Upregulation of serum exosomal SUMO1P3 predicts unfavorable prognosis in triple negative breast cancer.

Objective Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer (BC) with poor prognosis. Identification of reliable biomarkers for predicting prognosis of TNBC contributes significantly to improve the clinical outcome and disease management. Long non-coding RNAs (LncRNAs) have been demonstrated to play a critical role in tumorigenesis of TNBC. In this study, we aimed to investigate the prognostic significance of serum exosomal lncRNA small ubiquitin-like modifier 1 pseudogene 3 (SUMO1P3) in TNBC. Patients and methods The expression level and clinical significance of tissue lncRNA SUMO1P3 in BC were analyzed using the public The Cancer Genome Atlas (TCGA) dataset. Then,A. Na-er, Y.-Y. Xu, Y.-H. Liu, Y.-J. Gan the serum exosomal lncRNA SUMO1P3 levels were examined in patients with TNBC, patients with non-TNBC, patients with benign breast disease and healthy controls using the quantitative real-time PCR. The potential clinical significance of serum exosomal lncRNA SUMO1P3 was further evaluated. Results Based on the TCGA data, tissue lncRNA SUMO1P3 was upregulated in BC tissues, and its upregulation was significantly correlated with poor survival. Our findings showed that the expression level of serum exosomal lncRNA SUMO1P3 was significantly higher in patients with TNBC compared to patients with non-TNBC, patients with benign breast disease and healthy controls. In addition, serum exosomal lncRNA SUMO1P3 was closely correlated with lymphovascular invasion, lymph node metastasis and histological grade. The serum exosomal lncRNA SUMO1P3 levels were markedly decreased in chemosensitive cases, while not in the chemoresistance cases. Moreover, patients in the high serum exosomal lncRNA SUMO1P3 group had worse overall survival than the patients in the low serum exosomal lncRNA SUMO1P3 group. The multivariate analysis showed that serum exosomal lncRNA SUMO1P3 was an independent prognostic factor for TNBC. Conclusions Collectively, serum exosomal lncRNA SUMO1P3 might be a reliable and robust prognostic biomarker for TNBC.