Expression of Delta/Notch-like epidermal growth factor-related receptor in triple negative breast cancer and its clinical significance

Abstract

Objective To explore the expression of Delta/Notch-like epidermal growth factor-related receptor (DNER) in triple negative breast cancer (TNBC) and analyze its correlation with clinicopathological characteristics of TNBC patients. Methods The samples of cancer tissues and adjacent normal tissues were collected from 39 cases of TNBC in the Affiliated Hospital of North Sichuan Medical College from March 2017 to March 2018 for a retrospective study. The protein and mRNA expressions of DNER in samples were detected by immunohistochemistry and RT-PCR, respectively. The paired χ2 test (McNemar test) was used to compare the DNER-positive rates between breast cancer tissues and adjacent normal tissues. χ2 test or Fisher’s exact test was used to analyze the relationship between DNER protein expression and clinicopathological characteristics of TNBC patients. The DNER mRNA expression was compared between breast cancer tissues and adjacent normal tissues by paired t test. The correlation between DNER mRNA expression and clinicopathological characteristics was analyzed by independent-sample t test and analysis of variance. Pairwise comparison was performed using the LSD test. Results Immunohistochemical results showed that the positive rate of DNER protein in TNBC tissues was 82.1%(32/39), significantly higher than 23.1% (9/39) in adjacent normal tissues (P<0.001), and the positive rate of DNER protein was associated with tumor diameter (χ2= 6.121, P=0.026), TNM staging (P=0.030) and lymph node metastases (P=0.005). Results of RT-PCR showed that DNER mRNA expression in TNBC tissues was 0.768±0.067, significantly higher than 0.487±0.041 in adjacent normal tissues (t=4.793, P<0.001). The expression of DNER mRNA in TNBC tissues was correlated with tumor diameter (F=8.392, P=0.001), TNM staging (t=5.178, P<0.001) and lymph node metastases (t=4.925, P<0.001). Conclusion The high expression of DNER protein and mRNA is closely related to the occurrence, development and metastasis of TNBC, so DNER may be a potential target for the diagnosis and treatment of TNBC. Key words: Breast neoplasms; Lymphatic metastasis; Neoplasm staging; Receptors, Notch