Abstract
Triple-negative breast cancer (TNBC) has an aggressive phenotype and a poor outcome. The discovery that dysregulated microRNAs (miRNAs) play an important role in tumor progression has led to the suggestion that miRNAs (miRs) could be a potential target for the treatment of TNBC. In the present study, it was demonstrated that miR-598 expression was significantly decreased in TNBC tissues and was related to the degree of lymph node metastasis of patients with TNBC. Ectopic expression of miR-598 suppressed viability and colony formation, as well as increased the apoptosis of TNBC cells. To further understand the functional mechanism of action underlying miR-598 in TNBC, targets of miR-598 were predicted with the miRDB bioinformatics tool. Jagged 1 (JAG1) was identified as a direct target of miR-598, possessing a binding site for miR-598 in its 3'-untranslated region. Overexpression of miR-598 inhibited the expression of JAG1 in TNBC cells. In addition, JAG1 was highly expressed in TNBC tissues and its expression was negatively correlated with the expression of miR-598. Overexpression of JAG1 significantly attenuated the inhibitory effects of miR-598 on the proliferation and colony formation of TNBC cells. Collectively, these results provided novel insights into the functional mechanism of action for the miR-598/JAG1 pathway in the development of TNBC.