Clinical Significance of JAG1 Gene Methylation in Uygur Breast Cancer Patients

Objective To explore the clinical significance of JAG1 gene methylation in the occurrence and progression of breast cancer in Uygur.

Methods The methylation levels of JAG1 gene in 15 cases of usual ductal hyperplasia(UDH), 15 cases of atypical ductal hyperplasia(ADH), 15 cases of ductal carcinoma in situ (DCIS) and 50 cases of invasive ductal carcinoma (IDC) from women breast tissues were detected using MALDI-TOF MS method. Immunohistochemistry was used to detect JAG1 protein expression, and further the protein expression was associated with methylation in four groups of breast tissues.

Results The overall methylation levels of JAG1 gene in different stages tissues of breast carcinogenic process were gradually decreased. The hypomethylation levels of JAG1 gene were most obvious in CpG_11.12, CpG_14.15, and CpG_18.19 sites(P < 0.05). The level of CpG_1 methylation in low differentiation group was obviously reduced (P < 0.05) and low methylation rate of CpG_8.9.10 occurred in lymph node metastasis groups(P < 0.05). However, the methylation level of CpG_16.17 was markedly increased in clinical Ⅲ stage(P < 0.05). There was statistical significance between CpG_13, CpG_26 methylation levels and ER, PR, HER2 expression (P < 0.05). JAG1 methylation rate and protein expression showed a negative correlation relationship(r=-0.674, P < 0.001).

Conclusion Different methylation levels of CpG sites in JAG1 gene may play a distinct role in the progression of breast cancer. JAG1 methylation may be one mechanism of its protein expression.