Abstract
Background: Triple-negative breast cancer (TNBC) has a poor prognosis due to metastasis and recurrence. The LncRNA PWRN1 is lowly expressed in breast cancer, so we investigated the regulatory mechanism and prognostic value of PWRN1 in TNBC. Methods: 135 TNBC patients were included. PWRN1 levels and miR-21-5p level were analyzed by RT-qPCR. Independent prognostic factors for TNBC were analyzed using multifactorial Cox regression. CCK-8 was used to test the proliferative capacity of cells. The effects of PWRN1 and miR-21-5p on cell migration and invasive properties were analyzed by Transwell, and their target binding relationship was reported by DLR assay. Results: PWRN1 was lowly expressed in TNBC patients, while miR-21-5p was highly expressed. PWRN1 expressions were downregulated and miR-21-5p levels were upregulated in TNBC tissues. miR-21-5p is a downstream target gene of PWRN1 and their expression is negatively correlated. Overexpression of PWRN1 led to low expression of miR-21-5p, which reduced cell proliferation, migration, and invasion. In addition, PWRN1 was an independent prognostic factor. Patients in the PWRN1 low expression group had shorter overall survival. Conclusions: PWRN1 may be a prognostic marker for TNBC. Overexpression of PWRN1 leads to low expression of miR-21-5p, which affects cell proliferation, migration, and invasive behaviors, thereby preventing poor prognosis in TNBC patients.