Clinical Value of Differential Expression of Pim1 and Notch1 During Carcinogenesis of Breast Cancer

Objective To investigate the differential expression levels of Pim1 and Notch1 in breast tissues and their clinical and prognostic significance.

Methods qRT-PCR, immunohistochemistry and databases were used to detect the mRNA and protein levels of Pim1 and Notch1 genes in adjacent normal breast tissues (ANBT), usual ductal hyperplasia (UDH), ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). The relation between Pim1/Notch1 expression and the clinicopathological parameters of breast cancer patients was analyzed. The prognostic value of Pim1 and Notch1 protein in breast cancer was evaluated by Kaplan-Meier Plotter databases.

Results The expression of Pim1 mRNA in breast cancer tissues was increased. The expression of Pim1 protein in the breast cancer tissues was significantly decreased. The expression of Pim1 mRNA was markedly associated with lymph node metastasis and advanced TNM stage. The expression of Pim1 protein was significantly decreased in the patients with lymph node metastasis or histological grade 3. The patients with low expression of Pim1 had a shorter relapse-free survival (P=0.000). The expression of Notch1 mRNA and protein in breast cancer were higher than those in normal breast tissues. Notch1 mRNA was closely related to the lymph node metastasis, high grade and advanced stage. Notch1 protein expression in lymph node metastasis group had markedly increased. The overall survival time of patients with high level of Notch1 was shorter (P=0.025). The protein levels of Pim1 and Notch1 were negatively correlated in breast cancer tissues (r=-0.385, P=0.001).

Conclusion Low Pim1 expression and high Notch1 expression may promote the carcinogenesis and progression of breast cancer and may be risk factors for poor prognosis. Pim1 and Notch1 may be used as potential biomarkers for clinical evaluation of breast cancer patients.