PD-1 Expression In Human Breast Cancer And Its Clinicopathological Significance

Purpose To observe the expression of programmed death 1(PD-1)in different invasive human breast cancer cell lines and investigate the effect of PD-1 gene silencing on the ability of human breast cancer cells to migrate in vitro.To investigate the correlation between PD-1 expression and clinicopathological features in breast cancer.It provides a new idea for further biological immunotherapy of breast cancer.Methods:1.In vitro culture of highly aggressive human breast cancer cell line MDA-MB-231 and low invasive MCF-7,the expression of PD-1 protein in two kinds of human breast cancer cell lines was detected by Western blot.The expression of RT-PCR was used to detect the expression of PD-1 m RNA in two kinds of human breast cancer cell lines.The expression of PD-1 in MDA-MB-231 breast cancer cells was silenced by RNA interference technique.MDA-MB-231 cell lines and control cells stably expressing low PD-1 protein were screened and identified.Scratch-change.2.The immunohistochemical En Vision two-step method was used to detect the expression of PD-1 in breast cancer cells and interstitial infiltrating lymphocytes in 71 cases of breast cancer tissues,and statistical analysis between PD-1 expression and clinicopathological parameters Of the relationship;and based on the clinical follow-up of relevant information,draw the survival curve.Results 1.The protein and m RNA expression of PD-1 in highly aggressive breast cancer cell line MDA-MB-231 was significantly higher than that in low invasive MCF-7(P<0.05).The migration ability of MDA-MB-231 human breast cancer cells whose PD-1 expression was down-regulated was inhibited.2.There could be a positive correlation of the positive rate of PD-1 between the breast cancer cells was 61.2%(44/71)and the infiltration of lymphocytes in breast stromal was 71.3%(51/71)(P<0.05).The expression of PD-1 in breast cancer parenchyma cells was correlated with histological grading,tumor size(P<0.05),lymph node metastasis of breast cancer(P<0.05),However,there was no significant correlation between the expression of PD-1 and the patient age,expression of ER,PR,HER-2 and Ki-67 index in breast cancer(P>0.05).The expression of PD-1 in Interstitial infiltration of breast cancer lymphocytes was correlated with histological grading,tumor size(P<0.05),lymph node metastasis of breast cancer(P<0.05),However,there was no significant correlation between the expression of PD-1 and the patient age,expression of ER,PR,HER-2 and Ki-67 index in breast cancer(P> 0.05).The 5-year survival rate was lower in PD-1-positive patients(61.3%)than that in PD-1 negative patients(94.1%).Conclusion PD-1 could be an important potential marker for the biological behavior and prognosis of breast cancer.