1.56,while Luminal A,Luminal B and HER2+ have a lower expression of Foxp3,in which the average relative expression are 0.77,0.82 and 0.91 respectively.3.The co-cultural assay of breast cancer cells with activated PBMCs shows that MDA-MB-231 which overexpresses PD-L1 can cooperate with TGF-?to induce Tregs from activated PBMCs while SK-BR3 which has no expression of PD-L1 can't.4.In MDA-MB-231,SK-BR3,HCC1954,MCF-7,T47 D and BT474,the relative expression of TOPK is 1.37,1.01,1.03,0.64,0.58,and 0.5 respectively.TOPK mainly locates in cytoplasm in breast cancer tissues.TOPK is overexpressed in 35% breast cancer tissues.The level of TOPK expression is correlated with Ki67 expression(P<0.001),ER/PR expression(P<0.001),histological grade(P=0.003)and the subtype(P<0.001)of breast cancer.There is no relationship between TOPK expression and tumor size(P=0.061),Lymph node metastasis(P=0.681)and invasion(P=0.809).?Conclusion?TNBC has the highest expression of PD-L1 and Foxp3.PD-L1 may cooperate with TGF-?to induce Tregs from activated PBMCs,thus playing a role in anti-tumor immune.Foxp3 may become a therapeutic target of TNBC and targeting Foxp3 may have a milder side effect than PD-L1/PD-1 inhibitors.TOPK most frequently expresses in the triple negative breast cancer tissues and cells.The expression of TOPK in breast cancer tissues is positively correlated with Ki67 expression and histological grade.High TOPK expression seems to be a unique phenomenon for HER2+ and TNBC in breast cancer.TOPK may function as a prognostic indicator and therapeutic target of breast cancer.The mechanism of TOPK and its interaction with Ki67 need to be further explored.