Expression And Significance Of Notch1 And JAG1 Proteins In Different Subtypes Of Breast Cancer

Objective:Notch signaling pathway is closely related to breast cancer,and the protein in the signaling pathway is highly expressed in breast cancer,which has an important influence on the occurrence,development and prognosis of breast cancer and is one of the hotspots in recent years.Molecular classification is of great significance in guiding clinical treatment of breast cancer.At present,the study focused on the Notch signaling pathway with abnormal high expression in breast cancer tissues than in normal breast tissue,which was rarely reported in different molecular subtypes of breast carcinoma.So,we wanted to investigate the expressions and clinicopathological significances of Notch1 and JAG1 proteins in different molecular subtypes of breast invasive ductal carcinomas especially in triple-negative breast cancer(TNBC).Methods:Immunohistochemical method was employed to detect the expressions of Notch1 and JAG1 in 240 cases of breast invasive ductal carcinomas which were obtained between the period January 6,2012and December 30,2014 in Binzhou Medical University Hospital.And they were classified into luminal A,luminal B,HER2 positive and TNBC with every group of 60 cases by ER,PR,HER2 and Ki-67.Then we will analyzed the positive expression rates of Notch1 and JAG1 protein in breast cancer tissues by Statistical methods.Results:(I)Notch1 protein was mainly expressed in the cytoplasm with some cells membrane staining.There were significant differences in the expressions of Notch1 in different molecular subtypes of breast carcinoma(P=0.010,P<0.05)respectively between TNBC(86.67%)and luminal A(56.67%)breast carcinoma(P<0.001),HER2 positive(83.33%)and luminal A(56.67%)breast carcinoma(P<0.001).An association was identified between the expression of Notch1 and lymph node metastasis(P=0.017,P<0.05),clinical stages(P=0.005,P<0.01),tumor grade(P=0.009,P<0.01),negative ER(rs=-0.206,P=0.001,P<0.01)and PR(rs=-0.187,P=0.005,P<0.01),no association was observed for tumor size or patients' age.(2)There was a primary expression of JAG1 protein in the cytoplasm also with some cells membrane staining.The expression of JAG1 in different molecular subtypes of breast carcinoma showed differences(P =0.035,P<0.05),and TNBC exhibited higher JAG 1 expression than the other subtypes,there was no significant difference between each two molecular subtypes of breast carcinoma.The expression of JAG1 was associated with the negative ER(rs=—0.142,P=0.015,P<0.05)and PR(rs=—0.127,P=0.035,P<0.05).(3)There was no correlation between the expression of Notch 1 and JAG 1 in breast carcinoma.Conclusion:(1)The Notchl protein shows high expression in TNBC,and the expression of Notchl is not only related with tumor grade,lymph node metastasis and clinical stages but also with negative ER and PR.(2)The positive expression rate of JAG1 was universally low in breast cancer,and the expression of JAG1 is associated with negative ER and PR.(3)There is no relationship between the expression of Notchl and JAG 1 in breast cancer.